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ENHANCED COD REMOVAL FROM PHARMACEUTICAL
WASTEWATER USING POWDERED ACTIVATED CARBON ADDITION
TO AN ACTIVATED SLUDGE SYSTEM
Richard A. Osantowski, Manager
Industrial Waste Section
EnviroEnergy Technology Center
Rexnord, Inc.
Milwaukee, Wisconsin 53201
Clyde R. Dempsey, Acting Chief
Chemicals and Chemical Products Branch
Kenneth A. Dostal, Environmental Engineer
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
INTRODUCTION
The pharmaceutical manufacturing point source category manufactures biological products, medicinal chemicals, botanical products, and pharmaceutical products covered by Standard Industrial
Classification Code Numbers 2831, 2833, and 2834, as well as other commodities. The industry is
characterized by diversity of product, process, plant size, as well as wastewater quantity and quality.
For example, many plants will generate wastewaters with chemical oxygen demand (COD) concentrations ranging from 500 to 1500 mg/l whereas wastewaters from Subcategories A (Fermentation
Products) and C (Chemical Synthesis Products) may have COD concentrations up to 10,000 mg/l
and higher [1]. These latter plants may be able to discharge treated wastewaters meeting Best Practicable Control Technology Currently Available (BPT), which is defined as a COD removal of 14%
[1). However, these treated wastewaters may still contain COD concentrations of 2,600 mg/l and
higher.
On November 26, 1982, the U.S. Environmental Protection Agency (EPA) proposed Best Available Technology Economically Achievable (BAT) and New Source Performance Standards (NSPS)
designed to control the discharge of the nonconventional pollutant, COD, as well as other pollutants
from pharmaceutical manufacturing facilities 12,3]. The industry commented that the proposed regulations could not be met by A and C subcategory plants based on the proposed technology.
On October 27, 1983, the EPA promulgated final Pharmaceutical Manufacturing Point Source
Category Effluent Limitations Guidelines, Pretreatment Standards, and New Source Performance
Standards [4,5]. In this rulemaking, the Agency decided to return to the 1976 BPT subcategorization
scheme, and, as a result, the 1982 proposed COD regulations are no longer a valid point of comparison. A final decision on appropriate BAT limitations and NSPS for COD was postponed until
additional information could be obtained on applicable COD removal technologies and their achievable concentrations.
By way of responding to these additional information needs, the EPA initiated a program which
included studies designed to evaluate the ability of activated carbon adsorption technologies to reduce
the effluent COD concentrations.
Two technologies were evaluated at a Subcategories A and C pharmaceutical manufacturing plant
which employed secondary treatment and reported high COD concentrations in their discharge monitoring report. The two technologies were: 1) Powdered activated carbon (PAC) addition to the
activated-sludge aeration basin; and 2) granular activated carbon (GAC) treatment of the secondary
effluent.
This paper presents the results of the PAC/activated sludge studies. From September to December, 1984, an eighty-three (83) day study was conducted using the biological pilot plant shown on
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