CHARACTERIZATION AND BIOLOGICAL TREATABILITY
OF COAL CONVERSION WASTEWATERS
James C. Lamb, HI, Professor
Philip C. Singer, Professor
Roger D. Rader, Research Assistant
David A. Reckhow, Research Assistant
Gerald E. Speitel, Research Assistant
Department of Environmental Sciences and Engineering
School of Public Health
The University of North Carolina
Chapel Hill, North Carolina 27514
INTRODUCTION
One approach to satisfying current energy needs is conversion of coal to synthetic gaseous or liquid fuels, but all of the techniques for accomplishing that have serious air and
water pollution potential. The Environmental Protection Agency is supporting major efforts:
(a) to identify characteristics of wastewaters from different types of conversion processes,
(b) to evaluate environmental impact and fate of wastewater constituents, and (c) to assess
various measures for pollution control in this industry. A five-year project currently is underway at the University of North Carolina, in Chapel Hill, as part of that total program. This
paper describes procedures and preliminary results from those phases of the UNC investigation directed towards evaluating characteristics of coal conversion wastewaters and investigating their biological treatability.
OBJECTIVES AND SCOPE
Objectives of the biological treatability studies to be discussed in this paper may be
summarized as follows:
1. Identification of constituents of coal conversion wastewaters
2. Investigation of biodegradability of those constituents
3. Evaluation of toxic effects on biological treatment systems
4. Preliminary determination of design parameters
5. Assessment of toxic effects on aquatic life
6. Preliminary assessment of treatment effects on mammalian toxicity
7. Evaluation of the extent to which specific constituents are removed from the wastewater
during biological treatment.
Detailed investigations will be carried out subsequently to evaluate design parameters more
accurately and to assess performance of proposed systems when treating wastewaters from
operating coal conversion facilities.
CHARACTERISTICS OF COAL CONVERSION WASTEWATERS
The initial phase of UNC research was directed towards a review of characteristics of
wastewaters from coal conversion operations [ 1]. This permits preliminary assessment of
aquatic impact of the wastewaters and selection of treatment techniques for laboratory and
pilot investigations. Table I summarizes types of chemicals which have been reported to be
constituents of wastewaters from several conversion processes, as well as the number of
specific compounds within each category identified by past authors.
The composition of coal conversion wastewater depends on the conversion technology
used and type of coal fed to the system. Nevertheless, data reported in the literature suggest
relatively uniform composition, especially with respect to phenolic constituents, which are
predominant organics in the discharges. Information about other constituents, such as
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