Project Summary (1995-2000)

The broad, long-term objective of this project is to provide new scientific and engineering understanding for safely applying thermal treatment to soil decontamination. One aim is to identify details of commercially realizable thermal treatment schedules that do (and do not) give rise to rapid and efficient destruction or removal of organic and metallic contaminants without causing unacceptable public health impacts (e.g., toxic by-products). Another aim is to determine if pretreatment of soil with low cost additives (e.g., CaO, carbon-forming agents), can be combined with controlled thermal treatment to sequester metals or heteroatoms into solid matrices or as chemical compounds, suited to separation, storage, and reprocessing. A third aim is to use process simulation models to compare the public health impacts performance of various soil thermal desorption processes, using data and kinetics models from this project. Laboratory scale apparatus are used to mimic thermal treatment schedules pertinent to a range of current and emerging soil cleanup technologies, such as air stripping, thermal desorption, pyrolysis, incineration, plasma torches, while allowing products collection for chemical analysis and mutagenicity testing. Soil specimens include an EPA synthetic soil matrix, soil simulants, and actual soil from the Aberjona watershed. This research is expected to benefit environmental health sciences and the Superfund Program by identifying thermal treatment conditions that provide rapid and efficient removal of genotoxic and other soil contaminants without generating adverse by-products.