The purpose of this state-of-the-art publication is to provide up-to-date and pertinent scientific information concerning immobilized cell processes for treatment of wastewater. It comprehensively reviews and examines essential data on the feasibility of various immobilization methods, with special reference to wastewater treatment. It also discusses methods of identification of structure and composition of microbial aggregates and analytical methods for the estimation of biomass in the presence of carriers. This work reports the novel process of immobilized microalgae and cyanobacteria for wastewater treatment, while highlighting their future prospects. Additionally, it critically reviews the various fixed film bioreactor configurations. This book is a must for all engineers, planners, scientists, students and sewage treatment plant operators.