Page 437 - Academic Press Encyclopedia of Physical Science and Technology 3rd Chemical Engineering

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Encyclopedia of Physical Science and Technology EN012I-591 July 26, 2001 15:54

Pollution Prevention from Chemical Processes 603

VIII. THE INCENTIVE FOR Biodegradable aqueous waste
POLLUTION PREVENTION Incentive based on hydraulic $3000 per each additional gallon
flow per minute (gpm)
Incentive based on organic loading $6000 per each additional pound
There are several ways to determine the incentive for
organic per hour (lb/hr)
pollution prevention. The choice will depend on par-
Nonbiodegradable aqueous waste
ticular circumstances; that is, does a waste treatment
Incentive based on hydraulic $1000 per each additional gpm
or abatement system already exist or is a new treat- flow
ment or abatement system required? Three approaches Incentive based on organic Some technologies are sensitive
to determine the incentive for pollution prevention are loading to organic loading and some
described below. They are the incentive based on new end- are not
of-pipe treatment, raw material costs, and cost of manu-
facture. Each of these approaches is discussed in detail B. Raw Materials Cost
below.
Waste stream composition and flow rate can be used to
estimate the amount of raw materials lost as waste. The
A. New End-of-Pipe Treatment product of the amount lost to waste and the purchase price
sets the incentive for pollution prevention in terms of raw
Gaseous and aqueous waste streams often require capi-
material cost alone.
tal investment for new facilities or an upgrade of exist-
ing equipment, e.g., replacing an in-ground wastewater
treatment basin with an aboveground treatment system in C. Cost of Manufacture
tanks. Solid wastes (both hazardous and nonhazardous)
are normally handled with existing investment (e.g., site The cost of manufacture includes all fixed and variable
hazardous waste incinerator) or shipped off-site for dis- operating costs for the facility, including the cost for raw
posal. In the latter case, commercial disposal costs (in- materials. The cost of manufacture should be cast in the
cluding the cost of transportation) serve as the incentive form of dollars per pound ($/lb) of a key raw material.
for pollution prevention. Another number that is readily available is the product
selling price in dollars per pound of product. Depending
on the state of the business—excess capacity or sold out—
1. Gas Streams one of these two numbers can be used to determine the
A major opportunity for savings is to reduce the flow incentive for pollution prevention.
of diluent or carrier gas (often air or nitrogen) at the
source. For a gas stream containing both particulates and For a business operating with excess capacity, the
halogenated volatile organic compounds (VOCs), the product of the cost of manufacture ($/lb raw material)
minimum capital investment to abate this stream is about and the amount of raw material that goes to waste
$75 per standard cubic foot per minute (scfm) of waste (either directly or as a by-product of reaction) sets the
gas flow. incentive for pollution prevention.

For a sold-out business, every additional pound of
product can be sold; therefore, the product of
2. Wastewater Streams
the product selling price and the additional amount
Simply speaking, wastewater streams fall into one of two of product that can be sold determines the incentive for
general categories, those that are biologically treatable pollution prevention.
and those requiring pretreatment or stand-alone nonbi-
ological treatment (such as chemical oxidation, stripping,
and adsorption). When treating dilute aqueous organic IX. RESOURCES
waste streams at the end of the pipe, consideration must
be given to source reduction of both water flow and In many respects, the best set of resources for generating
organic loading. Substantial reductions in capital invest- waste reduction ideas consists of a business’ own people.
ment can result by reducing water flow and contam- However, a business will sometimes need to bring other
inant loading at the source. The magnitude of these expertise to the table to supplement its own resources.
reductions will vary with technology type, hydraulic flow, Some examples of other resources include a brainstorm-
and concentration; however, the minimum incremental ingfacilitator,technicalspecialists,outsidersorwildcards,
capital investments for new treatment facilities are as and sources of pollution prevention ideas found in the
follows: literature.