Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
Contents lists available at ScienceDirect
Journal of Environmental Chemical Engineering
journal homepage: www.elsevier.com/locate/jece
Efficiency of various recent wastewater dye removal methods: A review
⁎
T
Vanitha Katheresan, Jibrail Kansedo , Sie Yon Lau
Department of Chemical Engineering, Faculty of Engineering and Science, Curtin University Malaysia, CDT 250, 98009 Miri, Sarawak, Malaysia
A R T I C LE I N FO
A B S T R A C T
Keywords:
Wastewater dye removal
Adsorbents
Activated carbon
Enzyme peroxidase
Combined adsorbents
Dye effluents released from numerous dye-utilizing industries are harmful towards the environment and living
things. Consequently, existence of dye effluent in environmental water bodies is becoming a growing concern to
environmentalists and civilians. A long term sustainable and efficient dye effluent treatment method should be
established to eliminate this issue. Dye wastewater should be treated first before release to minimize its negative
impacts towards the environment and living things. However, due to lack of information on efficient dye removal methods, it is difficult to decide on a single technique that resolves the prevailing dye effluent issue.
Therefore, this paper reviews existing research papers on various biological, chemical and physical dye removal
methods to find its efficiency through percentage of dye removal. Although there are numerous existing tried
and tested methods to accomplish dye removal, most of them have a common disadvantage which is the generation of secondary pollution to the environment. This paper highlights enzyme degradation (biological) and
adsorption (physical) dye removal as these are known as one of the most efficient dye removal techniques these
days. This paper also suggests the usage of a combined adsorbent as it is envisioned that this technique has better
efficiency and is able to remove dyes at a faster rate.
1. Introduction
Synthetic dyes are a necessity in various significant industries such
as the leather, paper as well as textile industries for its colour-giving
properties. It is estimated that 700 000 tonnes of various colouring from
about 100 000 commercially accessible dyes are manufactured each
year [1,29,49,58,100]. Often, once dyes have served their purpose,
most of them are discarded without further care into environmental
water bodies. Five major industries, shown in Fig. 1, are known to be
responsible for the presence of dye effluents in the environment.
The textile industry (54%) releases the highest amount of dye effluent, contributing to more than half of the existing dye effluents seen
in the environment around the world. The dyeing industry (21%), paper
and pulp industry (10%), tannery and paint industry (8%) and the dye
manufacturing industry (7%) too are known to produce high amounts
of dye effluents from various associated processes [32,85]. The exact
amount of dye effluents ejected by each industry into the environment
is unknown but it can be said that the number is quite large to result as
a significant environmental issue.
Among other dye-utilizing industries, the textile industry is said to
utilize the highest amount of dyestuff at approximately 10 000 tonnes
per year worldwide [104]. Besides that, this industry is also known to
produce around 100 tonnes of dye effluent per year, the highest amount
⁎
of dye wastewater from one industry alone [114]. High usage of dyestuff in various processes of textile industries result in generation of
huge amounts of dye wastewater. Besides that, textile industries produces high amounts of dye effluents due to the tremendous water requirement by the industry [3,22,25,105].
For various processes in the textile industry, specific mixtures of
chemicals, dyestuff and water is prepared. Once the process is complete, the leftover mixture (dye effluent) is discharged into the environment. For instance, 85% dye effluent is ejected from the dyeing
process. This dye effluent is the leftover of the total amount of dye
mixture prepared at the beginning of the dyeing process. The percentage of dye mixture ejected at the end of each process of the textile
industry is shown in Fig. 2.
It is deduced that dye effluents from the textile industry exist due to
the inability of the dye mixture (dye molecules and chemicals) to
completely attach itself onto a fabric or textile [103]. Generally, only a
maximum 80% of dye and chemical molecules from dye mixtures are
able to be adsorbed by materials intended for colouring [92]. Fabrics in
particular, can only absorb a maximum 25% of dye mixture onto its
body due to its limited absorption capacity [39].
Dye effluents, better known as dye wastewater, is rich with numerous hazardous chemicals shown in Fig. 3. Dye effluents can endanger the lives of animals and humans as they are toxic by nature. It is
Corresponding author.
E-mail address: jibrail.k@curtin.edu.my (J. Kansedo).
https://doi.org/10.1016/j.jece.2018.06.060
Received 27 February 2018; Received in revised form 26 May 2018; Accepted 26 June 2018
Available online 26 June 2018
2213-3437/ © 2018 Elsevier Ltd. All rights reserved.
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
Fig. 1. Industries responsible for the presence of dye effluent in the environment [102].
Fig. 2. Discharge percentage of dye mixture from each process of the textile industry [22].
paper is to review studies on different dye removal methods according
to its dye removal percentage. This paper was composed due to the lack
of information on the efficiency of available dye removal methods in
literature. Following that, this paper highlights the most suitable dye
removal technique based on the review conducted. This paper highlights enzyme degradation (biological) and adsorption (physical) dye
removal as these are known as one of the most efficient dye removal
techniques these days. The highlighted methods are believed to efficiently remove dye particles from wastewater in a short period of time
with no harmful by-products.
easy to spot water bodies containing dye effluents as its colour gives it
away [7,72]. Presence of dye effluents in water sources are unacceptable as water is required by animals and humans for daily activities such as bathing, cooking, drinking and washing [132].
Nowadays, removal of dye molecules from water sources has not
only become a major environmental concern but also a challenge
[58,59,75]. Techniques of recovering and reusing dye wastewater received the limelight recently as clean water sources might soon begin to
deplete rapidly if no dependable solution is found. Developing a fixed
solution to permanently eliminate dye particles from textile effluents
would greatly benefit the environment [98,130].
Currently, various dye removal methods have been established in
countless research papers claiming successful dye removal. Although
there are a variety of applicable dye removal techniques, not all of them
are successful or even suitable to be practiced due to their disadvantages [43,78]. An ideal dye removal method should be able to
efficiently remove large quantities of dye from wastewater in a short
time span without producing secondary pollution. It is encouraged to
remove pollutants from wastewater with a method that does not produce more hazardous by-products (secondary pollution) [104].
This paper describes different types of dyes as well as dye removal
methods biologically, chemically and physically. The focal aim of this
2. Dyes
Dyes are colourful substances designed to give materials such as
fabrics, papers, or any colourable materials a hue. This is possible as
dyes can attach themselves onto any amenable materials [138,140].
Dyes have been utilized by humans for over a thousand years for various applications. Those days, dyes were usually produced on a small
scale from naturally available material such as insects or plants and are
known as natural dyes [63]. However, the drawback with natural dyes
was its limited variety as well as muted tones which fades when exposed to sunlight and washing [114].
4677
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
Fig. 3. Hazardous chemicals used along with dyes by dye-utilizing industries [55,63,86].
detergents or any other washing agents [7]. Dye molecules can withstand degradation even when exposed to extreme heat sources, oxidising agents or strong light [29,43,59,98].
Synthetic dyes were only recently discovered and its production in
large scales started due to the rise in dye demand. An extensive range of
synthetic dyes was invented by WH Perkins in the year 1856 spotting
various brilliant, colourfast tones for numerous uses [63]. This invention solved the problem natural dyes retained but new issues arose
whereby dye-utilizing industries ejected dye wastewater into the environment without proper treatment. This presented dire consequences
as presence of dyes in water sources posed a threat to living things in
the environment due to its toxic nature [47]. Although it seems that
resuming the usage of natural dyes are a better alternative, it was found
that this scenario was just as bad as utilizing synthetic dyes alone. This
is because in order to make sure the natural dyes bond with fabrics, a
mordant is required [104]. Mordants are a kind of binding agent that
aid in the attachment of natural dye to materials. Mordents are very
much toxic and more dangerous than synthetic dyes [63].
Nowadays, synthetic dyes have become a crucial ingredient widely
used to give colour to textiles, cosmetics, plastics and printing [1,4,92].
This is due to the fact that dyes are naturally recalcitrant substances and
degrading it is not easy nor possible. Synthetic dye molecules are
complex as well as stable structures due to the presence of auxochromes
(water soluble bonding compound) and chromophores (colour giving
compound) it contains [25,97,105]. This quality of dyes complicate its
degradation process using straightforward methods. The reason as to
why dyes are created this way is so that the colour of a dyed material
does not fade easily [35]. They are made as complex organic substances
so that they can resist getting degraded upon contact with water,
2.1. Types of dyes
There are many types of synthetic dyes and they can be classified
based on their molecular structure as tabulated in Table 1, as is commonly done. Sometimes, dyes are classified by their application or even
by their solubility. Acid, basic, direct, mordant and reactive dyes are
examples of soluble dyes while azo, disperse, sulphur and vat dyes are
example of insoluble dyes [102]. Among all dye types, azo dyes are the
highest produced dye type at 70% production rate and it is the most
frequently utilized dye worldwide [28].
Regardless of its structure, all synthetic dyes have a common disadvantage which is its hazardous nature [86]. Due to this, synthetic
dyes should not be allowed to enter the environment untreated to blend
with water sources. Due to its noxiousness, dyes have caused grave
concern to environmentalists and water consumers. Therefore, efforts in
methods and technologies that can permanently remove one or more
dye types from water bodies are greatly welcomed [72,85,132].
3. Importance of dye removal
Dye-utilizing industries usually store dye effluents as industrial
waste after dyes have fulfilled their role in colouring materials [114].
4678
4679
Inks, medicine, modified nylon, modified polyester,
paper, polyacrylonitrile, polyester, silk, tanninmordanted cotton and wool
Cotton, leather, nylon, rayon, silk and paper
Acetate, acrylic fibres, cellulose, cellulose acetate, nylon,
polyamide, polyester, polyester-cotton and plastic
All fibres, oils, paints, plastics and soaps as well as
detergents
Food, drug, and cosmetics
Basic (cationic dye)
(water soluble)
Direct (water soluble)
Disperse (water
insoluble)
Fluorescent
brighteners
Food, drug, and
cosmetics
Mordant
Oxidation bases
Fats, gasoline, inks, lacquers, lubricants, oils, plastics,
stains, varnishes and waxes
Cotton, leather, paper, polyamide fibres, rayon, silk and
wood
Cotton, cellulosic fibres, polyester-cotton, rayon and
wool
Solvent (water
insoluble)
Sulphur
Vat
(water insoluble)
Cellulosic, cotton, nylon, silk and wool
Reactive (water
soluble)
Anodized aluminium, natural fibres, leather and wool
Cotton, fur and hair
Cosmetics, food, leather, modified acrylics, nylon, paper,
printing ink, silk and wool
Acetate, cellulose, cotton, rayon and polyester
Acid (water soluble)
Azo
Applications
Type
Table 1
Various types and applications of dyes [3,49,58,117].
Aromatic substrate vatted with sodium sulfide and
reoxidized to insoluble sulfur-containing products on
fibre
Water-insoluble dyes solubilized by reducing with
sodium hydrogen sulphite, then exhausted on fibre and
reoxidized
Along with chromium salts
The substrate is oxidised with aromatic amines and
phenols
Reaction between functional group on fibre and
reactive site on dye. Covalently bonding under the
influence of heat and an alkaline pH
Substrate dissolution
Anthraquinone, azo, carotenoid and triarylmethane.
Mixing
Anthraquinone (including polycyclic quinines) and indigoids
Indeterminate structures
Vat Blue 4 (indanthrene).
Solvent red 26,
Solvent blue 35
Sulphur black 1
Reactive Blue 5
Anthraquinone, azo, basic, oxazine, formazan,
triphenylmethane and phthalocyanine
Anthraquinone, azo, phthalocyanine and triphenylmethane
Mordant Red 11
Direct Blue
Disperse Blue 27,
Disperse Red 4,
Disperse Yellow 3
4,4′-bis (ethoxycarbonylvinyl)
stilbene
Food Yellow 4 and tartrazine
Direct Orange 26
Methylene Blue
Bluish red azo dye
Acid Yellow 36
Example
Anthraquinone and azo
Aniline black and indeterminate structures
Anthraquinone, azo, benzodifuranone, nitro and styryl
Coumarin, naphthylamides, pyrazolos and stilbene
Acridine, anthraquinone, azine, azo, cyanine,
diazahemicyanine, diphenylmethane, hemicyanine, thiazine,
triarylmethane, oxazine and xanthene
Azo, phthalocyanine, polyazo, stilbene, and oxazine
Azo (including premetallized), anthraquinone, azine, nitro,
nitroso, triphenylmethane and xanthene
Azo
Chemicals Required
In dye baths with neutral or slightly alkaline
conditions with additional electrolyte.
Padded on cloth and either baked or thermofixed at
high pressure and temperature or low temperature
carrier methods
Mass dispersion, solution or suspension
Coupling component used to impregnate fibre and a
solution of stabilized diazonium salt is used for
treatment
In dye baths with acidic conditions
In dye baths with neutral to acidic conditions
Application Method
V. Katheresan et al.
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
These wastes are then purged into the environmental water bodies
changing colourless clean water into contaminated coloured water. The
appropriate act that should be performed by these industries before
releasing dye wastewater into the environment is treating it. Water
pollution due to the presence of dyes are unacceptable to environmentalists as well as the public because they are hazardous toxic
substances [104].
Sometimes, concentrated dye effluents with high pH (acidic) and
temperature are released immediately after dyeing processes. The
oxygen transfer mechanism and the self-purification process of environmental water bodies will get disturbed by this phenomenon
[19,63]. When released into the environment after usage, these effluents pose a threat to the ecosystem by polluting water sources disabling water usage. Dye effluents mixed with natural water source
produces a foul odour besides creating an eye sore to people. Beginning
with the aquatic animals and plants, textile effluents can harm living
things on land as well [57,75,140]. When dye effluents blend with
water sources, the turbidity of water increases as dye effluents tend to
form a visible layer above the water surface due to their lower density
at 0.8 kg/m3 compared to the density of water, 1.0 kg/m3. This blocks
the penetration of sunlight required by living things below the water for
processes like photosynthesis and respiration ceasing its existence
[25,49,102].
Next, damage to the soil productivity will occur if the dye effluent
finds its way into forests or fields proceeding to clog soil pores [122].
The quality of water will persistently deteriorate and become a
breeding ground for bacteria and viruses making it unsuitable for daily
usage or consumption. Animals utilizing this water source will suffer
the lack of clean drinking water. Villagers and indigenous people solely
depending on rivers as their source of water will be deprived of water
supply or worse, unknowingly consume the contaminated water and
fall sick [4,59]. Releasing dye effluents into the environment does
nothing but gradually degrade the environment and induce human
health issues.
Dye effluents that comes in contact with skin can cause skin irritation. If dye effluents comes into contact with one’s eye, eye burns or
even permanent eye injury may result for animals and humans alike
[103]. Chemicals present in dye effluents dumped into water sources
can evaporate into the surrounding and upon inhalation, shortness of
breath or difficulty in breathing can be experienced [104]. Ingesting
dyes can cause extreme sweating, confusion, methemoglobinemia,
mouth burns, nausea or vomiting [100,105]. Dyes are also conventional
carcinogens and long term effects to one’s body or unborn child is
unavoidable. Therefore, treating wastewater with detrimental dye effluents is significant to prevent its destructive impacts on receiving
waters, animals and humans [7,8,63,131].
Dumping dye wastewater into the environment was not given much
consideration in the past. This issue only got the deserved attention
after health troubles started to arise sometime in the past 30 years
[29,49]. Following that, information on dyes, its application, and
methods to remove it were delved into to find solutions. These solutions
were then implemented by dye manufacturers, dye utilizing industries
and even the government to remove dye particles from water sources
[92].
Recently, the environmental legislature set a law on the presence of
toxic coloured wastewater in water bodies [45,72]. As per this law, dyeutilizing industries have to ensure wastewater released from their factories abide by The International Dye Industry Wastewater Discharge
Quality Standards were adopted from the Zero Discharge of Hazardous
Chemicals Programme (ZDHC) [35].
Textile wastewater is rich with pollutants such as biological oxygen
demand (BOD), chemical oxygen demand (COD), colours, hazardous
chemicals, and dissolved salts (TDS and TSS) [58,117]. The international permissible standard dye effluent pollutant discharge is shown in
Table 2. Levels of biological oxygen demand (BOD), chemical oxygen
demand (COD), colour, pH, suspended solids and temperature of the
Table 2
International standard of dye effluent discharge into the environment
[17,78,85].
Factor
Standard allowed
Biological oxygen demand
Chemical oxygen demand
Colour
pH
Suspended solids
Temperature
Toxic pollutants
Below 30 mg/L
Below 50 mg/L
Below 1 ppm
Between 6–9
Below 20 mg/L
Below 42 °C
Not allowed to be released
dye effluent released should be below the amount permissible to be
released. Toxic pollutants are certainly not allowed to be released into
the environment due to its dreadful consequences.
Industries producing dye wastewater should start rectifying the
damage and harm they are inflicting towards the environment as well
as living things. Along with researchers working to eliminate dye
wastewater from the environment, dye-utilizing industries too should
make an effort to avoid releasing dye wastewater in to the environment.
Dye-utilizing industries should stop causing pollution and start establishing dye effluent treatment plans instead [102]. As for some of the
more responsible dye-utilizing industries, it is strongly recommended
that they reuse treated dye wastewater in their dyeing processes instead
of disposing it into the environment. That is a more economical concept
than buying and using fresh water for dyeing processes repeatedly.
Fresh water, at the amount required by dyeing industries does not come
cheap and cost cutting is usually a desired factor by all industries [132].
4. Methods of dye removal
In the late 90’s, dye removal methods include only preliminary
water purification processes such as equalisation and sedimentation
due to the fact that there were no dye effluent discharge limit [103].
After permissible dye effluent release standards were established, improvements were made by introducing more effective dye removal
methods such as dye degrading filter beds and activated sludge processes [82]. Following that, a system for dye wastewater treatment
shown in Fig. 4 was introduced. This system, known as the traditional
dye removal method, was implemented by the concerning industries for
some time till it was stopped due to its high cost of operation and
maintenance [3].
Currently, numerous researches are being done to find the ideal dye
removal method so that dye wastewater can be recovered and reused
according to that [107]. Existing methods of dye removal can be separated into three categories namely the biological, chemical, and
physical treatments [122]. Although many dye removal methods have
been researched in the past 30 years, only several are truly being implemented by the concerning industries these days because of limitations posed by majority of the methods [32,100,138].
4.1. Biological dye removal methods
In most countries, the typical biological method is the commonly
and extensively utilized dye removal method to treat dye wastewater.
Generally known as the conventional method, a combination of aerobic
and anaerobic process is carried out before dye effluents are released to
the environment [7]. This method was chosen as the go-to dye removal
method mainly because it is very cheap and can be accomplished easily
[103]. As a matter of fact, this treatment alone is insufficient to completely remove hazardous particles from textile dye wastewater which
is why coloured water is still seen in the environment [97]. Although
the conventional method does treat the chemical oxygen demand present in the wastewater, it does not make the water dye-free or toxicfree. Besides this method, other conventional biological dye removal
4680
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
removal methods are advanced oxidation process, electrochemical destruction, Fenton reaction dye removal, oxidation, ozonation, photochemical and ultraviolet irradiation. The mentioned methods are tabulated along with its description, advantages and disadvantages in
Table 4. Most of the chemical dye removal methods are costly compared to biological and physical dye removal methods with an exception to the electrochemical degradation dye removal method.
Chemical dye removal methods are also commercially unattractive,
requires specific equipment and requires high electrical energy [35].
High electrical energy is required to power equipment or reactors in
which chemical dye removal takes place. Besides that, chemical as well
as reagent consumption on a large scale is an issue commonly reported
by users of chemical dye removing methods [29]. Another undesirable
characteristic of this method is the generation of toxic secondary pollution resulting at the end of a chemical dye removal processes presenting an additional disposal problem [131].
4.3. Physical dye removal methods
Physical dye removal methods are usually straightforward methods
commonly accomplished by the mass transfer mechanism.
Conventional physical dye removal methods are adsorption, coagulation or flocculation, ion exchange, irradiation, membrane filtration,
nano filtration or ultra-filtration and reverse osmosis. These methods
are tabulated along with its description, advantages and disadvantages
in Table 5.
Among the three methods (biological, chemical and physical),
branches of physical dye removal are the most commonly used
methods. These methods are often chosen for its simplicity and efficiency. By far, this method requires the least amount of chemicals
compared to the biological or chemical dye removal methods [69]. This
method does not deal with living organisms hence is considered to be
more predictable than the other two dye removal methods.
4.4. Efficiency of dye removal methods
The mentioned dye removal methods biologically, chemically and
physically are methods that have been tried and tested by numerous
researches. It should be noted that not all dye removal methods can
guarantee a successful dye removal. Sometimes, the conditions set for
dye removal can influence the results obtained at the end of a dye removal process. Table 6 provides a list of research done by other authors
on the various dye removal methods with an exception of the membrane filtration (physical) method as this method was found be an inefficient method of dye removal. Table 6 compares research papers on
various dye removal techniques in terms of their dye removal percentage. The average success rate of each method was displayed for easier
efficiency comparison.
As shown in Table 6, chemical dye removal processes displayed the
highest percentage of dye removal ranging from 88.8 to 99%. However,
chemical dye removal methods often possess intolerable disadvantages
as shown in Table 4. Besides that, chemical dye removal processes with
the exception to upcoming electrochemical destruction technologies
depend on the dye solution pH and in most cases pose the issue of
secondary pollution generation. Due to the heavy weightage of disadvantages in chemical dye removal methods, these methods should be
not be considered for dye removal if possible [130].
Dye removal by biological or physical methods are fairly successful.
Biological dye removal methods have a removal percentage ranging
from 76 to 90.1% with the enzyme degradation method ranking highest
on the list. The enzymatic dye degradation method is an adequate and
reliable dye removal method. This method is cheap, efficient, non-toxic
and very importantly reusable. Its only disadvantage is its unreliable
amount of enzyme production but this issue can be easily solved with
the selection of a proper raw material and extraction method.
Physical dye removal methods have a removal percentage ranging
Fig. 4. Traditional wastewater treatment system [95].
methods are adsorption by microbial biomass, algae degradation, enzyme degradation, fungal cultures, microbial cultures as well as pure
and mixed culture.
The mentioned methods are tabulated along with its description,
advantages and disadvantages in Table 3. Biological dye removal
methods incorporates some form of living organism in its process. This
method should be used with caution and engineering ethics should be
uphold. Utilization of enzyme to remove dye is becoming quite famous
these days as it is believed that branches of biological dye removal
methods are the cheapest as well as safest methods of dye removal
[114]. Since this method deals with living things, its major disadvantage is its growth rate. System instability is common in biological
dye removal processes as predicting its growth rate and reactions can be
tricky at times.
4.2. Chemical dye removal methods
Chemical dye removal methods are methods utilizing chemistry or
its theories in accomplishing dye removal. Conventional chemical dye
4681
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
Table 3
Various biological dye removal methods along with its advantages and disadvantages [3,25,78,85,117].
Method
Description
Advantages
Disadvantages
Adsorption by microbial
biomass
Mixture of organic living
organisms fashioned to adsorb
dye molecules.
Algae consumes dye particle for
self-growth.
Selected dyes have an exceptional affinity
towards microbial biomass
Not an effective method for all dyes
Able to consume dyes. Cheap. Easily
assessable. Environmental friendly
process.
Able to fairly decolourize a variety of dye
types. Cheap. No foam formation.
Unstable system.
Algae degradation
Aerobic-anaerobic combination
(conventional method)
A prepared sludge breaks down
complex dye molecules.
Enzyme degradation.
Extracted enzyme used to
degrade dye molecules.
Fungal cultures
Fungus breaks down dye
molecules and consumes them
for self-growth.
Bacteria mixed with chemicals
or other bacteria to remove dye
particles.
Mixtures of algae, bacteria or
fungus with necessary chemicals
to remove dye.
Microbial cultures such as
mixed bacterial
Pure and mixed culture
Cheap. High efficiency. Non-toxic.
Possesses the ability to degrade dyes using
enzymes. Reusable.
Can eliminate various types of dyes at
once. Flexible method.
Takes a maximum of 30 h in
decolourization of dye wastewater which
is considered fast.
Reusable. Suitable only for azo dye
removal.
Does not completely eliminate all dye particles. Formation of
methane and hydrogen sulphide as by-products. Inflexible
method. Large land area requires. Produces sludge. Takes long
time.
Unreliable amount of enzyme production.
Lengthy growth phase. Needs a nitrogen confined area to grow.
Requires large reactors for complete dye removal. Unstable
system.
Effective to a limited number of dyes. Large scale application is
preferred due to high cost.
Colourless toxic by-products. Produces sludge. Requires
conventional method as post-treatment.
Table 4
Various chemical dye removal methods along with its advantages and disadvantages [43,49,59,105,142].
Method
Description
Advantages
Disadvantages
Advanced oxidation
process
Multiple oxidation process done simultaneously to
remove dye particles.
Expansive. Not flexible. Production of
undesirable by-products. pH dependent.
Electrochemical
destruction
Electro-coagulation or non-soluble anodes are used
to eat up dye molecules.
Can eliminate toxic materials. Can remove dye
in unusual conditions. Good dye removal
method.
Chemicals do not get consumed and no sludge
build-up. Fairly suitable soluble and insoluble
dye removal method.
Fenton reaction
Fenton’s reagent (mixture of catalyst and hydrogen
peroxide) to remove dye particles from wastewater.
Oxidation
Oxidising agents used to treat dye effluents. Agents
break down complex dye molecules to carbon
dioxide and water. Usage of catalyst can further
enhance the process.
Ozone produced from oxygen is used to eliminate
dye particles.
Ozonation
Photochemical
Ultraviolet irradiation
Fenton reaction coupled with ultraviolet light to
remove dye molecules from wastewater.
Usage of UV light to decompose dye particles in
wastewater.
Fairly suitable dye removal method for soluble
and insoluble dyes. Removes all toxins in water.
Suitable for dyes wastewater with solid content
Can completely degrade dyes. Common
chemical dye removal method. Short reaction
time. Straightforward application
Can be used in its gaseous state. Does not
increase wastewater volume. Effective dye
removal method. No sludge generation. Quick
reaction.
Effective dye removal method. No foul odours
production. No sludge production.
Hazardous chemical required. No sludge
production. Weakens foul odours.
Additional hazardous material production.
High cost of electricity. Less effective dye
removal compared to other methods due to
high flow rates.
Cannot remove disperse and vat dyes. High
iron sludge generation. Long reaction time.
Works only on low pH.
Costly. Difficult to activate hydrogen peroxide
agent. pH dependent. Requires catalyst for
efficient removal.
Has an extremely short half-life for only
20 min. High cost. Produces toxic by-products.
Unstable method.
Expansive. Forms a lot of by-products
Energy depletion. High cost. Limited
treatment times.
of dyestuff [3,29,100,105,117]. This method can even be used to purify
industrial wastewater or to clean drinking water. It is common
knowledge that synthetic dyes cannot be removed from dye wastewater
through conventional methods due to its inefficiency in completely
removing dye from dye wastewater [104]. This leaves adsorption as one
of the ideal methods to remove dye. Dye effluents treated by the adsorption method resulted in the production of higher treated water
quality compared to other dye removal methods [55,75,142]. The one
disadvantage this method had was its high cost of adsorbents but with
the discovery of cheap but equally efficient adsorbents, this method
rose to become an economical method of dye removal worldwide
[4,63,85].
Adsorption is a mass transfer process whereby elements gather at
the interface of two similar or different phases for instance gas-liquid,
gas-solid, liquid-liquid and liquid-solid [32,138]. Adsorption is an efficient equilibrium separation process commonly utilised for water
purification operations. Adsorption is a non-reactive process whereby a
solid surface is concentrated by a substance initially present in a
from 86.8 to 99% with the adsorption method ranking highest on the
list. The adsorption dye removal method is an outstanding dye removal
method capable of degrading almost any dye or a mixture of dyes easily. Similar to the enzyme degradation method, the adsorption method
too can be repeatable several times until the adsorbent is spent. The
only disadvantage of this method is certain adsorbents can be quite
expansive due to naturally high efficiency of the method. This issue can
be solved by selecting low cost raw materials to be fashioned as alternative adsorbents. Seeing that both the enzyme degradation and adsorption methods are efficient in dye removal, merging of these
methods into a single dye removal technique should be considered for
future dye removal technologies.
5. Dye removal through adsorption
Among the numerous tried and tested dye removal methods, adsorption (physical method) emerged as one of the preferred technique
of dye removal due to its outstanding ability to remove almost any type
4682
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
Table 5
Various physical dye removal methods along with its advantages and disadvantages [55,58,63,132,138].
Method
Description
Advantages
Disadvantages
Adsorption
Adsorbents fashioned from high adsorption
capacity materials to adsorb dye molecules.
Coagulation/flocculation inducing agents are
added to dye wastewater where dye particles
clump together. Clumps can then be removed
through filtration.
A reversible chemical process whereby ions from
the dye wastewater swaps with similar ions
attached to a stationary solid surface.
Radiation is used to remove dye molecules from
dye wastewater.
Dye wastewater is passed through a membrane
which separates dye particles from clean water.
Excellent removal method for a wide
variety of dyes. Re-generable adsorbent.
Cheap. Robust method. Suitable only for
disperse, sulphur and vat dye effluents.
Adsorbents can be costly
Coagulation and
flocculation
Ion exchange
Irradiation
Membrane filtration
Nano filtration and
ultra-filtration
Reverse osmosis
Dye wastewater is passed through a thin-pored
membrane which separates dye particles from
clean water.
Pressure driven system where water is passed
through an extremely thin membrane leaving
contaminants on one side and water on the other.
Can be regenerated. Good dye removal
method. Produces high quality water.
Effective at laboratory scale.
Effective for water recovery and reusing.
Can remove any type of dye
Common water recycling method.
Effective for decolouring and desalting a
variety of dyes. Produces clean and pure
water.
Generation of huge amounts of concentrated sludge. Not
suitable for acid, azo, basic, and reactive dye effluents.
Sometimes expansive due to requirement of special
chemicals. pH dependent system.
Effective to a limited number of dyes
A huge amount of dissolved oxygen is required.
Expansive.
Costly initial investment. Easy membrane fouling.
Produces concentrated sludge. Unsuitable for dye
removal.
High cost. High energy consumption. Membrane pores
constantly clogged by dye molecules. Requires high
pressure. Short life span.
Costly. Requires high pressure.
significant parameters affecting adsorption along with the effects of the
parameter in dye removal [1,3,58,138].
gaseous or liquid surrounding [59,92]. This process lowers the concentration of dissolved particles from an effluent. The substance that
gets adsorbed is called the adsorbate while the substance used to adsorb
the adsorbate is the adsorbent. Adsorption can be accomplished by two
approaches, chemical sorption (chemisorption) and physical sorption
(physisorption) [122].
Often, adsorption is conducted through physisorption with minor
exceptions where chemisorption is used instead. In physisorption, other
forces such as dipole-dipole, hydrogen bonds and polar bonds can also
ensure adsorption occurs. In most solid-liquid systems (a mixture of
solid adsorbent and dye effluent), the end result would be a colourless
treated solution. The adsorbent works by separating dye particles (solutes) from dye solution hence accumulating it on its surface. Once all
the dye molecules have been adsorbed onto the adsorbent, the system is
said to be in dynamic equilibrium.
Adsorption is an exceptional dye removal technique as it does not
require any additional special equipment and is easy to conduct [132].
Besides that, no pre-treatment is required for the commencement of
adsorption. Sometimes the adsorption technique is used as post-treatment after using the conventional method to decolourize dyes effluents
as shown in Fig. 4. The adsorption process is best conducted with
porous materials so that dye removal is efficient [31,45]. One desirable
quality of the adsorption technique is that no additional hazardous
material will result at the end of the process making it suitable for
pollution control applications [19,100]. To ensure the production of
high quality treated effluents, proper design of adsorption system is
crucial. Furthermore, in order to ensure a higher rate of adsorption, the
factors affecting adsorption should be acknowledged and used as guidance.
6. Adsorbents for adsorption dye removal method
An adsorbent is a porous insoluble sponge-like substance with the
ability to capture and trap adsorbate particles onto itself [1,69]. An
adsorbent is not necessarily made of solid raw materials but can be
fashioned from any other raw materials deemed suitable. Liquids-based
raw materials such as enzymes too can be synthesized into an adsorbent. An adsorbent is the most crucial element of the adsorption
process. The one issue frequently related to the adsorption technique is
the cost of the adsorbent utilized [29]. To eliminate this issue, cheaper
adsorbents were discovered and established in numerous research papers. (Rafatullah et al. [100]) gathered 185 scattered research papers
on low cost adsorbents and discussed it in a single review paper to
prove the existence of cheap as well as effective adsorbents. Natural
materials and even waste materials can be fashioned into an adsorbent
for textile wastewater dye removal [4].
Some of the materials mentioned can completely remove dyestuff
without a trace left from dye wastewater. The most crucial factor of an
adsorbent is its adsorption capacity, the amount of adsorbate it can
adsorb onto its surface. Another fundamental characteristic of a good
adsorbent is its surface area [103]. The more porous an adsorbent, the
higher the surface area of the adsorbent ensuring a high adsorption
capacity [17]. Thirdly, a short adsorption period is also a desired trait
of a good adsorbent. The time taken for the system to reach equilibrium
should be short so that dye removal can be done in a short period of
time. Fourthly, an adsorbent should be selected based on its diversity in
removing a wide range of pollutants [32]. A good adsorbent should be
able to function in varying dye concentrations, a wide range of pH as
well as temperature. A list of low cost high efficiency adsorbents are
listed along with its surface areas in Table 8.
5.1. Factors affecting adsorption
The adsorption method works efficiently on an industrial scale as
well as laboratory scale. The rate of adsorption depends on the parameters affecting the adsorption process such as the adsorbent dosage,
the contact time between the adsorbate and the adsorbent, the dye
concentration, the solution pH and the temperature of the solution
[17,131,142]. Changes in any of the five parameters will affect the rate
of adsorption. To ensure achievement of the desired rate of removal,
optimum adsorption conditions should be set when conducting labscaled experiments. This can help develop as well as establish industrial-scaled dye removal treatments. Table 7 describes the five most
6.1. Activated carbon as an adsorbent
These days, adsorption though activated carbon based adsorbents
are more conventional as well as efficient compared to other adsorbents
[3,32,138]. It is shown in Table 8 that activated carbons have a wide
range of surface areas and its highest value is 2000 mg/g. Activated
carbons can be produced from any material containing high levels of
carbon in its composition. Desirable characteristics of activated carbon
4683
Rathilene Scarlet Red
Acid Red 27
Methylene Blue
Remazol Black B
Direct Blue 2
Dead microbial Saccharomyces cerevisiae
Isolated microbial Plouritus ostreatus
Average success rate
Algae degradation
Immobilized Desmodesmus sp.
Dried green algae Chlorella vulgaris
Coagulated alginate taken from marine brown algae (Sargassum sp)
4684
A mixture of anthraquinone and azo dyes
Acid Black 10 BX
Green Domalan BL
Acid Violet 109
Malachite Green
Acid Red 151 and Orange II
Wool dyeing effluent treatment through sequencing batch reactor
Average success rate
Enzyme degradation.
Free and immobilized horseradish peroxidase
Peroxidase extracted from post-harvest Lentil (Lens culinaris L.) stubble
Horseradish peroxidase
Average success rate
Fungal cultures
Immobilized Aspergillus niger fungal biosorbent
Aspergillus flavus SA2 brown-rot fungi in the bio removal of azo dyes
Decolourization with sequencing batch reactor system with 15 day old
sludge
Remazol Black 5, Remazol Brilliant Red 21
and Remazol
Yellow RR
Reactive Red 198
Methylene Blue
Biological
Adsorption by microbial biomass
Spent immobilized rice straw biomass
Average success rate
Aerobic-anaerobic combination (conventional method)
Real textile wastewater decolourized in a two-phase partitioning
bioreactor
Dye
Method
Table 6
Efficiency of various dye removal methods.
Maximum dye adsorption occurred when the fungus adsorbent dosage was 15 g/L
and contact time was 72 h at a dye concentration of 15 mg/L. To ensure maximum
adsorption, the pH was set at 5.0 while the temperature of the solution was
maintained at 32 °C. Agitation speed for the process is ideally 140 rpm.
Best condition to remove dyes were found to be at a contact time of 8 days, dye
concentration of 20 mg/L, pH of 5.6 and temperature of 30 °C. Experiment will
produce better results when it is in shaking mode.
Contact time was varied from 0 till 90 min. Dye concentration was varied from 5
to 40 mg/l. Enzyme concentration was varied from 0.735 to 4.41 units/ml.
Hydrogen peroxide concentration was varied from 0.1 to 0.8 μl/l . pH was varied
from 2 till 9.
Highest dye removal through enzyme degradation occurred when the contact time
is 60 min, dye concentration is 76 mg/L and when enzyme dosage was set at 2.26
U/mL onwards. Hydrogen peroxide concentration of 0.3 mM in 20 mM acetic acid
or acetate buffer was considered ideal for this removal process along with
centrifugation performed at 10 000 rpm for 2 min, pH value 4 and a temperature
around 25 °C.
Optimum treatment condition was when contact time is 15 min, dye concentration
30 mg/L, enzyme concentration 0.15 IU/mL, hydrogen peroxide concentration
0.4 mM, pH value 4, and temperature 24 °C.
The Hytrel 8206 reactor along with the two-phase partitioning bioreactor (TPPB)
were functioned simultaneously to obtain the best dye removal results where the
pH was controlled from 4.5 to 7.5 and the reaction time was 23 h.
Dye removal system was showing best results with initial dye concentration of
about 20 mg/L. The system that produced best results was set to perform
anaerobic activities for 16 h and aerobic activities for 4 h. Ideal pH for this method
was 8.
Only BOD and COD successfully removed at 95% and 85%. Maximum dye
removal at contact time around 9 h at temperature around 20 °C.
Maximum dye removal after 6 days contact time when dye concentration was set
at 20 mg/L.
Highest rate of dye removal when temperature is 35 °C and pH is 2. Successful dye
removal until initial dye concentration reached 800 mg/L. Requires a contact time
of at least 24 h.
Batch studies were conducted and maximum dye removal was noticed when
coagulant dosage is 40 mg/L, calcium dosage is 6 g/L, initial dye concentration is
200 mg/L and initial pH 4.
Maximum dye removal at 1% adsorbent dosage, dye concentration of 300 mg/L,
pH value 7 and at temperature 30 °C in 2 days.
Ideal dye removal at contact time 30 min and temperature 25 °C.
Highest percentage of dye removal observed when contact time is 9 days, dye
concentration is 0.04 g/L and temperature is ambient. Decolourization was
maximum when pH is in between 4 and 5.
Conditions and results
[6]
[128]
85.2
86.1
67
82.6
90.1
(continued on next page)
[13]
[11]
[108]
[56]
88.6
94.7
[84]
87
80
[23]
[71]
88
67
[123]
85
89.9
[8]
[40]
[12]
[79]
References
98.6
86
84
85
88
Maximum
efficiency (%)
V. Katheresan et al.
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
4685
Average success rate
Methylene blue
Advanced oxidation process with hydrogen peroxide and UV.
Direct Blue 86
Average success rate
Chemical
Advanced oxidation process
Advanced oxidation process with a combination of ozone and UV.
COD and colour removal
Reactive black 5
Mixed culture of pure 1E1 and pure C1 bacterial for dye removal.
Advanced oxidation process with a combination of hydrogen peroxide,
ozone and UV.
Reactive red 198
Decolourization by pure bacteria Proteus mirabilis
Brilliant green and Evans blue
Acid red 151
Achromobacter xyloxidans and bacillus subtilis mixed bacterial consortium
for COD reduction and colour removal
Average success rate
Pure and mixed culture
Mixed fungal cultures of Pleurotus ostreatus (BWPH), Gloeophyllum
odoratum (DCa), and Fusarium oxysporum (G1).
Black B, Blue RR, Navy blue Red RR and
Yellow RR
Three isolated bacterial strains (Bacillus subtilis, Pseudomonas aeruginosa,
and Psuedomonas putida) for dye degradation
Acid Red-88, Direct Red-81, Disperse
Orange-3 and Reactive Black-5
Mixture of Malachite green, Nigrosin and
Basic fuchsin
Phanerochaete chrysosporium fungi isolated from contaminated
dye effluent sites
Average success rate
Microbial cultures such as mixed bacterial
Acinetobacter sp., Citrobacter freundii and Klebsiella oxytoca mixed
bacteria in dye and 4-nitroaniline degradation from textile dye
wastewater
Dye
Method
Table 6 (continued)
Optimum dye removal observed when initial concentration of dye is 100 ppm, pH
is 11 and reaction time is 35 min. Batch reactor was used for the experiment.
Temperature should not be set above 40 °C for better results. About 62% reduction
in COD was also noted.
COD removal was 99% successful when optimum dye removal conditions were
set. Aluminium Sulphate, Ferrous Chloride and Ferrous Sulphate are a necessity to
ensure the succession of this experiment. Optimum conditions of dye removal
were when 500 mg/L of chemicals were utilized, hydrogen peroxide concentration
of 300 mg/L is added, pH value is set around 3 and when reaction time of 90 min
were set.
The experiment was conducted under shaking conditions in a batch reactor. A
number of 8-watt UVC lamps were used to induce UV light radiation. Dye removal
was tested with hydrogen peroxide of 1 Mmol, initial concentration of MB of 3, 5
and 10 mg/L, reaction time of 3.5, 4.5 and 10.5 min and UV irradiation intensity
of 2400 μW/cm2. Rate of dye removal became higher as hydrogen peroxide
concentration and UV light intensity became higher.
Successfully removed Brilliant green at dye concentration of 0.06 g/L, Evans blue
at dye concentration of 0.15 g/L and a mixture of both dyes at a concentration of
0.08 g/L with 96 h of contact time.
Colour was best removed when contact time is around 20 h when dye
concentration is 1 g/L, pH is between 6.5–7.5 and temperature in between
30–35 °C.
Aerobic conditions proved to be best in this dye removal experiment. Shaking
conditions were favoured more than stationary conditions. Ideal dye removal
condition was found to be when pH is in between 4 till 10 and surrounding
temperature is 28 °C. Contact time should be set to be 6 h at least and ideal dye
concentration is 200 mg/L. Mixed culture produces better results than single
culture.
Bacterial mixed culture successfully removed 100 μmol/L of 4-nitroaniline with
yeast extract at 5 g/L within 72 h under aerobic conditions. Dye concentrations
were varied from 100 till 1000 μmol/L. Shaking conditions were adopted for this
experiment. Ideal pH for the experiment was found to be 7 and the temperature
was maintained at 35 °C
Experiment was successful whereby the concentration of dye mixture with traces
of glucose, sucrose and yeast extract was below 500 mg/l and contact time was
above 4 days. The pH of the solution was adjusted to 7 and the temperature was
maintained at 37 °C. To obtain high percentage of dye removal, centrifugation
process of dye solution at 8000 rpm for 20 min should be done.
Dye was removed from a 100 ml dye solution which was incubated with the
bacteria for 7 days (contact time) under aerobic conditions. A shaker type
incubator was used for maximum dye removal. Other conditions of the dye
solution include an incubation speed of 8000 rpm, a temperature of 32 °C and pH
of 7.
Experiment was conducted in both shaking conditions and stationary at
temperature 25 °C. Shaking conditions proved to produce better dye removal
results. Dye removal occurred more rapidly in acidic conditions (pH 1–6).
Conditions and results
[101]
78.4
[110]
70
[18]
89.56
97.3
(continued on next page)
[80]
[16]
96
98
[52]
98
86.3
[27]
95
74.3
[99]
[96]
82.9
81.6
[67]
92
76
References
Maximum
efficiency (%)
V. Katheresan et al.
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
4686
Alizarin Yellow R
Procion Red MX-5B
Conductive-diamond electrochemical oxidation
Reactive blue 19
Oxidation dye removal through combination of membrane-free up-flow
biocatalyzed electrolysis reactor and aerobic bio-contact oxidation
reactor
Average success rate
Oxidation
Oxidation through sono, photo and sonophotocatalytic oxidation using
visible light
Acid orange 24
Fenton reaction through application of advanced photo-oxidation
technique
Direct Blue 71
Average success rate
Fenton reaction
Fenton reaction through oxidation
Acid Red 14
Batik wastewater
Electrochemical destruction with an electro catalytic reactor
Fenton reaction using Taguchi orthogonal array design
Remazol Brilliant Blue
Textile wastewater
Electrochemical destruction
Electrochemical destruction with cylinder Ti/β-PbO2 electrode in an
electro catalytic tube reactor
Electrochemical destruction with in situ electro-generated active
chlorine
Dye
Method
Table 6 (continued)
Sulfur-covered titanium dioxide also known as S-TiO2 nanoparticles were utilized
to ensure the succession of this experiment. Best conditions for maximum dye
removal through the sonophotocatalytic reaction are a catalyst dosage of 50 mg,
sulfur weight of 5 wt%, initial dye concentration of 20 mg/L, pH value 3, weight
of nanoparticle of 5 wt% and ultrasonic power of 100. Operating temperature of
the experiment was maintained at 25 °C. The sonophotocatalytic process was
found to remove dye particles better than the other processes. Reaction time for
total dye degradation was 120 min.
Maximum dye removal conditions were noted at reaction time 2 h when dye
concentration was 100 mg/L. External power source of 0.5 V ensured high dye
removal percentage. Close to 100% electron recovery in the cathode zone was
noted. High dye removal was also due to a high loading rate of 780 g/m3d.
Boron covered diamond anodes were used in this experiment for high dye
removal. Ideal conditions for dye removal are when chloride concentration is
100 mg/dm3, current density is 10 mA/cm2, flow rate is 300 dm3/h and initial
pH is 7. Maximum reaction time was observed to be approximately 240 min no
matter what value of current density is applied. Electric charges of about 5 Ah/
dm3 is enough to remove high amounts of dye and COD.
A batch reactor was used to conduct the experiment successfully. Ideal parameters
for high percentage of dye removal include 3 mg/L (dosage of iron 2+), 100 mg/L
(dye concentration), 3 (initial pH), 132 mg/L (hydrogen peroxide concentration)
and 20–60 °C (temperature of the dye solution). Approximately 50.7% of COD was
successfully removed from this experiment. Reaction time of 20 min is required to
ensure high percentage of dye removal.
Ideal conditions for high dye removal are a dye concentration of 20 mg/L,
hydrogen peroxide concentration of 0.15 mmol, iron 2+ of 0.015 mmol, a pH
value of 3.5 and temperature. Optimization was done using the Taguchi fractional
factorial design. Volume of dye solution used in the experiment was 50 mL.
Optimal conditions to achieve high dye removal were when ferrous sulphate
dosage is 0.75 g/L, hydrogen peroxide concentration is 0.75 g/L, initial dye
concentration is 3 ml/L, pH is 3 and reaction time is 40 min. There was significant
reduction in COD level in treated dye solution.
Synthesis of anode was done through the anodic electrodeposition method. Dye
degradation was tested at hydraulic retention time 2 and 4 h, pH 6–9 as well as
salt concentration of 3000 and 4000 mg/L. Ideal dye removal parameters are
when direct current is 5.6 V, hydraulic retention time at 4 h, pH 6 and salt
concentration 4000 mg/L.
Electrode used was modified with titanium and lead dioxide. Dye degradation was
most successful when the concentration of sodium chloride solution was 4000 mg/
L, the dye degradation time allowed was in between 50–60 min and pH was in
between 5–10.
The experiment was conducted in batch using a full-scale electro catalytic reactor.
Ti/RuIrO2 electrode was designated as its anode while a stainless steel plate was
designated as its cathode. An electrode gap of 30 mm was set. To find optimal
conditions, the experiment was set up with parameters such as electrode
concentration (2500–4000 mg/L), hydraulic retention time (30–180 min) and
initial pH (3–9). Optimal conditions for treating batik wastewater was when direct
current of 5 V was applied, hydraulic retention time was 120 min, mixing speed
was set at 120 rpm, pH was 5 and salt concentration was 4000 mg/L.
Conditions and results
[89]
100
[37]
95
(continued on next page)
[28]
[30]
94.8
85
[68]
90
93.9
[113]
92.7
94
[41]
[88]
70.38
88.8
[87]
References
96
Maximum
efficiency (%)
V. Katheresan et al.
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
4687
Malachite green
Chicago Sky Blue, Methyl Orange and
Rhodamine B
Ultraviolet irradiation through pulsed discharge plasma in water
Average success rate
Physical
Adsorption
Adsorption by treated sawdust
Acid Blue 92, Acid Green 20, Acid Orange 7
and Acid Red 301
Ultraviolet irradiation using acrylic grafted nano membrane
Acid red 4092
Reactive Blue 222, Remazol Black B,
Reactive Blue 221 and Remazol Brilliant
Blue R
Semiconductor-assisted photochemical degradation
Average success rate
Ultraviolet irradiation
Ultraviolet irradiation with zinc oxide nanoparticles
Indigo Carmine
Photochemical degradation with Calcium Oxide catalyst
Methylene blue
Acid yellow 19
Optimized ozonation
Average success rate
Photochemical
Photochemical degradation with a combined system of titanium dioxide
and UV.
Acid Red 183
Nova cron super black G and Terasil red ww
3BS
Dye
Ozonation treatment
Average success rate
Ozonation
Ozonation Process
Method
Table 6 (continued)
Sawdust was treated by formaldehyde and sulphuric acid. It was found that
sulphuric acid treated sawdust removes more dye than formaldehyde treated
sawdust. Best conditions for highest dye removal by this process is when
adsorbent dose is 0.4 g/100 ml, pH is in between 6 and 9 and temperature is
around 26 °C. Dye removal is better done in a batch reactor or a stirred tank
reactor.
Experiments were conducted in a batch photo-reactor. Ideal parameters for
maximum dye removal was noted as catalyst dosage of 0.2 g/L, dye concentration
of 0.5 mg/L, irradiation time of 12 min, and a pH value of 5.
Slight modifications were done to the polysulfone ultrafiltration membrane with
the usage of acrylic acid. Ideal operating parameters for this experiment are an
irradiation time of more than 30 min and pressure around 4 bars. Addition of
about 80 mM of sodium sulfate in dye solution increases dye removal percentage.
Dyes with lower molecular weights have a higher chance of getting completely
removed.
Highest rate of dye removal noticed when discharge operates in the
spark–streamer mixed mode. Best conditions to ensure the succession of the
experiment include an initial dye concentration of 0.01 g/L, a pH value that is
acidic especially at 3.5, a reaction time higher than 100 min and a wavelength
above 300 nm.
Titanium dioxide was immobilized with polyvinyl alcohol to further enhance dye
removal in this process. Ideal process parameters were found to be when initial
dye concentration is 20 mg/L, light intensity of UV light at 4 W, liquid volumetric
flow rate is 2 mL/min and wavelength of 254 nm. Reaction time for maximum dye
removal was less than 20 h.
Maximum dye removal was noted when parameters were calcium oxide particle
size was in between 30 and 36 nm, concentration of calcium oxide was 0.12 g, dye
concentration is 5.0 mg/100 mL, pH is 12 and temperature is in between 298 and
300 K. Best source of light for this process was visible light (8 W lamps).
The experiment was carried out in an oxygenated UV coupled with zinc oxide
environment. Optimization was done by factorial design to produce better dye
removal results. Ideal parameters were recorded such as dye concentration of
50 mg/L at volume 100 ml, pH value 5.5 and required reaction time is
approximately 60 min. The zinc oxide semiconductor produced better results than
the titanium dioxide semiconductor.
A batch reactor was utilized for the ozonation process. Ideal process parameters
were when reaction time was 6 h, pH value was 9 and temperature was
maintained at 35 °C. Volume of wastewater prepared for dye removal was 500 ml.
Ideal dye removal parameters were found to be when contact time was 15 min,
dye concentration was 50 mg dm−3, ozone dosage was 300 mg dm−3 and when
the pH was in the acidic range.
Central composite design was utilized to optimize typical ozonation process in dye
removal. Favourable parameters for this experiment were initial concentration of
the dye 20 mg/L, initial pH of the solution around 7.5, temperature of 40 °C and
the ozone dosage of 400 mg/L.
Conditions and results
[65]
96.4
[127]
[48]
99
99
[119]
95
99.8
(continued on next page)
[46]
[14]
99.9
98.3
[33]
100
99
[112]
99
94.5
[109]
[135]
References
97
90
90
Maximum
efficiency (%)
V. Katheresan et al.
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
Basic blue 41
Adsorption through nano porous silica
4688
Acid brown 348
Congo red and direct blue
Irradiation by ultrasound exfoliated graphite
Irradiation by acrylamide as well as starch based hydrogel and
gamma
Acidic, direct, disperse and reactive dyes
90 Dalton membrane in nano filtration
Average success rate
Reverse osmosis
Acid red
Nano filtration coupled with reverse osmosis
Cibacron Yellow S-3R
Acidic indigo carmine
Average success rate
Irradiation
Irradiation with induced cationic hydrogels
Average success rate
Nano filtration or ultra-filtration
Nano filtration using Hydracore50 membrane coupled with
Electrochemical Process using Titanium and Platinum rods
Basic Blue 9
Acid Orange 7
Purolite C145 Macroporous Polymeric Ion Exchangers
Ion exchange by Lewatit MonoPlus MP 500 anion resins
C.I. Acid Orange 7, C.I. Direct Blue 71 and
C.I. Reactive Black 5
Cibacron Yellow FN-2R and Terasil Blue
BGE-01
Coagulation/Flocculation using coagulants an anionic coagulant aid,
alum, magnesium chloride and poly aluminium chloride
Average success rate
Ion exchange
Ion exchange by Amberlite IRA 958 anion resins
Disperse dye
Coagulation/flocculation process using aluminium-based water
treatment residuals
Acid red 119
Congo Red
Adsorption through bio-waste material such as ground nut shells
charcoal and eichhornia charcoal
Average success rate
Coagulation and flocculation
Coagulation/flocculation treatment using ferric chloride sludge from
water treatment plant
Dye
Method
Table 6 (continued)
Crucial parameters to ensure the succession of the experiment were current
density of 33 mA/cm2, a dye concentration of 0.1 g/L, a pH value of 3 and a salt
(sodium chloride) concentration of 60 g/L
Ideal parameters for high dye removal were noted as contact time of 2 h, dye
concentration of 65 mg/L, feed temperature of 39 °C, operating pressure of 8 bar
and pH of solution at 8.3.
Ideal parameters include a contact time of 2 h, a dye concentration of 50 mg/L, a
pressure of 12 bars and total dissolved solids concentration of 3000 mg/L.
Studies on this topic were done using the batch adsorption technique. Ideal
parameters for this experiment would be when contact time is 21 h, initial dye
concentration is 120 mg/L, irradiation dose is 5.3 kGy and pH is 2.8.
Maximum dye removal was achieved when contact time is 120 min, initial dye
concentration of 40 mg/L, sorbent dosage is 2 g/L, pH is 1 and temperature is
40 °C.
The optimal values for dye removal are a dye concentration of 100 mg/L, a
solution pH in between 3–10, radiation dosage of 30–40 kGy and a temperature of
20–60 °C.
The experiment is better done in shaking condition at 180 rpm in batches. Ideal
parameters for this experiment were when anion dosage is 0.5 g, contact time is
3 h, dye concentration is 10 mg/L, pH is around 5 and at a temperature of 24 °C.
Best conditions for the experiment were found to be when adsorption capacity is
1004.4 mg/g, anion dosage is 0.5 g, contact time is 3 h, dye concentration is
10 mg/L, pH is around 5 and at a temperature of 45 °C.
The mode is experiment is batch adsorption. Tried and tested successful
experiment parameters are when contact time is more than 5 h, initial dye
concentration is 29.6 mg/L, initial solution pH is 12, resin dose is 40 g/L and
temperature is 20 °C. The monolayer adsorption capacity of the cation was found
to be 31.9846 mg/g.
Process optimization was done through response surface methodology. Optimum
parameters for dye removal are coagulant dosage of 236.68 mg, initial dye
concentration of 65.91 mg/L and initial pH of 3.5.
Modelling was done for this experiment through artificial neural networks. Ideal
parameters for this experiment are aluminium dosage of 3 000 mg/L, initial dye
concentration of 25 mg/L and initial pH value of 3.
The jar test method was used to determine ideal process parameters. It was found
that coagulant dosage of 1000 mg/L, dye concentration of 1.0 g/L and pH ranging
from 3.8 till 5.2 are ideal for maximum dye removal.
Ideal parameters for dye adsorption was at an adsorbent dose of 1.2 g, contact
time of 60 min, dye concentration of 1 g/L, ionic strength of 0.05 M and
temperature of 318 K. Maximum adsorption capacity of ground nut shells charcoal
was found to be 117.6 mg/g while for eichhornia charcoal is was found to be
56.8 mg/g. When pH was in the acidic range, a higher dye removal was observed.
Ideal parameters found that removed the highest amount of dye is contact time of
60 min, dye concentration of 50 mg/L, pH of 7 and temperature of 25 °C.
Conditions and results
[44]
[136]
88
96.3
[74]
75
96.6
98
93.77
98
(continued on next page)
[53]
[2]
[21]
[115]
90
87.7
[106]
98.2
86.8
[120]
[133]
87
85
[134]
88.3
93.6
[83]
96.53
99
[139]
[66]
98
99
References
Maximum
efficiency (%)
V. Katheresan et al.
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
97.1
[90]
[64]
94
99.8
[10]
98.30
include its affinity with various compounds, its large surface area and
its ability of be regenerated [20]. Known as the oldest and most efficient adsorbent, activated carbon can be derived from any carbonaceous materials such as coal. Coal based activated carbon have been used
by numerous researches to successfully remove a wide variety of dye
molecules from wastewater and is typically known as commercial activated carbon. Apart from dye molecules, activated carbon is known to
remove heavy metals and other toxic pollutants as well [86,98].
Activated carbon is capable of removing any kind of dye and a
number of pollutants present in wastewater [45]. The problem with
coal based activated carbon is that coal itself is a fossil fuel and
therefore an expansive non-renewable resource which soon might cease
to exist. To overcome this, activated carbon nowadays is prepared from
renewable resources like biomass, natural materials and even waste
materials [100,105,117]. Besides being renewable, these alternatives
are way cheaper than activated carbon prepared from non-renewable
materials. Properties of activated carbon derived from different raw
materials differ as well. Activated carbon can be produced by following
two simple steps, first the selected carbonaceous raw material is carbonized in an inert surrounding at a temperature of 1000 °C then secondly, the carbonized material is activated with an appropriate chemical [4]. Activation of carbon can be done through one out of two
methods, chemically or physically [57]. The difference between these
two methods can be seen in Table 9.
Synthesizing activated carbon from waste material will help reduce
environmental waste. Not only is the environment being disposed of
these unwanted waste materials, the cost of obtaining raw materials for
activated carbon production would become less or sometimes none. The
adsorption capacity of an activated carbon depends on the raw material
used, its carbon content, and the method of treatment as well as
treatment conditions. Activated carbon prepared from different raw
materials will have different adsorption capacities and surface areas.
Other factors affecting the adsorption capacity of an activated carbon
are its pore structure as well as size, surface charge and surface
chemistry [32,100]. An ideal activated carbon should possess characteristics such as a high surface area, has large pores and is a multipored structure.
Microporous activated carbon is used to remove small molecules
(smaller than 1 nm) while macro porous or mesoporous activated carbons are used to remove big molecules (bigger than 1 nm) from wastewater [69]. Activated carbon these days comes is numerous sizes such
as blocks, fibres, granules, pellets and even in powdered form. Among
the many forms of activated carbons, the powdered form activated
carbon is the one conventionally used in dye removal due to their larger
surface area than the other forms [105]. Adsorption onto activated
carbon occurs with the aid of forces known as the van der Walls. Many
studies exist to prove that dye removal through activated carbon adsorption is an ideal way to completely remove all types of dye particles.
Usually, after continuous dye removal, adsorptive properties of the
activated carbon will gradually become weak [133]. Activated carbon
will not be able to adsorb dye molecules at the same capacity of fresh
activated carbon as their pores will no longer be able to accommodate
additional dye molecules. However, due to technology advancement,
regeneration of activated carbon is possible through reactivation of
activated carbon [141]. The downside of reactivating exhausted activated carbon is the loss of carbon and the decrease of adsorption capacity. It can be seen in Table 10 that activated carbon derived from
low cost raw materials do have large surface areas and can efficiently
remove dye molecules. Since the cost of obtaining alternative raw
materials are low, the overall cost of the adsorption process is still
cheap [122].
Anthrasol brown IBR
Methyl orange
Reverse osmosis
Reverse osmosis through a thin film composite membrane module
Average success rate
Direct yellow
Reverse osmosis through Polyamide Membrane
Experiments were performed in batches varying in parameters such as contact
time of 0.2 till 2.0 h, feed concentration of 75 to 450 ppm and operation
temperature from 30 to 50 °C. It was found that good results are produced when
the contact time is lower, when the feed concentration is low and when the
temperature is low.
Ideal parameters to be set for high dye removal are a dye concentration of 30 mg/
L, a feed concentration of 30 ppm, at pH value 4 and a temperature of 25 °C. The
number of times the dye effluent passed through the membrane is 4.
Optimal parameters to remove high percentage of dye is when the dye
concentration is 100 mg/L, feed pressure is 400 psi, flow rate is higher than 2 L/
min, pH value is in between 2–4, salt concentration is 100 mg/L and when
temperature is 25 °C.
References
Dye
Method
Table 6 (continued)
Conditions and results
Maximum
efficiency (%)
V. Katheresan et al.
6.2. Activated carbon bamboo as an adsorbent
Abundantly found in the African, Asian and Latin American continents, bamboo is a kind of perennial grass-plant with a long life span.
4689
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
Table 7
Effect of different parameters on the adsorption process.
Parameters
Adsorbent dosage
Contact time
Dye concentration
pH
Temperature
Description
Effect
- Measure of the amount of adsorbent used to adsorb dye particles.
- Depends on the number of sorption sites available on the surface of the adsorbent.
- Test can be done by preparing solutions with fixed dye concentration and pH but varying
adsorbent dosage.
- Measure of the amount of time the adsorbent and adsorbate is placed in contact with each
other.
- Test can be done by preparing solutions with a fixed adsorbent dosage, dye concentration
and pH but allowing differing contact time between the adsorbent and adsorbate.
- Measure of the amount of dye dissolved in water.
- Dye particle adsorption depends on the vacant binding sites on the surface of the adsorbent.
- Test can be done by preparing solutions with a fixed adsorbent dosage and pH with varying
dye concentrations.
- Measure of the acidity or alkalinity of a solution.
- A solution with pH less than 7 is considered acidic while a solution with pH more than 7 is
considered alkali.
- Controls the degree of electrostatic charges transmitted by ionized dye molecules resulting
in varying rate of adsorptions when the pH is changed.
- Test can be done by preparing solutions with a fixed adsorbent dosage and dye
concentration with varying pH.
- Measure of the temperature of the solution when adsorption takes place.
- Indicates the nature of adsorption whether it is endothermic or exothermic.
- Test can be done by preparing solutions with a fixed adsorbent dosage, dye concentration
and pH but heating the solution to varying temperatures.
- Higher rate of adsorption if adsorbent dosage is high
and vice versa.
- Optimum rate of adsorption when adsorbent dosage is
around than 10 g/L.
- Higher rate of adsorption if contact time is long and
vice versa.
- If the adsorbent is efficient enough, optimum time
required for complete dye removal is 3 h
- Higher rate of adsorption if dye concentration is low
and vice versa.
- Highest rate of adsorption when dye concentration is
around 0.1 g/L.
- Low rate of adsorption when pH is low and vice versa.
- Highest rate of adsorption if pH is around 6.
- Low rate of adsorption if temperature is too low or too
high.
- Higher rate of adsorption if temperature is around 30 °C.
carbonaceous mesoporous material with a large surface area as well as
adsorption capacity. Compared to materials like treated rice husk,
waste newspaper and sawdust, bamboo requires minimal processing to
convert it into activated carbon. Preparation and regeneration of activated carbon bamboo is easy and safe. Bamboo activated carbon can
potentially replace the usage of commercial activated carbon [50].
Commonly used for activities such as construction, furniture as well as
handicraft making and paper production, bamboo have become one of
the most sought after raw material these days [111]. Countries like
Malaysia, India and Japan is known to largely produce and process
bamboo plants resulting in huge amounts of bamboo waste being produced. This piqued the interest of researchers to develop a use for this
waste hence bamboo waste was established as a raw material in the
production of bioethanol. Next, it was found that waste bamboo can be
used as an adsorbent to remove moisture as well as odours due to its
absorptive characteristics which lead to the production of air fresheners, odour removers and water purifiers from bamboo [35]. Nowadays, bamboo is used in dye removal applications in the form of activated carbons as it can completely remove dyes and other pollutants
like heavy metals and organic pollutants due to its unique composition.
Utilizing bamboo waste as an adsorbent will not only help the nation
dispose bamboo waste but also reduce the cost of adsorbent production
for dye removal [57]. Among the various activated carbons listed in
Table 10, bamboo is highlighted due to the fact that Malaysia is one of
the leading producers of this plant in Asia [70]. Bamboo is easily assessable here in Malaysia, is cheap to acquire and is a naturally available non-hazardous material. Bamboo is known as a highly
7. Enzymes in dye removal
7.1. Free enzymes in dye removal
Enzyme also known as biocatalyst is a cheap, efficient, regenerable
and selective biological substance existing in liquid form [91]. Enzymes
can work to specifically remove particular stubborn pollutants by
converting them into products or through the precipitation process
[47]. Biocatalysts are an upcoming technology utilized in various sectors for numerous applications. Enzymes became famous due to its
easily accessibility, green chemistry and substrate specificity
[31,59,108]. The main attraction of an enzyme is its environmental
friendly and non-toxic nature along with its reusability factor. When an
enzyme is utilized to adsorb dye molecules from wastewater, they are
Table 8
List of adsorbents with their surface areas.
Adsorbent
Description
Adsorption capacity (mg/
g)
Reference
Activated carbon
Activated clay
Bark
Bentonite
Cane pith
Charred dolomite
Chitosan
Derived from any carbonaceous raw material.
Dried up naturally occurring porous structure
Outer hard layer of a plant or tree
An aluminium phyllosilicate clay consisting of montmorillonite
Spongy tissue available in sugar canes
An anhydrous carbonate mineral consisting of calcium magnesium carbonate burned till char
Treated chitin shells of shrimp or other crustaceans formed into a linear polysaccharide consisting of randomly
distributed acetylated and deacetylated unit.
Scraps of cotton disposed by cotton-making factories.
Combustible sedimentary carbonaceous material obtained from below the earth surface.
Dried partially decomposed organic materials commonly used as fertilizers.
A protective skin around rice grains disposed before cooking.
Disposed powder wood obtained from sawing factories.
Coagulated colloidal silicic acid commonly used as a desiccant
A commonly purged substance obtained in sugar industries.
Strengthened cotton fibres.
500–2000
585
1119
1667
941.7
950
973.3
[24]
[39]
[81]
[95]
[61]
[129]
[137]
875
588
324
838
294.12
900
519
589
[81]
[38]
[42]
[81]
[51]
[49]
[73]
[20]
Cotton waste
Natural coal
Peat
Rice husk
Sawdust
Silica gel
Sugar industry mud
Treated cotton
4690
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
effort. To overcome this issue, enzymes are immobilized instead of
being left as free enzymes. For dye removing processes, enzymes are
often immobilized onto an inert as well as insoluble material for resistance purposes. Enzyme immobilizing is practically the act of confining an enzyme onto a support system in order to stabilize it. For over
a century, enzyme immobilization has been practiced through various
applications such as diagnosis of disease, production of drug intermediates, and recovery of air, soil as well as water [26].
Whenever enzyme is required as part of a process, immobilization is
always advised due to the perks it present. When an enzyme is immobilized, handling it becomes much easier as it becomes a stable
substance immune to the physicochemical environment around it. This
immobilized enzyme can be reused and has been proven to produce
better separation results than free enzymes [36,117]. Enzyme immobilization is a straightforward flexible process that can be applied in
all industrial operations as well as all types of reactors. Certain enzymes
can be freeze-dried into powdered form known as lyophilized state. In
this state, enzymes exhibit the same characteristics of immobilized
enzymes [82].
Enzymes tend to behave like typical soluble enzymes once it has
been dissolved in solutions and this enzyme cannot be reused. Apart
from immobilization, enzymes have been further studied to areas like
DNA technology, genomics, protein engineering, and proteomics but
were found to pose unfavourable disadvantages such as its complicated
techniques, high cost, short lifespan, and its inability to be regenerated.
Enzyme immobilization possesses none of the said disadvantages thus
can be said to be the best way to utilize an enzyme. There are certain
factors that influences the immobilization process shown in Table 11.
Enzyme immobilization have received substantial interest compared
to soluble enzymes or other biological dye removal technologies only
because of the benefits of this method. This method is a reliable dye
removal method as it is cheap, stable, regenerable, easily assessable and
extremely efficient [31]. The regenerable characteristic of the immobilized enzyme aids in reducing the cost of the overall enzyme degradation method.
The cost of the enzyme degradation dye removal method is largely
affected by the raw material used for enzyme extraction. Often, enzymes are extracted from animals, microbes or plant raw materials and
their cost varies [26]. Cost of the method may also differ based on
method of enzyme extraction, enzyme isolation, enzyme purification,
chosen method of immobilization and finally the chemicals required for
immobilization [36].
The method of immobilization and the type of enzyme used for
immobilization determines the properties of an immobilized enzyme.
Due to the accomplishments of immobilized enzymes, various methods
of immobilizing an enzyme onto various surfaces have been developed
in the past century [82]. To date, the enzyme immobilization
Table 9
Difference between chemical and physical carbon activation methods.
Activation time
By-products
Number of steps
Requirement
Steps
Surrounding
Temperature
Washing
Advantages
End product
Chemical activation
Physical activation
Short
None
1
Carbon activation chemicals
(H3PO4, KOH, K2CO3,
NaOH, ZnCl2) and nitrogen
1. Raw material impregnated
with chemicals
2. Heated under a flow of
nitrogen gas
(1 and 2 carried out
simultaneously)
Inert (nitrogen)
Low (450-900 °C)
Needed (presence of other
chemicals that should be
eliminated)
- Less burnt activated
carbon
Long
Non-porous char
2
Inert and oxidising gases
(carbon dioxide and nitrogen)
1. Carbonization of raw
material by pyrolysis process
2. Activation with either air,
carbon dioxide, steam or a
mixture of oxidising gases
Inert (nitrogen)
High (600-1200 °C)
Not needed (no chemicals
used for activation)
- Mesoporous structure
- Suitable for dye adsorption
- Wider pore size
Activated carbon (porous structure with large surface area)
Table 10
List of activated carbon with their surface areas.
Activated carbon
Almond shell
Apricot shell
Bagasse
Bamboo
Cashew nut shell
Commercial
Corncob
Granule
Groundnut shell
Hazelnut shell
Pine sawdust
Pinewood
Plum kernel
Sawdust
Treated rice husk
Walnut shell
Waste newspaper
Adsorption capacity (mg/
g)
Surface area
1.33
4.11
391
454.2
476
980.3
1060
57.47
222.2
8.82
370.37
1176
904
183.8
290
3.53
390
783
783
1433
1896
984
650
943
1100
1114
793
1390
902
1162
516.3
2516
774
1740
Reference
(m2 /g)
[15]
[15]
[126]
[50,70]
[116,118]
[9,62]
[60]
[94]
[77]
[15]
[5]
[125]
[60]
[76]
[34]
[15]
[93]
called bio adsorbents or biosorbents [26].
Biosorbents are an upcoming approach in dye removal that is being
pursued by researchers nowadays [124]. It has the potential to be developed to remove dye on a large scale and can be categorised as an
alternative adsorbent [43,85]. Enzymes can function in a wide range of
pH and low temperatures. The biosorbent technology is still in the trial
stage and more research is required before it can be established as a
reliable adsorbent [4,25,29].
In Table 2, it can be seen that among the other listed biological dye
removal methods, enzyme degradation (90.1% average success rate) is
considered the best due to its multiple advantages. Besides that, this
method only has a single disadvantage, an unreliable amount of enzyme
production. This sole disadvantage of the enzyme degradation method
is harmless compared to the disadvantages of the other existing biological dye removal methods. This disadvantage can be easily remedied
through the usage of an exceptionally efficient raw material containing
dye removing enzymes and undertaking an efficient mode of enzyme
extraction.
Table 11
Factors affecting immobilization of enzymes.
Factor
Effect
Binding mode variation
Affects the activity and stability of an
enzyme
Hydrophobic nature of enzyme gets
stabilized
Enzyme thermal stability is enhanced
Enzyme activity decreases while enzyme
stability increases
Rate of reaction of the hydrophobic
substrate is enhanced
Large pore structure display high
enzyme activity and vice versa
Enzyme performance is improved
Enzyme activity depends on the physical
structure of the enzyme
Retention of high enzyme activity
Enzyme deactivation is prevented
Carrier microenvironment
Carrier multipoint attachment
Constraints of diffusion
Hydrophobic partition
Nature of carrier (physically)
Physical post-treatments
Physical structure of enzyme (pore
size)
Presence of inhibitors or substrates
Spacer arm of enzyme
7.2. Immobilized enzymes in dye removal
Maintaining the structural stability of an enzyme requires some
4691
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
Fig. 5. Enzyme immobilization methods [26].
consequences. More enzyme immobilization techniques are being researched on a trial and error basis. Although many support systems
have been researched, it cannot be said with certainty that one support
system alone is ideal for all enzymes [26]. Nevertheless, it can be said
with conviction from the numerous research conducted that enzymes
are most stable in immobilized state.
When enzymes are immobilized onto a solid surface, enzyme activities are confined to that particular surface where its concentration
magnifies at least a thousand fold [82]. This explains its stability once it
is immobilized onto a solid surface. The smaller the solid surface, the
greater the catalytic efficiency and stability of the enzyme. Currently,
nanoparticle research for enzyme immobilization is being studied.
Immobilized enzyme in dye removal received considerable attention
as well due to its efficiency [8]. Due to the usage of immobilized enzymes in various applications, interest for further research and enhancement of immobilization techniques are given importance. As
mentioned before, biocatalysts are being introduced to various industrial applications. To keep up its demand, more studies should be
conducted to improve aspects of it such as its activity, efficiency, regeneration and stability. It is hoped that further research will inaugurate novel applications for immobilized enzyme.
technology has been modified to promote its compatibility with upcoming applications and its evolution continues [9]. When developing
novel immobilization procedures, the factors that vouch for the feasibility of the method are the percentage of enzyme recovered and the
stability of the procedure mainly [36].
Enzyme immobilization is a more environmental friendly procedure
compared to other existing dye removal technologies as toxic or unstable chemicals are absent in this method. Enzyme immobilization can
be achieved using one of the two existing fundamental methods, the
chemical method or the physical method as shown in Fig. 5. The advantages and disadvantages of utilizing the various chemical and physical enzyme immobilization methods are shown in Table 12.
Enzyme immobilization onto solid surfaces have been performed
decades ago. This is mainly done to stabilize an enzyme by providing it
with a solid support. The enzyme can then be utilized in deferring
chemical or physical surroundings. In the year 1960, it was established
that enzymes can be made stable by its own with the usage of a solid
support through the crosslinking method [26,36]. In this method, a
binding agent such as glutaradehyde known as the bifunctional chemical cross linker forms an amide connection between a NH2 compound
on the enzyme surface and the binding agent. This act cross links the
enzyme and the binding agent chemically making it a stable structure
known as cross linked enzyme aggregates (CLEA) as shown in Fig. 6
[31,121].
Researchers Quiocho and Richards attempted crosslinking enzymes
using binding agent glutaradehyde for X-ray diffraction studies in the
year 1964. They received impressive results by which not only the
enzyme was found to be completely stable, it was also found to be fully
functioning in terms of catalytic activity [102].
Enzyme immobilization is a well-known technique to numerous
industrialists and scientific researchers these days [91]. Among the
various enzyme immobilization method, crosslinking appealed the most
due to its effectiveness and compatibility with almost any type of enzyme. Crosslinking is also cheap and does not result in disastrous
7.3. Enzyme peroxidase in dye removal
Degrading dye particles with exo enzymes such as peroxidase enzymes or phenol oxidases is an excellent method to resolve dye effluent
issues. In the presence of hydrogen peroxide, peroxidase enzymes, a
form of hemoprotein can catalyse reactions such as adsorption of dye
molecules from dye effluents. Peroxidase enzymes are enzymes that can
be extracted from animals, human, microorganisms as well as plants
and this enzyme can be categorized as a biosorbents. Common sources
of enzyme peroxidase are glycine max also known as soybean, horseradish, root vegetables and certain fungus [31]. Other kind of common
peroxidases are lignin peroxidase and manganese peroxidase.
4692
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
Table 12
Various enzyme immobilization methods along with its advantages and disadvantages [124].
Method
Chemical method
Covalent
Cross-linking
Ionic
Physical method
Adsorption
Entrapment
Microencapsulation
Description
Advantages
Disadvantages
Enzyme is naturally or synthetically attached directly
or through a spacer arm onto a solid surface through
covalent bonding.
Multiple covalent bonds are formed between the
enzyme and the solid surface through the usage of
multi-functional reagents.
Similar process to physical adsorption method. The
enzyme is bonded with the solid structure ionically.
Minimum change in enzyme conformational.
Fairly resistant structure.
Affects the catalytic properties of enzymes.
Harsh immobilization conditions. Strains the
enzyme.
Loss of enzyme as it diffuses into the solid
surface.
Minimum change in enzyme conformational.
pH and temperature dependent process.
Requires high maintenance.
Enzyme is attached to a solid support directly by a
non-covalent link. Optimization of adsorbent,
concentration of enzyme, ionic strength, nature of the
solvent, pH and temperature must be done in order to
immobilize an enzyme.
An enzyme is cross-linked to a polymer thoroughly by
physical entrapment within the polymer lattice. Only
allows penetration of appropriate sized substrates or
products.
Enzymes are immobilized within a permanent or nonpermanent spherical semi-permeable polymer
membrane with controlled porosity.
Simple method.
Intense optimization required.
Does not alter properties of enzyme. Less enzyme
required. No chemical modification required.
Numerous matrix shapes available.
Straightforward.
High catalytic efficiency. High enzyme
concentration. Large surface area.
Applicable only to a limited number of
enzymes. Delicate. Enzyme leakage. Suitable to
be used with only small sized products or
substrates.
Has flaws. Only works occasionally.
Effective for dye removal processes.
Straightforward method. Strong bonding.
this area so its application at an industrial level should be further researched upon.
Lignin peroxidase (LiP) as well as manganese peroxide (MnP) were
first extracted from an organism called P. chrysosporium, a kind of
fungus and are known to possess a similar reaction mechanisms to one
another [9]. Non-phenolic aromatic compounds such as veratryl alcohol can be oxidised by catalysis of LiP. Oxidation of Mn2 + to Mn3 + can
be accomplished by MnP where Mn3 + has the ability to oxidize various
phenolic compounds while Mn2 + is required in order to complete the
catalytic cycle of MnP [25,43,85]. There is prove in the form of researches papers that LiP and MnP from P. chrysosporium is an efficient
dye particle and xenobiotic compounds degrading substance.
Biosorbents function almost the same way regular adsorbent do, by
accumulating and attaching roaming dye molecules from an adsorbate
onto its surface through process a called reactive adsorption. There are
existing research papers proving reactive adsorption is an efficient as
well as cost-effective process in dye removal processes [117,138].
Peroxidase enzymes are a fairly novel enzymes used these days and it
was found that immobilizing these enzymes onto a solid surface is more
effective as it can function both in aqueous as well as organic solutions
[36].
Immobilized enzyme peroxidase are better than ordinary soluble
enzymes as they possess higher catalytic activities and is more stable
operationally. Besides that, it has been found that the three dimensional
structure of immobilized enzyme peroxidase is intact compared to other
enzymes that have undergone immobilization resulting in structural
damage [82]. So far, only laboratory level studies have been done on
7.4. Glycine max peroxidase in dye removal
Glycine max is commonly known as soybean belonging to the class
III secretory plant peroxidase family. The hull of glycine max approximately contains 37 kD of highly heterogeneous glycoprotein in the form
of enzyme peroxidase merely 20 days after the seed sprouts [8]. Many
countries are producers of soy milk and soy food products thus this raw
material is easily available internationally for a cheap price [9]. Spotting an identity similarity of 57% with glycine max peroxidase, the
horseradish peroxidase isoenzyme C (HRPC) is the most popular
member of the same peroxidase family [54]. Due to possessing astounding characteristics like high thermal stability, high reactivity, and
structural stability even in low pH, glycine max peroxidase has many
substantial applications [107].
In a comparison study between glycine max peroxidase and HRPC, it
was noticed that glycine max peroxidase will become inactive at a
temperature of 90.5 °C while HRPC will become inactive at a much
lower temperature at 81.5 °C [26]. Further studies showed that glycine
max peroxidase has a higher affinity for haem than HRPC. Upon
heating, glycine max peroxidase undergoes a loss of haem and can become irreversibly inactive. Even in low pH, optimally 2.4, glycine max
peroxidase can function actively as usual without undergoing the loss of
Fig. 6. Enzyme cross linking process.
4693
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
9. Conclusion and recommendations
haem whereas HRPC will become inactive due to the loss of haem [9].
As a result of their broad substrate specificity, peroxidases have a vast
diversity of applications although there are limitations for large-scale
utilization due to the environmental stability of an enzyme [47].
Glycine max peroxidase has a promising future in various industrial
applications and is an excellent enzyme to remove dye molecules due to
its phenomenal stability and catalytic characteristics. When mixed with
hydrogen peroxide, glycine max peroxidase can oxidise a large range of
organic or inorganic substances. As mentioned before, enzymes like
enzyme peroxidase are more efficient when immobilized rather than
left free [91]. The specificity of the enzyme will improve while the
stability of the enzyme structure strengthens prolonging its activity.
Immobilized enzymes have a longer life span than free enzymes
[82]. This peroxidase is powerful enough to breakdown and remove dye
particles from dye wastewater. Industrial wastewater treatment facilities have just begun exploring the potential of glycine max peroxidase
as a biocatalyst for dye removal [8]. It is hoped that glycine max enzyme
in dye removal will become an established process which can replace
the conventional dye removal method most countries seem to prefer.
Presence of dye effluents in the environmental water bodies is one
of the causes of water pollution. To avoid this phenomenon, efficient
dye removal techniques have to be utilized to treat dye effluents before
release into the environment. This paper reviewed the efficiency of
various dye removal methods biologically, chemically and physically.
The idea was to make readers aware of its existence along with its efficiency (dye removal percentage) in removing dye particles from
wastewater. The aim of this paper was to narrow down a single dye
removal process which is perceived to be effective in completely removing dye.
Releasing water with the least possible pollutants into the environment should be the aim of dye effluent treatment plants in
Malaysia as well as around the world. Dye-utilizing industries have to
be more responsible in releasing effluents as per the permissible standard set. Industries have to start exploring the reusability of treated dye
wastewater as a water source for their processes. Since it is well known
that the conventional method does not successfully remove all dye
particles, this method should no longer be implemented in treatment
plants.
This review paper has discussed a number of biological, chemical
and physical dye removal methods along with their efficiencies. The
mentioned methods can be adopted to treat dye effluent so that the
pollution in the water released from dye-utilizing industries can be
drastically decreased. Most of the dye removal method listed managed
to remove more than 80% of dye particles from wastewater while a few
methods removed 90% of dye particles from wastewater.
Chemical dye removal methods although extremely efficient should
not be implemented in dye removal processes due to its harmful disadvantages (secondary pollution generation). Among all dye removal
methods, adsorption (physical method) would be the best way to remove dye. The parameters affecting the rate of adsorption namely the
adsorbent dosage, contact time, dye concentration, solution pH and
temperature should be acknowledged as they are crucial to ensure the
succession of the process.
It should be noted that commercial activated carbon can be replaced
by low cost adsorbents provided they are able to remove dye molecules
at the same efficiency as commercial activated carbon and not just
decolourize dye wastewater. Usage of biocatalysts such as enzymes is
upcoming in various applications including dye removal. Biocatalysts
are perceived to be effective but research on it is still in the developing
stages. It is anticipated that combined adsorbent dye removal method
will produce a more favourable result than a single adsorbent dye removal method. Rather than wasting money combining different dye
removal methods to remove dye, it is better if a single method, adsorption, can be further improved. The adsorbent utilized for adsorption can be fashioned using a combination of activated carbon and
peroxidase enzyme. This method will surely be very efficient as they are
already efficient adsorbents on their own, cheap and best of all reusable
time and again. It should be noted that real industrial dye wastewater
may contain more than one dyestuff and a combined adsorbent may be
able to eliminate these pollutants better than single adsorbents.
Future researchers should further investigate combined adsorbents
instead of stand-alone adsorbents. It has already been established that
activated carbons are extraordinary adsorbents, so, in order to further
improve dye removal with combined adsorbents, new biosorbents
should be developed. Adsorbent selection should be done based on its
easy availability, its cost and its renewability. Although it is repeatedly
mentioned that the alternative adsorbents are of low cost, little effort
have been made to mention the cost of the adsorbents. Future researchers should conduct more studies on this area to cover the existing
gaps and make improvements on the adsorption method as well as the
choice of adsorbent. Once more information is obtained, the possibility
of utilizing these methods at industrial level should be considered.
Researchers also should experiment on the adsorption process with real
8. Combined adsorbent in dye removal
Certain literature suggests that using a combination of adsorbents
can radically increase the efficiency of dye removal compared to a
single adsorbent [59]. Other literatures suggest combining typical adsorbents (physical adsorbent) with a biocatalyst (biological adsorbent)
will produce outstanding dye removal results [4,49]. Researchers suggest activated carbon is already an extremely efficient dye adsorbing
material and combining it with an equally effective enzyme (biocatalyst) can perhaps further enhance dye removal [29,138].
Combined adsorbent may even be effective in removing a few hazardous substances at once. If the combined adsorbents do indeed
complement each other, its efficiency in dye removal may surpass the
highest recorded efficiency to date. Besides that, a combination of adsorbents will remove dye faster compared to single adsorbents. It is also
perceived that improvements such as longer time of retention and lower
cost can be achieved with combined adsorbent [69,141]. Low overall
cost can be achieved using a combination of adsorbents due to the
reusability factor of combined adsorbents. Individual adsorbents can
only be used once hence its overall production cost is much higher than
synthesis of combined adsorbents.
An example of a combined adsorbent is immobilizing enzyme peroxidase onto activated carbon bamboo. This will stabilize the enzyme
enabling enzyme recovery and reuse. Instead of synthesizing the adsorbent repeatedly, the same adsorbent can be reused until it is spent.
This saves adsorbent production cost hence lowers the overall cost of
the process. Unfortunately, information on this area of research is
scarce resulting in doubts of this reactive adsorption mechanism.
Researches are currently being done on this area but only on a small
scale. Surely if combined adsorbents were used to remove dye from real
industrial effluents, a higher dye decomposition rate can be achieved
[43,107,132].
It is anticipated from this review that combined adsorbents will
have a higher potential if not equal to single adsorbents to remove dye
particles from dye wastewater. In future, industrialists should consider
manufacturing combined adsorbents for wastewater treatment. It
should be kept in mind that not only will the combined adsorbent be
efficient in removing toxic particles but also economically feasible and
made of easily assessable raw materials. Unlike the experiments conducted in the laboratory, real industrial purged dye effluents contain a
mixture of chemicals, dyestuff and other pollutants. A high percentage
of dye removal is achieved at a lab scale when only a single dye is tested
without the interference of other pollutants. If the dyes were to be
mixed with other pollutants and tested, a completely different result
will be obtained [140]. This issue should be considered for future researches.
4694
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
industrial dye effluents where the operating condition are not pre-set.
Lastly, the issue of spent adsorbent disposal should be taken into account as there is a lack of information of what is done to the spent
adsorbent at the end of the adsorption process.
[19] Zineb B. Bouabidi, Muftah H. El-Naas, Dan Cortes, Gordon McKay, Steel-making
dust as a potential adsorbent for the removal of lead (II) from an aqueous solution,
Chem. Eng. J. 334 (2018) 837–844, https://doi.org/10.1016/j.cej.2017.10.073.
[20] I. Bouzaida, M.B. Rammah, Adsorption of acid dyes on treated cotton in a continuous system, Mater. Sci. Eng. C 21 (1–2) (2002) 151–155, https://doi.org/10.
1016/s0928-4931(02)00096-6.
[21] Valentina Buscio, María García-Jiménez, Mercè Vilaseca, Victor López-Grimau,
Martí Crespi, Carmen Gutiérrez-Bouzán, Reuse of textile dyeing effluents treated
with coupled nanofiltration and electrochemical processes, Materials 9 (12)
(2016) 490, https://doi.org/10.3390/ma9060490.
[22] Shameem Byadgi, Decolourization of textile dye effluents, Environment 3 (2015)
SlideShare https://www.slideshare.net/Shameem_Byadgi/decolourization-oftextile-dye-effluents.
[23] Cabral goncalves, Susana Penha Isolina, Manuela Matos, Amelia Rute santos,
Francisco Franco, Helena Maria pinheiro, Evaluation of an integrated anaerobic/
aerobic SBR system for the treatment of wool dyeing effluents, Biodegradation 16
(1) (2005) 81–89, https://doi.org/10.1007/s10531-004-0431-7.
[24] P.J.M. Carrott, M.M.L. Ribeiro Carrott, R.A. Roberts, Physical adsorption of gases
by microporous carbons, Colloids Surf. 58 (4) (1991) 385–400, https://doi.org/
10.1016/0166-6622(91)80217-c.
[25] Joshni T. Chacko, Kalidass Subramaniam, Enzymatic degradation of azo dyes—a
review, Int. J. Environ. Sci. 1 (6) (2011) 1250–1260 http://www.ipublishing.co.
in/jesvol1no12010/EIJES2075.pdf.
[26] Chagas, Pricila Maria Batista, Juliana Arriel Torres, Maria Cristina Silva, Angelita
Duarte Corrêa, Immobilized soybean hull peroxidase for the oxidation of phenolic
compounds in coffee processing wastewater, Int. J. Biol. Macromol. 81 (2015)
568–575, https://doi.org/10.1016/j.ijbiomac.2015.08.061.
[27] K.-C. Chen, W.-T. Huang, J.-Y. Wu, J.-Y. Houng, Microbial decolorization of azo
dyes by proteus mirabilis", J. Ind. Microbiol. Biotechnol. 23 (1) (1999) 686–690,
https://doi.org/10.1038/sj.jim.2900689.
[28] Salvador Cotillas, Javier Llanos, Pablo Cañizares, Davide Clematis,
Giacomo Cerisola, Manuel A. Rodrigo, Marco Panizza, Removal of procion Red
MX-5B dye from wastewater by conductive-diamond electrochemical oxidation,
Electrochim. Acta 263 (2018) 1–7, https://doi.org/10.1016/j.electacta.2018.01.
052.
[29] G. Crini, Non-conventional low-cost adsorbents for dye removal: a review,
Bioresour. Technol. 97 (9) (2006) 1061–1085, https://doi.org/10.1016/j.
biortech.2005.05.001.
[30] Dan Cui, Yu-Qi Guo, Hao-Yi Cheng, Bin Liang, Fan-Ying Kong, Hyung-Sool Lee, AiJie Wang, Azo dye removal in a membrane-free up-flow biocatalyzed electrolysis
reactor coupled with an aerobic bio-contact oxidation reactor, J. Hazard. Mater.
239–240 (2012) 257–264, https://doi.org/10.1016/j.jhazmat.2012.08.072.
[31] Sumitra Datta, L. Rene Christena, Yamuna Rani Sriramulu Rajaram, Enzyme immobilization: an overview on techniques and support materials, 3 Biotech 3 (1)
(2012) 1–9, https://doi.org/10.1007/s13205-012-0071-7.
[32] Sabino De Gisi, Giusy Lofrano, Mariangela Grassi, Michele Notarnicola,
Characteristics and adsorption capacities of low-cost sorbents for wastewater
treatment: a review, Sustain. Mater. Technol. 9 (2016) 10–40, https://doi.org/10.
1016/j.susmat.2016.06.002.
[33] Mohammad Hadi Dehghani, Parvin Mahdavi, Removal of acid 4092 dye from
aqueous solution by zinc oxide nanoparticles and ultraviolet irradiation, Desal.
Water Treat. 54 (12) (2014) 3464–3469, https://doi.org/10.1080/19443994.
2014.913267.
[34] Lei Ding, Hong-Bing Zeng, Wei Wang, Fei Yu, Improved stability criteria of static
recurrent neural networks with a time-varying delay, Sci. World J. 2014 (2014)
1–7, https://doi.org/10.1155/2014/391282.
[35] André B. dos Santos, Francisco J. Cervantes, Jules B. van Lier, Review paper on
current technologies for decolourisation of textile wastewaters: perspectives for
anaerobic biotechnology, Bioresour. Technol. 98 (12) (2007) 2369–2385, https://
doi.org/10.1016/j.biortech.2006.11.013.
[36] Alka Dwevedi, Basics of enzyme immobilization, Enzyme Immobil. (2016) 21–44,
https://doi.org/10.1007/978-3-319-41418-8_2.
[37] Ebrahiem E. Ebrahiem, Mohammednoor N. Al-Maghrabi, Ahmed R. Mobarki,
Removal of organic pollutants from industrial wastewater by applying photofenton oxidation technology, Arab. J. Chem. 10 (2017) S1674–S1679, https://doi.
org/10.1016/j.arabjc.2013.06.012.
[38] Emad N. El Qada, Stephen J. Allen, Gavin M. Walker, Adsorption of basic dyes
from aqueous solution onto activated carbons, Chem. Eng. J. 135 (3) (2008)
174–184, https://doi.org/10.1016/j.cej.2007.02.023.
[39] M.S. El-Geundi, H.M. Ismail, K.M.E. Attyia, Activated clay as an adsorbent for
cationic dyestuffs, Adsorpt. Sci. Technol. 12 (2) (1995) 109–117, https://doi.org/
10.1177/026361749501200203.
[40] Kranti Engade, S.G. Gupta, Adsorption of synthetic dye and dyes from a textile
effluent by dead microbial mass, J. Ind. Pollut. Control 23 (1) (2007) 145–150.
[41] Nese Ertugay, Filiz Nuran Acar, Removal of COD and color from direct Blue 71 azo
dye wastewater by Fenton’s oxidation: kinetic study, Arab. J. Chem. 10 (2017)
S1158–S1163, https://doi.org/10.1016/j.arabjc.2013.02.009.
[42] A.N. Fernandes, C.A.P. Almeida, C.T.B. Menezes, N.A. Debacher, M.M.D. Sierra,
Removal of methylene blue from aqueous solution by peat, J. Hazard. Mater. 144
(1–2) (2007) 412–419, https://doi.org/10.1016/j.jhazmat.2006.10.053.
[43] Esther Forgacs, Tibor Cserháti, Gyula Oros, Removal of synthetic dyes from wastewaters: a review, Environ. Int. 30 (7) (2004) 953–971, https://doi.org/10.1016/
j.envint.2004.02.001.
[44] Mahesh R. Gadekar, M. Mansoor Ahammed, Coagulation/flocculation process for
dye removal using water treatment residuals: modelling through artificial neural
networks, Desal. Water Treat. 57 (55) (2016) 26392–26400, https://doi.org/10.
1080/19443994.2016.1165150.
[45] Saheed A. Ganiyu, Oluwole O. Ajumobi, Saheed A. Lateef, Kazeem O. Sulaiman,
Idris A. Bakare, Muhammad Qamaruddin, Khalid Alhooshani, Boron-doped activated carbon As efficient and selective adsorbent for ultra-deep desulfurization of
Competing interest
No competing interest to declare.
Acknowledgement
Authors would like to thank Curtin University Malaysia for providing access to academic resources necessary for this project.
References
[1] Jafar Abdi, Manouchehr Vossoughi, Niyaz Mohammad Mahmoodi,
Iran Alemzadeh, Synthesis of metal-organic framework hybrid nanocomposites
based on GO and CNT with high adsorption capacity for dye removal, Chem. Eng.
J. 326 (2017) 1145–1158, https://doi.org/10.1016/j.cej.2017.06.054.
[2] Mohammad Fadhil Abid, Mumtaz Abdulahad Zablouk, Abeer Muhssen AbidAlameer, Experimental study of dye removal from industrial wastewater by
membrane technologies of reverse osmosis and nanofiltration, Iran. J. Environ.
Health Sci. Eng. 9 (1) (2012) 17, https://doi.org/10.1186/1735-2746-9-17.
[3] Kayode Adesina Adegoke, Olugbenga Solomon Bello, Dye sequestration using
agricultural wastes as adsorbents, Water Resour. Ind. 12 (2015) 8–24, https://doi.
org/10.1016/j.wri.2015.09.002.
[4] Akil Ahmad, Siti Hamidah Mohd-Setapar, ChuoSing Chuong, Asma Khatoon,
Waseem A. Wani, Rajeev Kumar, Mohd Rafatullah, Recent advances in new generation dye removal technologies: novel search for approaches to reprocess wastewater, RSC Adv. 5 (39) (2015) 30801–30818, https://doi.org/10.1039/
c4ra16959j.
[5] C. AkmilBasar, Y. Onal, T. Kilicer, D. Eren, Adsorptions of high concentration
malachite green by two activated carbons having different porous structures, J.
Hazard. Mater. 127 (1–3) (2005) 73–80, https://doi.org/10.1016/j.jhazmat.2005.
06.025.
[6] Z.ümriye Aksu, Sevilay Tezer, Biosorption of reactive dyes on the green alga
Chlorella vulgaris, Process Biochem. 40 (3–4) (2005) 1347–1361, https://doi.org/
10.1016/j.procbio.2004.06.007.
[7] Mahmoud A.M. Al-Alwani, A.Ludin Norasikin, AbuBakar Mohamad, Abd.Amir
H. Kadhum, Abduljabbar Mukhlus, Application of dyes extracted from
Alternanthera Dentata leaves and Musa Acuminata Bracts as natural sensitizers for
dye-sensitized solar cells, Spectrochim. Acta Part A: Mol. Biomol. 192 (2018)
487–498, https://doi.org/10.1016/j.saa.2017.11.018.
[8] Mohammad Mousa Al-Ansari, Beeta Saha, Samar Mazloum, K.E. Taylor,
J.K. Bewtra, N. Biswas, Soybean Peroxidase Applications in Wastewater
Treatment, 6th ed., Nova Science Publishers, Hauppauge, N.Y, 2011.
[9] Abdullah T. Al-Fawwaz, Mufida Abdullah, Decolorization of methylene blue and
malachite green by immobilized desmodesmus Sp. Isolated from North Jordan,
Int. J. Environ. Sci. Dev. 7 (2) (2016) 95–99, https://doi.org/10.7763/ijesd.2016.
v7.748.
[10] Nada Al-Nakib, H. Mustafa, Reverse osmosis polyamide membrane for the removal
of blue and yellow dye from waste water, Iraqi J. Chem. Petrol. Eng. 14 (2) (2013)
49–55.
[11] Md. Zahangir Alam, Mohammad Jakir Hossain Khan, NassereldeenA. Kabbashi,
S.M. Abu Sayem, Development of an effective biosorbent by fungal immobilization
technique for removal of dyes, Waste Biomass Valoriz. 9 (4) (2017) 681–690,
https://doi.org/10.1007/s12649-016-9821-9.
[12] N.F. Ali, R.S.R. El-Mohamedy, Microbial decolourization of textile waste water, J.
Saudi Chem. Soc. 16 (2) (2012) 117–123, https://doi.org/10.1016/j.jscs.2010.11.
005.
[13] Naeem Ali, Abdul Hameed, Safia Ahmed, Role of Brown-Rot Fungi in the
Bioremoval of Azo Dyes Under Different Conditions, Scielo, 2018, http://www.
scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822010000400009.
[14] Masoud Amini, Mokhtar Arami, Niyaz Mohammad Mahmoodi, Ahmad Akbari,
Dye removal from colored textile wastewater using acrylic grafted nanomembrane, Desalination 267 (1) (2011) 107–113, https://doi.org/10.1016/j.desal.
2010.09.014.
[15] A. Aygün, S. Yenisoy-Karakaş, I. Duman, Production of granular activated carbon
from fruit stones and nutshells and evaluation of their physical, chemical and
adsorption properties, Microporous Mesoporous Mater. 66 (2–3) (2003) 189–195,
https://doi.org/10.1016/j.micromeso.2003.08.028.
[16] N. Azbar, T. Yonar, K. Kestioglu, Comparison of various advanced oxidation
processes and chemical treatment methods for COD and color removal from a
polyester and acetate fiber dyeing effluent, Chemosphere 55 (1) (2004) 35–43,
https://doi.org/10.1016/j.chemosphere.2003.10.046.
[17] Niladri Ballav, Raghunath Das, Somnath Giri, Anthony M. Muliwa,
Kriveshini Pillay, Arjun Maity, L -Cysteine doped polypyrrole (Ppy@L-cyst): a
super adsorbent for the rapid removal of Hg +2 and efficient catalytic activity of
the spent adsorbent for reuse, Chem. Eng. J. 345 (2018) 621–630, https://doi.org/
10.1016/j.cej.2018.01.093.
[18] J.J. Bhuktar, A.V. Manwar, Decolourization of reactive black 5 by pure culture of
1E1, C1 and their mixture, J. Environ. Res. Dev. 10 (3) (2016) 423–435 http://
file:///C:/Users/Asus/Downloads/JeradDLId0423vol010issue003.pdf.
4695
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
[46]
[47]
[48]
[49]
[50]
[51]
[52]
[53]
[54]
[55]
[56]
[57]
[58]
[59]
[60]
[61]
[62]
[63]
[64]
[65]
[66]
[67]
[68]
[69]
[70]
[71]
[72] Lixia Liu, Juan Zhang, Yi Tan, Yucheng Jiang, Mancheng Hu, Shuni Li,
Quanguo Zhai, Rapid decolorization of anthraquinone and triphenylmethane dye
using chloroperoxidase: catalytic mechanism, analysis of products and degradation route", Chem. Eng. J. 244 (2014) 9–18, https://doi.org/10.1016/j.cej.2014.
01.063.
[73] Y.H. Magdy, A.A.M. Daifullah, Adsorption of a basic dye from aqueous solutions
onto sugar-industry-mud in two modes of operations, Waste Manage. 18 (4)
(1998) 219–226, https://doi.org/10.1016/s0956-053x(98)00022-1.
[74] Ghada Adel Mahmoud, Samia E. Abdel-Aal, Nabil A. El-kelesh, E.A. Alshafei,
Effective removal of hazardous dyes from aqueous solutions using starch based
hydrogel and gamma radiation, Environ. Ecol. Res. 5 (7) (2017) 480–488 http://
www.hrpub.org.
[75] Afshin Maleki, Unes Hamesadeghi, Hiua Daraei, Bagher Hayati, Farhood Najafi,
Gordon McKay, Reza Rezaee, Amine functionalized multi-walled carbon nanotubes: single and binary systems for high capacity dye removal, Chem. Eng. J. 313
(2017) 826–835, https://doi.org/10.1016/j.cej.2016.10.058.
[76] P.K. Malik, Use of activated carbons prepared from sawdust and rice-husk for
adsorption of acid dyes: a case study of acid yellow 36, Dyes Pigments 56 (3)
(2003) 239–249, https://doi.org/10.1016/s0143-7208(02)00159-6.
[77] R. Malik, D.S. Ramteke, S.R. Wate, Adsorption of malachite green on groundnut
shell waste based powdered activated carbon, Waste Manage. 27 (9) (2007)
1129–1138, https://doi.org/10.1016/j.wasman.2006.06.009.
[78] Narges Manavi, Amir Sadegh Kazemi, Babak Bonakdarpour, The development of
aerobic granules from conventional activated sludge under anaerobic-aerobic cycles and their adaptation for treatment of dyeing wastewater, Chem. Eng. J. 312
(2017) 375–384, https://doi.org/10.1016/j.cej.2016.11.155.
[79] Manju, Narsi R. Bishnoi, Adsorption of methylene blue on spent immobilized
biomass of rice straw left after enzyme production, Int. J. Adv. Multidiscip. Res.
(IJAMR) 3 (7) (2016) 12–18.
[80] Hossein Masoumbeigi, Abbas Rezaee, Removal of methylene blue (MB) dye from
synthetic wastewater using UV/H2O2 advanced oxidation process, J. Health
Policy Sustain. Health 2 (1) (2015) 160–166.
[81] G. McKay, J.F. Porter, G.R. Prasad, Water Air Soil Pollut. 114 (3/4) (1999)
423–438, https://doi.org/10.1023/a:1005197308228.
[82] Gergo Mezohegyi, Frank P. van der Zee, Josep Font, Agustí Fortuny,
Azael Fabregat, Towards advanced aqueous dye removal processes: a short review
on the versatile role of activated carbon, J. Environ. Manage. 102 (2012) 148–164,
https://doi.org/10.1016/j.jenvman.2012.02.021.
[83] S.Sadri Moghaddam, M.R. Alavi Moghaddam, M. Arami, Coagulation/flocculation
process for dye removal using sludge from water treatment plant: optimization
through response surface methodology, J. Hazard. Mater. 175 (1–3) (2010)
651–657, https://doi.org/10.1016/j.jhazmat.2009.10.058.
[84] S.Venkata Mohan, K. Krishna Prasad, N. Chandrasekhara Rao, P.N. Sarma, Acid
azo dye degradation by free and immobilized horseradish peroxidase (HRP) catalyzed process, Chemosphere 58 (8) (2005) 1097–1105, https://doi.org/10.1016/
j.chemosphere.2004.09.070.
[85] Kiro D. Mojsov, Darko Andronikov, Aco Janevski, Aco Kuzelov, Steven Gaber, The
application of enzymes for the removal of dyes from textile effluents, Adv.
Technol. 5 (1) (2016) 81–86.
[86] S. Montoya-Suarez, F. Colpas-Castillo, E. Meza-Fuentes, J. Rodriguez-Ruiz,
R. Fernandez-Maestre, Activated carbons from waste of oil-palm kernel shells,
sawdust and tannery leather scraps and application to chromium(VI), phenol, and
methylene Blue dye adsorption, Water Sci. Technol. 73 (1) (2015) 21–27, https://
doi.org/10.2166/wst.2015.293.
[87] Aris Mukimin, Hanny Vistanty, Nur Zen, Oxidation of textile wastewater using
cylinder Ti/Β-Pbo2 electrode in electrocatalytic tube reactor, Chem. Eng. J. 259
(2015) 430–437, https://doi.org/10.1016/j.cej.2014.08.020.
[88] Aris Mukimin, Karna Wijaya, Agus Kuncaka, Oxidation of remazolbrilliant Bluer
(RB.19) with in situ electro-generated active chlorine using Ti/Pbo2 electrode,
Sep. Purif. Technol. 95 (2012) 1–9, https://doi.org/10.1016/j.seppur.2012.04.
015.
[89] Aris Mukimin, Nur Zen, Agus Purwanto, Kukuh Aryo Wicaksono, Hanny Vistanty,
Abdul Syukur Alfauzi, Application of a full-scale electrocatalytic reactor as real
batik printing wastewater treatment by indirect oxidation process, J. Environ.
Chem. Eng. 5 (5) (2017) 5222–5232, https://doi.org/10.1016/j.jece.2017.09.053.
[90] S.K. Nataraj, K.M. Hosamani, T.M. Aminabhavi, Nanofiltration and reverse osmosis thin film composite membrane module for the removal of dye and salts from
the simulated mixtures, Desalination 249 (1) (2009) 12–17, https://doi.org/10.
1016/j.desal.2009.06.008.
[91] Thai Anh Nguyen, Chun-Chieh Fu, Ruey-Shin Juang, Effective removal of sulfur
dyes from water by biosorption and subsequent immobilized laccase degradation
on crosslinked chitosan beads, Chem. Eng. J. 304 (2016) 313–324, https://doi.
org/10.1016/j.cej.2016.06.102.
[92] Thai Anh Nguyen, Ruey-Shin Juang, Treatment of waters and wastewaters containing sulfur dyes: a review, Chem. Eng. J. 219 (2013) 109–117, https://doi.org/
10.1016/j.cej.2012.12.102.
[93] Kiyoshi Okada, Nobuo Yamamoto, Yoshikazu Kameshima, Atsuo Yasumori,
Adsorption properties of activated carbon from waste newspaper prepared by
chemical and physical activation", J. Colloid Interface Sci. 262 (1) (2003)
194–199, https://doi.org/10.1016/s0021-9797(03)00108-5.
[94] Mahmut Özacar, İ. Ayhan Şengil, Adsorption 8 (4) (2002) 301–308, https://doi.
org/10.1023/a:1021585413857.
[95] Mahmut Özacar, İ. Ayhan Şengil, A two stage batch adsorber design for methylene
Blue removal to minimize contact time, J. Environ. Manage. 80 (4) (2006)
372–379, https://doi.org/10.1016/j.jenvman.2005.10.004.
[96] Maulin P. Shah, Biodegradation of azo dyes by three isolated bacterial strains: an
environmental bioremedial approach, J. Microb. Biochem. Technol. S3 (2011)
1–5, https://doi.org/10.4172/1948-5948.s3-007.
[97] Yuan Pan, Youzhao Wang, Aijuan Zhou, Aijie Wang, Zongting Wu, Liting Lv,
Xianjin Li, Kuo Zhang, Tong Zhu, Removal of azo dye in an up-flow membrane-less
4,6-dimethyldibenzothiophene, Chem. Eng. J. 321 (2017) 651–661, https://doi.
org/10.1016/j.cej.2017.03.132.
V.K. Garg, Renuka Gupta, Anu Bala Yadav, Rakesh Kumar, Dye removal from
aqueous solution by adsorption on treated sawdust, Bioresour. Technol. 89 (2)
(2003) 121–124, https://doi.org/10.1016/s0960-8524(03)00058-0.
Fathollah Gholami-Borujeni, Amir Hossein Mahvi, Simin Naseri, Mohammad
Ali Faramarzi, Ramin Nabizadeh, Mahmood Alimohammadi, Application of immobilized horseradish peroxidase for removal and detoxification of azo dye from
aqueous solution, Res. J. of Chem. Environ. 15 (2) (2011) 217–222.
Carlos A.K. Gouvêa, Fernando Wypych, Sandra G. Moraes, Nelson Durán,
Noemi Nagata, Patricio Peralta-Zamora, Semiconductor-assisted photocatalytic
degradation of reactive dyes in aqueous solution, Chemosphere 40 (4) (2000)
433–440, https://doi.org/10.1016/s0045-6535(99)00313-6.
V.K. Gupta, Suhas, Application of low-cost adsorbents for dye removal—a review,
J. Environ. Manage. 90 (8) (2009) 2313–2342, https://doi.org/10.1016/j.
jenvman.2008.11.017.
B. Hameed, A. Din, A. Ahmad, Adsorption of methylene blue onto bamboo-based
activated carbon: kinetics and equilibrium studies, J. Hazard. Mater. 141 (3)
(2007) 819–825, https://doi.org/10.1016/j.jhazmat.2006.07.049.
B.H. Hameed, A.L. Ahmad, K.N.A. Latiff, Adsorption of basic dye (methylene blue)
onto activated carbon prepared from rattan sawdust, Dyes Pigments 75 (1) (2007)
143–149, https://doi.org/10.1016/j.dyepig.2006.05.039.
Mohamed A. Hassaan, Ahmed El Nemr, Fedekar F. Madkour, Testing the advanced
oxidation processes on the degradation of direct blue 86 dye in wastewater, Egypt.
J. Aquat. Res. 43 (1) (2017) 11–19, https://doi.org/10.1016/j.ejar.2016.09.006.
A.H. Hassani, R. Mirzayee, S. Nasseri, M. Borghei, M. Gholami, B. Torabifar,
Nanofiltration process on dye removal from simulated textile wastewater, Int. J.
Environ. Sci. Technol. 5 (3) (2008) 401–408, https://doi.org/10.1007/
bf03326035.
A. Henriksen, Structure of soybean seed coat peroxidase: a plant peroxidase with
unusual stability and haem-apoprotein interactions, Protein Sci. 10 (1) (2001)
108–115, https://doi.org/10.1110/ps.37301.
Afif Hethnawi, Nashaat N. Nassar, Abdallah D. Manasrah, Gerardo Vitale,
Polyethylenimine-functionalized pyroxene nanoparticles embedded on diatomite
for adsorptive removal of dye from textile wastewater in a fixed-bed column,
Chem. Eng. J. 320 (2017) 389–404, https://doi.org/10.1016/j.cej.2017.03.057.
Nazaret Hidalgo, Giulia Mangiameli, Teresa Manzano, Galina G. Zhadan, John
F. Kennedy, Valery L. Shnyrov, Manuel G. Roig, Oxidation and removal of industrial textile dyes by a novel peroxidase extracted from post-harvest lentil (Lens
Culinaris L.) stubble, Biotechnol. Bioprocess E 16 (4) (2011) 821–829, https://doi.
org/10.1007/s12257-010-0453-9.
Samorn Hirunpraditkoon, Panithan Intiya, Watchrapong Thonglert,
Kamchai Nuithitikul, Chemeca 2010, Barton, ACT], Engineers Australia, 2010.
Chandrakant R. Holkar, Ananda J. Jadhav, DipakV. Pinjari, Naresh M. Mahamuni,
Aniruddha B. Pandit, A critical review on textile wastewater treatments: possible
approaches, J. Environ. Manage. 182 (2016) 351–366, https://doi.org/10.1016/j.
jenvman.2016.07.090.
M. Joshi, R. Bansal, R. Purwar, Colour removal from textile effluents, Indian J.
Fibre Text. 29 (2003) 239–259 http://nopr.niscair.res.in/handle/123456789/
24631.
Ruey-Shin Juang, Feng-Chin Wu, Ru-Ling Tseng, Characterization and use of activated carbons prepared from bagasses for liquid-phase adsorption", Colloids Surf.
A: Physicochem. Eng. Aspects 201 (1–3) (2002) 191–199, https://doi.org/10.
1016/s0927-7757(01)01004-4.
Ruey-Shin Juang, Ru-Ling Tseng, Feng-Chin Wu, Role of microporosity of activated carbons on their adsorption abilities for phenols and dyes, Adsorption 7 (1)
(2001) 65–72, https://doi.org/10.1023/a:1011225001324.
Nagarethinam Kannan, Mariappan Meenakshi Sundaram, Kinetics and mechanism
of removal of methylene blue by adsorption on various carbons—a comparative
study, Dyes Pigments 51 (1) (2001) 25–40, https://doi.org/10.1016/s01437208(01)00056-0.
Rita. Kant, Textile dyeing industry an environmental hazard, Nat. Sci. 04 (01)
(2012) 22–26, https://doi.org/10.4236/ns.2012.41004.
Morteza Kashefi, Farzad Bahrami, Removal of vat dyes from colored wastewater
by reverse osmosis process, Bull. Georgian Natl. Acad. Sci. 8 (1) (2014) 260–267.
Masoud B. Kasiri, Nasser Modirshahla, Hasan Mansouri, Decolorization of organic
dye solution by ozonation; optimization with response surface methodology, Int. J.
Ind. Chem. 4 (1) (2013) 3, https://doi.org/10.1186/2228-5547-4-3.
Sumanjit Kaur, Seema Rani, Rakesh Kumar Mahajan, Adsorption Kinetics for the
Removal of Hazardous Dye Congo Red by Biowaste Materials as Adsorbents,
Hindawi, 2018, https://www.hindawi.com/journals/jchem/2013/628582/.
Azeem Khalid, Muhammad Arshad, David E. Crowley, Biodegradation potential of
pure and mixed bacterial cultures for removal of 4-nitroaniline from textile dye
wastewater, Water Res. 43 (4) (2009) 1110–1116, https://doi.org/10.1016/j.
watres.2008.11.045.
Muhammad Abdul Nasir Khan, Maria Siddique, Fazli Wahid, Romana Khan,
Removal of reactive Blue 19 dye by sono, photo and sonophotocatalytic oxidation
using visible light, Ultrason. Sonochem. 26 (2015) 370–377, https://doi.org/10.
1016/j.ultsonch.2015.04.012.
Nazmul Abedin Khan, Biswa Nath Bhadra, Sung Hwa Jhung, Heteropoly acidloaded ionic liquid@metal-organic frameworks: effective and reusable adsorbents
for the desulfurization of a liquid model fuel, Chem. Eng. J. 334 (2018)
2215–2221, https://doi.org/10.1016/j.cej.2017.11.159.
ByoungChul Kim, Young Han Kim, Takuji Yamamoto, Adsorption characteristics
of bamboo activated carbon, Korean J. Chem. Eng. 25 (5) (2008) 1140–1144,
https://doi.org/10.1007/s11814-008-0187-y.
H. Kocyigit, A. Ugurlu, Biological decolorization of reactive azo dye by anaerobic/
aerobic-sequencing batch reactor system, Glob. Nest J. 17 (1) (2015) 210–219
https://www.researchgate.net/publication/281951821_Biological_decolorization_
of_reactive_azo_dye_by_anaerobicaerobic-sequencing_batch_reactor_system.
4696
Journal of Environmental Chemical Engineering 6 (2018) 4676–4697
V. Katheresan et al.
[98]
[99]
[100]
[101]
[102]
[103]
[104]
[105]
[106]
[107]
[108]
[109]
[110]
[111]
[112]
[113]
[114]
[115]
[116]
[117]
[118]
[119]
[120]
J. Appl. Polym. Sci. 131 (1) (2013), https://doi.org/10.1002/app.39620 n/a–n/a.
[121] Sachin Talekar, Asavari Joshi, Gandhali Joshi, Priyanka Kamat,
Rutumbara Haripurkar, Shashikant Kambale, Parameters in preparation and
characterization of cross linked enzyme aggregates (Cleas), RSC Adv. 3 (31)
(2013) 12485, https://doi.org/10.1039/c3ra40818c.
[122] Lin Tang, Jiangfang Yu, Ya Pang, Guangming Zeng, Yaocheng Deng, Jiajia Wang,
Xiaoya Ren, Shujing Ye, Bo Peng, Haopeng Feng, Sustainable efficient adsorbent:
alkali-acid modified magnetic biochar derived from sewage sludge for aqueous
organic contaminant removal, Chem. Eng. J. 336 (2018) 160–169, https://doi.
org/10.1016/j.cej.2017.11.048.
[123] M. Concetta Tomei, Domenica Mosca Angelucci, Andrew J. Daugulis, Sequential
anaerobic-aerobic decolourization of a real textile wastewater in a two-phase
partitioning bioreactor, Sci. Total Environ. 573 (2016) 585–593, https://doi.org/
10.1016/j.scitotenv.2016.08.140.
[124] J.A. Torres, F.G.E. Nogueira, M.C. Silva, J.H. Lopes, T.S. Tavares, T.C. Ramalho,
A.D. Corrêa, Novel eco-Friendly biocatalyst: soybean peroxidase immobilized onto
activated carbon obtained from agricultural waste, RSC Adv. 7 (27) (2017)
16460–16466, https://doi.org/10.1039/c7ra01309d.
[125] Ru-Ling Tseng, Feng-Chin Wu, Ruey-Shin Juang, Liquid-phase adsorption of dyes
and phenols using pinewood-based activated carbons, Carbon 41 (3) (2003)
487–495, https://doi.org/10.1016/s0008-6223(02)00367-6.
[126] M. Valix, W.H. Cheung, G. McKay, Preparation of activated carbon using low
temperature carbonisation and physical activation of high ash raw bagasse for acid
dye adsorption, Chemosphere 56 (5) (2004) 493–501, https://doi.org/10.1016/j.
chemosphere.2004.04.004.
[127] Kirana Devarahosahalli Veeranna, Madhu Theeta Lakshamaiah, Ramesh
Thimmasandra Narayan, Photocatalytic Degradation Of Indigo Carmine Dye Using
Calcium Oxide, (2018).
[128] G. Vijayaraghavan, S. Shanthakumar, Efficacy of alginate extracted from marine
brown algae (Sargassum Sp.) as a coagulant for removal of direct Blue2 dye from
aqueous solution, Glob. NEST J. 17 (4) (2015) 716–726 https://journal.gnest.org/
sites/default/files/Submissions/gnest_01735/gnest_01735_published.pdf.
[129] G.M. Walker, L. Hansen, J.-A. Hanna, S.J. Allen, Kinetics of a reactive dye adsorption onto dolomitic sorbents, Water Res. 37 (9) (2003) 2081–2089, https://
doi.org/10.1016/s0043-1354(02)00540-7.
[130] Jing Wang, Lijuan Qin, Jiuyang Lin, Junyong Zhu, Yatao Zhang, Jindun Liu,
Bart Van der Bruggen, Enzymatic construction of antibacterial ultrathin membranes for dyes removal, Chem. Eng. J. 323 (2017) 56–63, https://doi.org/10.
1016/j.cej.2017.04.089.
[131] Jian Wang, Xiangxue Wang, Guixia Zhao, Gang Song, Diyun Chen, Hongxia Chen,
Jing Xie, Tasawar Hayat, Ahmed Alsaedi, Xiangke Wang, Polyvinylpyrrolidone
and polyacrylamide intercalated molybdenum disulfide as adsorbents for enhanced removal of chromium(VI) from aqueous solutions, Chem. Eng. J. 334
(2018) 569–578, https://doi.org/10.1016/j.cej.2017.10.068.
[132] Zongping Wang, Kai Huang, Miaomiao Xue, Zizheng Liu, Textile Dyeing
Wastewater Treatment, INTECH Open Access Publisher, Rijeka, 2011.
[133] Monika. Wawrzkiewicz, Anion exchange resins as effective sorbents for acidic dye
removal from aqueous solutions and wastewaters", Solvent Extr. Ion Exch. 30 (5)
(2012) 507–523, https://doi.org/10.1080/07366299.2011.639253.
[134] Monika Wawrzkiewicz, Zbigniew Hubicki, Anion exchange resins as effective
sorbents for removal of acid, reactive, and direct dyes from textile wastewaters,
Ion Exch. - Stud. Appl. (2015) 37–67, https://doi.org/10.5772/60952.
[135] Suphitcha Wijannarong, Sayam Aroonsrimorakot, Patana Thavipoke,
charaporn Kumsopa, Suntree Sangjan, Removal of reactive dyes from textile
dyeing industrial effluent by ozonation process, APCBEE Procedia 5 (2013)
279–282, https://doi.org/10.1016/j.apcbee.2013.05.048.
[136] Pei Wen Wong, Tjoon Tow Teng, Nik Abdul Rahman Nik Norulaini, Efficiency of
the coagulation-flocculation method for the treatmentof dye mixtures containing
disperse and reactive dye, Water Qual. 42 (1) (2007) 54–62.
[137] Y.C. Wong, Y.S. Szeto, W.H. Cheung, G. McKay, Adsorption of acid dyes on chitosan—equilibrium isotherm analyses, Process Biochem. 39 (6) (2004) 695–704,
https://doi.org/10.1016/s0032-9592(03)00152-3.
[138] Mustafa T. Yagub, Tushar Kanti Sen, Sharmeen Afroze, H.M. Ang, Dye and its
removal from aqueous solution by adsorption: a review, Adv. Colloid Interface Sci.
209 (2014) 172–184, https://doi.org/10.1016/j.cis.2014.04.002.
[139] Mansoureh Zarezadeh-Mehrizi, Alireza Badiei, Highly efficient removal of basic
Blue 41 with nanoporous silica, Water Resour. Ind. 5 (2014) 49–57, https://doi.
org/10.1016/j.wri.2014.04.002.
[140] Guangyong Zeng, Zhongbin Ye, Yi He, Xi Yang, Jing Ma, Heng Shi, Ziliang Feng,
Application of dopamine-modified halloysite nanotubes/PVDF blend membranes
for direct dyes removal from wastewater, Chem. Eng. J. 323 (2017) 572–583,
https://doi.org/10.1016/j.cej.2017.04.131.
[141] Qinghu Zhao, Fan Wu, Ke Xie, Ranjeet Singh, Jianhua Zhao, Penny Xiao, Paul
A. Webley, Synthesis of a novel hybrid adsorbent which combines activated
carbon and zeolite nausy for CO 2 capture by electric swing adsorption (ESA),
Chem. Eng. J. 336 (2018) 659–668, https://doi.org/10.1016/j.cej.2017.11.167.
[142] Yanbo Zhou, Yonghua Hu, Weiwei Huang, Guang Cheng, Changzheng Cui, Jun Lu,
A novel amphoteric B-cyclodextrin-based adsorbent for simultaneous removal of
cationic/anionic dyes and bisphenol A, Chem. Eng. J. 341 (2018) 47–57, https://
doi.org/10.1021/acs.est.5b02227.
bioelectrochemical system integrated with bio-contact oxidation reactor, Chem.
Eng. J. 326 (2017) 454–461, https://doi.org/10.1016/j.cej.2017.05.146.
Yaguang Peng, Yuxi Zhang, Hongliang Huang, Chongli Zhong, Flexibility induced
high-performance MOF-based adsorbent for nitroimidazole antibiotics capture,
Chem. Eng. J. 333 (2018) 678–685, https://doi.org/10.1016/j.cej.2017.09.138.
Wioletta Przystaś, Ewa Zabłocka-Godlewska, Elżbieta Grabińska-Sota,
Effectiveness of dyes removal by mixed fungal cultures and toxicity of their metabolites, Water Air Soil Pollut. 224 (5) (2013), https://doi.org/10.1007/s11270013-1534-0.
Mohd. Rafatullah, Rokiah Hashim Othman Sulaiman, Anees Ahmad, Adsorption of
methylene blue on low-cost adsorbents: a review, J. Hazard. Mater. 177 (1–3)
(2010) 70–80, https://doi.org/10.1016/j.jhazmat.2009.12.047.
Babita Rani, Vivek Kumar, Jagvijay Singh, Sandeep Bisht, Priyanku Teotia,
Shivesh Sharma, Ritu Kela, Bioremediation of dyes by fungi isolated from contaminated dye effluent sites for bio-usability, Braz. J. Microbiol. 45 (3) (2014)
1055–1063, https://doi.org/10.1590/s1517-83822014000300039.
Muhammad A. Rauf, S. Salman Ashraf, Survey of recent trends in biochemically
assisted degradation of dyes, Chem. Eng. J. 209 (2012) 520–530, https://doi.org/
10.1016/j.cej.2012.08.015.
Tim Robinson, Geoff McMullan, Roger Marchant, Poonam Nigam, Remediation of
dyes in textile effluent: a critical review on current treatment technologies with a
proposed alternative, Bioresour. Technol. 77 (3) (2001) 247–255, https://doi.org/
10.1016/s0960-8524(00)00080-8.
Susana Rodríguez-Couto, Johann Faccelo Osma, José Luis Toca-Herrera, Removal
of synthetic dyes by an eco-friendly strategy, Eng. Life Sci. 9 (2) (2009) 116–123,
https://doi.org/10.1002/elsc.200800088.
Mohamad Amran Mohd Salleh, Dalia Khalid Mahmoud, Abdul Karim Wan Azlina
Wan, Azni Idris, Cationic and anionic dye adsorption by agricultural solid wastes:
a comprehensive review, Desalination 280 (1-3) (2011) 1–13, https://doi.org/10.
1016/j.desal.2011.07.019.
Müfrettin Murat Sari, Removal of acidic indigo carmine textile dye from aqueous
solutions using radiation induced cationic hydrogels, Water Sci. Technol. 61 (8)
(2010) 2097, https://doi.org/10.2166/wst.2010.158.
Marco Sarro, Nonjabulo P. Gule, Enzo Laurenti, Roberta Gamberini, Maria Cristina
Paganini, Peter E. Mallon, Paola Calza, Zno-based materials and enzymes hybrid
systems as highly efficient catalysts for recalcitrant pollutants abatement, Chem.
Eng. J. 334 (2018) 2530–2538, https://doi.org/10.1016/j.cej.2017.11.146.
Nataša Ž. Šekuljica, Nevena Ž. Prlainović, Andrea B. Stefanović, Milena G. Žuža,
Dragana Z. Čičkarić, Dušan Ž. Mijin, Zorica D. Knežević-Jugović, Decolorization of
anthraquinonic dyes from textile effluent using horseradish peroxidase: optimization and kinetic study, Sci. World J. 2015 (2015) 1–12, https://doi.org/10.
1155/2015/371625.
Sevimli, F. Mehmet, Z. Hasan, Sarikaya, Ozone treatment of textile effluents and
dyes: effect of applied ozone dose, Ph and dye concentration, J. Chem. Technol.
Biotechnol. 77 (7) (2002) 842–850, https://doi.org/10.1002/jctb.644.
Praveen Sharma, Lakhvinder Singh, Jyoti Mehta, COD reduction and colour removal of simulated textile Mill wastewater By mixed bacterial consortium,
Rasayan J. Chem. 3 (4) (2010) 731–735 https://www.researchgate.net/
publication/286233909_COD_reduction_and_colour_removal_of_simulated_textile_
mill_wastewater_by_mixed_bacterial_consortium.
Sharma, K. Sanjay, Green Chemistry for Dyes Removal from Waste Water, 1st ed.,
John Wiley & Sons, 2015.
Jan Sima, Pavel Hasal, Photocatalytic degradation of textile dyes in Atio(2)/UV
System, 11th International Conference On Chemical and Process Engineering 32
(2013) 79–84, https://doi.org/10.3303/CET1332014.
Mahmood R. Sohrabi, Shahab Shariati Afrooz Khavaran, Shayan Shariati, Removal
of carmoisine edible dye by Fenton and photo fenton processes using taguchi orthogonal array design, Arab. J. Chem. 10 (2017) S3523–S3531, https://doi.org/
10.1016/j.arabjc.2014.02.019.
Myrna Solís, Aida Solís, Herminia Inés Pérez, Norberto Manjarrez, Maribel Flores,
Microbial decolouration of azo dyes: a review, Process Biochem. 47 (12) (2012)
1723–1748, https://doi.org/10.1016/j.procbio.2012.08.014.
Ya-Li Song, Ji-Tai Li, Hua Chen, Removal of acid Brown 348 dye from aqueous
solution by ultrasound irradiated exfoliated graphite, Indian J. Chem. Technol. 15
(2008) 443–448.
Angela A. Spagnoli, Dimitrios A. Giannakoudakis, Svetlana Bashkova, Adsorption
of methylene blue on cashew nut shell based carbons activated with zinc chloride:
the role of surface and structural parameters, J. Mol. Liq. 229 (2017) 465–471,
https://doi.org/10.1016/j.molliq.2016.12.106.
Asha Srinivasan, Thiruvenkatachari Viraraghavan, Decolorization of dye wastewaters by biosorbents: a review, J. Environ. Manage. 91 (10) (2010) 1915–1929,
https://doi.org/10.1016/j.jenvman.2010.05.003.
Ramalingam Subramaniam, Senthil Kumar Ponnusamy, Novel adsorbent from
agricultural waste (cashew NUT shell) for methylene blue dye removal: optimization by response surface methodology, Water Resour. Ind. 11 (2015) 64–70,
https://doi.org/10.1016/j.wri.2015.07.002.
Anto Tri Sugiarto, Shunsuke Ito, Takayuki Ohshima, Masayuki Sato, Jan D. Skalny,
Oxidative decoloration of dyes by pulsed discharge plasma in water, J. Electrostat.
58 (1–2) (2003) 135–145, https://doi.org/10.1016/s0304-3886(02)00203-6.
Daniela Suteu, Doina Bilba, Sergiu Coseri, Macroporous polymeric ion exchangers
as adsorbents for the removal of cationic dye basic Blue 9 from aqueous solutions,
4697