28    AEROBIC AND ANAEROBIC TREATMENT OF
HIGH-STRENGTH INDUSTRIAL WASTE RESIDUES
E. S. Venkataramani, Engineering Associate
Merck & Co., Inc.
Rahway, New Jersey 07065
Robert C. Ahlert, Professor II
Rutgers, The State University of New Jersey
Department of Chemical and Biochemical Engineering
Piscataway, New Jersey 08854
Patricia Corbo, Engineer
DuPont, Savannah River Works
Aiken, South Carolina 29801
INTRODUCTION
The pollution of groundwater by high-strength industrial waste residues, leaching from landfills, is
relatively recent and adds a new dimension to existing pollution problems. Many landfills have
inadvertently accepted chemical waste for disposal. Over a period of time, waste containers corrode
and release solvents, oils, and synthetic chemicals, that constitute potential problems of enormous
magnitude and complexity. The list of abandoned hazardous waste sites to be cleaned up under
Superfund could grow to between 1500 and 2500 [1]. Possible contamination of groundwater by
landfills is most serious in the Northeast. Depending on the wastes deposited at an industrial landfill
site, the leachate produced can contain various synthetic and toxic chemicals, including heavy metals
and known or suspected carcinogens [2]. Many represent classes of molecules that biologists and
biochemists have not investigated previously. Shukrow et al. [3] obtained composition data on leacha-
tes, contaminated aquifers, and surface waters in the proximity of twenty-seven sites containing
hazardous wastes. Ghassemi et al. [4] developed a data base for thirty different leachates from eleven
landfills. Hill et al. [5] investigated the relationships between BOD, COD, and TOC using a measurably larger data file in some industrial waste categories. An extensive discussion of biological treatment of high-strength leachates and industrial residues can be found in a review article by the authors
[6]. Recently, Kosson developed an efficient, cost-effective, in-situ bio-reclamation technique for
cleanup of hazardous leachates and soil contaminated with waste residues [7].
The present work was designed to establish that aerobic, as well as anaerobic, biological treatment
can be used effectively to stabilize organic compounds found in high-strength waste residues.
In the aerobic treatment step, an activated sludge biomass is used to develop microbial populations
capable of metabolizing the organic compounds. A research scheme was designed to identify the mode
of removal of synthetic organic compounds. The process kinetics were elucidated by following microbial responses to organic species in the high-strength waste.
In the anaerobic treatment step, an anaerobic population was developed from an industrial seed
acclimated to two feeds: 1) one containing the industrial residue; and 2) a second, synthetic feed
simulating the volatile fatty acid content of the industrial residue. Seed cultures were maintained for
nine months. The kinetics of volatile fatty acid uptake and methane production from industrial
residue containing other contaminants were compared with those of the synthetic waste to assess the
feasibility of application of anaerobic treatment for waste stabilization.
MATERIALS AND METHODS
High-Strength Industrial Waste Residue
The high-strength, complex industrial landfill leachate used in these studies is the aqueous phase of
a raw oil/water leachate mixture. This was provided by the USEPA Oil and Hazardous Materials
Spills Branch (Edison, NJ). Some of the recognized industrial pollutants found to be present in this
waste are illustrated by Table I [3]. Leachate samples designated as EPA-02, 04, and 07 were obtained
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