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21Pollution Prevention
J. Paul ChenNational University of Singapore, Singapore
Thomas T. ShenIndependent Environmental Advisor, Delmar, New York, U.S.A
Yung-Tse HungCleveland State UniversityCleveland, Ohio, U.S.A.
Lawrence K. WangZorex Corporation, Newtonville, New York, U.S.A. andLenox Institute of Water Technology, Lenox, Massachusetts, U.S.A.
21.1 INTRODUCTION
We are witnessing the evolution of a fully industrialized world, with global industrial
production, global markets, global telecommunication, global transportation, and global
prosperity. This prospect brings with it the realization that current patterns of industrialization
will not be adequate to sustain environmentally safe growth and therefore needs drastic
improvement. What is urgently needed is a total management systems approach to modern
civilization by focusing on pollution prevention activities as the first step.
In the past, pollution control by media-specific control technologies has improved
environmental quality to a certain extent. Generally, however, it not only fails to eliminate
pollutants, but waste treatment processes have produced a large amount of sludge and residue
that require further treatment prior to disposal so that they will not create secondary pollution.
Waste treatment systems require investment in design, installation, operation, and maintenance,
but these systems contribute no financial benefit to the industrial production. Pollution control
technologies may also transfer pollutants from one environmental medium (air, water, or land) to
another, causing potential secondary pollution problems that require further treatment and
disposal. Pollution control technologies addressed only short-term problems, rather than
eliminate pollutants. Costs of pollution control, cleanup, and liability have risen every year, as
have the costs of resource inputs, energy, and raw materials. Through many years of research, we
are beginning to understand the complexities of pollution management problems [1–10].
Some professionals still believe that pollution control via end-of-pipe strategies, such as a
wastewater treatment plant, flue gas cleaning system, land disposal, or incineration can solve
pollution problems. This is because such equipment or systems limit the release of harmful
pollutants compared to uncontrolled discharge into the environment. As with pain-relieving
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medication, pollution control methods attempt, although imperfectly, to minimize the effect of
releasing pollutants into the environment. Some releases and effects are curtailed, but the
original toxic or environmentally harmful pollutants and products remain behind or are
transformed into different hazardous substances to some degree.
It is important to realize that pollution prevention applies beyond industrial sectors to a
variety of economic sectors and institutional settings. Many organizations and institutions can
apply pollution prevention concepts, which not only reduce generation of pollutants and wastes,
but also minimize use of certain environmentally harmful products and services. In practice,
pollution prevention approaches can be applied to all pollution-generating activities, including
energy production and consumption, transportation, agriculture, construction, land use, city
planning, government activities, and consumer behavior.
Economics plays an increasingly important role in environmental decision making. The
resolution of virtually every environmental issue involves an economic component.
Traditionally, most industry and business decision makers who invested in control technologies
such as waste treatment and disposal facilities considered these nonproductive, because such
added costs to production would be hard to recover. Product prices could be increased to offset
these costs, but this was not an option in a competitive market. Such perspectives seemed valid
in the past because decision makers did not know the various benefits of pollution prevention
that will be described later in this chapter.
Accepting the primacy of pollution management strategy and preventive technologies
does not mean abandoning traditional waste management strategy and pollution control
technologies or the government regulatory and legal systems designed to ensure their
implementation. In fact, not all waste and pollution can be eliminated or prevented, either
immediately or in the long run. The remaining waste that cannot be prevented needs to be
adequately treated and disposed of. What is absolutely crucial, however, is to recognize the
importance of pollution prevention in the hierarchy of environmental options [1].
This chapter highlights the concept and applications of pollution prevention, focusing on
the expanding environmental problems from municipal and industrial wastes to toxic chemicals,
hazardous products and services, as well as the pollution management challenges to search for
new cost-effective technologies such as pollution prevention (P2). Discussions include P2 laws
and regulations, project feasibility analyses, implementation, as well as systematic examination
of industrial P2. The purpose is to provide readers with a better understanding of pollution
sources and pollution prevention. While subtopics may not necessarily be covered in depth,
references can provide additional P2 knowledge and information.
21.2 TRADITIONAL MANAGEMENT OF POLLUTANTSAND WASTEWATER
The demand for fresh water rises continuously as the world’s population grows. From 1940 to
1990, withdrawals of fresh water from rivers, lakes, reservoirs, and other water sources increased
about fourfold. Water is used for various purposes. In the United States, irrigation, electric
power generation, and other utilities respectively consume 39, 39, and 12% of water; industry
and mining uses 7%, and the rest is used for agricultural livestock and commercial purposes.
Table 1 gives a list of major parameters that have great environmental impacts.
Wastewater contains mainly human sewage, industrial wastewater, and agricultural
chemicals such as fertilizers and pesticides. According to the US Environmental Protection
Agency (USEPA), some 37% of lakes and estuaries, and 36% of rivers are too polluted for basic
uses such as fishing or swimming during all or part of the year [2]. In developing nations, more
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than 95% of untreated urban sewage is discharged into rivers and bays, which can result in a
serious human health hazard. For example, in China, the fastest developing country in the last 20
years, overall municipal wastewater treatment is still less than 5%.
Industrial processes of all types almost invariably produce wastes having numerous
sources, forms, and names. For example, wastewater in a petroleum refinery is generated by
units when water is contacted with process materials in desalting, stream stripping, and washing
operations throughout the refinery processes. In addition, wastewater can be generated by utility
systems, from boiler feedwater treatment processes, boiler blowdown, and cooling tower
blowdown. The strength and quantity of the wastewater is dependent on the design and operation
of the processes.
Until the middle of the 20th century, industrial wastes were considered only a casual
nuisance and were handled as such by generators. Industrial plants of the time disposed of most
wastes by burial in landfills, discharge into seepage basins, or by pumping directly to a body of
water or into a deep well. Refinements were added over the years; for example, much waste was
drummed and the containerized waste sent for offsite disposal. However, little if any thought was
given to the fact that these wastes, once generated, ultimately ended up being released to the
environment unless they were destroyed by treatment.
Industrial waste generators have been made increasingly aware of the nature of their
wastes and the problems that waste disposal imposes on our environment. Spurred by mandates
from the USEPA as well as by their own sense of corporate responsibility, industries addressed
air pollution emissions, wastewater discharges, industrial hygiene/worker safety, and a variety
of related issues. With rare exception, however, the actual generation of wastes was never
questioned.
New information regarding industrial wastes was developed and complementary federal
regulations required industries to reexamine the overall concept of waste generation. First, it was
determined that many chemicals present in industrial wastes exerted a permanent deleterious
effect on human health. In fact, exposure to some chemicals can alter human genetic material so
that the effects of exposure are passed on to future generations.
Secondly, industrial wastes that are not properly treated and disposed of will ultimately
release that constituents to the environment. For example, wastes disposed of in landfills may
release constituents to subsurface aquifers that serve as drinking water supplies.
Thirdly, testing methods have been developed to evaluate whether an industrial waste
contains any constituents of concern to human health or the environment. Furthermore, the tests
determine whether and at what rate a waste will release constituents into the environment.
Table 1 Typical Parameters in Wastewater
Item Name
Physical parameters Color; conductivity; settleable solids; suspended solids; temperature;
turbidity
Chemical parameters pH; alkalinity or acidity; arsenic; hardness; biochemical oxygen demand
(BOD); chemical oxygen demand (COD); total organic carbon (TOC);
aluminum; cadmium; calcium; hexavalent chromium; total chromium;
copper; iron; lead; magnesium; manganese; mercury; nickel; zinc; total
phosphate; ammonium nitrate; total nitrogen; cyanide; oil and grease
pesticides; fluoride; sulfate; phenol; surfactants; chlorinated
hydrocarbons
Biological parameters Coliform bacteria; fecal streptococci bacteria
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Wastes that contain any of an extensive list of hazardous constituents or that exhibit a hazard
characteristic or that are generated by certain industrial processes are referred to as hazardous
wastes under the Resource Conservation and Recovery Act (RCRA). About 400 million metric
tons of hazardous wastes are generated each year. The United States alone produces about 250
million metric tons; 70% comes from the chemical industry. The treatment, storage, and disposal
of these wastes are now governed by strict regulations.
Wastewater treatment and disposal for industrial residues have assumed growing
importance. In particular, those wastes defined as RCRA-hazardous require meticulous attention
to treatment and ultimate disposal. During the late 1980s, federal regulations were enacted
eliminating any form of land disposal for a variety of hazardous wastes, thereby making
imperative the treatment of these wastes to render them nonhazardous.
21.3 POLLUTION PREVENTION: MOTIVATION AND CONCEPT
21.3.1 Motivation
According to Webster’s Dictionary, the environment is the complex of climatic, economic, and
biotic factors that act upon an organism or an ecological community and ultimately determine its
form and survival. It is the aggregate of social and cultural conditions that influence the life of an
individual or human behavior such as production and consumption.
Environmental pollution is formed as a result of inefficiencies in manufacturing processes,
both operational practices and improperly designed and utilized equipment. Pollutants can be
unused raw materials, on byproducts resulting from production processes. Pollution represents a
loss in profits during manufacturing. It also can be a result of careless human activities in social
developments. Releasing pollutants and wastes into the environment creates pollution.
Environmental pollution from human activities is never avoidable.
End-of-pipe measures include wastewater treatment, hazardous waste incineration,
landfills, and monitoring equipment. They have been used in environmental protection for many
years and act as an important component in the P2 in environmental protection. In the last 20
years, however, many environmental accidents, complaints, and concerns have pressured
industries to shift from the traditional end-of-pipe approaches to sound pollution prevention
strategies.
Public concern about the environment continues to grow. Public education through various
media, such as school, television, and the Internet, has become powerful tools for spreading
information about the environment and its impact on human health. Protection of the
environment increasingly becomes a social responsibility. With increasing understanding of
pollutants and their long-term consequences in the environment, some pollutants that were
considered less harmful become more important. Dioxin is a good example. Pollution is no
longer a site-specific problem; it has become a global issue. For example, mercury has
been detected in deep-sea animals (e.g., salmon), which are not supposed to be exposed to
polluted environments. The mercury accumulation in the animals is a result of its transport in
seawater.
Pollution means loss of raw materials and production of wastes (which are also
byproducts). These activities can definitely cause a loss in profits. In addition, pollution created
in the workplace can pose either high or low risks to workers, and faces the public most of the
time. For example, an improperly operated swine farm can cause water pollution as well as
unpleasant odors. The property value in industrial estates can be depreciated and the image of
companies deteriorate.
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21.3.2 Principles of Environmental Pollution
Socioeconomic development is necessary for meeting people’s basic needs of food, clothing,
transportation, and shelter, and also to improve living standards; however, such development
must be sustainable. That means development should be balanced with the environment.
Environmental laws and regulations have focused on media-specific, end-of-pipe, and
commend-and-control of pollutants and wastes. Such pollution control technologies have
reduced pollution to a certain extent, but are not cost-effective and need to be upgraded to
pollution prevention whenever possible. With that recognition, Shen [3] has addressed
environmental pollution from a practical point of view by outlining three principles of
environmental pollution, which are comparable to some of the thermodynamic laws familiar to
most engineers and scientists. Table 2 gives these three important principles of environmental
pollution.
21.3.3 Concept
Environmental practitioners in various organizations define P2 based on their own
understanding and applications, resulting in somewhat different interpretations. Essentially, it
means to prevent or reduce the sources of pollution before problems occur [1]. It is generally
contrasted with the media-specific and end-of-pipe control approaches. The difference between
pollution prevention and pollution control can be illustrated by the following instances. Vaccines
prevent illnesses, while antibiotics control illnesses; seat belts prevent injury, while casts and
crutches help cure injury from car accidents. The P2 concept and practices find broad
applications such as waste minimization, clean production, green chemistry, green product,
waste utilization, ISO 14000, and a number of other related terminologies.
Table 2 Shen’s Three Principles of Environmental Pollution
Principle Description
Pollution from
human activities
is unavoidable
Pollution is created by releasing pollutants and wastes into the environment as well
as by producing certain environmentally harmful products and services as a result of
careless human activities related to social and economic development.
Prevent pollution
whenever possible
As a result of the first law, pollution needs to be cost-effectively managed. Pollution
can be prevented or minimized, but may not be completely eliminated. The
remaining residual pollution from human activities must be properly treated and
disposed in order to protect human health and the environment.
Minimal pollution
is acceptable
Ecosystems can safely handle and assimilate certain amounts of pollution. If
pollution is within the environmental quality standards, its impacts to human health
and the environment can be acceptable. We must work within the confines of the
natural laws to prevent pollution problems in a new planned and economically
feasible fashion.
Note. Human activities cover production, distribution, transport, storage, mining, urban development, construction,
consumption, and services. The word products can be industrial, agricultural, mineral, structural, commercial, and others.
The word services can be conceptual, technical, and physical such as professional and nonprofessional, government and
nongovernment services, including design, plan, operation, construction, transportation systems, repair, maintenance,
education and training, management, and others.
Source: Ref. 1.
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According to the Pollution Prevention Act of 1990 and other related regulations, the
United States defines pollution prevention as follows [4]:
. Reduction of the amount of any hazardous substance, pollutant, or contaminant
reentering any waste stream or otherwise released into the environment prior to
recycling, treatment, and disposal.
. Reduction of the hazards to public health and the environment associated with the
release of such substances, pollutants, or contaminants.
. Reduction or elimination of the creation of pollutants through (a) increased efficiency
in the use of raw materials; or (b) protection of natural resources by conservation.
The Canadian Ministry of Environment defines pollution prevention as any action that
reduces or eliminates the creation of pollutants or wastes at the source, achieved through
activities that promote, encourage, or require changes in the basic behavioral patterns of
industrial, commercial, and institutional generators or individuals.
Traditionally, pollution prevention was defined more narrowly as waste reduction or toxic
material cutback at sources, focused on waste releases from existing manufacturing operations.
Releases of waste from production operations, including those from stacks, vents, and outfalls
(called point sources) and those from leaks, open vats, paint areas, and other nonconfined
sources (called fugitive emissions) are often the major sources of pollution. Certain products,
while leaving the manufacturing plant for distribution through transport, storage, consumption,
as well as used-product disposal can cause serious environmental pollution problems, such as
hazardous waste treatment, disposal, and remedial sites.
The definition of P2 needs to be updated as our knowledge increases. It should mean a
broader sense of minimizing or eliminating the sources of the pollution from every place where
they are created in industry, agriculture, commercial establishments, government and
nongovernment organizations, and homes. It seeks not only to eliminate or reduce pollutants
and wastes, but also certain harmful products and services. It optimizes total materials cycle
from virgin material, to finished material, to components, to product, to obsolete product, to
ultimate disposal, and also to various technical and nontechnical services. Pollution prevention
includes practices that reduce or eliminate the creation of pollutants through increased efficiency
in the use of raw materials, energy, water, or other resources, or protection of natural resources
by conservation. In practice, pollution prevention approaches can be applied not only to
industrial sectors, but all sectors of our society, including energy production and consump-
tion, construction, transport, land use, city planning, government activities, and consumer
behavior [5].
21.3.4 Industrial Pollution Prevention
Industrial operations traditionally have adopted a variety of media-specific waste management
techniques to control releases of pollutants and wastes. Most environmental legislation in the
past had little economic incentive for industries to properly manage their wastes and
manufacture green products. P2 is a relatively new pollution management strategy that involves
prevention of pollutant and waste as well as promotion of environmentally friendly products and
services. As mentioned in Section 21.3.2, pollution should be prevented whenever possible –
from product design, production, distribution, and consumption activities. In the event that waste
may not be completely prevented, the remaining residual waste from the manufacturing facilities
should then be properly treated and disposed in a safe way.
Pollution prevention is the logical extension of pollution control. Environmental
management strategies are gradually being transformed as more professionals adopt the
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pollution prevention concept. It should be emphasized that there are many sources of
environmental pollution. Industry is only one sector of pollution sources and surely it is the
major one because of waste quantity and toxicity. Other pollution sectors include agriculture,
commerce, mining, transport, energy, construction, and consumption. P2 technology in the
energy sector, for example, can reduce environmental damages from extraction, processing,
transport, and combustion of fuels. Its activities include: (a) increasing efficiency in energy use;
(b) substituting fossil fuels by renewable energies; and (c) design changes that reduce the
demand for energy [2]. More detailed P2 methods and technologies used in the industrial sector
are described in Sections 21.4 and 21.7.
21.4 P2 TECHNOLOGIES AND BENEFITS
21.4.1 P2 Technologies
Today’s rapidly changing technologies, industrial processes, and products may generate
pollutants that, if improperly managed, could threaten public health and the environment. Many
pollutants, when mixed, can produce hazards through heat generation, fire, explosion, or release
of toxic substances.Toprevent thesehazards, pollutiongeneratorsmust be required todescribe and
characterize their pollutants accurately, by including information as to the type and the nature of
the pollutants, chemical compositions, hazardous properties, and special handling instructions.
In practice, preventive technologies not only reduce the generation of waste materials, but
also encourage environmentally friendly products and services. It can be applied also to all
pollution-generating activities, including energy production and consumption, transportation,
agriculture, construction, land use, city planning, government activities, and consumer behavior.
In the energy sector, for example, pollution management can reduce environmental damages
from extraction, processing, transport, and combustion of fuels. Major preventive technologies
applied in industrial processes are described in Section 21.8.
Pollution prevention is receiving widespread emphasis internationally within multi-
national organizations and within individual countries. The driving force behind the emphasis is
the concept of sustainable development and the hold that this concept has over planning
strategies and long-term solutions to global limits and north–south economic issues. Examples
of some pollution prevention technologies are:
. Raw material substitution – eliminating or reducing a hazardous constituent used
either in the product or during manufacture of the product.
. End product substitution – producing a different product that accomplishes the same
function with less pollution than the original product.
. Process modification – changing the process design to reduce waste generation.
. Equipment redesign – changing the physical design of equipment to reduce waste
generation.
. Direct recycling – reusing materials directly in the manufacturing process without
prior treatment. These materials would otherwise become wastes.
. Good housekeeping – instituting new procedures, such as preventive maintenance, to
reduce waste generation.
. Inventory control – minimizing the quantities of raw materials or manufactured
product in stock, to eliminate surplus that could become waste when the product is
changed or discontinued [2].
In the energy sector, for example, pollution prevention can reduce environmental damage
from extraction, processing, transport, and combustion of fuels. Pollution prevention
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technologies include: (a) increasing efficiency in energy use; (b) substituting fossil fuels by
renewable energies; and (c) design changes that reduce the demand for energy. During the past
few years, considerable progress and success have been achieved in attaining pollution
prevention in various sectors of our society.
21.4.2 P2 Benefits
The most important benefit of P2 is that it can achieve national environmental goals while
coinciding with the industry’s interests [6]. Businesses will have strong economic incentives to
reduce the toxicity and volume of the waste they generate. Some reported benefits of P2
practices are that it can:
. avoid inadvertent transfer of pollutants across media by treatment and disposal
systems;
. reduce the risks from any release of pollutants and wastes into the environment;
. protect natural resources for future generations;
. save money by preventing excessive use of raw material, energy, and natural
resources;
. reduce costs of regulatory violations and costs for waste treatment and disposal;
. avoid long-term potential liabilities associated with releases of wastes and disposal
sites;
. increase production efficiency and company reputation;
. improve product quality for world trade market competition.
With P2, some wastes can be reused as raw materials. Waste reduction means increasing
production efficiency and generating more profits. Reducing wastes also provides upstream
benefits because it reduces ecological damage from raw material extraction and pollutant release
during the production process as well as waste recycling, treatment, and disposal operations. A
company with effective, ongoing P2 plans may well be the lowest-cost producer and enjoy
significant benefits in a competitive world market as a result. Costs per unit produced will drop
as P2 measures reduce liability risks and operating costs. Cost savings from prevention come not
only from avoiding environmental costs such as hazardous waste disposal fees, but also from
avoiding costs that are often more challenging to count, such as those resulting from injuries to
workers and ensuing losses in productivity. In that sense, prevention is not only an
environmental activity, but also a tool to promote workers’ health and safety. Furthermore, P2
activities may enhance the company’s public image, public health, and public relations. Among
all the benefits, the economic benefits of P2 have proven to be the most compelling argument for
industry and business to undertake prevention projects [7].
Many successful P2 cases are available in the literature (Table 3) [8–13]. The P2 program
in the USEPA website (www.epa.gov) provides a series of good examples. A study was carried
out by Bendavid-Val et al. [9] to compare the cost saving from the adoption of the P2. It can be
seen from Table 3 that the nine randomly selected plants had different savings ranging from 0 to
100%. Among them, four plants had a saving of 100%. Another example is the dramatic
reduction of the wastes from the pulp and paper processing industry [10]. It was reported that,
through the implementation of P2 programs, the industry has witnessed the reduction of its
biochemical oxygen demand (BOD) and total suspended solids (TSS) by 75 and 45%,
respectively, from 1975 to 1988. The US paper recovery rate increased from 22.4% in 1970 to
45.2% in 1997. Other items, such as emissions of total reduced sulfur, SO2, and ClO2, were also
reduced significantly.
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The benefits from the P2 exercises based on long-term evaluation are obvious; however,
their short-term advantages may not be significant. Sometimes implementation of P2 may even
cause a negative impact on industrial performances. Sarkis and Cordeiro [11] carried out an
empirical evaluation of environmental efficiencies (by end-of-pipe or P2 approaches) and US
corporate financial performance. Interestingly, they found that there was a negative correlation
between the above two performances. The negative relationship became more obvious when P2
was implemented. The corporate greening could cause depreciation of stock values. However,
higher pollution levels can negatively affect a firm’s market values. Therefore, a sound balance
must be carefully maintained.
21.5. P2 LAWS AND REGULATIONS
21.5.1 Federal Regulations and Laws
In the United States, Congress enacted the Clean Water Act (CWA) of 1972 to achieve a goal of
“fishable and swimmable” surface waters. It covers regulations of wastewater discharges [12].
Most industries must meet discharge standards for various pollutants. Specific methods of
control such as pollution prevention are not specified. Many facilities use pollution prevention as
a means of reducing the cost of compliance with federal regulations. State and local authorities
also have responsibilities to implement the provisions of the CWA. These authorities must
enforce the federal guidelines at a minimum, but may choose to enforce more stringent
requirements. Some localities include pollution prevention planning requirements into discharge
permits [12].
The Emergency Planning and Community Right-to-Know Act (EPCRA, also known as
SARA Title III) requires certain companies to submit an annual report of the amount of listed
“toxic chemicals” entering the environments. Source reduction and waste management
information must be provided for the listed toxic chemicals.
The Resource Conservation and Recovery Act (RCRA), and Hazardous and Solid Waste
Amendments (HSWA) to RCRA require that the reduction or elimination of hazardous waste
Table 3 List of Industrial Case Studies in P2
Case Industrial operation/product P2 action Main benefits
1 Cardboard box manufacturer
and printer
“Good housekeeping” to
reduce ink wastes
90% savings in waste disposal
and reduction of costs for
raw materials
2 Manufacturer of sliding rear
windows of automotive
industry
Installation of an in-line
computer monitoring
system and replacement of
a pump
90% reduction of hazardous
wastes and improvement of
safety
3 Brewing Use waste as fertilizer Reduction of waste disposal
4 Furniture manufacturing Hazardous waster reuse Reduction of waste disposal
5 Textile printing Solvent recovery 100% cost saving
6 Manufacturer of automatic
fluid controls
Replacement of
trichloroethylene (TCE)
with a waterbased,
nontoxic detergent cleaner
Elimination of TCE
emissions and related
wastes and improvement of
safety
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generation at the source should take priority over other management methods such as treatment
and disposal. Hazardous waste generators are required to certify on their hazardous waste
manifests that they have programs in place to reduce the volume or quantity and toxicity of
hazardous waste generated to the extent economically practicable. Materials that are recycled
may be exempt from RCRA regulations if certain conditions are met.
The Water Quality Act of 1987 further strengthened the CWA, and amendments to the
Safe Drinking Water Act required numerous treatment facility upgrades. Although all these acts
are dramatic in their protection of US citizens against waterborne diseases and the improvement
of water quality, they placed little emphasis on source reduction or elimination of the root cause
of pollution.
To address this issue of the need of regulation upgrading, the Pollution Prevention Act of
1990 was passed. It formalized a national policy and commitment to waste reduction,
functioning primarily to promote the consideration of pollution prevention measures at the
federal government level. This act crosses media boundaries by establishing a national policy on
pollution prevention, including programs that emphasize source reduction, reuse, recycling, and
training. All these areas are key to the successful implementation of a P2 industrial wastewater
management program [1]. According to the act, the USEPA should review existing and proposed
programs and new regulations to determine their effect on source reduction [12]. Source
reduction activities among the USEPA programs and other federal agencies are coordinated. It
provides public access to environmental data and fosters the exchange of source reduction
information. It establishes pollution prevention training programs for Federal and State
environmental officials. Finally, the USEPA is required to facilitate adoption of source reduction
by businesses, as well as identify and make recommendations to Congress to eliminate barriers
to source reduction.
Since 1990, the USEPA has implemented a diverse set of programs and initiatives to meet
their obligations defined by the law. A series of achievements has been reported, including
33/50, Climate Wise, Green Lights, Energy Star, WAVE, the Pesticide Environmental
Stewardship Program, Indoor Air, Indoor Radon, Design for the Environment, the
Environmental Leadership Program, and the Common Sense Initiative [12]. For example,
reduction of a series of key pollutants was achieved through the 33/50 programs [13]. The
Program targeted 17 priority chemicals (e.g., benzene, tetrachloroethylene, and toluene) and set
as its goal a 33% reduction in releases and transfers of these chemicals by 1992 and a 50%
reduction by 1995, measured against a 1988 baseline. Its primary purpose was to demonstrate
whether voluntary partnerships could augment the USEPA’s traditional command-and-control
approach by bringing about targeted reductions more quickly than would regulations alone. The
program sought to foster a pollution prevention ethic, encouraging companies to consider and
apply pollution prevention approaches to reducing their environmental releases rather than
traditional end-of-pipe methods for treating and disposing of chemicals in waste. The 33/50Program achieved its goal in 1994, one year ahead of schedule, primarily through program
participants’ efforts. Facilities also reduced releases and transfers of the other 33/50 chemicals
by 50% from 1988 to 1995 [13].
Traditionally, environmental laws and regulations have controlled the releases of
pollutants and wastes. Only in recent years have laws and regulations gradually covered the
production of certain environmentally unfriendly products and services that also caused
environmental pollution. For example, DDT, CFCs, asbestos, leaded gasoline, certain kinds of
plastics, medicines, cosmetics, fertilizers, pesticides, and herbicides have been restricted in
production. Similarly, consulting services in designing products and process, in equipment
manufacturing and supply, and in education and training reduce significantly adverse impacts of
the environmental quality.
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Effective pollution management requires cost-effective regulations and standards,
followed by a combination of incentives and partnership approaches, and monitoring
activities to enforce the standards. Some targeting will be required toward the most polluting
subsectors or the most polluted regions. If there is sufficient institutional capacity to
implement industry-specific or other-specific programs, government agencies may also
provide information and other incentives to encourage the adoption of new and emerging
preventive technologies for various pollution sources to protect the environmental and natural
resources.
21.5.2 State Pollution Prevention Laws
Many US states (e.g., Arizona, California, Minnesota, and Texas) have passed laws to
incorporate aspects of P2 into RCRA and EPCRA requirements. The laws require manufacturers
that produce wastes to develop a source reduction and waste minimization plan, including an
implementation schedule, and to track and report waste reduction progress. A number of states
have implemented voluntary pollution prevention programs. The foundation of these programs
is generally educational outreach and technical assistance mechanisms. Tables 4 and 5 give
lists of state mandatory and voluntary P2 programs [12]. The following are some examples of
provisions from state laws.
The Arizona law applies only to facilities that must file the annual Toxic Chemical Release
Inventory Form R required by EPCRA Section 313 or during the preceding 12 months generated
an average of 1kg per month of an acutely hazardous waste. The California law only applies to
facilities that generate more than 12,000kg of hazardous waste or 12kg of extremely hazardous
waste in a calendar year. The programs require facilities to perform P2 planning that identifies
waste sources and specific technical steps that can be taken to eliminate or reduce the generation
of hazardous wastes. The facilities are required to submit progress reports with the length of time
between reports ranging from one to two years [12].
Table 4 List of State Mandatory Pollution Prevention Programs
Mandatory P2
programs Statute
Arizona AZ Rev. Stat. Ann. 49-961 to -73
California CA Health & Safety Code 25244.12 to .24
Georgia GA Code Ann. 12-8-60 to -83
Louisiana LA Rev. Stat. Ann. 30.2291 to .2295
Maine ME Rev. Stat. Ann., tit. 38, 2301 to 2312
Massachusetts MA Ann. Laws ch. 211,1 to 23
Minnesota MN Stat. Ann. 115D.01 to .12
Mississippi MS Code Ann. 49-31-1 to -27
New Jersey NJ Stat. Ann. 13: 1D-35 to -50
New York NY Envtl Conserv. Law 27-0900 to -0925
Oregon OR Rev. Stat. 465.003 to .037
Tennessee TN Code Ann. 68-212-301 to -312
Texas TX Title 30, Ch 335
Washington WA Rev. Code 70.95C.010 to .240
Source: Ref. 12.
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21.5.3 Local Pollution Prevention Requirements
According to the CWA, qualified local publicly owned treatment works (POTWs) are given the
authority to administer pretreatment programs (e.g., regulation of industrial dischargers). The
POTWs can have the authority to implement regulations that are more stringent than federal
guidelines (e.g., 40 CFR 433). A number of local agencies therefore use this authority to reduce
the impact of industrial discharges on the operation of the POTW, reduce the concentration of
toxic pollutants in POTW sludge, and/or to reduce the mass of pollutants discharged by the
POTW. This can be accomplished by lowering the permissible concentration limits of industrial
discharges below the federal standards.
One local program administered by the Palo Alto Regional Water Quality Control Plant
(RWQCP) incorporates P2 requirements into pretreatment discharge permits. This is one of
the first examples of the use of such requirements in place of more traditional pollutant
concentration limitations. In response to its own stringent copper discharge limit, the RWQCP
had to reduce the copper content of the influent at the plant. This effort focused upon all sources
of copper mainly targets on computer parts manufacturers, who are given the choice between
mass-based discharge limits or concentration limits in the P2 program. There were a total of 13
facilities in the RWQCP service area in 1995. One made an unrelated decision to move out of the
service area; eight facilities chose the concentration-based limits and installation of Reasonable
Control Measures (RCMs) [12].
21.6 POLLUTION PREVENTION FEASIBILITY ANALYSES
The level of required analysis depends on the complexity of the considered pollution prevention
project. A simple, low-capital cost improvement such as preventive maintenance would not need
much analysis to determine whether it is technically, environmentally, and economically
feasible. On the other hand, input material substitution could affect a product specification, while
a major modification in process equipment could require large capital expenditures. Such
changes could also alter process waste quantities and compositions, thus requiring more
systematic evaluation.
Table 5 List of State Voluntary Pollution Prevention Programs
Voluntary P2 programs Statute
Alaska AK Stat. 46.06.021 to .041
Colorado CO Rev. Stat. Ann. 25-16.5-101 to -110
Connecticut CT Gen. Stat. Ann Appendix Pamphlet, P.A. 9 1-376
Delaware 7 DE Code Ann. 7801 to 7805
Florida FL Stat. Ann. 403 .072 to .074
Illinois IL Ann. Stat. Ch. 111 ,7951 to 7957
Indiana IN Code Annl 3-9-1 to-7
Iowa IA Code Ann. 455B.516 to .518
Kentucky KY Rev Stat. Ann. 224.46-3 10 to -325
Ohio HB 147, HB 592
Rhode Island RI Gen. Laws 37-15.1-1 to .11
South Carolina SC Code Ann. 68-46-301 to -312
Wisconsin WI Stat. Ann. 144.955
Source: Ref. 12.
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Various options of pollution prevention projects may be evaluated, depending on the
resources currently available. It may be necessary to postpone feasibility analyses for some
options; however, all options should be evaluated eventually. This section describes how to
screen and narrow identified options to a few that will be evaluated in greater detail. Detailed
analysis includes evaluation of technical, environmental, economical, and institutional
feasibilities. It is important to note that many of the issues and concerns during pollution
prevention feasibility analyses are interrelated.
21.6.1 Technical Feasibility Analysis
Technical feasibility analysis requires comprehensive knowledge of pollution prevention
techniques, vendors, relevant manufacturing processes, and the resources and limitations of the
facility. The analysis can involve inspection of similar installations, obtaining information from
vendors and industry contacts, and using rented test units for bench-scale experiments when
necessary. Some vendors will install equipment on a trial basis and payment after a prescribed
time, if the user is satisfied.
Technical analysis should determine which technical alternative is the most appropriate
for the specific pollution prevention project in question. Such analysis considers a number of
factors and asks very detailed questions to ensure that the pollution prevention technique will
work as intended. Examples of facility-related questions to be considered include:
. Will it reduce waste?
. Is space available?
. Are utilities available or must these be installed?
. Is the new equipment or technique compatible with current operating procedures,
workflow, and production rates?
. Will product quality be maintained?
. How soon can the system be installed?
. How long will production be stopped in order to install the system?
. Is special expertise required to operate or maintain the new system? Will the vendor
provide acceptable service?
. Will the system create other environmental problems?
. Is the system safe?
. Are there any regulatory barriers?
All affected groups in the facility should contribute to and review the results of the technical
analysis. Prior consultation and review with the affected groups (e.g., production, maintenance,
purchasing) will ensure the viability and acceptance of an option. If a change in production
methods is necessary, the project’s effects on the quality of the final product must be determined.
21.6.2 Environmental Feasibility Analysis
The environmental feasibility analysis weighs the advantages and disadvantages of each option
with regard to the environment. Most housekeeping and direct efficiency improvements have
obvious advantages. Some options require a thorough environmental evaluation, especially if
they involve product or process changes or the substitution of raw materials. The environmental
option of pollution prevention is rated relative to the technical and economical options with
respect to the criteria that are most important to the specific facility. The criteria may include:
. reduction in waste quantity and toxicity;
. risk of transfer to other media;
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. reduction in waste treatment or disposal requirements;
. reduction in raw material and energy consumption;
. impact of alternative input materials and processes;
. previous successful use within the company or in other industry;
. low operating and maintenance costs;
. short implementation period and ease of implementation;
. regulatory requirements.
The environmental evaluation is not always so clear-cut. Some options require a thorough
environmental evaluation, especially if they involve product or process changes or the
substitution of raw materials. To make a sound evaluation, information should be gathered on
the environmental aspects of the relevant product, raw material, or constituent part of the
process. This information would consider the environmental effects not only of the production
phase and product life cycle but also of extracting and transporting the alternative raw materials
and of treating any unavoidable waste. Energy consumption should also be considered. To make
a sound choice, the evaluation should consider the entire life cycle of both the product and the
production process.
21.6.3 Economic Feasibility Analysis
Economic feasibility analysis is a relatively complex topic, which is only briefly discussed here.
Economic analysis deals with the allocation of scarce, limited resources to various pollution
prevention modifications, and compares various investments to help determine which
investments will contribute most to the company.
A benefit is usually defined as anything that contributes to the objectives of the pollution
prevention project; costs are defined as anything that detracts from the achievement of a
project’s objectives. Normally, benefits and costs are evaluated from the perspective of whether
they contribute to (or detract from) the maximization of a company’s income. Economic cost–
benefit analysis uses a number of measures of profitability such as net present value, internal rate
of return, and benefit–cost ratio.
When measuring savings, it is important to look at not only the direct savings but also the
indirect savings of pollution prevention. In addition, there are intangible benefits that are difficult
to quantify in financial terms; nevertheless, they are an important aspect of any pollution
prevention project, and should be factored into the decision-making process. The economic
feasibility analysis of pollution prevention alternatives examines the incremental costs and
savings that will result from each pollution prevention option. Typically, pollution prevention
measures require some investment on the part of the operator, whether in capital or operating
costs. The purpose of economic feasibility analysis is to compare those additional costs to the
savings (or benefits) of pollution prevention.
For most capital investments, the direct cost factors are the only ones considered when
project costs are being estimated. For pollution prevention projects, direct cost factors may only
be a net cost, even though a number of the components of the calculation will represent savings.
Therefore, confining the cost analysis to direct costs may lead to the incorrect conclusion that
pollution prevention is not a sound business investment. In performing the economic analysis,
various costs must be considered. As with any project, the direct costs should be broken down as:
. Capital expenditures – for purchasing process equipment, additional equipment,
materials, site preparation, designing, purchasing, installation, utility connections, train-
ing costs, start-up cost, permitting costs, initial charge of catalysts and chemicals,
working capital, and financing charges.
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. Operating costs – typically associated with costs of raw materials, water and energy,
maintenance, supplies, labor, waste treatment, transportation, handling, storage, and
disposal, and other fees. Revenues may partially offset operating costs from increased
production or from the sale or reuse of byproducts or wastes.
Unlike more familiar capital investments, indirect costs for P2 are likely to represent a
significant net savings. Indirect costs are hidden in the sense that they are either allocated to
overhead rather than to their source (production process or product), or altogether omitted from
the project financial analysis. A necessary first step in including indirect costs in an economic
analysis is to estimate and allocate them to their source. Indirect costs may include:
. administrative costs;
. regulatory compliance costs such as permitting, record keeping and reporting,
monitoring, manifesting;
. insurance costs;
. workman’s compensation; and
. onsite waste management and control equipment operation costs.
Estimating and allocating future liability costs involves much uncertainty. It may be
difficult to estimate liabilities from actions beyond our control, such as an accidental spill by a
waste hauler. It is also difficult to estimate future penalties and fines for noncompliance with
regulatory standards that do not exist yet. Similarly, it is difficult to estimate personal injury and
property damage claims that result from consumer misuse, disposal of waste later classified as
hazardous, or claims of accidental release of hazardous waste after disposal. Allocation of future
liabilities to the products or production processes also presents practical difficulties in a cost
assessment.
A pollution prevention project can benefit from water, energy, and material savings as well
as from waste reduction, recycling, and reuse. It may also deliver substantial benefits from an
improved product and company image or from improved employee health. These benefits
remain largely unexamined in environmental investment decisions. Although they are often
difficult to measure, they should be incorporated into the assessment whenever feasible. At the
very least, they should be highlighted for managers after presenting costs that can be the more
easily quantified and allocated. Intangible benefits may include:
. increased sales due to improved product quality, enhanced company image, and
consumer trust in products;
. improved supplier–customer relationship;
. reduced health maintenance costs;
. increased productivity due to improved employee relations; and
. improved relationships with regulators.
21.6.4 Institutional Feasibility Analysis
Institutional analysis is concerned with evaluating the strengths and weaknesses of the
company’s involvement in the implementation and the operation of investment in pollution
prevention projects. It includes, for example:
. staffing profiles;
. task analysis and definitions of responsibility;
. skill levels;
. processes and procedures;
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. information systems and flows for decision making; and
. policy positions on pollution prevention priorities.
The analysis should cover managerial practices, financial processes and procedures,
personnel practices, staffing patterns, and training requirements. Issues of accountability need to
be addressed. Proper incentives, in terms of money and career advancements, will encourage
employees to achieve pollution prevention goals.
21.7 P2 PROJECT IMPLEMENTATION AND REVISION
After a pollution prevention project or plan of program is established and its technical,
environmental, economic, and institutional feasibilities are analyzed, team members will be able
to more easily encourage management to implement chosen projects. All members of the
company may not embrace a pollution prevention project immediately, especially if they do not
fully understand the benefits and the cost savings of pollution prevention. To implement a
pollution prevention plan or program most effectively, the true cost of waste generation and
management must be constantly emphasized. The true cost includes all environmental
compliance costs such as manifesting, training, reporting, accident preparedness; future liability
costs; and intangible costs such as product acceptance, labor relations, and public image.
This section describes the essential elements and methods of (a) understanding processes
and wastes, (b) selecting a pollution prevention project, (c) obtaining funding, (d) implementing
projects through various engineering steps, (e) reviewing and revising projects, and (f) project
progress monitoring and revising.
21.7.1 Understanding Processes and Wastes
Understanding processes is important as it can provide useful information on both quantity and
quality of waste. It includes the following aspects: (a) gathering background information,
defining production units, (b) characterization of general process, (c) understanding unit
processes, and (d) performing materials balance. A detailed discussion is given in Section 21.9.
21.7.2 Selecting Projects
Final selection of a project from among the various proposed projects for implementation
depends primarily upon the pollution prevention feasibility analyses. The selection should
generally rely on the hierarchy for waste reduction, which emphasizes more source reduction;
results of the waste reduction assessment; availability of specific clean technologies or
procedural applications; qualitative assessment of technical and economic feasibility;
institutional feasibility; and other considerations. The next step is to develop a schedule for
implementation. The selected pollution prevention projects should be flexible enough to
accommodate possible alternatives or modifications. The pollution prevention team should be
willing to do background and support work, and anticipate potential problems in implementing
projects.
21.7.3 Obtaining Funding
The pollution prevention team must seek funding for those selected projects that will require
expenditures. Within a company, there are probably other projects such as expanding production
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capacity or moving into new product lines that compete with the pollution prevention projects
for funding. If the team is part of the overall budget decision-making process, it can make an
informed decision on whether the selected pollution project should be implemented right away
or whether it can await the next capital budgeting period. The team needs to ensure that the
pollution prevention projects will be reconsidered at that time.
Some companies will have difficulty raising funds internally for capital investment,
especially companies in developing countries. External funds are available to implement
pollution prevention projects. Private sector financing includes bank loans and other
conventional sources of financing. Financial institutions and international organizations (e.g.,
Asian Development Bank) are becoming more cognizant of the sound business aspects of
pollution prevention and cleaner production [15]. Government financing should be available in
some cases to help small- and medium-sized plants.
A strong engineering approach helps ensure proper implementation of the selected
projects. Outside process engineering support may be required if company personnel do not
have the time to implement tasks. Many pollution prevention projects may require
changes in operating procedures, purchasing methods, materials inventory control, equipment
modification, or new equipment. Such changes may affect a company’s policies and
procedures. However, the implementation phases resemble those of most other company
projects.
Personnel who will be directly affected by the project (line workers and engineers) should
participate from the start. Those personnel indirectly affected (e.g., controllers, purchasing
agents) should also participate as project implementation proceeds. Any additional training
requirements should be identified and arrangements made for instruction. All employees should
be periodically informed of the project status and should be educated as to the benefits of the
projects to them and to the company. Encouraging employee feedback and ideas may ease the
natural resistance to change.
21.7.4 Project Implementation
Implementation of a pollution prevention project will generally follow the procedures
established by the company for implementing any new procedure, process modification, or
equipment change. Implementing a major pollution prevention project typically involves several
steps:
. Preparing a detailed design. It is helpful to discuss the project with representatives
from production, maintenance, safety, and other departments who may be affected by
the change or who may have suggestions regarding equipment manufacturers, layout,
scheduling, or other aspects of implementation.
. Preparing a construction bid package and equipment specifications. If construction is
required, details of the necessary construction will need to be assembled into a
construction bid package. Depending on the established procedures in the company,
specifications for new equipment or particular manufacturers and models may be
necessary.
. Selecting construction staff and purchasing materials. Construction may be performed
by an in-house or outside company, depending on cost and availability.
. Installing new equipment. Construction will generally involve installation of the
necessary equipment. Timing and scheduling of installation may be critical in some
operations.
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. Training personnel. Personnel from maintenance as well as production may need
training. Proper operation and maintenance are critical for effective, safe, and trouble-
free operation. Training is sometimes available from equipment vendors.
. Starting operation. Extra care is necessary during the initial stages of operation to
ensure that all proceeds smoothly; first impressions of the effectiveness of the system
are often lasting.
. Monitoring and evaluating performance. Monitoring is typically an integral part of
operations, and is performed by the production staff. Depending on the complexity of
the chosen pollution prevention project, only a few of these steps may be necessary.
21.7.5 Reviewing and Revising Projects
The pollution prevention process does not end with implementation. After the pollution
prevention plan is implemented, we need to track its effectiveness and compare it to previous
technical and economic assessments. Options that do not meet the original performance
expectations may require rework or modification. This can be done through the knowledge
gained by continuing to evaluate and fine-tune the pollution prevention projects. The success of
the initial pollution prevention project may be only the first step along the road to establishing
pollution prevention as either a stand-alone program or as an important criterion for
consideration in other ongoing plant programs within the company. Developing the pollution
prevention ethic is usually a step-by-step evolutionary process. It starts slowly and gradually
builds momentum. Each successful pollution prevention experience provides even more
incentive for management to support and diversify pollution prevention within the company.
To ensure that the pollution prevention momentum is preserved from the end of one
pollution prevention project to the beginning of the next, it is important to provide an
opportunity for feedback and evaluation. This opportunity should be used not only to critique the
previous effort, but also to promote it and raise its visibility; that is, to “wave the banner” for
pollution prevention and demonstrate that pollution prevention has even broader applications in
the company. In this way we can use each pollution prevention experience as a promotional
device for the next project, so that the role of pollution prevention within the company will
continue to grow. With time, pollution prevention will become a natural part of the company’s
infrastructure and operating practices.
21.7.6 Project Progress Monitoring
In order to track the facilities’ achievements and the overall effectiveness of the regulatory
approach, pollution prevention related data must be available. Industry also needs independently
verifiable data, which effectively measure pollution prevention progress both to demonstrate
compliance with newly evolving environmental laws and to promote an environmentally
sensitive image.
A successful pollution prevention measurement needs to identify the specific objective,
resource availability, and proper approach. If the industrial plant has the appropriate resources,
the pollution prevention measurement can help develop a rapid understanding of the relationship
between wastes and the manufacturing process.
The needs cover pollution prevention data acquisition, data analysis, and methods of
measuring pollution prevention progress with the emphasis on source reduction in various
industrial processes. It also discusses toxic release inventories, material accounting data, and
expansion of the Community-Right-to-Know program used by the US regulatory agencies to
measure the progress of pollution prevention and project revisions.
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Measuring pollution prevention progress is to evaluate the progress against the established
goals, which can be different in various settings; it includes data acquisition and analysis.
Different data collection approaches might be required in different types of industrial processes
and we must select a quantity in terms of waste volume or waste toxicity. In the analysis, the
most cost-effective methods must be selected for specific situations. Semiquantitative data are
easier to obtain but have less utility.
Methods of measuring pollution prevention progress consist of toxic release inventory,
materials accounting data and evaluation. Experience indicates that changes in reporting
requirements, and in respondents’ understanding of them, can introduce errors in analyses.
21.8 P2 APPLICATIONS IN INDUSTRIAL PLANTS
Industry involves thousands of products and production processes, resulting in a decentralized
enterprise system. Technical progress toward pollution prevention is likewise decentralized,
since it is driven by economic consideration, and frequently specific to one of thousands of
different industrial processes. Current pollution prevention technology generally employs
conventional engineering approaches. Even as priority shifts from waste treatment and control to
prevention, engineers will still employ available technology at first to achieve their objectives. In
the future, however, process modifications and friendly product designs will become more
innovative for the environment.
Pollution prevention techniques for industrial manufacturing facilities such as waste
minimization and source reduction can be understood by observing the path of material as it
passes through an industrial site. Even before materials arrive at the site, we could avoid toxic
materials when less toxic substitutes exist. Pollution prevention technologies for industries can
be generalized into five groups: improved plant operations, in-process recycling, process
modification, materials and product substitutions, and materials separations.
21.8.1 Improved Plant Operations
Manufacturers could implement a variety of improved management or “housekeeping”
procedures that would aid pollution reduction; they could conduct environmental audits,
establish regular preventive maintenance, specify proper material handling procedures, imple-
ment employee training, as well as record and report data.
Environmental Audits
Environmental audits may be conducted in many different settings by individuals with varied
backgrounds and skills, but each audit tends to contain certain common elements. It is better to
identify and correct problems associated with plant operation to minimize waste generation. One
aspect of improved plant operation is cost saving. Production costs and disposal costs can be cut
simultaneously by improving plant operation. The practice of environmental auditing also
examines critically the operations on a site and, if necessary, identifying areas for improvement
to assist the management to meet requirements. The essential steps are as follows.
(1) Collecting information and facts,
(2) Evaluating that information and facts,
(3) Drawing conclusions concerning the status of the programs audited with respect to
specific criteria,
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(4) Identifying aspects that need improvement, and
(5) Reporting the conclusions to appropriate management.
Audits enable manufacturers to inventory and trace input chemicals and to identify how
much waste is generated through specific processes. Consequently, they can effectively target
the areas where waste can be reduced and formulate additional strategies to achieve reductions.
The audit consists of a careful review of the plant’s operations and waste streams and the
selection of specific streams and/or operations to assess. It is an extremely useful tool in
diagnosing how a facility can reduce or eliminate hazardous and nonhazardous wastes. It focuses
on regulatory compliance and environmental protection.
Regular Preventive Maintenance
Preventive maintenance involves regular inspection and maintenance of plant equipment,
including lubrication, testing, measuring, replacement of worn or broken part, and operational
conveyance systems. Equipment such as seals and gaskets should be replaced periodically to
prevent leaks. The benefits of preventive maintenance are increased efficiency and longevity of
equipment, fewer shutdowns and slowdowns due to equipment failure, and less waste from
rejected, off-specification products. Maintenance can directly affect and reduce the likelihood of
spills, leaks, and fires. An effective maintenance program includes identification of equipment
for inspection, periodic inspection, appropriate and timely equipment repairs or replacement,
and maintenance of inspection records.
Corrective maintenance is needed when the design levels of a process change and
adjustments to indirect factors are required. This type of maintenance includes recognizing the
signs of equipment failure and anticipating what repairs or adjustments need to be made to fix the
problem or improve the overall efficiency of the machinery. Visual inspection ensures that all of
the elements of the process system are working properly. However, routine inspections are not a
substitute for the more thorough annual compliance inspections. After each visual inspection, it
is important to document the results and evaluate the effectiveness of corrective previous
actions. Any necessary future corrective action should also be identified.
In reducing fugitive emissions, conscientious leak detection and repair programs have
proven to be extremely effective at a fraction of the cost of replacing conventional equipment
with leafless technology components. Besides being expensive, changing to leafless technology
is not always feasible, and reduces emissions over well-maintained, high-quality conventional
equipment only marginally.
Material Handling and Storage
Material handling and storage operations can cause two types of fugitive emissions: (a) low-
level leaks from process equipment, and (b) episodic fugitive emissions, where an event such as
equipment failure results in a sudden large release. Often, methods for reducing low-level
equipment leaks result in fewer episodes, and vice versa. Methods for reducing or eliminating
both types of fugitive emissions can be divided into two groups: (a) leak detection and repair and
(b) equipment modification. Such emissions can be prevented by good practices. Proper
materials handling and storage ensures that raw materials reach a process without spills, leaks, or
other types of losses that could result in waste generation. Some basic guidelines for good
operation practices are suggested to reduce wastes by:
. spacing containers to facilitate inspection;
. labeling all containers with material identification, health hazards, and first aid
recommendations;
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. stacking containers according to manufacturers’ instructions to prevent cracking and
tearing from improper weight distribution;
. separating different hazardous substances to prevent cross-contamination and facilitate
inventory control; and
. raising containers off the floor to inhibit corrosion from “sweating” concrete.
Spills and leaks are major sources of pollutants in industrial processes and material
handling. When material arrives at a facility, it is handled and stored prior to use; material may
also be stored during stages of the production process. It is important to prevent spillage,
evaporation, leakage from containers or conduits, and shelf-life expirations. Standard operating
procedures to eliminate and minimize spills and leaks should take place regularly. Better
technology might consist of tighter inventory practices, seal-less pumps, welded rather than
flanged joints, bellows seal valves, floating roofs on storage tanks, and rolling covers vs. hinged
covers on openings. While these techniques are not novel, they could still lead to large
replacement costs if a company has many locations where leakage can occur. Conversely, they
could provide large economic benefits by reducing the loss of valuable materials.
Waste from storage vessels takes many forms, from emissions due to vapor displacement
during loading and unloading of storage tanks, to wastes formed during storage, to the storage
containers themselves if they are discarded. Reducing waste from storage vessels therefore
consists of a variety of activities. Storage tanks for storing organic liquids are found at petroleum
refineries, organic chemical manufacturing facilities, bulk storage and transport facilities, and
other facilities handling organic liquids. They are used to dampen fluctuation in input and output
flow. Storage tanks can be disastrous sources of waste when weakly active undesired reactions
leak out, and it is important to monitor temperatures where this can occur and to design tanks so
that heat dissipation effects dominate. Inadequate heat dissipation is of particular concern in the
storage of bulk solids and viscous liquids. Other aspects of pollution prevention for storage tanks
involving tank bottoms, standing and breathing losses, and emissions due to the loading and
unloading of storage tanks.
Vapors that are displaced in loading and off-loading operations can be a significant source
of VOC emissions from storage containers. Vapor recovery devices that trap and condense
displaced gases reduce losses due to loading and unloading of fixed-roof storage tanks by 90–
98%. Vapor balance, where vapors from the container being filled are fed to the container being
emptied, is another technique that can be applied in some cases to reduce emissions. Spills due to
overfilling of storage containers are another source of emissions that occur during loading and
unloading operations. These spills can be prevented through the use of appropriate overflow
control equipment and/or overflow alarms.
Employee Training
Employee training is paramount to successful implementation of any industrial pollution
prevention program. All the plant operations staff should be trained according to the objectives
and the elements of the program. Training should address, among other things, spill prevention,
response, and reporting procedures; good housekeeping practices; material management
practices; and proper fueling and storage procedures. Properly trained employees can more
effectively prevent spills and reduce emission of pollutants.
Well-informed employees are also better able to make valuable waste reduction
suggestions. Plant personnel should comprehend fully the costs and liabilities incurred in
generating wastes. They should have a basic idea of why and where waste is produced and
whether the waste is planned or unplanned.
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Employee training can take place in three stages: prior to job assignment, during job
training, and ongoing throughout employment. Before beginning an assignment, employees
should become familiar with toxic properties and health risks associated with exposures to all
hazardous substances that they will be handling. In addition, employees should learn the
consequences of fire and explosion involving these substances. Finally, they should learn what
protective clothing or gear is required and how to use it. During job training, employees should
learn how to operate the equipment safely, the methods and signs of material releases, and what
procedures to follow when a spill or leak occurs. Ongoing education includes regular drill,
updates on operating and cleanup practices, and safety meetings with other personnel.
The challenge of education and training today is how to integrate air–water–land
pollution management through integrated waste prevention prior to the application of waste
treatment and disposal technologies. A multimedia plan would help to implement pollution
prevention. Cross-disciplinary education and training will enable trainees to understand the
importance of multimedia pollution prevention principles and strategies so that they can carry
out such principles and strategies for pollution prevention.
Operating Manual and Record Keeping
Over the past decade, governments and industry trade organizations have developed guides and
handbooks for reducing wastes. These materials are useful for analyses of individual facilities,
although some guides attempt to be more general. Good facility documentation can have many
benefits for the plant, including waste reduction. Facility documentation of process procedures,
control parameters, operator responsibilities, and hazards in a manual or set of guidelines will
contribute to safe and efficient operation. It also promotes consistency, thereby lessening the
likelihood of producing an unacceptable product, which must be discarded. A facility operating
manual will assist the operators in monitoring waste generation and identifying unplanned waste
releases and will also assist operators in responding to equipment failure.
Diligent record keeping with regard to waste generation, waste handling and disposal
costs, and spills and leaks helps to identify areas where operating practices might be improved
and later will help in assessing the results of those improved practices. Record keeping can be
instrumental in assuring compliance with environmental regulations and is a sign of concern and
good faith on the part of the company. An industrial pollution prevention program should
document spills or other discharges, the quality and quantity of accidental releases, site
inspections, maintenance activities, and any other information that would enhance the
effectiveness of the program. In addition, all records should be retained for at least three years.
21.8.2 Process Modification
Pollution can be prevented in many ways specific to particular processes. Many industrial plants
have prevented pollution successfully by modifying production processes. Such modifications
include adopting more advanced technology through process variable controls, changing
cleaning processes, chemical catalysts, segregating and separating wastes as follows.
Process Variable Controls
Temperature and pressure applications are critical variables as materials are reacted and handled
in industrial processes. They can significantly alter the formation of toxins. Improvements
include better control mechanisms to meter materials into mixtures; better sensors to measure
reactions; more precise methods, such as lasers, to apply heat; and computer assists to automate
the activity.
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Changing Cleaning Processes
The cleaning of parts, equipment, and storage containers is a significant source of contamination.
Toxic deposits are common on equipment walls. The use of solvents to remove such
contamination creates two problems: disposal of the contaminants and emissions from the
cleaning process itself. Some changes include the use of water-based cleansers vs. toxic solvents,
nonstick liners on equipment walls, nitrogen blankets to inhibit oxidation-induced corrosion, and
such solvent-minimizing techniques as high-pressure nozzles for water rinse-out.
Chemical Catalysts
Because catalysts facilitate chemical reactions, they welcome pollution prevention research.
Better catalysts and better ways to replenish or recycle them would induce more complete
reactions and less waste. Substitution of feedstock materials that interact better with existing
catalysts can accomplish the same objective.
Coating and Painting
The paints and coatings industry will have to change technologies to accommodate
environmental preventive goals. Manufacturers of architectural coatings under increasing
environmental regulations will reduce the volatile organic compounds contained in their
coatings by displacing oil-based products with water-based coatings. In particular, the paint
industry will center its research upon reformulations and increasing the efficiency of coating
applications via water-based paints, powder coatings, high-solids enamels, reactive diluents, and
radiation curable coatings. For the common source of toxic waste, technical improvements
include better spray equipment, such as electrostatic systems and robots, and alternatives to
solvents, such as bead blasting.
Segregating and Separating Wastes
A drop of pollutant in a pure solution creates a container of pollution. Segregating wastes and
nonwastes reduces the quantity of waste that must be handled. Various technical changes and
modifications provide more precise and reliable separation of materials unavoidably mixed
together in a waste stream by taking advantage of different characteristics of materials, such as
boiling or freezing points, density, and solubility. Separation techniques such as distillation,
supercritical extraction, membranes, reverse osmosis, ultrafiltration, electrodialysis, adsorption,
separate pollutants or mixed wastes back to their constituent parts (Table 6). Although simple in
principle, these processes become high-tech in the precision with which they are applied to
facilitate other options in the hierarchy such as recycling, treatment, and disposal.
Support Activities
Garages, motor pools, powerhouses, boilers, and laboratories – all can produce wastes that must
be addressed. Their sources of pollution may be significantly reduced through improvement of
operation practices.
21.8.3 In-Process Recycling
Materials are processed frequently in the presence of heat, pressure, and/or catalysts, to form
products. As materials are reacted, combined, shaped, painted, plated, and polished, excess
materials not required for subsequent stages become waste, frequently in combination with toxic
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solvents used to cleanse the excess from the product. The industry disposes of these wastes either
by recycling them into productive reuse or by discharging them as wastes into the air, water, or
land. Costly treatment is often required to reduce the toxicity and pollutants in the waste
discharge before final disposal. These liquid, solid, or gaseous wastes at each stage of the
production process are the source of pollution problems. Onsite recycling of process waste back
into the production process will often allow manufacturers to reduce pollution and save costs for
less waste treatment and disposal.
For example, solvents are being recycled in many industrial processes. The current goal
of solvent recycling is to recover and refine its purity similar to virgin solvent for reuse in the
same process, or of sufficient purity to be used in another process application. Recycling
activities may be performed either onsite or offsite. Onsite recycling activities include: (a)
direct use or reuse of the waste material in a process. It differs from closed-loop recycling, in
that wastes are allowed to accumulate before reuse; and (b) reclamation is achieved by
recovering secondary materials for a separate end-use or by removing impurities so that the
waste may be reused.
Advantages of onsite recycling include:
. less waste leaving the facility;
. control of reclaimed solvent’s purity;
. reduced liability and cost of transporting waste offsite;
. reduced reporting (manifesting);
. possible lower unit cost of reclaimed solvent.
Disadvantages of onsite recycling must also be considered, including:
. capital outlay for recycling equipment;
. liabilities for worker health, fires, explosions, leaks, spills, and other risks as a result of
improper equipment operation;
. possible need for operator training; and additional operating costs.
Offsite commercial recycling services are well suited for small quantity generators of
waste since they do not have sufficient volume of waste solvent to justify onsite recycling.
Commercial recycling facilities are privately owned companies that offer a variety of services
ranging from operating a waste recycling unit on the generator’s property to accepting and
recycling batches of solvent waste at a central facility.
Table 6 Applicable Treatment Technologies for Wastewater Reuse
Treatment technology Applications
Reverse osmosis Remove BOD, COD, TSS, TDS, nitrogen, and
phosphorus
Electrodialysis Remove TDS and recover metal salts
Micro/Ultrafiltration Remove TSS, turbidity, and oil
Ion exchange Remove TDS and toxic metal ions; reduce hardness
Activated carbon adsorption Remove many organic and inorganic compounds
Sedimentation Remove solids that are more dense than water
Filtration Dewater sludges and slurries; remove TSS from liquid
Evaporation Treat hazardous wastes, solvent wastes with nonvolatile
constituents; separate dissolved and suspended solids
Dewatering Reduce the moisture content of sludges
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21.8.4 Materials and Product Substitutions
The issues involving materials and product substitutions are complex and include economic and
consumer preferences as well as technological considerations. Obviously, the use of less toxic
materials in production can effectively prevent pollution in a decentralized society. Scientists
and engineers are actively evaluating and measuring material toxicity and developing safer
materials. Likewise, the life-cycle approach requires that products be designed with an
awareness of implication from the raw material stage through final disposal stage. Examples of
the product life-cycle applications include substitutes for fast-food packaging, disposal of
diapers, plastic containers, and certain drugs and pesticides.
Materials Substitution
Industrial plants could use less hazardous materials and/or more efficient inputs to decrease
pollution. Input substitution has been especially successful in material coating processes, with
many companies substituting water-based for solvent-based coatings. Water-based coatings
decrease volatile organic compound emissions, while conserving energy. Substitutes, however,
may take a more exotic form, such as oil derived from the seed of a native African plant,
Vernonia galamensis, to substitute for traditional solvents in alkyd resin paints.
Product Substitution
Manufacturers could also reduce pollution by redesigning or reformulating endproducts to be
less hazardous. For example, chemical products could be produced as pellets instead of powder,
decreasing the amount of waste dust lost during packaging. Unbleached paper products could
replace bleached alternatives. With uncertain consumer acceptance, redesigning products could
be one of the most challenging avenues for preventing pollution in the industrial sector.
Moreover, product redesign may require substantial alterations in production technology and
inputs, but refined market research and consumer education strategies, such as product labeling,
will encourage consumer support.
Changes in endproducts could involve reformulation and a rearrangement of the products’
requirements to incorporate environmental considerations. For example, the endproduct could
be made from renewable resources, have an energy-efficient manufacturing process, have a long
life, and be nontoxic as well as easy to reuse or recycle. In the design of a new product, these
environmental considerations could become an integral part of the program of requirements.
In both the redesign of existing products and the design of new products, additional
environmental requirements will affect the methods applied and procedures followed. These
new environmental criteria will be added to the list of traditional criteria. Environmental criteria
for product design include:
. using renewable natural resource materials;
. using recycled materials;
. using fewer toxic solvents or replacing solvents with less toxic replacements;
. reusing scrap and excess material;
. using water-based inks instead of solvent-based ones;
. reducing packaging requirements;
. producing more replaceable component parts;
. minimizing product filter;
. producing more durable products;
. producing goods and packaging that can be reused by consumers; and
. manufacturing recyclable final products.
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21.8.5 Materials Separation
In the chemical process industry, separation processes account for a significant portion of
investments and energy consumption. For example, distillation of liquids is the dominant
separation process in the chemical industry. Pollution preventive technology aims to find
methods that provide a sharper separation than distillation, thus reducing the amounts of waste,
improving the use of raw materials, and yielding better energy economy. The relationship of
various separation technologies to particle size is given in Figure 1 [1]. The figure describes the
physical selection parameter with respect to particle size for various separation techniques.
In examining separation equipment for waste reduction, three levels of analysis can be
considered. One level of analysis involves minimizing the wastes and emissions that are
routinely generated in the operation of the equipment. A second level of analysis seeks to control
excursions in operating conditions. The third level of analysis seeks to improve the design
efficiency of the separation units. Waste reduction opportunities derived from each of these
levels of analysis are presented below.
Distillation columns produce wastes by inefficiently separating materials, through off-
normal operation, and by generating sludge in heating equipment. The following solutions to
these waste problems have been proposed:
. Increase the reflux ratio, add a section to the column, retray/repack the column, or
improve feed distribution to increase column efficiency.
. Insulate or preheat the column feed to reduce the load on the reboiler. A higher reboiler
load results in higher temperatures and more sludge generation.
. Reduce the pressure drop in the column, which lowers the load on the reboiler.
. In addition, vacuum distillation reduces reboiler requirements, which reduces sludge
formation.
. Changes in tray configurations or tower packing may prevent pollution from
distillation processes.
. Another method for preventing pollution from distillation columns involves reboiler
redesign.
Supercritical Extraction
Supercritical extraction is essentially a liquid extraction process employing compressed gases
instead of solvents under supercritical conditions. The extraction characteristics are based on the
solvent properties of the compressed gases or mixtures. Researchers have known about the
solvent power of supercritical gases or liquids for more than 100 years, but the first industrial
application did not begin until the late 1970s.
From an environmental point of view, the choice of extraction gas is critical, and to date,
only the use of carbon dioxide would qualify as an environmentally benign solution. From a
chemical engineering point of view, the advantage offered by supercritical extraction is that it
combines the positive properties of both gases and liquids, that is, low viscosity with high
density, which results in good transport properties and high solvent capacity. In addition, under
supercritical conditions, solvent characteristics can be varied over a wide range by means of
pressure and temperature changes.
Membranes
Membrane technology offers other new techniques for combining reaction and separation
activities when the product molecules are smaller than the reactant molecules. Removal of
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Figure 1 Separation technologies for particles of various sizes.
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product also makes membrane reactors advantageous if the product can react with a reactant to
form a waste. Membranes are important in modern separation processes, because they work on
continuous flows, are easily automated, and can be adapted to work on several physical
parameters, such as molecular size, ionic character of compounds, polarity, and hydrophilic/hydrophobic character of components.
Microfiltration, ultrafiltration, and reverse osmosis differ mainly in the size of the
molecules and particles that can be separated by the membrane (Table 6). Liquid mem-
brane technology offers a novel membrane separation method in that separation is affected by
the solubility of the component to separate into a liquid membrane rather than by its permeation
through pores, as is the case in conventional membrane processes, such as ultrafiltration and
reverse osmosis. The component to be separated is extracted from the continuous phase to the
surface of the liquid membrane, through which it diffuses into the interior liquid phase.
Promising results have been reported for a variety of applications, and it is claimed to offer
distinct advantages over alternative methods, but liquid membrane extraction is not yet widely
available.
Ultrafiltration
Ultrafiltration separates two components of different molecular mass. The size of the membrane
pores constitutes the sieve mesh covering a range on the order of 0.002–0.05 microns. The
permeability of the membrane to the solvent is generally quite high, which may cause an
accumulation of the molecular phase close to the surface of the membrane, resulting in increased
filtration resistance, that is, membrane polarization and back diffusion. However, the application
of transmembrane feed flow is being used effectively to reduce membrane polarization.
Reverse Osmosis
Reverse osmosis is generally based on the use of membranes that are permeable only to the
solvent component, which in most applications is water. The osmotic pressure due to the con-
centration gradient between the solutions on both sides of the membrane must be counteracted
by an external pressure applied on the side of the concentrate in order to create a solvent flux
through the membrane. Desalting of water is one area where reverse osmosis is already an
established technique. The major field for future work will be increasing the membrane flux and
lowering the operating pressure currently required in demineralization and desalination by
reverse osmosis.
Electrodialysis
Electrodialysis is used to separate ionic components in an electric field in the presence of
semipermeable membranes, permeable only to anions or cations. Applications are de-
mineralization and desalination of brackish water or recuperation of ionic components such as
hydrofluoric acid.
Adsorption
Adsorption involves physical and/or chemical interactions between the molecules in gas or
liquid and a solid surface. It can be used to remove a pollutant from a gas or liquid stream. Gas
adsorption processes, for example, can be used to separate a wide range of materials from
process gas streams. Normally adsorption processes are considered for use when the pollutant is
fairly dilute in the gas stream. The magnitude of adsorption force, which determines the
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efficiency, depends on the molecular properties of the solid surface and the surrounding
conditions.
Adsorbents may be polar or nonpolar; however, polar sorbents will have a high affinity for
water vapor and will be ineffective in gas streams that have any appreciable humidity. Gas
streams associated with industrial processes will be humid or even saturated with water vapor.
Activated carbon, a non-polar adsorbent, is effective at removing most volatile organic
compounds (Table 6). Examples of adsorbents for separating gaseous pollutants include
activated carbon, activated alumina, silica gel, molecular sieves, charcoal, and Zeolite.
21.8.6 Solvent Alternative Technologies
The following alternative technologies are being investigated and implemented at the Douglas
Aircraft Company (DAC) [1].
High Solids Topcoats
This is an alternative technology to painting aircraft with conventional topcoats, which contain
high levels of solvents for sprayability and drying, while it was recently acceptable to simply
substitute exempt solvents, such as 1,1,1-trichloroethane, in order to comply with regulations.
Chromium Elimination
This covers a variety of processes, such as painting, sealing, plating, and chemical processing.
Chromium has long been a main ingredient of many airframe processes because of its excellent
corrosion and wear-resistance properties. In 1990 DAC expanded the use of a thin film sulfuric
acid anodize process to include some commercial work, thus reducing the use of the popular
chromic acid anodize. Chrome-free aircraft sealers, alternative plating technologies, and
nonchromated deoxidizers are also being researched by DAC engineers.
Alkaline/Aqueous Degreasing Technologies
There are cleaning processes that uses solvent vapors alone to effectively remove a variety of
contaminants from the workpiece. It is a relatively simple, one step process that provides a clean,
dry part ready for subsequent processing. Tests are presently being conducted on various
immersion-type cleaners to replace solvent vapor degreasing. Some of the candidates are
aqueous cleaners, terpene-based cleaners, and the use of ultrasonic technology with immersion
cleaners.
Aqueous cleaners are typically alkaline in nature, their pH being in the range 9–11. Many
chemical suppliers already provide alkaline cleaners on the open market. Alkaline/aqueouscleaning is presently the leading contender to replace vapor degreasing, but the implementation
of this will require some change in process and equipment, which will require some operator
training and/or familiarity.
Alternative Handwipe Solvents Cleaners
These are used extensively for cleanup and repair during the manufacture and assembly of
transport aircraft. For example, the solvents used for vapor degreasing may be ozone depletors
and/or carcinogens. The Douglas Aircraft Company’s engineers are working with their
suppliers to develop cleaners that will work effectively at ambient temperatures to remove the
common aircraft industry contaminants.
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CFC Elimination
Chlorofluorocarbons (CFCs) are used as cleaners of small electronic parts such as printed
circuit boards (PCBs), in wire assembly areas, and in many maintenance tasks. They are also
used in air conditioners and machine tool chillers, and as propellants in aerosol can applications.
There are several lubricants and mold release compounds at DAC that are comprised of CFCs.
These are not used in high volume, but do provide an opportunity for reduction of CFC
emissions. DAC has begun the process of substituting the propellants used in some of aerosol
lubricants.
Resource Recovery and Waste Minimization
This is another broad category that encompasses many technologies: chemical processing, waste
disposal, recycling, and housekeeping are just a few. There are many opportunities for
improvement under this category as environmental technology continues to advance.
Waste minimization was highlighted during DAC’s recent implementation of the Total
Quality Management philosophy. This effort enlightened and encouraged every employee to
consider his/her impact on the environment and the workplace. An effective example of waste
minimization was accomplished by simply reducing the size of their vendor-provided wipe rags.
An onsite survey conducted to evaluate the usage of wipe rags discovered that the three-foot
square rags were too large for convenient wipe operations. The supplier agreed to provide
smaller rags at less cost to DAC, thus reducing both the volume and weight of rag-generated
wastes. Because of the wide variety of uses for wipe rags, they are liable to become
contaminated with many products including hazardous substances, requiring the disposal of
these rags as hazardous waste.
Each of these projects contributes to eliminate the negative impact of manufacturing
processes upon the environment. At DAC they are working diligently with their suppliers and
subcontractors to develop, test, and implement new alternative technologies. Alternative
technologies are becoming increasingly necessary to meet the ever-tightening demands of an
aware public when it comes to environmental legislation. It is noteworthy that environmental
professionals tend to share technological developments and breakthroughs to lead society to
be come a better, cleaner, and healthier place to live.
Chlorinated hydrocarbon solvents and chlorofluorocarbons are used extensively in
cleaning operations in the Department of Energy (DOE) defense program, the nuclear
weapons complex, the Department of Defense (DOD) weapons refurbishment facilities, and
in industry. A Solvent Utilization Handbook has been published by their joint task force to
provide guidelines for the selection of nontoxic environmentally safe substitute solvents
for these operations. The information contained will include cleaning performance, corrosion
testing, treatability operations, recycle/recovery techniques, volatile organic compound
emissions and control techniques, as well as other information. The Handbook will be
updated on an annual basis with information on new solvent substitutes that appear in the
marketplace. The handbook database is under revision. Toxicological information, handl-
ing and disposal, and economics of solvent usage will also be included in the updated
handbook.
A series of databases has been developed for implementation of P2. For example, Krewer
et al. [16] developed software called PoProf for selection of solvent and waste minimization. It
was based on two principles: (a) the selected solvents for a given process exhibit good
environmental behavior in addition to good performance; and (b) the waste from the process can
be minimized.
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21.8.7 Pollution Prevention Incentives
Economic, regulatory, and institutional incentives are needed for adopting pollution prevention
plans and programs, including:
. Effectiveness of incentive regulatory policy, economic, and legislative efforts is
critical in controlling human behavior.
. Assessment of tools for identifying contradictory regulations.
. Comparative evaluation of levels of benefit/cost derived from pollution prevention by
industries and societies.
. Internalization and externalization.
. Evaluation of waste/cost accounting systems for small and large industries.
. Comparative economics of disposal, treatment, and pollution prevention with regard to
products and processes.
. Effectiveness of taxes and tax credits in affecting pollution generation.
. Use of regulatory approaches to active pollution prevention objectives.
. Effectiveness of technical assistance programs.
. Research stimulation in the private and public sectors.
. Usefulness of grant programs.
. Economic modeling.
21.9 SYSTEMATIC ANALYSIS OF POLLUTION GENERATIONAND PREVENTION
A generalized industrial manufacturing plant is illustrated in Figure 2. As shown, mass and
energy flow enter the manufacturing processes, which include raw materials, energy (e.g., heat
and electricity), water used for manufacture and/or cooling purpose, and air. In order to enhancechemical reactions, catalysts, which may be very expensive (e.g., rhodium, gold, and silver),
are added into the reactors. The inflow can include the above substances and energy. Through the
manufacture, profitable products are produced, together with byproducts and wastes. Byproducts
have their own values only when they are used for adjustable applications; otherwise, they can
become wastes.
Wastes can be categorized as harmless or harmful. The former essentially does not have an
environmental impact, while the latter is important. Identification of harmful wastes, design of
new manufacturing processes, and retrofits of existing plants can be conducted with help of
knowledge-based approaches and/or numerical optimization approaches. Conceptual tools have
also been used in the development stages of a design. A hierarchical decision procedure
described by Douglas is a good example [17].
The knowledge-based system, sometimes called an expert system, is a system of rules
based on an area of expert proven knowledge. It also can be used for hierarchical design and
review procedures. Computer programs based on the system can simulate human thought
processes and can therefore be used to design cleaner manufacturing facilities to produce less
polluted (or greener) products. This system is essentially dependent upon a long-term
accumulation of experts’ knowledge. It can be used for new plant design as well as retrofit of an
old plant. More recently, Halim and Srinivasan [18] developed an intelligent system for
qualitative waste minimization analysis. A knowledge-based expert system, called ENVOP
Expert was used to identify practical and cost-effective P2 programs. A case study of the
hydrodealkylation process was tested with satisfactory results.
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Figure 2 Illustration of manufacture production and subsequent waste generation.
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Numerical optimization approaches are based on several considerations, such as energy
consumption and mass transfer. Economic analysis together with consumption of both energy
and mass have been incorporated by some researchers.
The well-cited pinch analysis (or pinch technology) originally developed based on
fundamental thermodynamics has been used to analyze heat flows through industrial processes.
It can be used for reduction of energy consumption. It also can be used to minimize wastewater
in process industries [19]. Through water reuse and/or other the internal rearrangements in the
manufacturing facility, the emission of waste to the environment can therefore be minimized.
This approach was used for P2 in a citrus plant [20]. An initial diagnosis indicated that the
maximum theoretical freshwater consumption or wastewater generation was reduced by 31%.
Single- and multi-objective optimization approaches have been used in the analysis of
pollution prevention. The integration approach has been used in pollution prevention/wastewater minimization programs [21–24]. The fundamentals of the approach are
optimization/minimization of capital and operating costs with minimum waste production
and energy consumption. A series of case studies is available in the literature. For example,
Parthasarathy and Krishnagopalan [25] used mass integration for the systematic reallocation of
aqueous resources in a Kraft pulp mill. An optimal allocation of chloride in different streams
throughout the plant was achieved, which led to a built-up concentration below undesirable
levels. More importantly, the freshwater requirement was reduced by 57%. For more technical
information on P2 and case histories see Chapter 1.
REFERENCES
1. Shen, T.T. Industrial Pollution Prevention Book, 2nd Ed.; Springer-Verlag: Germany, 1999.
2. USEPA. Pollution Prevention 1997 – A National Progress Report, EPA-742-R-97-000; USEPA:
Washington, DC, 1997.
3. Shen, T.T. New Directions for Environmental Protection; The Chinese–American Academic and
Professional Society Annual Meeting, New York, August, 2002.
4. Hagler Bailly Consulting, Inc. Introduction to Pollution Prevention, Training Manual, EPA-742-B-
95-003; Hagler Bailly Consulting, Inc.: Arlington, VA, July, 1995.
5. Shen, T.T. Sustainable Development: Strategy and Technology. Keynote speech at the Sustainable
Development and Emerging Technology Forum sponsored by the United Nations and hosted by the
Chinese Ministry of Science and Technology, Beijing, April 2002.
6. USEPA. Facility Pollution Prevention Guide, EPA/600/R-92/088; USEPA: Washington, DC, 1992.
7. Ling, J. Industrial Waste Management. A speech published in the Vital Speeches of the Day,
Vol. LXIV, No. 9, February 18, 1998, 284–288.
8. Overcash, M. The evolution of US pollution prevention, 1976–2001: a unique chemical engineering
contribution to the environment – a review. J. Chem. Technol. Biotechnol. 2002, 77, 1197.
9. Bendavid-Val, A.; Overcash, M.; Kramer, J.; Ganguli, S. EP3 – Environmental Pollution Prevention
Project Paper; US Agency for International Development, project No 936-5559, Washington, DC,
1992; 71.
10. Das, L.K.; Jain, A.K. Pollution prevention advances in pulp and paper processing, Environ. Prog.
2001, 20(2), 87.
11. Sarkis, J.; Cordeiro, J.J. An empirical evaluation of environmental efficiencies and firm performance:
pollution prevention versus end-of-pipe practice. Eur. J. Opl Res. 2001, 135, 102.
12. USEPA. Printed Wiring Board Pollution Prevention and Control Technology: Analysis of Updated
Survey Results, EPA 744-R-95-006; USEPA: Washington, DC, 1995.
13. USEPA. 33/50 Program, The Final Record, Office of Pollution Prevention and Toxics, EPA-745-R-
99-004; USEPA: Washington, DC, March, 1999.
14. Metcalf and Eddy, Inc. Wastewater Engineering Treatment, Disposal, and Reuse, 4th Ed. McGraw-
Hill, New York, 2002.
Pollution Prevention 1003
Copyright #2004 by Marcel Dekker, Inc. All Rights Reserved.
15. Evans, J.W.; Hamner, B. Cleaner production at the Asian Development Bank. J. Cleaner Prod. 2003,
11, 639.
16. Krewer, U.; Liauw, M.A.; Ramakrishna, M.; Babu, M.H.; Raghavan, K.V. Pollution prevention
through solvent selection and waste minimization. Indust. Engng Chem. Res. 2002, 41, 4534.
17. Douglas, J.M. Process synthesis for waste minimization. Indust. Engng Chem. Res. 1992, 31(1), 238.
18. Halim, I.; Srinivasan, R. Integrated decision support system for waste minimization analysis in
chemical processes. Environ. Sci. Technol. 2002, 36, 1640.
19. Wang, Y.P.; Smith, R. Wastewater minimization. Chem. Engng Sci. 1994, 49(7), 981.
20. Thevendiraraj, S.; Klemes, J.; Paz, D.; Aso, G.; Cardenas, G.J. Water and wastewater minimization
study of a citrus plant Res. Conserv. Recycling 2003, 37, 227.
21. El-Halwagi, M.M. Pollution Prevention Through Process Integration: Systematic Design Tools;
Academic Press: San Diego, 1997.
22. Alva-Argaez, A.; Kokossis, A.C.; Smith, R. Wastewater minimization of industrial systems using an
integrated approach. Comput. Chem. Engng 1998, 22, 741.
23. Savelski, M.J.; and Bagajewicz, M.J. On the optimality conditions of water utilization systems in
process plants with single contaminants. Chem. Engng Sci. 2000, 55, 5035.
24. Bagajewicz, M.; Rodera, H.; Savelski, M. Energy efficient water utilization systems in process plants.
Comput. Chem. Engng 2002, 26, 59.
25. Parthasarathy, G.; Krishnagopalan, G. Systematic reallocation of aqueous resources using mass
integration in a typical pulp mill. Adv. Environ. Res. 2001, 5, 61.
1004 Chen et al.
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