The increasing concern for odour abatement, and more generally for reduction of air pollution, has caused a rapid growth in the development of air pollution control techniques, several of which are based on biological degradation of the polluting compounds. This book presents a state-of-the-art overview of recent developments in biological techniques for air pollution control. It describes in detail processes for the prevention of odour nuisances and reduction of odour emissions. It also deals with process design and construction of equipment as well as with odour policy measurements at an international level.