This volume emphasizes pilot- and field-scale applications of bioremediation technology for petroleum hydrocarbon and chlorinated solvent contamination. Described are a variety of biological process units used to treat hazardous waste aerobic bioreactors, fluidized-bed reactors, fixed-film bioreactors for chlorinated solvent treatment, rotating biological contactors, slurry-phase bioreactors, biopile systems for treating ethylbenzene- and styrene-contaminated soils, microbial mats, and biofilters for VOC treatment.