This course is one of the main courses for environmental engineering majors. By means of introducing different treatment methods, this course aims at water purification. The main content of this curriculum includes: the principles and characteristics of physicochemical processes for water and wastewater treatment; the basic calculation methods, the applications, the main components and the operational characteristics of these processes; the latest typical water and wastewater treatment processes and technology at home and abroad. The course will mainly cover coagulation, sedimentation and clarification, flotation, filtration, disinfection, oxidation and reduction, membrane separation, softening and desalination, and so on. This course will familiarize students with physicochemical theories for water and wastewater treatment, and enhance their ability to resolve the problems in this field.