This book is written to a fairly advanced level and should be interest to the graduate, postgraduate and scientists dealing with biological wastewater treatment especially relevant to phosphorus removal from wastewater. Though there are many excellent textbooks that elucidate the theory and design of biological wastewater treatment such as EBPR, it was nevertheless felt that there was a need for another book that would not only describe with the design approach but also cover the microbiological analysis related to the EBPR system.Chapters have been organized to address basic concepts related to the needs for biological treatment and design fundamentals of EBPR. It also covers the factors influencing the EBPR and types of reactors most commonly used. The final part involves the molecular methods used to study the polyphosphate-accumulating organisms (PAO) related to EBPR. It is hoped that this book will be referred by those related in engineering, environmentalists, government and regulatory bodies.