Industrial wastewaters (including agro-industrial wastewaters) are efŠuents that result from human activities associated with raw material processing and manufacturing. These wastewater streams arise from washing/cleaning, cooling, heating, extraction, reaction by-products, separation, and quality control resulting in product rejection. Water pollution occurs when potential pollutants in these streams mix with a receiving water source. In addition to the industrial wastewaters from such processing or manufacturing sites, wastewaters from some domestic sources may also be present; however, they may not constitute a major component. Domestic sewage may be present because of the washrooms and hostels provided for workers at the processing or manufacturing facility. Examples of industrial wastewaters include those arising from chemical, pharmaceutical, electrochemical, electronics, petrochemical, and food processing industries. Examples of agro-industrial wastewaters include those arising from industrial-scale animal husbandry, slaughterhouses, ‹sheries, fruits and vegetable processing, and oil seed processing. Pollutant concentrations are not usually high in agro-industrial wastewaters, except in the animal processing units.