Successful operation of the activated sludge process relies heavily on the ability to effectively separate mixed liquor into return activated sludge (RAS) and a high quality final effluent. Solids separation efficiency is dictated in large part by the relative population of floc-forming and filamentous microorganisms present in the activated sludge. During normal operation, mixed liquor will be composed primarily of floc-formers with relatively low levels of filamentous organisms. Some population of filamentous organisms is necessary to promote the formation of larger flocs and prevent development of a "pin-floc" condition, which often results in high effluent turbidities (Jenkins, 2004). However, when conditions favoring the growth of filaments over floc-formers occur, a condition commonly referred to as filamentous "bulking" may occur.

Following in the footsteps of previous highly successful and useful editions, Biological Wastewater Treatment, Third Edition presents the theoretical principles and design procedures for biochemical operations used in wastewater treatment processes. It reflects important changes and advancements in the field, such as a revised treatment of the micr

Contemporary Municipal Wastewater Treatment Plant Design Methods Fully revised and updated, this three-volume set from the Water Environment Federation and the Environmental and Water Resources Institute of the American Society of Civil Engineers presents the current plant planning, configuration, and design practices of wastewater engineering professionals, augmented by performance information from operating facilities. Design of Municipal Wastewater Treatment Plants, Fifth Edition, includes design approaches that reflect the experience of more than 300 authors and reviewers from around the world. Coverage includes: Integrated facility design Sustainability and energy management Plant hydraulics and pumping Odor control and air emissions Thoroughly updated information on biofilm reactors Biological, physical, and chemical liquid treatment Membrane bioreactors, IFAS, and other integrated biological processes Nutrient removal Sidestream treatment Wastewater disinfection Solids minimization, treatment, and stabilization, including thermal processing Biosolids use and disposal

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.