International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
Decolorization of Malachite Green Dye Using UV + H2O2 and
Photo Fenton Processes
Yogendra D. Thakare#1, Vijay R. Diware*2, Kishor S. Wani#3
#1
Assistant Professor, Department of Chemical Engineering, SSBT’s College of Engineering and Technology,
Bambhori, Jalgaon, 425001 (MS), India.
*2
Associate Professor and Head, Department of Chemical Engineering, SSBT’s College of Engineering and
Technology, Bambhori, Jalgaon, 425001 (MS), India.
#3
Professor and Principal, SSBT’s College of Engineering and Technology, Bambhori, Jalgaon, 425001 (MS),
India.
ABSTRACT:
In the present work, it has been studied the
decolorization of malachite green dye using UV +
H2O2 and photo Fenton processes. The effect of
different operating conditions such as concentration
of dye (10, 20 and 30 ppm), pH (3, 6 and 9), H2O2
dosage (10, 20, and 30 µl/L), Fe2+ dosage (5, 10, 20
and 30 mg/L) has been studied for the decolorization
of malachite green dye. Under optimum conditions (10
ppm concentration of dye, 3 pH, 20 µl/L H2O2 dosage
and 30 mg/L of Fe2+ dosage) observed that the photo
Fenton process is found to be more efficient than UV
+ H2O2 process.
Keywords- Decolorization, Malachite Green Dye, UV
+ H2O2 Process, Photo Fenton Process.
I. INTRODUCTION
The dye effluents from textile industries are major
sources in environmental pollution [1]. Synthetic dyes
have been used in different industries such as textile,
paper printing, food, pharmaceutical, leather and
cosmetics [2]. Removal of dyes from colored effluents
due to their complex composition, toxicity, poor
degradability and high solubility, have attracted great
interest in the last few years [3]. Conventional
methods such as chemical precipitation / adsorption
and biological treatment cannot effectively remove
and degrade dyes from effluents, hence finding an
effective technique is necessary.
Advanced oxidation processes (AOPs) have been
introduced to treat wastewater, which has been
developed to oxidize organic pollutants into carbon
dioxide, water and inorganic ions or transform into
less complex structures [4]. AOPs are based on the
generation of highly reactive species such as hydroxyl
radicals (OH●), which have strong oxidation potential
and oxidize a large number of organic pollutants [5].
In recent years attention have been focused on
photochemical advanced oxidation processes using
Fenton reagent with UV light for the treatment of
wastewater. The oxidation power of Fenton reagent is
ISSN: 2231-5381
due to the generation of hydroxyl radical (OH●) during
the iron catalyzed decomposition of hydrogen
peroxide in acid medium [6]. The degradation of
pollutants can be considerably improved using UVradiation. This is due to the generation of additional
hydroxyl radicals. This photo Fenton process had been
effectively used to degrade the pollutants [7].
The malachite green dye is extensively used in textile
dying and paper printing. It is considered highly toxic
for humans and animals because it can cause
permanent injury to eyes. It’s contact with skin results
in irritation with redness and pain. It also causes
irritation to the respiratory tract that leads to cough
and shortness of breath. It can cause irritation to the
gastrointestinal tract, which has the symptoms of
nausea, vomiting and diarrhea in human beings. It is
also considered as a mutagen in microorganisms. It
produces hazardous products like carbon oxides,
nitrogen oxides and sulfur oxides when heated to
decompose [8]. Therefore for the removal and
degradation of the malachite green dye using UV +
H2O2 and photo Fenton processes are studied. In the
present work, study includes the effect of various
experimental parameters on the photo oxidation and
the optimization of their parameter for the effective
degradation of malachite green dye. The degradation
of the dye is measured in terms of decolorization.
The properties of malachite green dye are shown in
Table 1 and absorption spectra are shown in Figure 1.
Table: 1. Properties of Malachite Green Dye
Name
Malachite Green Dye (Oxalate)
Chemical name
Bis (N-{4-[[4-dimethylamino)
phenyl](phenyl)methylene]
cyclohexa-2,5-dien-1-ylidene}N-methylmethanaminium)
trioxalate
C52H54N4O12
620
Cationic
927.02
Formula
λ(nm)
Chemical Class
M.W. (g mol-1)
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International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
In UV + H2O2 process, 300 ml of malachite green dye
solution in a glass beaker with different concentration
of H2O2 (10, 20 and 30 µl/L) were treated for 30
minute at optimum concentration of malachite green
dye and pH.
In photo Fenton process, 300 ml of malachite green
dye solution in a glass beaker with different
concentration of FeSO4.7H2O (5 mg/L to 30 mg/L)
were treated for 10 minutes at optimum concentration
of malachite green dye, pH and H2O2.
Figure: 1. Absorption Spectra of malachite green
dye
The aim of the work is to study the decolorization of
malachite green dye by using UV + H2O2 and Photo
Fenton process.
II. MATERIALS AND METHODS
Materials:
Malachite green dyes (Oxalate), Hydrogen peroxide
(30% W/V H2O2) and Ferrous sulfate heptahydrate
(FeSO4.7H2O) were purchased from Fisher Scientific,
Mumbai. Stock solutions of Malachite green dye were
prepared in distilled water. All chemicals were used as
received from the suppliers.
A standard stock solution of 500 mg/L malachite
green dye was prepared by diluting the corresponding
mass of malachite green dye in distilled water and
protected from sun light. Different initial
concentrations of malachite green dye were prepared
by further dilution of standard stock solutions.
Figure: 2. Experimental setup of Photolytic reactor
The absorbance of malachite green dye at different
parameter
was
measured
using
UV–Vis
Spectrophotometer (Agilent Technologies) at 620 nm.
Calibration Plot of Malachite Green Dye:
Methods:
The calibration plot for malachite green dye was
obtained by measuring absorbance of the dye at
various concentration of the dye (Figure 3) which was
used for determining the concentration of malachite
green dye.
The photolytic reactor used in the present study is as
shown in Figure 2. The source radiation is four UV
lamps emitting UV light of 125 Watt, manufactured
by Phillips. Initially 300 ml of malachite green dye
solution of different concentration (10, 20 and 30
ppm) were taken in a glass beaker with different pH
(3, 6 and 9) and put it on the magnetic stirrer
maintaining constant stirrer speed for 60 minutes
under UV light in the photocatalytic reactor. Then
sample from each of different concentration and pH
were analyzed using UV-Vis spectrophotometer
(Agilent Technology) at 620 nm. The optimal
conditions of experimental parameters such as
concentration dye, pH, H2O2 and Ferrous ions were
determined at room temperature.
Figure: 3. Calibration plot for malachite green dye
ISSN: 2231-5381
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International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
Further the percentage of decolorization of malachite
green dye was calculated according to the Equation
(1) mentioned below.
% of Decolorization =
((CA0 – CA) / CA0) × 100 -------- (1)
CA0: initial concentration of the dye (mg/L);
CA: concentration of the dye after treatment (mg/L).
III. RESULTS AND DISCUSION
1.
Effect of dye concentration
The concentration of dye is one of the important
parameter in photolytic, UV+ H2O2 and Photo Fenton
processes. The effect of initial dye concentration in this
process is shown in Figure 4.
Figure: 4. Effect of dye concentration on the
decolorization of malachite green dye by photolytic
process (at natural pH = 6).
The figures clearly revealed that the increase in dye
concentration
decreases
the
percentage
of
decolorization. Increase of dye concentration from 10
to 30 ppm decrease the decolorization from 38.33 %
to 14.89 % for photolytic processes in 60 minutes.
Hence, 10 ppm concentration of malachite green dye
is found to be the optimum concentration for UV +
H2O2 and Photo Fenton processes. Hydroxyl radical is
mainly responsible for dye decolorization and its
concentration remains constant for all dye
concentrations. The increase in dye concentration
increases the number of dye molecules and not the OH
radical concentration and so the removal rate
decreases.
2.
Effect of pH
The pH of the solution controls the production rate of
hydroxyl radical and the concentration of Photo
Fenton processes. Hence, pH is an important
parameter for Photo Fenton processes. The effect of
pH on the decolorization of malachite green dye by
photolytic processes is shown in Figure 5.
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Figure: 5. Effect of pH on the decolorization of
malachite green dye by photolytic process (at
optimum concentration of dye = 10 ppm).
Decrease of the pH of the solution from 6 to 3
increases the decolorization suddenly from 38.33 % to
50.19 % and increases pH from 6 to 9, the
decolorization decreases up to 29.18 % in photolytic
processes at 60 minutes. Hence, pH 3 is found to be
the optimum pH for photolytic as well UV + H2O2 and
Photo Fenton processes. The results are in good
agreement with early reports [9, 10]. In these
processes the decrease in decolorization at pH above 3
is due to the coagulation of hydroxo complex of Fe 3+
formed during the reaction [11]. At low pH the
removal rate is limited due to the hydroxyl radical
scavenging effects of H+ ion [12].
3.
Effect of H2O2 dosage
Initial concentration of H2O2 plays an important role
in the UV + H2O2 and photo Fenton processes. The
effect of addition of H2O2 (10 to 30 µl/L) on the
decolorization of malachite green dye is shown in
Figure 6. In UV + H2O2 processes, the addition of
H2O2 from 10 to 20 µl/L increases the decolorization
from 74.50 % to 88.26 % at 30 minutes. Further
increase from 20 to 30µl/L causes decrease in
decolorization from 88.26 % to 83.46 %. The increase
in the decolorization is due to the increase in hydroxyl
radical concentration by the addition of H2O2. But at
high dosage of H2O2 the decrease in decolorization is
due to the hydroxyl radical scavenging effect of H 2O2
[Eqs. (2) and (3)] and recombination of hydroxyl
radicals [Eq. (4)] [13]. Hence 20 µl/L of H2O2 appear
as optimal dosages for photo Fenton processes,
respectively.
H2O2 + OH● → H2O + H2O● --------------- (2)
H2O● + OH●→H2O + O2 --------------- (3)
OH● + OH●→H2O2 -------------- (4)
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International Conference on Global Trends in Engineering, Technology and Management (ICGTETM-2016)
IV.CONCLUSION
Figure: 6. Effect of H2O2 on the decolorization of
malachite green dye by photolytic process (at
optimum concentration of dye = 10 ppm and pH =
3).
Based on the results the following conclusions have
been drawn. Increase in dye concentration from 10 to
30 ppm, decreases the decolorization from 38.33 % to
14.89 %. The photochemical oxidation and percentage
of decolorization in UV + H2O2 and Photo Fenton
process is optimum at 3 pH. H2O2 concentrations of
20µl/L appear as optimum dosages for UV + H2O2
and photo Fenton processes, respectively. The
decolorization of dye increases by increasing the Fe2+
dosage from 5 mg/L to 30 mg/L. Though UV + H2O2
and photo Fenton processes can be used for the
decolorization of malachite green dye, the Photo
Fenton process is more efficient as compared to UV +
H2O2 processes for decolorization of malachite green
dye.
V.REFERENCES
4.
Effect of ferrous dosage
1.
Amount of ferrous ion is one of the main parameters
to influence the photo Fenton processes. The effect of
addition of Fe2+ ion (5 mg/L to 30 mg/L) on the
decolorization of malachite green dye has been
studied. The results are shown in Figure 7.
2.
3.
4.
5.
6.
7.
8.
Figure: 7. Effect of addition of Fe2+on the
decolorization of malachite green dye by Photo
Fenton process (at optimum concentration of dye =
10 ppm, pH = 3 and H2O2 dosage 20 µl/L)
In Fenton process addition of Fe2+ from 5 mg/L to 30
mg/L increases decolorization from 92.77 % to 99.14
% in 10 minutes. More hydroxyl radicals are produced
with the increase in the concentration of Fe2+. The
decolorization is faster in the early stage of the
reaction than in the later stage, because most of the
H2O2 dosages were consumed in the early stage of the
Photo Fenton reaction. Since ferrous ion catalyses
H2O2 to form hydroxyl radical quickly in the first
stage of reaction, more decolorization occurs in the
early stage of reaction [14].
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9.
10.
11.
12.
13.
14.
Wang, K. S., Chen, H. Y., Huang, L. C., Su, Y. C., Chang, S.
H., "Degradation of Reactive Black 5 using combined
electrochemical degradation-solar-light/immobilized TiO2 film
process and toxicity evaluation", Chemosphere, 72, 299-305
(2008).
Choi, H. D., Shin, M. C., Kim, D. H., Jeon, C. S., Beak, K.,
"Removal characteristics of reactive black 5 using surfactantmodified activated carbon", Desalination, 223, 290-298
(2008).
Baocheng, Q. U., Jiti, Z., Xuemin, X., Chunli, Z., Hongxia, Z.,
Xiaobai, Z., "Adsorption behavior of Azo Dye C. I. Acid Red
14 in aqueous solution on surface soils", Journal of
Environmental Sciences, 20, 704-709 (2008).
Thakare, Y. D., Jadhav, S. M., “Degradation of brilliant green
dye using cavitation based hybrid techniques”, International
Journal of Advanced Engineering Technology, 4, 31-36
(2013).
Kang, S. F., Liao, C. H., Po, S. T., “Decolorization of textile
wastewater by photo-Fenton oxidation technology”,
Chemosphere, 41, 1287-1297 (2000).
Ruppert, G., Bauer, R., “The photo-Fenton reaction - an
effective photochemical wastewater treatment process”,
Journal of Photochemistry and Photobiology A: Chemistry,
73, 75-78 (1993).
Muruganandham, M., Swaminathan, M., “Decolourisation of
Reactive Orange 4 by Fenton and photo-Fenton oxidation
technology”, Dyes and Pigments, 63, 315-321, (2004).
Aliyan, H., Fazaeli, R., Jalilian, R., “Fe3O4@mesoporous
SBA-15: A magnetically recoverable catalyst for photo
degradation of malachite green”, Applied Surface Science,
276, 147-153 (2013).
Solozhenko, E. G., Soboleva, N. M., Goncharuk, V. V.,
“Decolourization of azo dye solutions by Fenton’s oxidation”,
Water Research, 29, 2206-2210 (1995).
Maletzky, P, Bauer, R., “The photo-Fenton method
degradation of nitrogen containing organic compounds”,
Chemosphere, 37, 899-909 (1998).
Kim, S. M., Geissen, S., Vogelpohl, A., “Landfill Leachate
treatment by a photoassisted Fenton reaction”, Water Science
and Technology, 35, 239-248 (1997).
Spinks, J. W. T., Woods, R. J., “An introduction to radiation
chemistry”, 3rd ed. New York, NY: John Wiley & Sons;
(1990).
Yang, M., Hu, J., Ito, K., “Characteristics of Fe2+/H2O2/UV
oxidation process”, Environmental Technology, 19, 183-191
(1998).
Thakare, Y. D., Jadhav S. M., Diware, V. R., “Degradation Of
Acid Orange 7 Dye Using Combination Ultrasonic Cavitation
(US) With H2O2”, Cyber Time International Journal of
Engineering and Management, 7, 77-84 (2014).
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