These articles focus on methods for optimizing the effectiveness of microorganisms for biodegradation. This volume includes discussions of the biodegradation and toxicity of PAH-, PCP-, PCB-, and BTEX-contaminated soil and aqueous sediments. Both bench-scale and pilot-scale studies deal with microbial issues such as surfactant-enhanced aromatic hydrocarbon degradation, nutrient addition and bioavailability, and various dispersion techniques. Selected case studies include discussions on pre-culture and consortium biodegradation of various petroleum hydrocarbons.