The removal of chemical pollutants in biological treatment systems and during bioremediation activities is dependent on the capacity of micro-organisms to degrade synthetic chemicals. This book presents, for more than 100 synthetic compounds, an overview of the biodegradation processes and pathways that yield detoxification and mineralization. Results on the removal of synthetic pollutants in treatment systems are summarized. The book aims to help engineers to understand the potential and the possible limitations of biological treatment techniques for soil, groundwater, waste water and air.