Water is the most important natural gift for human being and aquatic life. Due to continuous technological growth and industrialization, the water has been fully polluted and categorized as water pollution. The outlet water of industries and human which accedes the limit of organic and inorganic components in the water is called wastewater (polluted water).

Sources of Waste Water:

Industrial

Municipal

Commercial

Characteristics of Waste Water:

Physical Characteristics

Chemical Characteristics

Biological Characteristics

Impurities in Waste Water:

Suspended Impurities

Dissolved Impurities

Colloidal Impurities

Some of them appear in dissolved form, some of suspended form and some of colloidal form. To maintain the quality of water, its need the treatment of wastewater. The basic treatments of wastewater are:

Preliminary Treatment

Primary Treatment

Secondary treatment

Advanced treatment.