The objective of this course is to deal with different types of pollutants and how to control and reduce them. Different topics are covered in this course, including an introduction to environmental chemistry (hardness, alkalinity, COD, BOD), the basis of microbiology, the purifications and clarifications of drinking water from groundwater and surface water and all treatment processes (pretreatment, primary treatment and secondary treatment). Waste water treatment processes are also considered at the third topic, as well as air pollutions problems, dust removal, green house effect, introduction to solid wastes and hazardous.