Thermal Desorption Treatment of Dioxin-Contaminated Soil at the Former Allied Feeds Site, Sydney, Australia

摘要

The former Allied Feeds site is located on the Rhodes Peninsula adjacent to Homebush Bay, in Sydney, Australia.nThe adjacent Lednez site was historically used for manufacturing a range of chemicals, including tar, explosives,nand chlorinated compounds. Through these activities, both sites and the Homebush Bay were contaminatednwith dioxins=furans, chlorobenzenes, chlorophenols, and organochlorine pesticides. Both properties have beennremediated for open space, medium- and high-density residential use, and commercial development. ThenLednez-site remediation activities also include dredging and treating contaminated sediments from HomebushnBay. Combined, these projects represent the largest dioxin remediation project that has been undertaken innthe world using a thermal treatment technology. On the Allied Feeds site, about 175,000 tonnes of dioxincontaminatednsoil has been treated using a directly heated thermal desorption plant. The project is significantnbecause (1) it is the first large-scale thermal remediation project conducted in Australia, (2) the project has beennimplemented at a time when local environmental regulations were evolving, (3) the feed material contains highnconcentrations of dioxins=furans and potential dioxin=furan precursor compounds (e.g., chlorophenols andnchlorobenzenes), (4) the feed material contains a high proportion of fine-grained spent lime with a high moisturencontent, (5) the project is being conducted adjacent to a major waterway in a highly developed urban area,nand (6) the site is being redeveloped for residential and commercial use concurrently with remediation activities.nThe project has included a number of regulatory, technical, and logistical challenges, including the developmentnof best practice regulatory standards, control of fugitive emissions, processing of a difficult and complexnfeed material, and compliance with stringent environmental requirements. This article discusses a number ofnproject issues, the results of the regulatory compliance test program, and the production operations phase of thenproject.