Sequestration Mechanisms and Bioavailability of Tetrachloroethene and Toluene in Solid Waste

North Carolina State University, Raleigh NC

Investigators

Abstract

0001700 Barlaz The objective of this research is to study factors that control the fate and bioavailability of tetrachloroethene (PCE) and toluene in landfills with a specific focus on contaminant sequestration and biodegradation as influenced by the presence of humic substances in solid matrices, and acidogenic and methanogenic leachate. The specific objectives are to: (1) estimate the distribution of sorbed contaminants in solid waste by measuring the sorptive capacity of the dominant organic waste components in both fresh and biodegraded form, (2) determine whether contaminant sorption is reduced as a result of contaminant binding by dissolved organic macromolecules in landfill leachate, (3) determine the impacts of aging and leachate composition on contaminant desorption rates, (4) identify relationships between chemical and physical changes in the decomposing sorbent matrix and the bioavailability and sequestration of PCE and toluene, (5) compare rates of desorption and biodegradation of fresh and aged contaminants to determine whether desorption limits bioavailability, and (6) identify whether covalent and/or noncovalent associations with humic materials are important for the sequestration of PCE and toluene in the solid waste. This research will provide information on how contaminants may be expected to behave in landfills over long periods of time and will support the development of models to predict contaminant fate in landfills. ***