handbook of industrial and hazardous wastes treatment

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

971

Copyright #2004 by Marcel Dekker, Inc. All Rights Reserved.

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

972 Chen et al.


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

Pollution Prevention 973


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.

974 Chen et al.


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.



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

976 Chen et al.


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



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.

978 Chen et al.


http://www.epa.gov

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



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.

980 Chen et al.


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.



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.

982 Chen et al.


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;



. 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.

984 Chen et al.


. 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;



. 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

986 Chen et al.


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.



. 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.

988 Chen et al.


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,



(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;

990 Chen et al.


. 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.



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.

992 Chen et al.


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



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

994 Chen et al.


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.



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

996 Chen et al.


Figure 1 Separation technologies for particles of various sizes.

Pollu

tionPreventio

n997

Copyright

#2004

by M

arcel D

ekker, Inc. A

ll R

ights R

eserved.

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

998 Chen et al.


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.



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.

1000 Chen et al.


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.



Figure 2 Illustration of manufacture production and subsequent waste generation.

1002

Chenetal.

Copyright

#2004

by M

arcel D

ekker, Inc. A

ll R

ights R

eserved.

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.



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.


handbook of industrial and hazardous wastes treatment

Documents