22    EMERGING TECHNOLOGIES FOR THE TREATMENT OF
PCB-CONTAMINATED SOILS
Ernst J. Jabouin, Project Manager
Division of Hazardous Materials Management
New York City Department of Environmental Protection
Corona, New York 11368
INTRODUCTION
In the United States alone, 400 million pounds of polychlorinated biphenyls (PCBs) have polluted
the environment, and PCB-contaminated sites are located throughout the country.' Until recently,
landfilling and incinerations were the only mode of treatment available for PCB-contaminated soils.
Today, chemical and biological technologies are emerging very rapidly and are either less expensive or
very competitive with landfilling and incinerations, respectively.
The purposes of this study were to evaluate state-of-the-art technologies for the treatment of PCB-
contaminated soils, and to identify the most successful processes that can compete with both incinerations and landfilling. Technologies falling within the categories of chemical and biological treatments,
namely the nucleophilic substitution reactions, ultraviolet radiation, supercritical water oxidation,
pyrolysis, a slurry-based (congener specific) process, and a potential in situ bioremediation were
investigated. The selected technologies are, respectively, the APEG-Plus treatment system, LARC
(Light Activated Reduction of Chemicals) process, Modar system, Advanced Electric Reactor, Bio-
Clean process, and EBDS (Engineered Bioremediation System). The above technologies were examined based on the factors such as range of PCB concentration handled, removal efficiency, residual
PCBs, development status, conditions, treatment costs, limits and capacity.
The major source of data for this evaluation was the U.S. Environmental Protection Agency's
Alternative Treatment Technology Information Center (ATTIC). The center is accessible by a computer database network through an online system where titles and abstracts can be searched. The full
articles or reports can be obtained by contacting the firm that manages the system. Other sources of
data include open literature and contact with the company or its project coordinator.
PROCESS DESCRIPTION
Chemical Treatments
Chemical treatability of PCBs in soils investigated by industries include adsorption, dispersion of
metallic sodium in oil, and the use of sodium biphenyl or naphthalene mixtures.2 Unfortunately, these
methods had little success in eliminating PCBs in soils. In the late 1970's, an investigation of nucleophilic substitution reaction using the sodium polyethylene glycol reagent (NaPEG) was undertaken by
scientists at the Franklin Research Institute.1,3 The limited success of the NaPEG reagent has lead to a
family of polyethylene glycol (PEG) reagents. Other emerging chemical technologies include ultraviolet radiation, supercritical water oxidation, and pyrolysis.
Nucleophilic Substitution
Nucleophilic Substitution is a chemical process associated with the cleavage of carbon-halogen
bonding. Nucleophiles that have been investigated for the dechlorination of PCBs include: (1) alkali
metal hydroxide in polyethylene glycol (PEG)4 and (2) sodium naphthalide prepared by complexing
naphthalene and metallic sodium with the solvent tetrahydrofuran.5 The APEG-Plus system is a
technology of current interest, particularly in view of demonstrated ability to destroy PCBs in soils.
The APEG-Plus treatment system, previously referred as "Terraclean-Cl," was developed to detoxify and chemically decompose wastes containing dioxin, PCBs and other chlorinated hydrocarbons.
The process has been employed in many in-field pilot test and small scale clean up projects involving
PCBs and dioxin. Reportedly, a full-scale soil decontamination unit was built and tested.
48th Purdue Industrial Waste Conference Proceedings, 1993 Lewis Publishers, Chelsea, Michigan 48118. Printed in
U.S.A.
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