532 ABSTRACTS

will be monitored as a function of temperature and time. The product distribution of the organics remaining will

be studied by extracting the acidified reaction mass and analyzing the components by GLC, HPLC, GCMC, MS, and nmr. At higher temperatures, it is expected that dehalogenation will go to completion to give inorganic halide salts (e.g., CaC12 if CaO was the base) and organic

residues containing only carbon, hydrogen, and oxygen. If the halogen ends up as an inorganic salt, it will

subsequently be possible to completely oxidize the

organic residues to CO2 and water without the formation of HCl or dioxins. This would be done by passing hot air or oxygen directly over the solid mixture containing the organic residue. This sequence might lead to a cheap and acceptable means to destroy pesticide wastes and PCBs. That is the key goal of this research. For example, waste

PCBs could be slurried with an excess of CaO/CaCO3 and then be heated to a temperature where dechlorination

would be completed. The resulting CaO/CaC12/CaCO3 organic residue mixture would then be subjected to oxygen to burn off the organic residue. The remaining solid could be recycled with make-up CaO added if

necessary. Reactions at phase boundaries are frequently acceler-

ated using microwave (MW) heating. Thus, the reaction of halogenated organics (PCBs) with a hydrated Ca(OH) 2 layer at the surface of CaO particles might be promoted by microwave energy initially absorbed by water. Deha- logenations will be compared in the same temperature ranges using thermal and MW systems heating. After combustion, the resulting CaO/CaCI 2 from thermal or MW might be a suitable feed for cement manufacture. Alternatively, after dehalogenation has been completed, the combustion step to destroy the organic residue might be carried out in a cement kiln. This new research will draw on experience gained, and equipment acquired, by both principal investigators in earlier work sponsored by the Gulf Coast Hazardous Substance Research Center.

WHAT YOU SEE IS NOT WHAT YOU GET: BUSINESS PERCEPTIONS OF PUBLIC OPINION AND GOVERNMENT REGULATION OF HAZARDOUS WASTE

Philip H. Pollock Ill, M. Elliot Vittes and Stuart A. Lilie Department of Political Science, University of Central Florida, Orlando, FI 32816

As specialists in the field of opinion research, over the past three years we have gained a firm grasp of public at- titudes on waste-related issues, and we have identified the factors that shape those attitudes. Yet it is here that we encounter a paradox. Through active interaction with the waste industry and its consultants, we have learned

that many professionals within the business community do not accurately perceive the bases of public resistance to, and acceptance of, hazardous waste and treatment technologies. This misinterpretation, we believe, has hindered constructive dialogue between business and the public over prospective technologies, siting, and a raft of related challenges. Importantly, such misperceptions also serve to dramatize this disparity: As understanding of public opinion on waste issues has grown in range and sophistication, knowledge of industry perceptions and beliefs remains alarmingly limited. Our one-year study is aimed directly at this imbalance. We will determine industry attitudes on issues having key importance for public communication and government policy. Our pro- ject calls for a large-scale survey of firms involved in all facets of hazardous waste: producers, transporters, tech- nology-support firms, public communication consultants, and others. Our findings will, of course, be of great in- terest to scholars in a variety of specialized fields. But since this project's key objective is the enhancement of industry-based knowledge, we will focus major effort on an annotated summary that is accessible to all informed readers.

IN SITU REMEDIATION OF EDC CONTAMINATED VADOSE SOIL: A TOXICOLOGICAL ASSESSMENT

Ralph J. Portier, Barbara S. Shane, Maud M. Walsh and Millie B. Williams Institute for Environmental Studies, Louisiana State University, Baton Rouge, LA 70803-5705

Chlorinated aliphatic compounds are among the most common soil and groundwater contaminants because of their widespread use as industrial solvents. Our on-going study has two main objectives. The first is to examine the in situ biodegradation of one of these compounds, ethylene dichloride (EDC), in the vadose (unsaturated) soil zone above the groundwater, both in the desired aerobic setting and in a system in which anaerobiosis and subsequent production of vinyl chloride has occurred. We will also test whether an upset system can recover if oxygen, nutrients, and, possibly, inoculum are sub- sequently added. The second objective is to develop and refine a method for conducting mutagenicity assays on volatile organics compounds and to test the assay under anaerobic conditions. We have completed laboratory and field studies of treatment of EDC in the mobile phase in saturated systems to optimize bacterial consortia for EDC degradation in the vadose-zone experiments. A water stream containing 50 parts per million (ppm) EDC was treated in a laboratory-scale Immobilized Microbe Biore- actor (IMBR). The system was able to sustain an aver- age removal rate of 96.4% with a 24-hour retention time over the last 8 days of the experiment. An LSU pilot- scale IMBR was installed at The Dow Chemical Corn-

A B S T R A C T S 533

pany's Northwest Landfill site at the Plaquemine, Louisi- ana, plant. The average vinyl chloride loading in the feed was 78 parts per billion. The average removal rate for the 24-day test was 76.5%. Although we had origi- nally planned to use the microscreen phage induction as- say for assessment of mutagenicity of EDC and its metabolites produced during biodegradation, preliminary testing indicated that it was not suitable. Two ap- proaches were used to test the assay using EDC; one in- volved the evaluation of high concentrations of EDC as a means of comparison to values reported in the literature, and the second evaluated the concentrations of EDC ex- pected in the waste mixture after bioremediation. The number of plaques induced by EDC were not signifi- cantly different from the control values. This sensitivity of the assay could be related to the extremely high vola- tility of EDC. As a result of these preliminary experi- ments with EDC, and its equivocal response in the Microscreen phage induction assay, it has been decided that a second mutagenicity assay be evaluated for its ap- plicability and sensitivity to EDC. The umu assay is based on the ability of DNA-damaging agents to induce an SOS-repair gene, the umu C gene, in Salmonella ty- phimurium TA1535/pSK1002. Previous reports have shown that volatile compounds such as ethylene di- bromide elicit a positive response in the umu assay, thus we are confident that this assay will be more suitable for the evaluation of the mutagenicity of the volatile EDC than the phage induction assay.

A C T I V E M U N I C I P A L S O L I D W A S T E

LANDFILL O P E R A T I O N : A

B I O C H E M I C A L R E A C T O R

Debra R. Reinhart University of Central Florida, Civil & Environmental Engineering, Orlando, FL 32816-4450

Landfills remain the most frequently used method of municipal waste (MSW) disposal. Landfills are designed

and constructed to prevent contact between the waste and

the environment. Modern designs include hydraulic

barriers to collect and control liquids. Gas production from MSW landfills also requires collection and control. Landfill management alternatives and options must

consider the potential uses of these landfill outputs.

Active Landfill Management (ALM), as used herein, includes management of a waste disposal facility to mini- mize risk to human health and the environment while op- timizing landfill volume by promoting decomposition of landfilled waste, reducing the potential health risks by immobilizing constituents in the waste mass, and opti- mizing the quality and quantity of decompositional gases such as methane.

In order to identify design, construction, and opera-

tional requirements for ALM, and recognizing the need to avoid duplication of ongoing or past related efforts, the objective of this research is to support studies neces- sary to initiate a full-scale demonstration of ALM to opti- mize solid waste stabilization, leachate control, and gas production.

The principal investigator, Dr. Debra R. Reinhart, as contracted by the Gulf Coast Hazardous Substance Re- search Center, will provide support to a United States Environmental Protection Agency funded project with the above described objective.

Selection of full-scale sites for the demonstration of Active Municipal Solid Waste Landfill technology was accomplished. Candidate site nomination forms were distributed in December of 1991. Nine sites were nomi- nated representing a broad spectrum of geographical lo- cations, ages, and designs. A ranking system was developed to aid in site selection. From site ranking, two sites which best fit the needs of the project were identi- fied: the Southwest Landfill in Alachua County, Florida, and the Mill Seat Landfill located in Monroe County, New York.

A meeting was held in Albany, New York, on June 9, 1992, and was hosted by the New York State Energy Re- search and Development Authority. The purpose of this meeting was to provide a forum for the site researchers to present landfill design and operating plans for the two sites and to solicit input from leading experts in the field. The meeting was attended by 24 people.

D E T O X I F I C A T I O N O F

P O L Y C H L O R I N A T E D B I P H E N Y L S B Y

C A T A L Y T I C S T E A M R E F O R M I N G

James T. Richardson Department of Chemical Engineering, University of Houston, Houston, TX 77204-4792

Since 1929, about 1.4 billion pounds of

polychlorobiphenyl (PCB) compounds have been used in

power and other industries. PCBs threaten the

environment when discarded because, although mildly

toxic in low concentrations, PCBs bioaccumulate in soil and water and reach toxic proportions in many living

organisms. Furthermore, combustion of PCBs releases toxic intermediates, such as dioxins. Production ceased in

1977, but one billion pounds still exist in dumps, land

fills, contaminated soils and water, and in industrial use. The only feasible technology for destroying PCBs is costly high-temperature incineration, which is becoming socially less acceptable.

A novel alternative that is cleaner and more cost ef- fective is destruction by catalytic steam reforming. Re- search at the University of Houston applied this approach to the destruction of chlorinated solvents to a level of 8