The Activated Sludge (AS) Process is old technology but is still widely adopted worldwide for its convenience and simplicity: an impressive number (many hundred of thousands) of this kind of system are in operation. Occasionally, problems such as bulking and foaming occur, causing regulation violations and large investment is often required immediately to control them. For this reason, an intense research effort has been made during the last few decades to face these problems, and this report details the work undertaken by the IWA Specialist Group on Activated Sludge Population Dynamics. This Scientific and Technical Report describes the main reasons fslyuor the growth of the different filamentous microorganisms in activated sludge, and the biological molecular tools available today for the identification of the main biomass components. The wide range of experiences around the world is documented and the methods to avoid the proliferation of these organisms are presented and critically reviewed. Activated Sludge Separation Problems consists of seven chapters, presenting up-to-date technical and scientific aspects of these processes. Scientific and Technical Report No. 16

This manual describes methods for diagnosing and rectifying activated sludge solids separation problems, which are one of the most common causes of permit violations in activated sludge wastewater treatment plants. The book is written in an easy-to-understand format that will help you resolve real-life problems. Lab techniques, theoretical considerations, design and control methods, and case histories are provided. The clear discussions make it ideal not only for practitioners and consultants, but also for students and professors. Every environmental consulting company, wastewater treatment plant, laboratory, and university should have at least one copy of this hands-on practical manual.

The most common activated sludge operating problems causing poor plant performance are related to solids separation. Especially common are bulking and foaming. Without a proper scientific foundation to support the efforts of wastewater treatment plant management, many attempts to thwart bulking and foaming have failed. Manual on the Causes and Control of Activated Sludge Bulking, Foaming and other Solids Separation Problems provides the critical scientific and practical underpinnings needed to understand and combat these problems. The third edition of this flagship text is a comprehensive, concise guide to the microbiological and technical aspects of controlling all types of solid separation problems. The scientific theory is applied to real-world scenarios, greatly increasing the number of real-world examples of successful control methods. New information is also included on filamentous organism growth and its application in the control of sludge bulking and foaming. Now plant operators, regulators and wastewater engineers have a complete guide for battling these formidable design and operating problems. Features of the Manual include: Discussion of the mechanisms of the bioflocculation involved in the formation of activated sludge flocs Many new case histories of the practical diagnosis and resolution of activated sludge solids separation problems Re-examination of the filament backbone concept of floc structure, with additional focus on strong flocs that are devoid of filamentous organisms Analysis of bulking and foaming caused by nocardioform organisms and Microthrix parvicella, with emphasis on their origins and control methods New photographs and descriptions of filamentous organisms responsible for bulking and foaming Results of recent studies of activated sludge and previously unknown microorganisms - and the potential use of molecular biological tools in diagnosing bulking and foaming problems.

The most common activated sludge operating problems causing poor plant performance are related to solids separation. Especially common are bulking and foaming. Without a proper scientific foundation to support the efforts of wastewater treatment plant management, many attempts to thwart bulking and foaming have failed. Manual on Solving Activated Sludge Bulking, Foaming, and Other Solids Separation Problems provides the critical scientific and practical underpinnings needed to understand and combat these problems. The third edition of this flagship text is a comprehensive, concise guide to the microbiological and technical aspects of controlling all types of solid separation problems. The scientific theory is applied to real-world scenarios, greatly increasing the number of real-world examples of successful control methods. New information is also included on filamentous organism growth and its application in the control of sludge bulking and foaming. Now plant operators, regulators and wastewater engineers have a complete guide for battling these formidable design and operating problems.

Activated Sludge Separation Problems: Theory, Control Measures, Practical Experiences, Second Edition, describes the most common activated sludge separation problems and explains the main reasons for the growth of the different filamentous microorganisms in activated sludge. The book summarizes the identification techniques for important groups of activated sludge microorganisms both based on conventional microscopic analysis and using the biological molecular tools available today (FISH and PCR). This new edition, with 70% new and updated material, also provides explanation of basic activated sludge process principles and of parameters necessary for process control and operation. The theory of secondary clarifies is described to the extent necessary for understanding the construction and operation of secondary clarifiers. The activated sludge reactor and secondary clarifies are treated as one system and the interactions are explained. The wide range of experiences around the world is documented and the methods to avoid the proliferation of these organisms are presented and critically reviewed. Activated Sludge Separation Problems consists of six chapters, presenting up-to-date technical and scientific aspects of these processes. The new edition also features an extended list of literature references for further reading. The book will be a valuable help for students of environmental engineering, wastewater specialists, plant operators and designers of activated sludge plants. It is also useful for specialists in wastewater operation laboratories, especially for those studying activated sludge separation properties.

This title is only available as a free copy to download from the WaterWiki. To download your free copy of the eBook, click here. The manual can be used independantly but when used in combination with the CD-ROM, it makes a unique tool for process operators to diagnose and solve operational problems. It is also a valuable educational and training package for universities and post experience courses. Click here for more details about the CD-ROM Process stability and final effluent quality largely depend upon the composition of the biomass in an activated sludge plant. Operational problems such as bulking and scum formation occur when the wrong micro-organisms are dominating the sludge population. Microscopic sludge investigation is therefore essential for process control and stable plant operation. The manual outlines the theoretical framework, extensively illustrated with full-colour micrographs. Contents Microscopy Microscopic sludge investigation Characteristics of activated sludge flocs Filamentous micro-organisms Protozoa and metazoa Conclusions of microscopic sludge investigation The activated sludge process Operational problems Bulking sludge Scum formation

FROM THE PREFACE In this time of dwindling budgets, increasing service needs, and increasing regulatory requirements, wastewater treatment professionals are continually called upon to upgrade their wastewater treatment plants. To do so efficiently and effectively, one must develop a clear approach to use in upgrading a plant and have the proper tools available to implement that approach. This book is meant to assist readers in developing and implementing their upgrading projects. First, Chapter 1 details the upgrading approach. The tools to be used are presented in Chapters 2 through 6. Finally, in Chapter 7, six case histories are presented to illustrate the plant upgrading techniques presented in the previous chapters. Through this book, the authors hope to assist readers in meeting their upgrade requirements, while making the most efficient use of the resources at hand.