Filamentous bulking and foaming are the most frequent operational problems in activated sludge plants. This recent book provides a comprehensive, concise guide to the microbiological and technical aspects of bulking and foaming control. The result of over 25 years of research, the book stresses practical control measures based on kinetic and metabolic selection theories, as well as on case histories. Topics in the book include: biochemical processes in wastewater treatment, evaluation ofseparation problems, settling and foaming principles, bulking and foaming control methods, and system design. More than 100 tables and figures illustrate complex processes, and over 500 references provide a detailed compendium of available resources. It was the intention of the author to summarize in this book all essential pieces of information on both the microbiological and technical aspects of bulking and foaming control, so microbiologists and engineers can find new and helpful information from each other's field without studying vast numbers of primary literature sources. Naturally, the practical pieces of information required for solving practical operational problems are more stressed. The book is arranged into six major chapters which are subdivided into uniform topical sections. The reader interested in a particular problem or searching for a particular solution does not necessarily need to read the whole book to get the answer. There are many cross-references in the text which will lead the reader to the background of the problem, and to show its connection to similar problems and their solutions.