This comprehensive book provides a unified course in wastewater treatment and disposal. It deals with environmental and biological aspects, as well as fundamental physical and chemical principles. Though written primarily for students in the natural sciences--microbiology, chemistry, and environmental science--who wish to pursue a career in the water industry or research, the text also provides engineers and chemists with a comprehensive overview of wastewater treatment, the role of micro-organisms in treatment process, and the operational management of treatment and disposal systems.