Solidification/Stabilization of PCB-Contaminated Wastewater Treatment Sludges: Fid-Bau Portal

Solidification/Stabilization of PCB-Contaminated Wastewater Treatment Sludges

Aydilek, Ahmet H. / Edil, Tuncer B.

Treatment of polychlorinated biphenyl (PCB) contaminated sediments and sludges has been a challenge to the geotechnical and environmental community. Among various treatment options, solidification/stabilization (S/S) technology has often been considered. The technique can particularly be of interest for remediation of PCB-contaminated geomaterials as PCBs are quite insoluble and do not transport with water. The S/S approach requires knowledge of geotechnical properties of the treated waste and leaching of contaminants into the environment. The objective of this study was to investigate the applicability of the S/S technology to PCB-contaminated municipal sewage sludges at a U.S. EPA Superfund site located in Madison, Wisconsin. A battery of unconfined compression tests were conducted on the specimens prepared with various ratios of sludge and selected stabilizers (cement, fly ash, and lime) to study solidification. The effects of climatic stresses were observed by means of wet-dry and freeze-thaw tests on the solidified specimens. Consolidation behavior of one of the selected stabilized samples was also investigated. Moreover, PCB leaching from selected stabilized blocks was studied. The results indicated that successful encapsulation of the PCBs in the stabilized block of sewage sludges is possible by use of traditional binders.