51    REMEDIAL BIODEGRADATION OF LOW ORGANIC
STRENGTH COOLING WATER USING CARBON
FLUIDIZED BED REACTOR
Arthur H. Kuljian, Jr., Senior Project Manager
McNamee Industrial Services, Incorporated
Ann Arbor, Michigan 48108
Peter A. Van Meter, Site Manager
Charles D. Fifield, Senior Vice President/Principal
Jerald O. Thaler, Manager of Advanced Technology
McNamee, Porter & Seeley, Incorporated
Ann Arbor, Michigan 48108
INTRODUCTION
In 1991, a Midwestern chemical manufacturer determined that its existing retention pond-based
wastewater handling system would be unable to consistently comply with the regulatory requirements
of its anticipated NPDES permit renewal. Furthermore, the state's proposed stringent water quality
standards coupled with other environmental and social factors had made it evident that upgrading the
existing treatment system would be required. This paper describes the investigations and results from
treatability studies undertaken by McNamee Industrial Services, Incorporated (MIS) in determining
the optimal treatment and design criteria for a full-scale treatment system.
BACKGROUND
The chemical company's storm sewer transports once-through cooling water and stormwater from
its manufacturing complex to surface waters, a discharge which periodically contains low levels of
organic compounds. When the existing NPDES permit for this site is renewed, the state agency has
indicated that there may be effluent limitations for over forty additional compounds. Those of
greatest concern due to their extensive usage at the site are methanol, acetone, and methylene chloride. Others of particular concern due to the frequency or quantity of use at the facility are t-butanol,
1,2-dichloroethane, tetrahydrofuran, and toluene.
In mid-1991, a preliminary treatability study was conducted by McNamee to evaluate the capability
of a biological fluidized bed reactor (FBR) for treating methanol and other organic compounds; sand
was used as the reactor media in this evaluation. The results indicated promising performance by the
FBR process at relatively high organic loading conditions, as well as a reasonable capacity to handle
shock loads.
In late-1991 and early-1992 as the proposed effluent limitations became more stringent, McNamee
next performed a bench-scale study to further evaluate the sand FBR versus two other alternatives: a
biological FBR using granular activated carbon as the reactor media, and a submerged fixed-media
reactor or "biofilter." In addition, polishing filters using granular activated carbon were evaluated for
the potential to further improve final effluent quality from any of the three configurations. Figure 1
depicts the relative removal mechanisms for each alternative. It was concluded from this study that
both FBRs provided more effective treatment at steady-state than the biofilter and, in addition, that
the carbon FBR was superior for treatment of shock loads. Also demonstrated was that final polishing filters did not significantly improve effluent quality for the measured organics from the carbon
FBR.
Based on these results and as a continuation of the overall program, the chemical manufacturer
commissioned McNamee in mid-1992 to test the carbon FBR on a pilot scale. The specific goal of this
study was to finalize the process design parameters for a full-scale carbon fluidized bed reactor (FBR)
system, using a prototype of commercially available equipment (by Envirex, Ltd., Waukesha, Wis-
49th Purdue Industrial Waste Conference Proceedings, 1994 Lewis Publishers, Chelsea, Michigan 48118. Printed in
U.S.A.
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