The book describes the composition and properties of wastewater, shows the main methods of sewage treatment, the basic techniques of sludge treatment, as well as hardware design of these processes. Also in the manual covers the methods, processes and devices for mechanical and biological wastewater treatment, as well as processing and recycling of sludge, are the methods of calculations related equipment. Compliant with the Federal state educational standard of the latest generation of higher education. The publication is intended for students directions "Technosphere safety" (20.03.01, 20.04.01), "Ecology and Nature" (05.03.06, 05.04.06), as well as the "Industrial Ecology and Biotechnology» (19.00.00). Also, the benefit will be useful to professionals working in the field of environmental engineering.