Pollution Prevention
Pollution prevention is a carefully planned investment aimed at reducing an enterprise's operating costs through the elimination of harmful pollution.
From: Green Profits, 2001
Related terms:
Contaminant, Reuse, Hazardous Waste, Management, Raw Material, Recycling,
Solvent, Waste Minimisation, waste water
View all Topics
Learn more about Pollution Prevention
Pollution Prevention
Woodard & Curran, Inc., in Industrial Waste Treatment Handbook (Second
Edition), 2006
Pollution Prevention Leads to Environmental Sustainability
Once pollution prevention practices are implemented throughout the industrial
process, a business will be well on its way to achieving environmental sustainability.
Sustainability, as defined by the Brundtland Commission in 1987, is “development
that meets the needs of the present without compromising the ability of future
generations to meet their own needs.” While cost savings and regulatory drivers are
important, environmental sustainability represents a higher goal—one that should
be strived for because it's the right thing to do.
The benefits of pollution prevention and environmental sustainability not only
include cost savings and regulatory compliance, but also improved working conditions for employees, competitive advantages with environmental-sawy clients and
consumers, and improved community and regulator relations.
> Read full chapter
Removal of Organic Compounds From
the Environment
Dr.James G. Speight, in Environmental Organic Chemistry for Engineers, 2017
5.5 Options
Pollution prevention is the responsibility of everyone and preventing pollution may
be a new role for production-oriented managers and workers, but their cooperation
is crucial. It will be the workers themselves who must make pollution prevention
succeed in the workplace.
The best way to reduce pollution is to prevent it in the first place. Some companies have creatively implemented pollution prevention techniques that improve
efficiency and increase profits while at the same time minimizing environmental impacts. This can be done in many ways such as reducing material inputs,
reengineering processes to reuse by-products, improving management practices,
and substituting benign chemicals for toxic ones. Some smaller facilities are able to
actually get below regulatory thresholds just by reducing pollutant releases through
aggressive pollution prevention policies. Furthermore, it is critical to emphasize that
pollution prevention in the chemical industry is process specific and oftentimes
constrained by site-specific considerations. As such, it is difficult to generalize
about the relative merits of different pollution prevention strategies. The age, size,
and purpose of the plant will influence the choice of the most effective pollution
prevention strategy. Commodity chemical manufacturers redesign their processes
infrequently so that redesign of the reaction process or equipment is unlikely in
the short term. Here operational changes are the most feasible response. Specialty
chemical manufacturers are making a greater variety of chemicals and have more
process and design flexibility. Incorporating changes at the earlier research and
development phases may be possible for them.
Several options have been identified that production facilities can undertake to
reduce pollution. These include pollution prevention options, recycling options,
and waste treatment options. Furthermore, pollution prevention options are often
presented in four different categories, viz.: (1) pollution prevention options, (2) waste
recycling, and (3) waste treatment. Either one or the other or any combination of the
three options may be in operation in any given process.
Pollution prevention options are usually subdivided into four areas: (1) good operating practices, (2) processes modification, (3) feedstock modification, and (4) product
reformulation (Lo, 1991). The options described here include only the first three of
these categories since product reformulation is not an option that is usually available
to the environmental analyst, scientist, or engineer.
5.5.1 Operating Practices
Good operating practices (Table 9.6) prevent waste by better handling of feedstocks
and products without making significant modifications to current production technology. If feedstocks are handled appropriately, they are less likely to become wastes
inadvertently through spills or outdating. If products are handled appropriately, they
can be managed in the most cost-effective manner.
For example, a significant portion of process waste arises from oily sludge found
in combined process/storm sewers. Segregation of the relatively clean rainwater
runoff from the process streams can reduce the quantity of oily sludge generated.
Furthermore, there is a much higher potential for recovery of oil from smaller, more
concentrated process streams.
Solids released to the process wastewater sewer system can account for a large
portion of a process's oily sludge. Solids entering the sewer system (primarily
soil particles) become coated with oil and are deposited as oily sludge in the API
oil/water separator. Because a typical sludge has a solids content of 5-30% by weight,
preventing one pound of solids from entering the sewer system can eliminate several
pounds 3-0 pounds of oily sludge.
Methods used to control solids include using a street sweeper on paved areas, paving
unpaved areas, planting ground cover on unpaved areas, relining sewers, cleaning
solids from ditches and catch basins, and reducing heat exchanger bundle cleaning
solids by using antifoulant materials in cooling water. Benzene and other solvents
in wastewater can often be treated more easily and effectively at the point at which
they are generated rather than at the wastewater treatment plant after it is mixed
with other wastewater.
5.5.2 Process Modifications
The organic chemicals industry requires very large, capital-intensive process equipment. Expected lifetimes of process equipment are measured in decades. This
limits economic incentives to make capital-intensive process modifications to reduce
wastes generation. However, some process modifications (Table 9.7) or process
improvement (Table 9.8) reduce waste generation.
The organic chemicals industry has made many improvements in the design and
modification of processes and technologies to recover product and unconverted raw
materials. In the past, they pursued this strategy to the point that the cost of further
recovery could not be justified. Now the costs of end-of-pipe treatment and disposal
have made source reduction a good investment. Greater reductions are possible
when process engineers trained in pollution prevention plan to reduce waste at the
design stage. For example, although barge loading is not a factor for all production
facilities, it is an important emissions source for many facilities. One of the largest
sources of volatile organic carbon emissions is the fugitive emissions from loading
of tanker barges. These emissions could be reduced by more than 90% by installing
a vapor loss control system that consists of vapor recovery or the destruction of the
volatile organic carbon emissions in a flare.
Fugitive emissions are one of the largest sources of process hydrocarbon emissions.
A leak detection and repair program consists of using a portable detecting instrument to detect leaks during regularly scheduled inspections of valves, flanges, and
pump seals. Older process boilers may also be a significant source of emissions
of sulfur oxides (SOx), nitrogen oxides (NOx), and particulate matter. It is possible
to replace a large number of old boilers with a single new cogeneration plant with
emissions controls.
Since storage tanks are one of the largest sources of VOC emissions, a reduction
in the number of these tanks can have a significant impact. The need for certain
tanks can often be eliminated through improved production planning and more
continuous operations. By minimizing the number of storage tanks, tank bottom
solids and decanted wastewater may also be reduced. Installing secondary seals on
the tanks can significantly reduce the losses from storage tanks containing gasoline
and other volatile products.
Solids entering the crude distillation unit are likely to eventually attract more oil
and produce additional emulsions and sludge. The amount of solids removed from
the desalting unit should, therefore, be maximized. A number of techniques can be
used such as: using low shear mixing devices to mix desalter wash water and crude
oil, using lower pressure water in the desalter to avoid turbulence, and replacing
the water jets used in some production facilities with mud rakes which add less
turbulence when removing settled solids.
Purging or blowing down a portion of the cooling water stream to the wastewater
treatment system controls the dissolved solids concentration in the recirculating
cooling water. Solids in the blowdown eventually create additional sludge in the
wastewater treatment plant. However, minimizing the dissolved solids content of
the cooling water can lower the amount of cooling tower blowdown. A significant
portion of the total dissolved solids in the cooling water can originate in the cooling
water makeup stream in the form of naturally occurring calcium carbonates. Such
solids can be controlled either by selecting a source of cooling tower makeup water
with less dissolved solids or by removing the dissolved solids from the makeup water
stream. Common treatment methods include: cold lime softening, reverse osmosis,
or electrodialysis.
In many production facilities, using high-pressure water to clean heat exchanger
bundles generates and releases water and entrained solids to the process wastewater
treatment system. Exchanger solids may then attract oil as they move through the
sewer system and may also produce finer solids and stabilized emulsions that are
more difficult to remove. Solids can be removed at the heat exchanger cleaning pad
by installing concrete overflow weirs around the surface drains or by covering drains
with a screen. Other ways to reduce solids generation are by using antifoulants on
the heat exchanger bundles to prevent scaling and by cleaning with reusable cleaning
chemicals that also allow for the easy removal of oil.
Surfactants entering the process wastewater streams will increase the amount of
emulsions and sludge generated. Surfactants can enter the system from a number of
sources including: washing unit pads with detergents; treating gasoline with an end
point over 200°C (> 392°F), thereby producing spent caustics; cleaning tank truck
tank interiors; and using soaps and cleaners for miscellaneous tasks. In addition,
the overuse and mixing of the organic polymers used to separate oil, water, and
solids in the wastewater treatment plant can actually stabilize emulsions. The use of
surfactants should be minimized by educating operators, routing surfactant sources
to a point downstream of the DAF unit and by using dry cleaning, high pressure
water or steam to clean oil surfaces of oil and dirt.
Replacing 55-gallon drums with bulk storage facilities can minimize the chances of
leaks and spills. And, just as 55-gallon drums can lead to leaks, underground piping
can be a source of undetected releases to the soil and groundwater. Inspecting, repairing or replacing underground piping with surface piping can reduce or eliminate
these potential sources.
Finally, open ponds used to cool, settle out solids and store process water can be
a significant source of volatile organic carbon emissions. Wastewater from coke
cooling and coke volatile organic carbon removal is occasionally cooled in open
ponds where volatile organic carbon easily escapes to the atmosphere. In many cases,
open ponds can be replaced with closed storage tanks.
5.5.3 Material Substitution Options
Spent conventional degreaser solvents can be reduced or eliminated through substitution with less toxic and/or biodegradable products. In addition, chromate containing wastes can be reduced or eliminated in cooling tower and heat exchanger
sludge by replacing chromates with less toxic alternatives such as phosphates.
Using catalysts of a higher quality will lead in increased process efficiency,
while the required frequency of catalyst replacement can be reduced. Similarly, the
replacement of ceramic catalyst support with activated alumina supports presents
the opportunity for recycling the activated alumina supports with the spent alumina
catalyst.
> Read full chapter
Environmental Laws and Regulations
Ravi Jain Ph.D., P.E., ... M. Diana Webb M.L.A., in Handbook of Environmental
Engineering Assessment, 2012
Key Provisions
The Pollution Prevention Act of 1990 established as national policy the following
waste management hierarchy:
1.
2.
3.
4.
Prevention. The waste management priority is to prevent or reduce pollution
at the source whenever feasible.
Recycling. Where pollution cannot be prevented, it should be recycled in an
environmentally safe manner whenever feasible.
Treatment. In the absence of feasible prevention and recycling, pollution should
be treated to applicable standards prior to release or transfers.
Disposal. Only as a last resort are wastes to be disposed of safely.
The Pollution Prevention Act further directed the EPA to:
1.
2.
3.
4.
5.
6.
Establish a prevention office independent of the agency's single-medium
program offices (the EPA added pollution prevention to the existing function
of Assistant Administrator for Pesticides and Toxic Substances).
Facilitate the adoption by business of source-reduction techniques by establishing a source-reduction clearinghouse and a state-matching grants program.
Establish a training program on source-reduction opportunities for state and
federal officials working in all agency program offices.
Identify opportunities to use federal procurement to encourage source reduction.
Establish an annual award program to recognize companies that operate
outstanding or innovative source reduction programs.
Issue a biennial status report to Congress.
7.
Require an annual toxic chemicals source-reduction and recycling report for
each owner or operator of a facility already required to file an annual toxic
chemical release form under Section 313 of SARA (presented earlier).
The EPA is integrating pollution prevention into all its programs and activities and
has developed unique voluntary reduction programs with the public and private
sectors.
The executive branch of the federal government has sought to apply pollution-prevention requirements broadly throughout the government. Under Executive Order
13148, “Greening the Government through Leadership in Environmental Management,” April 21, 2000, federal agencies became responsible for integrating environmental accountability and more stringent pollution prevention considerations
into their day-to-day decisions and long-term planning. The executive order is
administered by the EPA, with certain responsibilities delegated to the CEQ.
> Read full chapter
Sustainable Approaches
Daniel Vallero, in Fundamentals of Air Pollution (Fifth Edition), 2014
32.8 Socioeconomic Costs and Benefits
Pollution prevention has the distinct advantage over stack controls in that most
of the time the company or other prospective air pollution source (e.g. university
facilities and maintenance departments, city public works departments, and state
highway departments) not only eliminates or greatly reduces the release of hazardous materials but also saves money. The most obvious costs are those normally
documented in company and departmental records, such as direct labor, raw materials, energy use, capital equipment, site preparation, tie-ins, employee training,
and regulatory recordkeeping (e.g. permits).16 However, there are numerous other
savings, including those resulting from not having to spend time on submitting
compliance permits and suffering potential fines for noncompliance. Future liabilities weigh heavily where hazardous wastes have to be buried or injected, as well as
air pollution control equipment that cannot meet prospective emission standards.
Additionally, there are the intangible benefits of employee relations and safety (see
Table 32.2).
In many ways, the transition from command and control approaches to prevention
has been incremental; an evolution rather than a revolution. Regulatory requirements and good engineering practice will continue to call for better approaches
in both areas. Control technologies and pollution prevention are not separate
endeavors. In fact, the life cycle view prohibits such dichotomies. They are both
crucial tools in green design. The advances will continue toward sustainability and
beyond, e.g. regenerative materials and technologies. By focusing on the function
and eliminating inefficiencies, we can expect even better results will be attained.
Engineers and other designers are dedicated to continuous improvement and total
quality. As such, regenerative strategies for design, manufacturing, use, and reuse
will increasingly be embraced. Process modifications usually involve the largest
investments of human and financial resources, and can result in the most rewards.
For example, using wash water countercurrently instead of a once-through batch
operation can significantly reduce the amount of wash water needing treatment.
However, such a change requires new and redirect conduits, pipes, and valves;
all necessitating a new process protocol. In industries where materials are dipped
into solutions, such as in metal plating, the use of drag-out recovery tanks as an
intermediate step has resulted in the savings of the plating solution and reduction
in the volume of waste generated.
Pollution prevention has the distinct advantage over stack controls in that most of
the time the company not only eliminates or greatly reduces the release of hazardous
materials, and may also reduce energy requirements. The potential for future costs
and liabilities weigh heavily on decisions about air pollution prevention and control.
Indeed, solving an air pollution problem is a systems problem. Removing a contaminant from the gas stream, only to have be concentrated in solid or liquid phase, must
include a plan for addressing this new problem, i.e. where and how to handle this
new hazardous wastes. Additionally, there are intangible benefits, such as employee
relations, occupational safety, and trust from the public. A company or departmental
ethos must be one of stewardship and concern for the next generations. Green
engineering and sustainable approaches to prevent air pollution must be part of that
ethos.
> Read full chapter
FINANCIAL PLANNING TOOLS
Nicholas P. Cheremisinoff Ph.D., Avrom Bendavid-Val, in Green Profits, 2001
Final Remarks on Pollution Prevention
Pollution prevention works best in the context of an EMS. In fact, P2 should become
an integral component of the EMS as opposed to a stand-alone program being
implemented by a group of engineers.
Indeed, it would be wrong to place a P2 program entirely in the hands of the technical
staff because the real driving force is improving bottom-line financial performance.
Reducing the four cost categories associated with pollution management is the
ultimate objective of any P2 program. For this reason, the proper mix for a P2
audit team should be a financial planner, technology-specific specialists, and either
a compliance officer or attorney (see Figure 5). By matching the skills, backgrounds
and experiences of the team members with the cost categories, we can ensure that
P2 recommendations will focus on as many opportunities as possible.
Figure 5. Matching skills of the audit team members with the cost savings categories.
Ultimately, if P2 is to have a significant impact in your enterprise, it cannot remain
focused on one portion of the plant. The EMS is the vehicle by which the examples
and benefits of localized P2 activities can be rolled-out to other parts of a plant
operation, and to satellite and affiliate operations of your enterprise.
All too often management views P2 as a long-term collection of activities, which can
present incremental advantages and improvements. Indeed, P2 can start off that
way, but when embraced in a macro-sense throughout the business, its impact can
be much more dramatic. We maintain that if enterprises were practicing elements
of pollution prevention 30 years ago, Superfund sites would likely not exist today.
The third-party liabilities resulting from off-site property damages and class-action
toxic tort cases of today and over the last 20 years, are a direct result of practices that
not only ignored fate and transport characteristics of pollution, but simply did not
focus on efficient manufacturing. Clearly we can argue that strict enforcement of
environmental laws is what has brought industry to understanding that it must be
responsible for how its operations interact with the environment and public safety,
but from a business standpoint we must recognize that the cost of compliance has
become excessive in some cases such that more effective approaches are needed
in order to sustain operations. Industry has always had the incentives to reduce
waste-full by-products. The thousands of tons of waste and spent solvents and
off-spec chemical products stockpiled in corroding drums, saturated soils from
careless spills and dumping, the percolation of these wastes into groundwaters that
ultimately impacted on drinking water supplies in parts of our country, the hundreds
of millions of dollars spent on fines, penalties, litigations due to off-site property
damages from careless waste management, not to mention site remediation efforts
that have gone on for decades at some facilities – all represent the reasons for
investing in pollution prevention and cleaner production.
And what about those parts of the world where many heavy industries operate within
the framework of weak environmental enforcement? These enterprises not only face
the same future liabilities that U.S. corporations did 30 years ago, but if they view
pollution in its broadest sense – as waste and inefficiency, then their incentives
exist. These enterprise simply have not quantified their losses and don't realize the
money being lost through by-products flowing down sewer drains, flowing out
of their stacks, and being washed away from stockpiles due to stormwaters. In
addition, globalization of industry and business practices are making it exceedingly
difficult for such operations to compete in world markets. Enterprises operating in
transitioning economies are simply finding that their ability to penetrate markets in
technologically advanced nations, where the general public recognizes the benefits
of a Green Stamp of approval on goods and services are poor.
Bear in mind that rigorous applications of the procedures and practices outlined for
both P2 and EMS are not what is important. Successful programs must be flexible
and adapted to the specific needs of the enterprise. The objective should not be
to restructure your entire enterprise, but rather to incorporate certain tools and to
refocus priorities so that the economics of the operations benefit through improved
environmental performance.
The following is a glossary of important financial terms to bear in mind. The
appendix contains a list of P2 and EMS resources, which includes both printed
references and Web sites we have visited and feel may assist you. And finally – if
you have any questions, the authors are available to assist.
> Read full chapter
Waste Characterization
Woodard & Curran, Inc., in Industrial Waste Treatment Handbook (Second
Edition), 2006
Choice of Sampling Location
Since pollution prevention is always a primary objective of any waste management
program, waste sampling programs should always be designed to determine at
which locations in an industrial processing plant significant amounts of waste
are generated. Otherwise, it would be necessary to sample only the final composite
effluent from the entire plant. The following example illustrates some of the choices
to be made when designing a wastes sampling program.
Figure 5-1 is a schematic of an electroplating shop with four different plating
processes, designated Process 1, Process 2, Process 3, and Process 4. At the present
time, all four processes discharge to a common drain that leads to the municipal
sewer system. The task at hand is to develop a waste sampling and analysis program
to provide data for a waste reduction program, as well as to enable calculation of
design criteria for one or more treatment devices to pretreat the wastewater prior to
its discharge into the municipal sewer system, within compliance with all applicable
regulations. If the sole objective were to treat the wastewater to within compliance
with the regulations, it would make sense to locate one composite sampler at the
end of the building to sample the mixed effluent from all four plating processes. The
questions then, would be, “How many days should the sampling period cover?” and
“Over how long a time should each compositing period take place?”
Figure 5-1. Schematic of an electroplating shop with four different processes.
The answer to the first question depends on the processing schedule and whether
or not different processes are run on a campaign basis in one or more of the four
processing units. It is more or less standard practice to sample the wastes from a
given process (or set of processes) over a three-consecutive-day period. Five would
be better than three, but a decision has to be made between the greater costs for the
longer sampling period and the greater risk associated with the shorter sampling
period. A prudent engineer will develop more conservative design criteria if the risk
of not having accurate waste characteristics is higher. The higher cost for the more
conservatively designed treatment system may well be more than the higher cost for
the longer sampling period.
The second question addresses the length in time of each compositing period. Four
six-hour composites per day produce four discrete samples to be analyzed, whereas
two 12-hour composite samples taken each day will cost only half as much to have
analyzed. Using any statistical approach available, the more discrete samples taken
during the 24-hour operating day (that is, the shorter the compositing periods), the
more accurate the results of the wastes characterization study will be. Here, again,
a prudent engineer will recognize that more conservatism, and, therefore, higher
cost, will have to be designed into a system. When the compositing periods are long,
the number of discrete samples each day is low, and the risk of not having accurate,
detailed characterization information is higher.
If the four plating processes are quite different from each other, a less expensive
overall treatment system might result if one or more are treated separately. If such
is the case, it would be appropriate to locate composite samplers at the discharge
point of each of the four processes. Now, the number of samples to be analyzed
for a given number of sampling days and a given number of composites each day
is multiplied by four. Still, the considerations of risk, conservatism in design, and
total cost apply, and it is often cost effective to invest in a more expensive wastes
characterization study to obtain a lower total project cost.
It is seldom prudent to consider that the sole reason for carrying out a wastes characterization study is to obtain data from which to develop design criteria for a wastes
treatment system. Rather, pollution prevention should almost always be a major
objective, as it should be with any wastes management initiative. As discussed in
Chapter 4, the many benefits of pollution prevention include lower waste treatment
costs, as well as lower costs for disposing of treatment residuals.
When taken in the context of a pollution prevention program, a wastes characterization study takes on considerations in addition to those discussed above. Using
the same example illustrated in Figure 5-1, it is seen that locating only one composite sampler to sample the combined wastewater from all four plating processes
would yield little information useful for pollution prevention purposes. For pollution
prevention purposes, it is necessary to locate at least one composite sampler at the
wastes discharge from each of the four plating processes. Furthermore, there is an
important consideration of timing regarding execution of the sampling program.
In order to enable measurement of the effectiveness and therefore the value, in
terms of cost savings, of the pollution prevention program, a complete wastes
characterization study should be carried out before wastes minimization or other
aspects of pollution prevention take place. These data, however, will not be useful for
developing design criteria for wastes treatment, since implementation of the pollution prevention program will, hopefully, significantly change the characteristics of
the waste stream to be treated.
A second wastes characterization study, then, should be conducted after the implementation and stabilization of the pollution prevention program. Stabilization
is emphasized here, because improved housekeeping—in the form of spill control,
containment, and immediate in-place cleanup; water conservation, containment,
and recycling of “out of spec, product or intermediate” (rather than dumping
these “bad batches” to the sewer); and other process efficiency improvement
measures—is implemented (as part of the pollution prevention program). If some of
the former poor housekeeping and materials control inefficiency creeps back into
the industry's routine operations, treatment processes designed using data obtained
during full implementation of the pollution prevention program will be overloaded
and will fail.
The principal objectives of a waste management program, which include pollution
prevention along with wastes characterization, are to ensure: (1) that truly representative samples are taken, (2) that the appropriate samples are taken and the
appropriate analyses performed, as dictated by the Clean Water Act and RCRA, (3)
that the information obtained is appropriate and sufficient to produce an optimal
waste-minimization result, and (4) that the optimum balance is struck between the
cost of the waste characterization study and the cost for the treatment facilities
ultimately designed and constructed.
> Read full chapter
Pollution prevention and best practices
for the wood-preserving industry
Nicholas P. Cheremisinoff, Paul E. Rosenfeld, in Handbook of Pollution Prevention
and Cleaner Production, 2010
Publisher Summary
This chapter deals with pollution prevention techniques and best practices for
the wood-preserving industry. Modern wood-treating plants are considerably less
polluting than they were two decades ago, but still it is classified as a ‘‘dirty”
industry because of its dependence on chemicals that are toxic and carcinogenic.
This chapter discusses scientific and industry studies, which claim that chemicals
are most effective in killing pests and fungi and in destroying agents that cause the
decay of engineered wood articles. The industry should be obliged to use the best
available technologies and practices to control emissions and discharges. Finally, the
recommended best management practices and technologies are also defined.
> Read full chapter
Pollution and pollution controls
Nicholas P. Cheremisinoff, Paul E. Rosenfeld, in Handbook of Pollution Prevention
and Cleaner Production, 2010
Publisher Summary
This chapter deals with pollution prevention practices. Major waste and emission streams are discussed. The fate and transport of major pollution streams are
considered in this chapter along with various control technologies and practices.
Wood-treating plants generate fugitive and point sources of air emissions plus both
solid and liquid wastes. A point source is an emission that is fixed and/or uniquely
identifiable, such as a stack or vent. Fugitive emissions are those emissions entering
into the atmosphere that are not released through a stack vent, duct, pipes, storage
tank, or other confined air stream. These emissions include area emissions and
equipment leaks. This chapter details some of the sources of waste and pollution:
solid wastes, liquid wastes, and air emissions.
> Read full chapter
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