12
CHAPTER II
LITERATURE REVIEW
2.1
Waste Management Strategy
The production of waste throughout Malaysia and the rest of the world is
increasing at a rapid pace. As countries become more industrialized and the wealth
of the citizens increases, there is an increase demand for goods and services.
Corporation looking to increase sales and therefore profits often feed this craving
with advertising for their products. The results is an ever-spiraling demand for goods
resulting in more and more wastes (Goh, Kiam Seng, 1990, Kreith, F., 1994 and
Bishop, P.L., 2000). The environmental impacts of this have been all too evident:
despoiled air and water, hazardous waste dumps, rapidly depleted resources and
other environmental problems.
As the types and amounts of wastes generated very considerably community
to community and countries, the good management system is required to determine
the most effective means for managing the wastes. As such waste management
decisions depend heavily on waste generation and populations together with other
local factors as well, such as availability of waste treatment facilities, waste
generators particularly industries, public attitudes and behaviours, applicable
regulations and financial constraints (Kreith, F., 1994).
Attempts to eliminate the problem through end-of-pipe treatment of wastes
after they are produced have helped (Peavy, H.S; et. al., 1985), but the problems are
too large for this to be a solution. What is needed is a major overhaul of the way we
manage wastes and the environment (Markandya Anil and Dale, N., 2001). The
13
recent and proposed industrial waste management practices are as shown in Figure
2.1.
In the past, industry showed little concern for the types or amounts of waste
generated and the public had little knowledge of the impacts of these wastes on the
environment. These wastes were usually just discharged into the air or nearby river,
or they were dumped or buried on land as shown in Figure 2.1.
Disposed materials that we thought to be gone forever through dilution in air
or water or by burial in ground may have some adverse effects on human health and
the environment. As these impacts became known, industries began to treat their
wastes to remove the most egregious one. Eventually, some industries began
recycling and reusing some of their waste materials as shown in the current pollution
prevention practices. Other industries, recognizing the product and pollution
prevention are intimately related, began marketing the environmental “greenness” of
their products as a way to attract new customer (Freeman, H.M, (1995), Ortolano L.,
(1997), Voorhees, J. and Wollner, R.A. (1998) and Bishop, P.L., (2000)).
This was the beginning of the pollution prevention era. What is needed is a
goal of “zero pollution” of which most process waste production is eliminated
through process changes, as much remaining waste as possible is recycled, reused or
recovered at either facility of origin or another facility (Nemerow, N. L., 1995) as
shown in Figure 2.1. The little residue remaining after recycling and reuse can be
treated and disposed of in environmentally acceptable manner.
2.2
Regulations Motivate Pollution Prevention
The Government of Malaysia has set out its position clearly in respect of a
strategy for sustainable development in the Sixth Malaysia Plan 1991-1995 (Sham
Sani, 1993 and Sixth Malaysia Plan,1991-1995). The Sixth Malaysia Plan contains a
clear policy statement regarding the need to fully integrate environmental concerns
into the overall planning and development process. The attention is drawn to the
need to maintain a balance between the competing demands of growth and
sustainable development. The need for more effective environmental management is
14
Past Industrial Practices
Products
Raw Materials
Process
Energy
Waste Environment
Recent Industrial Practices
Products
Raw Materials
Energy
Process
Treatment
Waste
Residual waste to
environment
Current Pollution Prevention Practices
Raw Materials
Energy
Products
Process
Residuals
Recycles
Recycle,
Reuse,
Recovery
Waste
Treatment
Residual waste to
environment
Secondary
Products
Ideal Future Industrial Practices
Raw Materials
Energy
Products
Process
Residuals
Recycle,
Reuse,
Recovery
Recycles
Secondary
Products
Residuals
Reprocess
Reprocess
Recycle,
Reuse,
Recovery
Recycles
Source: Bishop, P.L., 2000.
Figure 2.1:
Recent and Proposed Industrial Waste Management Practices
15
stressed, as is the need of careful management of natural resources as a further basis
for sustainable development.
It is the further aim of the Government to render all scheduled waste harmless
at the site of origin or at specially designed treatment plants. Disposal of nondegradable waste and treatment residues must take place in properly constructed
secure landfill. Further, the National Policy on the Environment was approved by the
Government on the 2nd October 2002 and formally launched on 14th November 2002
(Hajah Rosnani Ibarahim, 2002). The National policy on the Environment is based
on eight principles that harmonize economic development goals with environmental
imperatives, under the topics: stewardship of the environment; sustainable use for
natural resources; integrated decision – making; role of private sector; commitment
and accountability; and active participation in the international community.
The linkages exist between government regulations and corporate decisions
to adopt pollution prevention. Some companies see pollution prevention as a strategy
for complying with regulations in a cost-effective manner. Other companies are proactive and view pollution prevention as a means to cut costs and risks by reducing
pollution below levels required by regulations. Some companies have even gone as
far as adopting the goal of eliminating all waste discharge (Ortolano, L., 1997).
As a comparison Table 2.1 and Table 2.2 list some regulatory programmes
that are linked to the surge in corporate interest in pollution prevention within the
United States and Malaysia. Two items on the list that are predominant are: liability
for future cleanup costs and cost of compliance with regulations issued. According to
Freeman (1995), the complex regulatory maze created by government is not the only
one faced by industries. Firms also face stringent requirements under federal air and
water pollution control laws as well as penalties for violating environmental laws
include both substantial fines and the possibility of imprisonment for corporate staff.
Collectively, these regulations and penalties for non-compliance have motivated
many companies to embrace waste source reduction and recycling as a way of
avoiding the paperwork, time and expense to satisfy waste management regulations
(Freeman, H.M., 1995; and Norhayati Mohd. Yusof, 2001). In addition, waste source
reduction and recycling provides a way for companies to buffer themselves against
16
the uncertainties associated with satisfying regulations that are subject to continual
modification and reinterpretation by environmental agencies and the courts.
Table 2.1:
Malaysia: Examples of Federal Laws and Programmes
Encouraging Source Reduction in Relation to Toxic and
Hazardous Waste
 Federal laws, Environmental Quality Act (EQA), 1974 concerning air and
water pollution control and hazardous waste management.

The Environmental Quality (Clean Air) Regulations, 1978.

The Environmental Quality (Sewage and Industrial Effluent) Regulations,
1979.

The Environmental Quality (Scheduled Waste) Regulations 1989.
 Malaysian Agenda for Waste Reduction (MAWAR), Department of
Environment, 1996 (Environmental Management for Sustainable
Development).
 Cleaner Production, Ministry of Science, Technology and Environment
(MOSTE) and SIRIM Berhad, 2000.
Table 2.2 also lists three measures passed by Congress of the United States
that have fostered pollution prevention. One measure is a requirement under the
programme for generators of hazardous waste to certify (on shipping manifests) that
a program is in place “to reduce the volume and toxicity of waste generated” where
economically practicable.
According to Ortolano, L., 1997, a second regulatory measure that has led
firms to prevent pollution is the Toxic Release Inventory (TRI), which
Environmental Protection Agency (EPA) issues annually under the Emergency
Planning and Company Right to Know Act (EPCRA) of 1986. Each year, firms
releasing more than minimal quantities of or more of hundreds of toxic chemicals
listed by Environmental Protection Agency (EPA) must report those releases to EPA.
The annual Toxic Release Inventory is made available as a written report and in
digital form (on a CD-ROM), and this has provided governments, interested citizens,
and environmental groups with details of toxic discharges by individual companies.
17
Table 2.2: United States: Examples of Federal Laws and Programmes
Encouraging Sources Reduction in Relation to Toxic and
Hazardous Wastes
 Comprehensive Conservation Response, Compensation and Liability Act
(CERCLA)’s liability provisions.
 Federal Laws concerning air and water pollution control and hazardous
waste management.
 Resource Conservation and Recovery Act, 1976 (RCRA)’s requirement
for certifying that waste reduction programmes are in place.
 Emergency Planning and Community Right to Know Act (EPCRA)’s
1986 – Toxic Release Inventory.
 Pollution Prevention Act, 1990.
Source: Ortolano L., 1997.
Soon after the first Toxic Release Inventory (TRI) was issued in 1988,
environmental groups publicized information on which firms had the largest releases
of toxics. The resulting adverse publicity led many companies to improve their
ranking in the TRI by reducing discharges of toxics. Public pressure, which is often
heightened by information on toxic releases, has been a factor leading some
companies to take a pro-active stance regarding pollution prevention. The TRI can
work in favor of companies, since improvements in rankings among companies listed
in the TRI are a source of positive publicity and allow firms to gain the public’s
confidence.
Further to Ortolano, L., 1997, outlined the third federal mandate fostering
Pollution Prevention Act of 1990. The act directs Environment Protection Agency
(EPA) to establish a pollution prevention office, and to compile and disseminate
information on techniques for waste source reduction. In addition the act requires
companies to report annually to EPA, providing details of their toxic waste under
EPCRA.
Thus rigorous hazardous waste laws such as RCRA and CERCLA, in the
United States and EQA, 1974 with the three subsidiaries of the Scheduled Waste
Regulations in Malaysia; along with demanding requirements in the control of toxic
18
wastewater and air discharges, have led many companies to adopt pollution
prevention as a keystone in their efforts to manage wastes. These measures are
illustrated as in Table 2.3
Table 2.3:

Hierarchy of Pollution Prevention Measure’s
Waste source reduction. Minimize amount and harmfulness of wastes by
 Improving operating procedures
 Changing inputs
 Redesigning production processes
 Reformulating products

Onsite recycling and reuse
 Reduce final waste discharge by processing intermediate wastes to recover
materials valuable for use as process inputs or for sale to others.

Off-site recycling and reuse
 Transport wastes off-site for processing to recover materials valuable for use as
process inputs or for sale to others.

End-of-pipe treatment
 Use chemical, physical and biological process and incineration to transform
wastes into less harmful substances.
Source: Ortolano, L., 1997.
2.3
Toxic and Hazardous Waste Management
Toxic and hazardous waste is one of the environmental key issues of the
1980’s. (Abbou, R., 1988). Monitoring of these wastes means that the whereabouts
of such wastes are known at all times; “ from cradle to grave” as shown in Figure
2.2 (Sinha, R.K., 1994 and Mariana, Md. Nor, 1998).
Control of hazardous wastes can fully be achieved when adequate facilities
are available. Control means that competent authorities can act rapidly to assure that
the possibility for inappropriate handling of wastes or dumping are minimized.
Control means also that the authorities have the power, both legally and financially,
to act quickly in order to reduce danger posed to men and the environment. For
adequate monitoring and control, countries need legislation on hazardous waste. In
19
the legislation, definition of ‘waste’ and ‘hazardous’ must be assured (Lindgren,
G.F., 1983 and Abbou, R., 1988).
Waste Generator
Cradle
Recovery or Treatment
Facilities
Disposal Facilities
Grave
Figure 2.2: Principle of Toxic and Hazardous Waste Management - Cradle to
Grave
20
A policy of hazardous waste management is consistent with policies to
control the use of toxic and dangerous substances, to conserve resources, to preserve
health and to protect the environment, the main objectives of hazardous waste
legislation are:

The prevention of generation

The promotion of re-use and recycling

The reduction of emissions of final disposal; e.g. incinerator.

The abatement of diffuse dispersion of hazardous wastes into the
environment.
Thus the essential objectives of all provisions are the protection of human
health and the safeguarding of the environment (Sinha, R.K., 1994, Dupont, R.R.,
et.al, 2000 and Lee, Heng Keng, 2003).
2.4
Identification and Classification of Toxic and Hazardous Wastes
Hazardous wastes are a category of industrial waste needing special care in
handling, treatment and disposal due to the potential adverse impact resulting from
the hazardous properties of the waste. In general, the basic for determining if a waste
is a hazardous typically occurs in either of two ways; identification and classification
as outlined by the Environment Protection Agency of the United States (EPA) and
European Economic Community (EEC) (Abbou, R., 1988, and La Grega, M.D., et.
al., 2001). Malaysia has also adopted a system similar to that of EPA in determining
the toxic and hazardous wastes (Department of Environment, Malaysia, 2000).
Firstly, identification of toxic and hazardous wastes is the procedure of
determining whether a specific waste from an industrial source is scheduled waste or
not. This may be done from information on it chemical composition, its properties or
source of waste. Laboratory test may indicate that it exhibits one or more of the
characteristics deemed to make a hazardous waste. For Malaysia, the hazardous
waste must first be identified as scheduled waste.
21
Secondly, classification of scheduled waste is the procedure used to specify
the type of waste. It may be a list of specific wastes compiled and classified by the
government because it is known or suspected of having the potential to exhibit
hazardous characteristics. These scheduled wastes are classified into different types
and are given a specific waste code.
As been used in other countries such as the USEPA (Lindgren. G.F., 1983
and La Grega, M.D. et.al, 2001), the underlying principle of identification and
classification in Malaysia also requires at least any of the following characteristics
that will make a waste hazardous.

Explosively/Ignitability
Waste easily ignited or exploded and thus posing a fire hazard during
routine management.

Corrosivity
Waste is capable of injuring human tissue, and of corroding containers
holding hazardous substances, enhancing the introduction of
contaminants into the environment; waste that is highly acidic or alkaline.

Reactivity
Waste has a tendency to become chemically unstable under normal
management condition; has tendency to react violently and explode.

Toxicity (Human toxicological properties and toxicological Properties)
Substances and preparation which, if they are inhaled or ingested or if
penetrate the skin may involve serious, acute or chronic health risks and
even death.
Another alternative to the regulatory classification system is to classify a
waste according to the following hierarchy:
(i) Form or phase distribution (e.g. liquid or solid);
(ii) Organic or inorganic;
22
(iii) Chemical class (e.g. Solvents or heavy metals);
(iv) Hazardous constituent as it affects treatability (e.g. hexavalent chromium).
This system is effective for engineering purpose as shown in Table 2.4.
Table 2.4:
Engineering Classification System for Hazardous Waste
Major Category
Characteristics
Inorganic aqueous
waste
Liquid waste composed
Primarily water but
containing acids/alkalis
and/or concentrated
solutions of inorganic
hazardous substances
(e.g. heavy metals,
cyanide).
-
Organic aqueous
waste
Liquid waste composed
primarily of water but
containing admixtures
or dilute concentrations
of organic hazardous
substances (e.g.,
pesticides).
-
Rinse water from pesticide containers
Washing of chemical reactors and formulation
tanks
Organic liquids
Liquid waste containing
admixtures or
concentrated solutions
of organic hazardous
substances.
-
Spent halogenated solvents from metal
degreasing and dry cleaning.
Distillation residues from production of
chemical intermediates
Liquid wastes
composed primarily of
petroleum-derived oils.
-
Oils
Examples
-
-
-
Inorganic
sludges/solids
Organic
sludges/solids
Sludges, dusts, solids
and other nonliquid
waste containing
inorganic hazardous
substances
-
Tars, sludges, solids
and other nonliquid
waste containing
inorganic hazardous
substances
-
-
-
Source: La Grega, M.D., et. al, 2001.
Spent sulfuric acid from galvanizing
Spent caustic baths from metal finishing
Spent ammoniacal etchants from
manufacturing electronic components
Rinse water from electroplating
Spent concentrates from hydrometallurgy
Used lubricating oils from internal combustion
engines.
Used hydraulic and turbine oils from heavy
equipment operations.
Used cutting oils from machinery manufacture
Contaminated fuel oils
Wastewater treatment sludge from mercury
cell process of chlorine production
Emission control dust from steel manufacture
and smelters
Waste sand from coking operations
lime sludge from coking operations
Dust from deburring of chromium parts in
fabricated metal industry
Sludges from painting operations
Tar residues from production of dyestuff
intermediates
Spent filter cake from production of
pharmaceuticals
Distillation bottom tars from production of
phenols
Soil contaminated with spilled solvents
Slop oil emulsion solids
23
In summary, the basic procedure for identification and classification of
scheduled waste in Malaysia is shown in flow chart, Figure 2.3.
Obtain description of
waste from producer
Is description
in First
Schedule?
Yes
No
Is the waste
nonscheduled?
Yes
Consider source of
waste and whether
hazardous materials are
used in process
Determine basic
properties of waste
Does the waste
appear to conform
with the
description
No
Yes
Does the waste
appear to have
hazardous
properties?
Yes
Demand an
analysis
Use classification
provided
Probably not
scheduled waste
Identify components
and classify accordingly
Source: Department of Environment, 2000.
Figure 2.3:
The Procedure for Identification and Classification of
Scheduled Waste in Malaysia.
No
24
2.5
Legislation and Policy on the Toxic and Hazardous Waste Management
in Malaysia
Most actions taken today to manage wastes especially toxic and hazardous
wastes are done in response to legal requirement, as these wastes are potentially
harmful. For this reason legislation has been introduced in the Environment Quality
Act 1974 (EQA) to control the way, which they are stored, handled, treated and
disposed off (Mariana Md. Nor, 1998 and Lee, Heng Keng, 2003). The Environment
Quality Act 1974 (EQA) came into force on 15 April 1975 and was amended in
1976,1985 and 1996.
2.5.1
Definition of Waste
Waste is defined in EQA 1974 as:
“Any matter prescribe to be scheduled waste or any matter whether in a solid,
semisolid or liquid form, or in the form of a gas or vapour, which is emitted,
discharge or deposited in the environment in such volume, composition or manner as
to cause pollution”
This definition is appreciably different from that which is widely used
internationally. In the European Union (EU) and many other countries, waste is
defined as any material, which the holder discards or intends to discard (Lieben, P.
and Huisman, J.W, 1988). The Basel Convention definition is similar but uses
“dispose of” instead of “discard” (UNEP, 1998).
In Malaysia, therefore a material only become waste at the point at which it is
emitted, discharged or deposited and then only if it causes pollution. Could thus be
argued that material which would, in most countries, be considered to be waste may
not be waste if it is managed in a manner so as to cause no pollution. According to
Bishop, P.L., (2000), a waste may not be necessarily have to be waste and suggested
that a better definition of waste:
“ A waste is a resource out of place”
It is the responsibility of pollution prevention personnel to find the right place to turn
the waste into a resource.
25
2.5.2
Definition of Toxic and Hazardous Waste
The hazardous waste definition distinguishes between these wastes that can
be safety manage at non-hazardous waste facility (i.e., a municipal landfill), and
those that require management under more stringent standards (Abbou, R., 1988).
A number of countries have defined “ hazardous wastes” in their respective
laws (Lieben, P., and Huisman J.W., 1998). Examinations of a compilation of these
definitions indicators that these are no universally accessed definition of toxic and
hazardous wastes. The definitions that are use in various countries or international
organization are somewhat similar, only different in term use as shown in Table 2.5.
Table 2.5: Terms of Toxic and Hazardous Wastes in Selected Countries and
International Organizations
Term
Country/Organisation

Hazardous
 Basel Convention, United States of America,
Canada, China, Organisation for Economic
Cooperation and Development (OECD)

Chemical
 Denmark, the Netherlands

Special
 United Kingdom, Federal Republic of
Germany

Toxic and dangerous
 Italy, France, European Economic Community
(EEC)

Toxic
 Belgium

Problem
 Finland

Scheduled wastes
 Malaysia
The primary legislation influencing the classification of scheduled waste in
Malaysia is the Environment Quality Act, 1974. Section 2 of EQA 1974 has defined
scheduled wastes means “any waste prescribed by the Minister in the regulations as
scheduled wastes”.
26
In addition specific subsidiary has been introduced under the provisions of
section 18,21 and 51 of Environmental Quality Act, 1979 in the form of three
regulations specifically related to scheduled wastes namely:

Environmental Quality (Scheduled Wastes) Regulations, 1989

Environmental Quality (Prescribed Premises)(Scheduled Wastes
Treatment And Disposal Facilities) Order, 1989.

Environmental Quality (Prescribed Premises) (Scheduled Waste
Treatment And Disposal, Facilities) Regulations 1989.
In addition to the scheduled wastes management, various other environment
regulations are in force and apply to the toxic and hazardous wastes:

Environmental Quality (Prescribed Activities) (Environmental Impact
Assessment) Order 1987.
2.5.3

Custom (Prohibition of Export) Order (Amendment) (No.2) 1993;and

Custom (Prohibition of Import) Order (Amendment) (No.2) 1993.
Environmental Quality (Scheduled Wastes) Regulations, 1989
These regulations are generally referred to as the “Scheduled Waste
Regulations” and provide the specific rules for the handling, treatment and disposal
of scheduled wastes. They provide for “cradle to grave” control.
The important sections are:
Section 2
Interpretation- gives the definitions of term used. One of the most
significant is the definition of scheduled waste, being “any waste
falling within the categories of waste listed in the First Schedule”
First schedule of the regulation defines 107 categories of scheduled
wastes covering all except radioactive waste which are controlled by
the Atomic Energy Licensing Act, 1984. Specifically excluded from
the definition also are municipal waste and municipal sewers.
27
Every waste type mentioned in the First Schedule, must be considered
as scheduled waste regardless of its hazardous properties. The list of
waste types is divided in two parts: the first part identifies certain
wastes by their composition only, whilst the second also includes a
specific source in addition to composition.
 Part I: Scheduled wastes from non-specific sources
-49 types of waste from 28 different non-specific sources. The
numbering Nxxx indicates waste from non-specific sources.
 Part II: Scheduled wastes from specific sources
-59 types of waste from 30 different specific sources. The
numbering Sxxx indicates waste from specific sources.
Examples of waste listed in Parts I and II of the First Schedule are
given below: The complete list is available in the Schedule Waste
Regulations.
Part I: Scheduled waste from non specific sources
1.
Mineral oil and oil contaminated waste
NO11
NO12
NO13
NO14
NO15
NO16
Spent oil or grease used for lubricating industrial machines
Spent hydraulic oil from machines, including plastic injection
moulding machines, turbines and die-casting machines.
Spent oil-water emulsion used as coolants
Oil tanker sludges
Oil-water mixture such as ballast water
Sludge from storage tank
2.
Waste containing polychlorinated biphenyls (PCB) or polychlorinated
triphenyls (PCT)
NO21
Spent oil contaminated with PCB and PCT
NO22
Discarded electrical equipment or part containing or
contaminated with OCB or PCT
NO23
Containers contaminated with PCB or PCT
Part II: Scheduled wastes from specific sources
1.
Mineral oil and oil contaminated waste
SO11
SO12
SO13
SO14
Waste oil or oily sludge from wastewater treatment plant oil refinery
or crude oil terminal
Oily residues from automotive workshop or service station oil or
grease interceptor
Oil contaminated earth from re-refining of use lubricating oil
Oil or sludge from oil refinery maintenance
2. Tar or tarry residues from oil refinery or petrochemical plant
SO11
Tar or tarry residues from oil refinery or petrochemical plant
28
Section 3
Notification of the generation of scheduled waste- introduces a
requirement for schedule wastes generators to notify the Department
of Environment (DOE) of the types and amounts of generated using
the form set out in the Second Schedule.
Section 4/5
Treatment and disposal of scheduled wastes-require that Scheduled
wastes must be treats and disposed of at prescribed (and therefore
licenced) premises and that, as far as practicable, it must be rendered
“innocuous” (by treatment) before disposal.
Section 6
Reduction in the generation of scheduled wastes-requires that
scheduled wastes must be reduces (in quantity) to the maximum extent
using the best practical means.
Section 7
Responsibility of waste generator- to handle waste properly at all
times (handling storage, treatment, delivery for treatment/disposal)
Section 8
Storage of scheduled wastes- gives direction on how to store and label
scheduled wastes. Incompatible wastes, which are described in the
Fourth Schedule, must be stored in separate containers. Labeling must
be done in accordance with the Third Schedule.
Section 9/10 Inventory and Consignment Notes- waste generators must keep an
inventory of schedule wastes generated, treated and disposed of and
complete a consignment note for every consignment of scheduled
wastes sent for treatment/disposal. It specifies how this information is
to be distributed (to the DOE and, for consignment notes, to other
parties). The forms to be used for the inventory are set out in the Fifth
Schedule and for the consignment note in the Sixth Schedule.
Section 11
Information to accompany scheduled wastes being transported- the
information required is set out in the Seventh Schedule. These
include:
a) Properties of wastes, including associated risks
b) Safe handling procedures
c) Precautions in case of spill or accidental discharge causing
personal injury
d) Steps to be taken in case of spill or accidental discharge causing
material damage.
29
Section 12
Spill or accidental discharge- describes the responsibilities of the
waste generator and the contractor (transport) in the case of accidental
discharge including the obligation to inform the Director General.
Section 13
Compounding of offences- gives the direction for compounding of
offences according to the procedure prescribed in Environmental
Quality (Compounding Offences) Rules 1978.
The schedule to the regulations, each of which has been explained above are
as follows:
First Schedule
Definition of schedule wastes;
Part I - Schedule wastes from non specific sources
Part II - Scheduled wastes from specific sources
2.5.4
Second Schedule
Form for notification of scheduled wastes
Third Schedule
Labelling requirement for scheduled wastes
Fourth Schedule
Scheduled wastes of potential incompatibility
Fifth Schedule
Form of inventory of scheduled wastes
Sixth Schedule
Consignment note for scheduled wastes
Seventh Schedule
Information to accompany scheduled wastes
consignments
Environmental Quality (Prescribed Premises) (Scheduled Wastes
Treatment and Disposal Facilities) Order, 1989
This order prescribes the types of scheduled wastes facilities, which are to be
treated as prescribed premises – and therefore require:

An Environmental Impact Assessment (EIA) (Section 34A, EQA,
1974)

A written permission for construction (Section 19)

A licence to occupy and use the premises (Section 18)
30
The prescribed premises are:
2.5.5

Off-site storage facilities

Off-site treatment facilities

Off-site recovery facilities

Scheduled wastes incinerators

Land treatment facilities

Secure facilities
Environmental Quality (Prescribed Activities) (Scheduled Waste
Treatment and Disposal Facilities) Regulations, 1989
These regulations require occupiers of the scheduled wastes facilities defined
in the above Order to maintain records of the types and quantities of Scheduled
wastes received, stored and processed and to submit this on a quarterly basis to the
Department of Environment, Malaysia (DOE).
They also specify the measures to be taken when an occupier ceases to be a
licence holder, where upon any scheduled wastes which have not been treated or
disposed of must be transferred to a licenced facility within 30 days.
2.5.6
Environmental Quality (Prescribed Activities) (Environmental Impact
Assessment) Order, 1987
This order defines the prescribed activities, which require an Environmental
Impact Assessment (EIA) before they may construct or operated. EIA is a mandatory
legal requirement for all Prescribed Activities under the EIA Order, 1987. According
to Harrop, O.D. and Nixon, A.J., (1999), there are now around 70 developing and
transitional countries with EIA legislation in place and some of these countries, there
are considerable activity with respect to the reorganization of government
responsibilities for EIA at national and regional levels, the revision of EIA systems
and the development of more detail procedures or guidelines to support EIA practice.
31
Section 34A of the EQA, 1974 specifies legal requirement in respect of EIA
for Prescribed Activities:

It empowers the Minister of Science, Technology and Environment,
after due consultation, to prescribe any activity which may have
significant environmental impact as a ‘Prescribed Activity’

The section further requires the Project Proponent of a Prescribed
Activity to submit a report (the EIA) to the Director General of
Environment Quality before approval for the proposed activity is
granted by the relevant approving authority.
The Department of Environment, Malaysia has outlined that the EIA report
must contain an assessment of the impact of the Prescribed Activity on the
environment. It also detail the proposed measures that shall be instituted to prevent,
reduce or control adverse impact on the environment and the report should be in
accordance with the guidelines issued by the Department of Environment particularly
“A Handbook of Environment Impact Assessment (EIA) Guidelines, 2000”. In
practice the EIA must be approved by DOE before the approval from the final
Authority. The ultimate approval body will usually be one of the following:

The National Development Planning Committee for Federal
Government sponsored projects

The respective State Planning authorities for State Government
sponsored projects

The Regional Development Authorities or State Executive
Committee (EXCO)

The Ministry of International Trade and Industry (MITI) for
industrial projects.
All prescribed waste treatment and disposals projects are subject to an EIA
under the EIA Order, 1987. These prescribed premises include all the five (5)
Prescribed Activities listed under sections 18(a) of EIA Order, 1987. Figure 2.4,
32
demonstrates the possible inter-relationship within these Prescribed Activities. The
relevant items under the Schedule of Prescribed Activities are quoted below:
Section 18 - Waste Treatment and Disposal
a. Toxic and Hazardous Waste
(i) Incineration plant
(ii) Recovery plant (off-site)
(iii)Wastewater treatment plant (off-site)
(iv) Secure landfill facility
(v) Storage facility (off-site)
It is noted that toxic and hazardous (or scheduled) wastes can be treated or
recovered at sources without the requirement for a separate EIA other than the EIA
that might be requires for the industrial or selected activity producing the wastes
(Rosli Zul, 1998).
The aims of an EIA are to ensure that potential problems are foreseen and
addressed at an early stage in the project’s planning and design (Canter, L.W., 1996).
To achieve this aims, the assessment’s findings are communicated to be various
group who will make decisions about the proposed project; the Project Proponents
and their investors, as well as regulators, planners and politicians. Having read the
conclusions of an EIA, projects planners and engineers can shape the project so that
its benefits can be achieved and sustained without causing inadvertent environmental
problems. (Morgan, R.K., 1998, Harrop, O.D., and Nixon, A.J., 1999).
The legal frameworks, procedure and guidelines for EIA introduced in
countries and organizations around the world follow some generally agreed
principles, which have been described as a hierarchy of core values, guiding
principles and operational principles. (Sadler, 1996 and Lee, N. and George, C.,
2000).
33
34
According to Sadler, (1996) the core values of EIA are:

Integrity
The EIA process should conform to accepted
standards and principal of good practice.

Utility
The process should provide balance, credible
information for decision making

Sustainability
The process should promote environmentally
sound development
The same sources gives the main guiding principles as:

A well-founded legislation base with clear purpose specific
requirement and prescribed responsibilities

Appropriate procedural controls to ensure the level of assessment,
scope and consideration and schedule for completion are relevant to
the circumstances

Incentive for public involvement with structured opportunities tailored
to the issues and interest at stake

Problem –and decision –orientation, concerned with the issues that
matter, the provision of consequention information, and explicit
linkage to approvals and condition setting.

Follow-up and feedback capability, including compliance and effects
monitoring, impact management, and audit and evaluation
Sadler (1996), further also sets out the main operational principles for
effective EIA practice. EIA should be applied:

To all development projects or activities likely to cause potentially
significant adverse impacts or add to actual potential foreseeable
cumulative effects;

As a primary instrument for an environmental management to ensure
that impacts of development are minimized avoided or rehabilitated;

In a way that the scope of review is consistent with the nature of the
project or activity and commensurate with the likely issues and
impacts; and
35

On the basis of will defined roles, rules and responsibilities for key
actors.
Further, EIA should provide the basic for:

Environmentally sound decision making in which terms and
conditions are clearly specified and enforced;

The design, planning and construction of acceptable development
projects that meet environmental standards and management
objectives;

An appropriate follow–up process with requirements for monitoring,
management, audit and evaluation;

Follow-up requirements that are based on the significance of potential
effects and on the uncertainties associated with prediction and
mitigation; and

Learning from experience with a view to making future improvements
to the design of projects or the application of the EIA process.
2.6
Licensing And Inspection of Scheduled Waste Management Facilities
The overall legislation relating to licensing of prescribed premises/activities
and to scheduled waste management facilities is the Environmental Quality Act 1974
(as amended)- and the subsidiary regulations. The licensing is described in Part III,
Licences of EQA, 1974 and the general explanation of the licensing requirements are
covered in Section 10 to Section 17 of the EQA, 1974 as shown in Table 2.6. Under
this Act, the Director General of Department of Environment shall be the licensing
authority. The Director General of the Department of Environment:
(i) May grant any application for licence or for a renewal or transfer there of,
either to conditions or unconditionally and where an applications is granted
subject to conditions, the conditions shall be specified in the licence to which
the application relates;
(ii) May during the currency of a licence or vary any condition attached to the licence
revolve or vary any condition attached to the licence or attach new conditions
36
thereto whether in addition to or in substitution for existing conditions and shall
notify the holder of the licence of his action in that behalf; or
(iii) Shall not grant any application for a licence in respect of any premises the use
whereof as such would contravene any town planning scheme or any law
respecting the use or development of land.
These sections also explain the licences application should be made in writing
and before varying any condition attached to the licence, consideration are taken into
account (Environmental Quality Act, 1974):
(i) Whether it would be practicable to adapt the existing equipment or industrial
plant to conform with the varied or new condition;
(ii) The economic life of the existing equipment, control equipment or industrial
plant, having regard to the data of purchase;
(iii) The quantity or degree of out-back of emission discharge or deposit of wastes
to be achieved by the varied or new condition;
(iv) The estimated cost to be incurred by the licences to comply with the varied or
new conditions; and
(v) The nature and size of the trade, process or industry being carried out in the
premises.
Further the licensing procedure has been elaborated explained in the
Environmental Quality (Licensing) Regulations, 1977(Department of Environment,
2002).
Table 2.6: Malaysia: Environmental Quality Act, 1974. Licences, Part III
Section 10
:
Licensing Authority
Section 11
:
Licences
Section 12
:
Power to attach conditions to licences
Section 13
:
Duration and Renewal of licences
Section 14
:
Transfer of licences
Section 15
:
Register of licences
Section 16
:
Licences to comply with licence
Section 17
:
Licence Fees
37
2.6.1
Outline of Licensing Process
The licensing process for prescribed premises/conveyances involves a four
stage process (Rosli Zul and Azhar Daud, 1998) namely:
(i) Environmental Impact Assessment (EIA);
(ii) Processing of the Written Permission;
(iii) Pre-licensing Inspection.
(iv) Processing of the Operating Licence
For all types of applications for scheduled wastes treatment and disposal
facilities except land treatment/disposal, the application are required to obtain an
approval for the EIA from the Department Environment prior to submitting their
application for written Approval/Permission for establishing the facilities, EIA has a
key role to play in the way in which new development proposals are designed,
approved and implemented. To be effective, the process needs to be integrated into
the project planning cycle with environmental studies taking place in parallel with
the project design as it provides a useful framework within which environmental
consideration and design can interact. Used in this ways, the EIA can indicate how
the project design might be modified to anticipate and minimize possibly adverse
effects and provide for a better environmental option or alternative
process/design/location (Department Environment, Malaysia, 2000).
The Written Permission is required before any construction or start-up
operation can begin. It imposes conditions relating to the design and construction of
a facility. After the facility has been constructed, it is inspected for conformance to
the written permission approval conditions under the pre-licensing visit. Following
the issuance of Written Permission, the applicants are required to construct/establish
the premises according to conditions stipulated in the Written Permission. The main
purpose of the visit is also to ensure that the premises had been constructed
according to the drawing/plan submitted to the Department of Environment as well
as to ensure all the approval conditions of the EIA and Written Permission are fully
complied with (Rosli Zul and Azhan Daud, 1998).
38
An operating licence (usually referred to simply as a licence) is required
before a facility/conveyance can operate. The operating licence specific a set of
conditions pertaining to operation and maintenance. It is issued on confirmation that
the facility conforms to the conditions of the Written Permission. It is based on the
pre-licensing visit and the full compliance to the conditions stipulated. According to
the Department of Environment, 2002) even before the application, the written
permission and licence for premises can be considered, the applicant of the
prescribed premises must:

Meet to have obtained planning approval from the relevant planning
authority under the requirement of Section 20, EQA, 1974.

Have already obtained the EIA approval (EQA Section 34A) for the
prescribed activity- where applicable
Under Section 11(3)(b) of the EQA and reaffirmed in Section 4 of the
Environmental Quality (Licensing) Regulations, 1977 licences can however be
varied, revoked or suspended by the Director General if found necessary
(Environmental Quality Act, 1974). In general the flow chart of the application
licensing of the Waste Management Facilities in Malaysia is shown in Figure 2.5.
2.7
Classification of Toxic and Hazardous Waste Management Facilities
A hazardous waste facility may involve the contiguous land, structure, and
other improvements and appurtenances used for storing, recovery, recycling, treating
or disposing of hazardous waste (La Grega, M.D., et. al., 2001).
Many hazardous waste generators recognized the need for specialized
treatment and disposal of these wastes. Many generators constructed and operated
their own hazardous wastes facilities referred to as on-site facilities (Nemerow, N.L.,
1995). Other generators, not having a suitable site or not generating a sufficiently
large volume of waste to justify the investment on-site facility, transported their
waste off-site to specialized facilities for treatment and disposal. Such facilities are
referred to as commercial, off-site facilities (Sinha, R.K., 1994 and Nemerow, N.L.,
1995).
39
APPLICATION
ACCEPTED
Prescribed Activity
Submit RM 1000.00
payment together with
required documents
No
Conduct EIA
Initial Site Assessment
EIA Approval
EIA Approval
No
Submit information as
required together with RM
1000.00 payment (if not yet)
Yes
Written Permission
Yes
Pre-Licensing Visit
Submit Form AS 1 and RM
100.00 payment (if not yet)
Licence and
Compliance Table
Record
Applicant
Source: Department of Environment, Malaysia, 2002.
Figure 2.5:
Flow Chart of Processing of Written Permission and New Licence
for Prescribed Premises (Schedule Wastes)
A hazardous waste facility may function with just one technology or it may
combine multiple technologies (for recovery and treatment of hazardous waste)
particularly if it in a commercial facility serving a number of generators.
According to La Grega, M.D. et. al., (2001), the main types of facilities as
shown in Figure 2.6, other than storage facilities are classified under the following
major categories:
40
(i) Recovery or recycling facilities of recovered material as a saleable product
(typically solvent, oils, acids or metals), some recovered energy values in
waste;
(ii) Treatment facilities involve changes in the physical or chemical characteristic,
using any of a wide variety of physical, chemical, thermal or biological
methods;
(iii) Land disposal facilities are permanent placement of waste on or below land
surface;
(iv) Fully Integrated Facility.
Some large commercial facilities employ aqueous treatment, incineration,
land disposal and possibly other components to form a fully integrated facility as
shown in Figure 2.7. Example of this category is Kualiti Alam Sdn. Bhd. (kualiti
Alam, undated).
The approach to technically evaluate a licence application will differ from
facility to facility. Consequently, a classification system is needed to classify the
more common toxic and hazardous facilities types. The following are currently the
identified classifications of toxic and hazardous facilities for licensing purposes:

Scheduled waste transportation

Off-site storage and transfer stations*

Secure landfill*

Scheduled waste incineration – on site incineration and off-site
incineration*

Clinical waste incineration

Off-site physico-chemical treatment/solidification*

Centralized waste treatment facility (e.g. electroplating park)

Resource recovery – spent oil and oily wastes, spent solvent, metal
dross/metal hydroxide and catalyst

Land treatment
41
Waste Generation
Recovery / Recycling
-
Solvent recovery
Fuel blending
Metal recovery
Oil recovery
Energy recovery
Products
Land Disposal
Treatment
-
Residuals
- Landfill
- Deep well
injection
Thermal destruction
Aqueous treatment
Stabilization
Biological treatment
Residuals
Source: La Grega, M.D, et. al, 2001.
Figure 2.6:
Recovery, Treatment and Disposal Technology
It should be noted that the classification types marked with an asterisk are
facilities provided by Kualiti Alam (Mariana Md. Nor, 1998). Under the terms of
Kualiti Alam’s 15 years concession (as from 18 December 1995), the Ministry of
Science, Technology and The Environment has given an assurance that no further
facilities of these types will be licenced during the period of Kualiti Alam’s
concession. However, existing licences before 18 December 1995 date can continue
to be renewed.
Pre-Shipment
Waste analysis
Waste
Receiving
Storage &
Preparation
Organic residue
Scrubber water
Incineration
Liquid Organic
Recovery
Leachate
Physical
Chemical
Treatment
Stabilization
Slag
Fuel, Solvent
Land Disposal
Source: La Grega, M.D, et. al, 2001.
Figure 2.7:
Waste Management Flow Diagram for Fully Integrated
Hazardous Waste Management Facility
42
2.7.1
Exclusive Right of Kualiti Alam -The History of Scheduled Waste
Management System in Malaysia
During the mid 1960’s rapid growth began to occur within the manufacturing
sector in Malaysia and this trend seems set to continue well into the foreseeable
future. The contribution of these manufacturing industries to the Gross National
Product (GNP) increased from 11% in 1966 to 24% in 1988, doubling in 20 years.
This era was the beginning of the generation of hazardous waste in Malaysia. By the
early 1980’s the government recognized the growing problem of this waste
production and by 1981 an Australian Consultant is assigned to compile a desktop
report concerning this matter. The report recommended a general waste management
strategy consisting of the following aspects; a secure landfill, chemical fixation plant,
incineration plant and recycling/reuse center. These should be backed up by
legislation/regulations, notification by waste generators of waste arising and licences
for transport, treatment and disposal sites (Goh, Kiam Seng, 1990)
In October 1984, a Danish consultancy conducted a survey, which resulted in
the formation of draft regulations on hazardous waste management, but these were
not implemented. By 1985 the Department of Environmental (DOE) initiated a
hazardous waste survey/programme to collect data on the volumes and types of
hazardous waste arising within the country. A total of 700 factories were investigated
in order to identify which waste could be recycled, treated, incinerated or landfill.
During1985 to 1998, 29 sites were investigated on Peninsular Malaysia to find a
central site as recommended in the Danish study. At the same time the French
Government studied the hazardous waste arising from the metal finishing industries
in Klang Valley and designed a physio-chemical treatment plant to deal with this
waste. They also began work on developing a computer system for tracking and
monitoring the scheduled waste within the country (Goh, Kiam Seng, 1990).
During April to December 1987, Consultancy of Dames and Moore, working
on from the 1985, DOE work, conducted a study on the feasibility of central
treatment and disposal facility within Malaysia. A preliminary site was proposed but
was subsequently rejected by the government, as they could not guarantee the
minimum volume of waste, which would be delivered to the site. The study
43
estimated that a total of 377,000 MT of scheduled waste was generated within the
country during 1987. In addition to this it was estimated that a further 600,000
containers contaminated with scheduled waste were disposal of annually within the
solid waste system. The study also discovered that the waste generation was not
evenly distribution throughout Malaysia, each state was slightly different in terms of
volumes and types (Department of Environment, Malaysia, 1995).
Many solid disposal sites exist throughout the country but during the study all
found to be unsuitable for hazardous waste. The study concluded by recommending
that a central integrated treatment and disposal facility to be built, including facilities
for storage, incineration, physical-chemical treatment, stabilization and secure
landfill. They estimated that in 1992 there would be a total 200,000 MT of scheduled
waste which would be ‘landfill able’ and therefore secure sites for future disposal
need to be develop in order to prevent the growing stockpile of stored waste from
building up any further. The report suggested that this facility be built in the state of
Selangor and is also fairly central within the country. The government stated that any
development would be done only on private basis due to the huge finance (Goh,
Kiam Seng, 1990).
Following on from the Dames and Moore study the Department of
Environment, Malaysia in 1995, conducted a further study to determine the exact
breakdown of the waste types generated. This would enable the best management
and treatment strategy to be developed concerning toxic hazardous waste. The result
of the study is shown in Table 2.7 (Department of Environment, 1995).
Subsequently in March 1989, the Government of Malaysia, realizing the
growing problem, brought into force the first formal legislation in an attempt to
control; the nations hazardous waste arising from’ cradle to grave”. The legislation
was in the form of the three Environmental Quality Regulations brought in under the
provisions of Section 18, 21 and 51 of EQA, 1974.
44
Table 2.7:
Major Types of Scheduled Waste Arising in Malaysia
Rank No
Waste type
Rank No
Waste type
1
Acids (with heavy metals)
11
Rags /paper/plastic.
Contaminated
2
Sludge with heavy metals
12
Paints/dye/ink/pigment
(solvent based)
3
Mineral Sludge
13
Oil sludge
4
Asbestos
14
Pathogenic/pathological
5
Paint/dye/ink/pigment
15
Spent solvents, non
halogenated
6
Dust/Slag/Cinder/Ashes
16
Sludge- paints etc (water
based)
7
Alkalis
17
Sludge – paints etc (solvent
based)
8
Oil & Hydrocarbons
18
Spent solvents, halogenated
9
Others
19
Resin and glue
10
Photographic wastes
Source: Department of Environment, 1995.
However there was still no actual waste strategy for dealing with the waste
itself and in December 1995 the government commissioned the Department of
Environment, Malaysia to conduct a second study into the selection of potential
regional disposal sites. Based on the previous reports, a national scheduled waste
programme is to be developed. This study involved selecting and recommending one
site in each of the eleven (11) states across the Peninsular for developing an
integrated plant, primarily a secure landfill but also storage, treatment and
incineration units. The philosophy of the selection site selection was to locate the
sites as close to the major waste sources as possible. This would reduce transport
distances and therefore costs and also minimize risk of accidents. Dames and Moore
in the 1987 report suggested that the optimum acceptable distance to transport wastes
would be within a 25-30km radius from source to final destination. They also
estimated that the cost will be paid by the generators and should be kept at a minimal
so to avoid illegal dumping.
With regard to this philosophy a regionalisation and zoning approach was
adopted for the Master National Plan. This involved dividing the 11 Peninsular States
45
up into four regions according to waste generation, industrial densities and transport
routes. Each region consisted of several states and division was set as follows:

Northern Region; Perak, Penang, Kedah, Perlis

Central Region; Negeri Sembilan, Selangor, Melaka, Federal
Territory

Southern Region; Johor

Eastern Region; Kelantan, Terengganu, Pahang
It was anticipated that at least one integrated plant be located in each region,
with possible extra sites within the major producing states (Department of
Environment, 1995).
According to the 1995 Report, after the selection procedure had been
completed a total of 11 potential sites had been identified as being suitable for the
development as a secure landfill site with two sites were selected for each region.
*

Northern Region
:

Central Region
:

Southern Region
:

Eastern Region
:
1. Ladang Bukit Mertajam*
2. Lahat
1. Bukit Nanas *
2. Bukit Lanchong
1. Foh Chong Estate *
2. Sedenak Estate
1. Bukit Mak Indah
2. Gambang
The asterik are the final recommended or preferred sites. The others are suggested can be used as
alternative or emergency sites.
In June 1989, the government selected two private firms to design the
proposed plant at Bukit Nanas. On the 18th of December 1995 the company Kualiti
Alam Sdn.Bhd. was given approval to develop the Integrated Scheduled Waste plant
and run the national strategy. This is a consortium made up of Malaysia and Danish
companies. To ensure the long term viability of the project, Kualiti Alam was given
the exclusive right to establish and operate the plant for 15 years covering Peninsular
Malaysia (Mariana Md. Nor, 1998 and Alfred Ang, 1999). This national concession
46
also includes the responsibility for the collection, transport, treatment, and disposal
of the nation’s waste with charges set for these services, which each generator must
pay. They actual site of the integrated Scheduled Waste Management facility is
located on Lot 1918, Tanah Merah Estate, Bukit Nanas, Negeri Sembilan (Kualiti
Alam, undated).
2.7.2
Kualiti Alam Sdn.Bhd. - The Integrated Scheduled Waste Management
System
The Malaysian Government has privatized the management of scheduled
waste based on ‘ polluters pay’ principle. For a period of 15 years from the start of
operation of the waste management system, the company, Kualiti Alam Sdn. Bhd.
(KA) has been granted the exclusive rights to collect and treat all scheduled waste
generated in Peninsular Malaysia which can not treated within the premises of the
waste generators (on-site treatment). The Integrated Scheduled Waste Management
System of Kualiti Alam consists of:

A centralized integrated Waste Management Centre (WMC) to treat and
dispose of the different types of scheduled wastes (Kualiti Alam, undated).
Kualiti Alam will provide complete waste management of collection of
scheduled wastes from the waste generator’s premises, transportation, and treatment
to final disposal.
The Waste Management Centre (WMC) is located in the middle of an oil
palm plantation, and covers an area of 56 hectares of which 19 hectares have been
cleared (Alfred Ang, 1999). The Waste Management Centre (WMC) has four main
treatment facilities:
 Incineration plant
 Physical/chemical treatment plant
 Solidification plant
 Secure landfill
47
All treatment and disposal facilities are now fully operational. The WMC
treats all 107 categories of scheduled wastes as listed in the Environmental Quality
(Scheduled Wastes) Regulation 1989, except:

Radioactive waste

Pathological waste

Explosive waste
The solidification plant stabilizes neutral inorganic waste from waste
generators and internally produced waste (originating from physical/chemical
treatment plant in the form of sludge or from the incineration plant in form of flyash). This unit is expected to have a capacity of 15,000 MT/year.
In the physical/chemical treatment plant, inorganic wastes will be pHneutralized cyanides will be destroyed by oxidation and heavy metals will be
precipitated as very insoluble products. These products are then stabilized and finally
placed in the landfill. This plant is designed to have a capacity of 15,000 MT/year.
The incineration plant will treat all organic waste classified to be applicable
for thermal destruction. It is consist of rotary kiln at 1200oC with a capacity of
30,000 MT/year.
The incineration process produces slag, fly ash and flue gas cleaning
products. While slag is deposited directly into the landfill, other residues will be
solidified and deposited in the secure landfill. The landfill is constructed and
monitored according to all environmental requirements.
Beside these three treatment facilities, the secure landfill is also located at the
Waste Management Centre, it has a system of containment for the final disposal of
treated wastes and should be enough capacity to last 25-30 years (Alfred Ang, 1999).
Each landfill cell is protected by meter thick compacted clay at the base, and a layer
of geomembrance and another layer of geonet further fortify it. There is also a piping
system to channel leachate into the collection sump where leachate is regularly
pumped out for testing. The overall waste management flow chart of Kualiti Alam is
48
shown in Figure 2.8. As mark of its commitment towards the environment and
excellence, Kualiti Alam Sdn. Bhd. has four certifications, namely OHSAS 1S001,
1S0/ IEC 17025,1S0 14001 and ISO 9002, (Kualiti Alam, undated).
2.8
Licence Application Overview
Permitting or licensing is the action of regulatory agencies to authorize
construction and operation of a facility. Facilities cannot operate without holding a
valid permit with the facility site, design, and operations do not violate health and
environmental standards (LaGrega, M.D., et. al, 2001).
2.8.1
Types of Licence Application and Fees
According to the Department of Environment, Malaysia, there are five (5)
different of licence applications that may be required for the scheduled waste-related
premises or conveyance. The processing fee, which is non-returnable, varies
according to the application. These are as summarized as shown in Table 2.8.
2.8.2
Functional Issues in Licence Application
As the licensing process involves the stages of written permission, the prelicensing visit and the operating licence; according to the Department of
Environment, Malaysia there are some of the functional issues to be addressed in the
application as shown in Table 2.9.
As a comparison, by any measure; according to La Grega, M.D., et. al,
(2001); the USEPA permit application process for a hazardous waste facility is
length, expansive, and burdensome. Unlike Malaysia, in many states in the United
States, a facility developer must also submit a separate permit application to satisfy
the state’s particular requirements specify the technical requirements of a permit
application. The major elements of a typical application are as follows:
49
Source: Kualiti Alam Sdn. Bhd.
Figure 2.8: Waste Management Flow Chart of Kualiti Alam Sdn. Bhd. Table
50
Table 2.8:
Types of Licence Application and Fees
Application Type
Processing
Application Fee
1
Application for new
licence
 Written permission
 Licence to operate
 RM 1,000
 RM 100
2
Application to renew
licence
 Renewal of licence
 Exceeding expiry date
 Late renewal
 RM 100
 RM 10,000 penalty
 RM 10 per day delay
3
Application to
transfer licence
 Transfer of licence
 RM 30
4
Application to amend
conditions of licence
 Amendment of
Licence Compliance
Schedule
 No processing fee
5
Application for
Contravention
Licence for Land
Disposal
 Contravention licence under  No processing fee
Section 24(1) for land
disposal applicable to local
Councils
Source: Environmental Quality Act., 1974.
Table 2.9:
Functional Issues to Address in Written Permission/Licence
Application
Functional issues
1. General Issues
1.1 Documents
1.2 Drawings
1.3 Design
1.4 General
Requirements
2. Operation and Maintenance
2.1 Waste identification
2.2 Operation
2.3 Maintenance
2.4 Safety procedures
2.5 Emergency
response plan
2.6 Pollution control
2.7 Record keeping
3. Monitoring
3.1 Monitoring plan
3.2 Sampling/testing
3.3 Record keeping
Source: Department of Environment, 2002.
Written
Permission




Inspection
Operating
Inspection
(once/twice
Licence
a year)























51
In general the approval conditions for Written Permissions and Operating
Licences should fulfill four criteria as follow, (i) necessary; (i) enforceable; (iii)
unambiguous; (iv) comprehensive (Department of Environment, Malaysia, 2002).
It must be equally recognized that well-operated waste management facilities
(especially for resource recovery) are to be encouraged to promote the effort towards
sustainable development, which actively benefits the environment. Therefore, in
preparing the approval conditions the Department of Environment always take into
conditions that the approval conditions must:

Be proportionate to the risks and costs
(e.g. not to insist on in-house resource recovery)

Reflect the underlying regulatory objectives
(e.g. to at least comply with regulatory limits)

Not impose unwarranted burden on those regulated
(e.g. not to impose high-tech cleaner technology)
Very often, many of the approval conditions will come from the supporting
data submission giving the description of facility design, operating plan and closure
plan ( Rosli Zul and Azhar Daud,1998). Other approval conditions to be included
must address the technical and procedural requirement to protect the environment
and health. They should include the:

Types and quantities of waste;

Technical requirements;

Safety and security precautions;

Reporting procedures.
For Malaysia, it should be noted that the Department of Environment since
1999 has recently introduced the following new compulsory approval conditions for
all facilities (Rosli Zul,1999):

Waste permitted, including quantities and specific waste generators

Waste Acceptance Criteria
52

Standard Operating Procedure (SOP)

Procedure and training in accident response

Waste disposal procedures

Control of ambient air quality

Records keeping

Copies of all information to be sent to State DOE
Thus, most approval conditions are generic in nature and the licence holder
are obligated to comply with the standard conditions imposed in operating the
specific waste management facility.
2.9
Inspection of Waste Management Facilities
According to the Department of Environment, Malaysia, inspections may be
carried out as part of standards procedures, e.g. Waste Management Facilities
licensing, but they may also are undertaken at random to ensure conformity with
legislation (Rosli Zul, 1999).
As could be expected:

The passage of time shown up deficiencies in operating practices and
possibly in the original licence conditions

Operators new to the field of waste management may experience
problems
In view of the above, as least on a yearly basis, the inspection the Waste
Management Facilities to be checked on compliances with the approval conditions
and the environmental regulations. This will, in any event, be required by virtue of
the licence renewal process (Rosli Zul and Azhar Daud, 1998).
2.9.1
Types of Inspection
There are a number of different of Waste Management Facilities inspection:
53

Inspection of Schedule of Compliance for Written Permission

Pre-Licence inspection

Annual inspection before renewal

Inspection when contravention of licence conditions is suspected
In Malaysia, when undertaking an inspection of the Waste Management
Facilities, normally following documentation are pre-assessed (Rosli Zul, 1999):

Written Permission Conditions

Licence Conditions

EIA Conditions

Set of Schedule Waste Regulations

Check list

Waste Acceptance Criteria

Standard Operating Procedure
The detailed inspection process for licenced waste management facility will
depend on the facility and Table 2.10 shows a generic checklist for waste
management facilities.
Each of the documents are carefully perused before the inspection and each
item contained are carefully inspected so as to ensure compliance (Department of
Environment, Malaysia, 2002).
2.10
Treatment and Disposal Methods for Scheduled Wastes
Treatment and disposal facilities together with treatment technologies are
therefore designed to change the character of waste thus rendering it less hazardous
or altering it into a more environmentally acceptable form. Despite this, treatment
only changes the form or state of the waste and one still left with fraction or residue
to dispose of (Wentz, C., 1995 and LaGrega, M. D. et. al, 2001).
54
Table 2.10: Inspection of Waste Management Facilities
CONDITION
General
 Process
 Housekeeping
 Personnel Safety
INSPECTION
 Current process
 Cleanliness
 Use of protective clothing
 Use of safety equipment:
- Eye wash solutions
- Fire Extinguishers
- Spill cleanup equipment
 Emergency Response Plan (ERP)  Emergency escape
 ERP - exist and be approved by DOSH
 ERP manual
Documentation
 Consignment notes
 Copies of all consignment notes
 Waste acceptance
 Waste Acceptance Criteria
 Operation Procedure
 Standard Operating Procedure
 Plant maintenance
 Plant maintenance register
 Accidents
 Accident register
 Storage
 Storage inspection records
 Availability
 Document accessibility
Waste handling
 Storage methods
 Conform with methods
 Segregation
 Incompatible wastes must be segregated
 Containers
 Good containers condition
 Labeling
 Labeling of waste code and danger
symbols
 Storage ventilation
 Ventilation
 Holding duration
 Inventory records - not exceed 180 days
Operation
 Waste acceptance
 Waste acceptance criteria
 Operating Procedures
 Standard Operating Procedure
 Specific conditions
 Licence conditions adherence
 Management supervision
 Level of supervision
Monitoring
 Air emissions
 House monitoring records conform with
licence conditions
 Ambient air
 House monitoring records
 Effluent
 House monitoring records conform with
licence conditions
 Noise
 House monitoring records conform with
licence conditions
Source: Modified from Department of Environment, 2002.
55
There are now several forms of treatment available, the main processes used
are often divided up into chemical, physical, thermal and biological. These
technologies are used for volume reduction, separation, detoxification, destruction,
and storage and material recovery.
Consequently, recovery and reuse are strongly preferred options over
treatment or disposal as accepted internationally of waste management hierarchy
approach (Government Institutes, Inc., 1987, Abbou, R., 1988 and Price, R.L., 1991).
The choice of treatment method will depend firstly on available methods and
secondly on environmental and economic considerations. The options are related to
the particular of hazardous substances in the waste such as:
 Composition of the waste
 Concentration of relevant substances
 Availability of appropriate recovery methods
 Value of the substances to be recovered
 Content of “other” hazardous substances.
According to United Nation, a material is recycled if it is used, reused, or
reclaimed (recovered). A material is “ reclaimed” if it is processed to recover a useful
product, including conversion into energy as fuel (Abbou, R., 1988) Recycling is the
concept of any utilization of hazardous waste for some applications, now or
traditional, one type of recycling is disintegrating the product or waste and mixing it
with primary raw materials in the production of new products of the same kind.
Another type of recycling, recovery or reclaiming, is the more complete
disintegration of the product or waste into bulk material, including elements (e.g.
metals), which can be traded or used in the origin production.
Table 2.11 and Figure 2.9 give a simplified overview of general recovery/
treatment options, for the main group of industrial wastes.
In Malaysia treatment and disposal facilities for schedule waste are regulated
by the Environmental Quality (Schedule Wastes) Regulations, 1989, together with
the subsequent orders and regulations.
56
Acids, Alkalis, reactive (3)



Solids containing metals/heavy
metals




Solution containing metals/heavy
metals




Inorganic sludge



“Inert” inorganic waste
Secure landfill
PCT (1)

Scheduled Wastes
Incineration (2)
Recovery
Solidification (2)
Table 2.11: Overview of Recovery/Treatment Option
Inorganic waste

Organic waste

Solvents



Oils



Pesticides


PCB, Chlorinated hydrocarbons


Organic sludge, resins, paints


Note:
1.
2.
3.
PCT (Physical/ Chemical treatment will often be followed by solidification).
The residues from the solidification process and incineration have at a secure landfill.
The acids can often be used in the neutralization of alkalis and vice versa.
In the Environmental Quality (Prescribed Premises). (Scheduled Waste
Treatment and Disposal Facilities) Order, 1989, the following scheduled wastes
treatment and disposal facilities are considered as prescribed premises:
 Off-site recovery facilities i.e. premises occupied or used for the
recovery material or product scheduled wastes which are not produced
on those premises.
57
WASTES
Low- concentration effluents,
wastewaters
Acids, alkalis
TREATMENT
DISPOSAL
Pretreatment
Neutralisation
Sewer
Reactive wastes
Toxic inorganic
Physical and / or chemical
Heavy metals
Solidification
Water
Landfill
Land
Nontoxic inorganic
Solvents, Oil
Resins, paints, organic
sludge
Recovery
Organic chemicals
Chemicals
Pesticides
Incineration
Chlorinated
Hydrocarbons
Biodegradable wastes
Air
Biological
Land, water
Source: Adapted from: Wentz, C., 1995.
Figure 2.9: Treatment and Disposal Alternatives for Industrial Wastes
58
 Off-site storage facilities i.e. premises occupied or used for the storage,
collection or transfer of schedule wastes which are not produced on
those premises.
 Off-site treatment facilities i.e. premises occupied or used for the
processing of schedule wastes which are not produced on those
promises.
 Schedule waste incinerators i.e. premises occupied or used for the
thermal destruction of scheduled wastes.
 Secure landfills i.e. premises occupied or used for the disposal of
scheduled waste on land
 Land treatment facilities i.e. premises used for the land treatment of
scheduled wastes.
According to Lee, Heng Keng, et. al, 2001, the Department of
Environment, Malaysia has outlined the minimum percentage of recoverable
components from scheduled wastes must in accordance to the Guidance
Document on Transboundary Movements of Hazardous Wastes Destined for
Recovery Operation as shown in Table 2.12.
Table 2.12: Recoverable Components from Scheduled Wastes
Types of Wastes
Metal Hydroxide Sludge
Spent Catalysts
Recoverable
Components
Copper (Cu)
Gold (Au)
Nickel (Ni)
Silver (Ag)
Zinc (Zn)
Chromium Oxide
Cobalt (Co)
Copper Compounds
Nickel Oxide
Nickel (Ni)
Palladium (Pd)
Platinum (Pt)
Zinc Oxide (ZnO)
Minimum Percentage
(dry weight basis)
10
0.05
5
2.5
20
10
20
10
10
8
1.0
0.2
10
The most commonly available technologies for the scheduled wastes are as
summarized in Table 2.13.
59
Table 2.13:
Treatment and Disposal Technologies for Scheduled Wastes
Technology
Resource Recovery
Treatment
Final Disposal
2.11
Process
Methodologies

Gravity separation

Coalescence separation

Filtration / ultra-filtration

Emulsion splitting

Air floatation
Solvent recovery

Distillation
Metal recovery

Precipitation of metals

Ion Exchange

Electrolytic cell
Physical Chemical

Neutralization
Solidification

Immobilization
Incineration

High temperature destruction
Land treatment

Biological degradation
Secure landfill

Burial with protection of groundwater
Oil recovery
Resource Recovery Technologies
As disposal of scheduled wastes gets more strictly regulated and more
expensive, the recovery of valuable materials from the wastes will become more
attractive. Economic will always be the driving force for an industry to choose
between resource recovery and their disposal (Government Institute Inc., 1987,
Duport, R., et. al, 2000 and Anil Markandya and Dale.N., 2001). The resource
recovery technologies considered are:
 Oil recovery processes
 Solvent recovery processes
 Metal recovery processes
The recovery facilities can be situated on-site as well as off-site; their
characteristics are described as follows:
60
2.11.1 Oil Recovery
A generalized method of oil recovery is not possible since oil can be present
in wastewater in one of three distinct forms and its form will directly affect the
method of recovery:
 Free oil
_
Easily rises to the surface and can be readily skimmed off
by any of several available mechanisms
 Emulsified oil
_
A bit difficult to remove unless the emulsion is first broken
 Dissolved oil
_
Removable biologically or by adsorption with activated
carbon
Basically, oil recovery consists of 2 or 3 stage. There is, however, a number
of processes to choose from in each step (La Grega, M.D., et. Al, 2001), as shown in
Table 2.14.
Table 2.14:
Step
1
Oil Recovery Processes
Examples of
Involvement
Activity
Pre-treatment
 Waste volume
reduction
 Removal of
impurities
 Emulsion splitting
2
Treatment

Oil water
separation
Typical Processes
 Settling
 Filtration
 Additional of emulsification
Chemicals
 Application of heat

Gravity separation

Coalescence separation

3
Refining
(Optional)

Purification
Ultra-filtration

Air floatation

Distillation Acid/clay
process
As mentioned earlier, the recovery process option to be depends on the form
of the wastes oil. The objective is to select the most appropriated process to segregate
the oil and water for the intended use the recovered oil (Price, R.L., 1991).
61
As such, the decision on the recovery process cannot be made without
knowing the:

Actual composition of the waste oil in terms of:

Oil droplet velocity (where applicable)

Oil Droplet size distribution

Emulsified state

Concentration of oil on the wastewater

Recovery processes available for waste oil

Cost of using the different process for actual waste oil quality

Utilization of the recovered oil.
The options of the treatment and recovery of waste oil are presented in Figure
2.10.
Option 1
Option 2
Treatment
(Oil water separation)
Pre-Treatment
Refining
(Distillation)
Option 3
Reuse for original
purpose
Reuse fuel
supplement
Option 4
Source: Adapted from Department of Environment, 2002.
Figure 2.10: Treatment and Recovery of Waste Oil
Refining waste oil by distillation produces either a product that can be reused
for the original purpose or waste oil with low content of impurities suitable for
burning in a combustion plant for energy production. However, it is noteworthy that
distilling waste oil can also give rise to:
62

A wastewater fraction which has to be treated before discharge e.g. by
ultra-filtration.

A distillation residue, which will require final treatment/destruction at
Kualiti Alam .
2.11.2 Recovery Methodologies
The different technologies used in the recovery of waste oil are briefly
described below.
(a)
Gravity Separation of Oil and Water
Gravity separation of oil and water/particulate matter is the simplest process
used in recovery of waste oil. It is a passive process that utilizes the principle of the
difference in specific gravity between oil and water.
In simple terms, the wastewater is allowed to collect and settle in a vessel.
The vessels used for gravity separation are either the API (American Petroleum
Institute) Separators or the Parallel Plate Interceptors (PPI).
The free oil, being lighter than water, rises to the surface. Once the oil-water
separation is completed, the top oil layers are separated from the surface to an oil
recovery tank using a belt on rope-skimmed facility or by pumping. The API
separator is designed to remove oil droplets down to 150 microns in size. However,
the resultant effluent has typically an oil concentration greater than 100 ppm.
Further, API separators are ineffective in treating emulsions. (Department of Natural
Resources, King Country, Washington, October 1995 adapted from Department of
Environment, Malaysia, 2002).
(b)
Coalescence Separation
A coalescing separator unit can handle the separation of non-emulsified oil.
The separator has special elements with oleophilic and oleophobic properties.
63
Usually, a substance that is oleophilic will also be hydrophobic. Similarly,
oleophobic substances are also hydrophilic.
When oily water hits the knitted mesh surface of the coalescer elements, oil
droplets in the water will spread out and be adsorbed onto the oleophilic surface of
the elements. Similarly, the water portion wills be adsorbed onto the oleophobic
surface of the elements. When more incoming oil and water droplets accumulate on
these two surfaces and grow, larger droplets are formed. These larger droplets then
migrate from one area of the elements to another. This migrating motion gradually
accomplishes the coalescing effect, resulting in a hundred fold increase in liquid drop
diameter, this in turn accelerates the oil/water separation. As a result of the
coalescence effect, only large drops of oil emerge at the outlet.
The coalescing plate interceptor (CPI) separator is typically designed to
remove droplets down to 60 microns. They can attain effluent concentrations down
to 10 to 20 ppm but are ineffective in treating emulsions. (Department of Natural
Resources, King Country, Washington, October 1995; adapted from Department of
Environment, Malaysia, 2002).
(c)
Emulsion Splitting
Emulsion splitting is the best solution for removing emulsified oil. It is
usually brought about by a pH change through the addition of chemicals such as lime
or polyelectrolytes. Lime was the chemical of choice some years ago with
polyelectrolytes no more popular because less sludge is produced using it. The
applications of heat can also assist in splitting emulsions.
The optimum chemical does and an optimum wastewater pH to be
considered. Too little or too much chemical dosage can markedly affect separated
from the water. For this, the air floatation method is usually applied.
(d)
Air Floatation
Air floatation is used to separate low-density solids and hydrocarbon solids
from liquids by air floatation. Air is introduces into the waste liquid in the form of
64
micro bubbles, which attach to the free oil (and suspended particles) to be removed.
With a specific gravity less than water, the bubble-attached oil rises to the surface.
Mechanical skimmers then remove the floating particles from the floatation unit
while the liquid is withdrawn from the bottom.
The air floatation system is capable of removing droplets down to 5 microns.
They are usually used for secondary treatment producing an effluent having 1 to 25
ppm oil. Floatation systems can remove unstable emulsion. (Department of Natural
Recourses, King Country, Washington, October 1995; adapted from Department of
Environment, Malaysia, 2002).
(e)
Ultra Filtration
Ultra- filtration is an alternative method for the treatment of emulsified oil. In
this process, oil-contaminated wastewater is pumped through a membrane. Under
applied static pressure, the ultra-filtration membrane allows the passage of water and
most of the dissolved substances (chlorides, sulphates etc) while large molecules
(emulsified oil being one of them) are retained. Ultra-filtration can be operated as
batch, single-stage continuous or multi stage operation
(f)
Distillation
In the distillation process the waste oil is separated into fractions depending
on their individual boiling-points wherein the compounds with low boiling- points
are first distilled off and so on. When the light and the heavier fractions are distilled
off, a distillation residue- a kind of tarry material- remains in the plant. The residue is
considered as scheduled waste and has to be treated at Kualiti Alam.
(g)
Acid/clay Process
Another process for refining that is sometimes used is the acid/clay process,
when concentrated sulphuric acid and diatomataceous earth is used to remove water
and other impurities. It should be noted that this process produces a very hazardous
65
acid tar waste by-product, which is extremely difficult to treat or dispose of.
Consequently, its use should be discouraged.
2.11.3 Use Recovered Oil and /or Waste Oil
(a)
As a fuel
The uses of recovered oil and / or waste oil as supplementary fuel deserve
special mention. Both are often used as fuel in combustion plants or brick kilns,
replacing fresh fuel oil. However, the quality of some recovered oil and waste oil
may contain contaminants depending on the recovery method and the source of the
oil. Burning of waste oil of low quality usually results in air emissions above the
acceptable level, unless suitable emission controls are in place- such as at Kualiti
Alam, where they could be used as a replacement for fresh fuel, if the price levels
were attractive.
Currently, no quality requirement exists in Malaysia for the recovered oil
and/or waste oil used as supplementary fuel in combustion plants. Unlike in
Denmark, if the recovered oil or waste is not up to specifications, it may need to be
distilled before it can be used as a supplementary oil (Ministry Environment and
Energy, Denmark, 1977)
An alternative is to blend waste oils, possibly together with non-halogenated
solvents and other high calorific value wastes to form fuel of relatively constant
specification. This can then be used as fuel of somewhat higher quality- for example
in cement kilns. These are particularly attractive because they offer a higher
temperature and a longer residence time than a hazardous waste incinerator and
combust in alkaline conditions, thus removing harmful acid gases. Air emissions
from the kiln when using waste oil tend to be similar or even better than when they
use normal fresh fuel.
66
(b)
Other Uses
Waste oils may also be used as a timber preservative or may be converted
into low-grade grease or lubricant.
2.12
Solvent Recovery
Solvents are used in almost every industry to some extent. In the chemical
industry for example, they are materials and to increase the efficiency of the reaction
(Freeman, H.M.,1995). The rate of a reaction is dependent on the free energy of
activation, Go, which is the difference between the energy of reactions and the
transition state (Bishop. P.L., 2000). As such, the rate of reaction can be altered by
proper selection of the solvent used.
Most solvent used in organic chemical synthesis have been organic
compounds; the most commonly used solvents are volatile organics, such as
alcohols, chlorinated hydrocarbon, arenas, and nitriles, which cause many problem in
the environment.
The main technology used in the recovery of solvent is distillation. The
feasibility and extent of recovery are governed largely by the quantity involved and
the complexity of solvent mixtures to be separated (Freeman H.M., 1995).
In addition, however, some paint solvents, mainly white spirit, are recovered
for the making of low-grade paints in Malaysia. The waste types suitable for the
technology are organic solvents, such as:

White spirit

Methanol

Iso-propyl alcohol (IPA)

Acetone

Methyl ethyl ketone (MEK)

Dimethyl formamide (DMF)

Trichlorethylene (TCE)
67
2.12.1 Solvent Recovery Methodologies
Ideally, the various solvents used in the different processes should first be
segregated and then recovered separately. Center for Hazardous Materials Research,
University of Pittsburgh (1991), outlines, the main solvent recycling and
minimization techniques are:

Distillation
Separation techniques that rely on boiling point differences between
the components of a liquid waste;

Solids Removal
Elimination of suspended particles to reduce fouling;

Emulsion or Dispersion Breaking
Separation of solvent or oil droplets in water, or of water droplets in
oil;

Dissolved and emulsified organic recovery
Organic separations techniques that concentrate the organics so they
can be recovered.
There are numerous manufacturing of solvent recovery equipment in a
variety of sizes. The smallest of these units recover solvents having a boiling point at
160oC or less. The waste solvent is recovered in batches, although clean solvent can
be drawn of during operation. Recovery levels range from 80 to 95 percent,
depending on the amount and type of contamination.
Other separation technologies used by solvent processors include filtration,
simple evaporation centrifugation and stripping (La Grega, M.D. et.al, 2001).
2.13 Metal Recovery
There are a number of different processes for the treatment of waste
containing metals, depending on the source of the waste and the objective of the
treatment. Typical processes are:
68

Precipitation of metals

Ion exchange

Electrolytic cell

Re-melting
The first two technologies are pre-treatment steps to be followed by the metal
recovery activities. The electrolytic method results in the direct recovery of the
metals. The waste types suitable for the technology are as shown in Table 2.15.
Table 2.15:
Metal Recovery
Recovery Process
Waste Types
Metal Recovery
Metal precipitation
Electroplating wastes
Chromium
Ion Exchange
Electroplating wastes
Chromium, Copper etc
Electrolytic recovery
Photo-finishing wastes
Silver
Electronic wastes
Precious metals
Solder dross
Solder
Re-melting
2.13.1 Metal Recovery Methodologies
(a)
Metal Precipitation.
There are basically three metal precipitation methods, namely:
-
Precipitation by chemical reduction (using a reducing agent)
-
Precipitation by alkali/hydroxide and
-
Precipitation by sulphide
A brief description of each of these methods is described below:

Alkali/Hydroxide Precipitation
Optimum precipitation of solid metal hydroxide is achieved by adjusting the
pH the wastewater to the usually moderate alkaline range. This accomplished
by measured addition of lime or caustic soda to the wastewater with
concurrent pH monitoring.
69
The precipitated metal hydroxides are coagulated (using coagulating agents)
in a clarifier and deposited as sludge. Proper clarifier design and good coagulation
are important for efficient metals removal. It must be mentioned that this method is
subject to interference when mixed wastes are treated.

Sulphide Precipitation
In this process, heavy metals are precipitated as a sulphide precipitate.
Sulphide is added to the waste solution with the pH maintained within a
narrow pH range above eight (8). The sulphide normally used is:
-
Either a soluble suphide such as sodium sulphide, calcium
polysulphide, sodium hydrosulphide
-
Or the less soluble ferrous sulphide (as powder or slurry form)
Careful management of this type of precipitation is important. Usually, an
automatic controller adds the sulphide as pH control is critical. A well-operated
sulphide precipitation system can remove most of the metals from the wastewater.
The disadvantage of the soluble sulphide method is that in the presence of
excess sulphide, some hydrogen sulphide gas can be produced, which is extremely
toxic.
(b)
The Ion Exchange Technique
Example of the off-site recovery facility of chemical waste:

Ion exchange cartridges are installed at the electroplating factory to
absorb the heavy metals from the drag-out/rinse waste system into the ion
exchanges resins. Most of the metals ions are absorbed as monometallic
ions. In other words, these ion-specific cartridges absorb only copper or
only zinc or only chromium ions.

The “loaded” ion exchanges cartridges are collected for regeneration at
the off-site facility. Regeneration releases the heavy metals into the
washing liquor. The heavy metals are then recovered from the washing
liquor using the electro-winning process.
70

In the electro-winning process, an electric field is applied between two
electrodes immersed in an electrolyte, the positive metal ions are drawn to
and deposited at the cathode.

The deposited metal, which has a purity of 99%, is removed for re-use.
The type of metallic ions which the ion exchanges facility can handle are
chromium (VI), copper, lead, nickel, tin, silver, zinc and cyanide.
(c)
Electrolytic Metal Recovery (EMR)
The waste types suitable for the technology are mainly waste from the metal
finishing industry (Electroplaters, rolling mills, printed circuit board manufacturers
and metal coating firms). The following are examples of electrolytic metal recovery.

Chromium Recovery
An EMR unit is usually positioned at the rinse tank immediately downstream
of the plating tank to capture the bulk of the drag-out. Solution from the rinse tank is
made to circulate through an electrolytic cell.
In the electrolytic cell, a direct current is passed through the metal bearing
solution. Element metal is deposited on the cathode while oxygen is evolved at the
anode. Metal deposition is allowed to build up to a thickness of about one-half inch.
The power is then shut off and the deposited metal is removed from the cathode.
Most electrolytic cells, under favorable, can recover 99% of the dissolved metal from
the drag-out/rinse solutions.
The chief hurdle to EMR is the cost of power required to deposit metal from
low concentration solutions. However, this is increasingly offset by the rising cost of
the primary metals recovered.

Silver Recovery
In the electrolytic silver recovery, the silver-bearing solution is passed
between two electrodes through which a controlled direct electric current flows.
Silver plates out on the cathode as almost pure metal. Considerable agitation and
large plating surface areas are necessary to achieve good plating efficiency and high
71
quality silver up to 96-98 percent purity. The cathodes are removed periodically and
the silver is stripped off.

Electronic Wastes
Electronic wastes contain precious metals, in particular gold and platinum.
These may also be recovered by electrolytic means.
(d)
Re-melting
Re-melting is used for the recovery of solder dross. This technology for
recovering metals can grouped as pyrometallurgical (La Grega, M.D., et.al. , 2001).
Pyrometallurgy uses the differences in melting and boiling properties to separate
metals at high temperature. Roasting or smelting typically provides the heat. It is a
simple process and is used extensively in Malaysia (Department of Environment,
2002).