As a result of Progress towards industrialization in the country, the volume of industrial wastewaters is gradually increasing and it is estimated to reach 1 to 1.5 billion cubic meters in 2007. With respect to great volume and pollution of these wastewaters, the necessity for their treatment looks obvious. Biological Treatment is a cost - effective solution of industrial wastewater management problems. Many factors affect process selection for biological treatment, but raw wastewater characteristics and the treatment objectives are the most important for The process selection for
biological treatment of industrial wastewaters. In this study, some of the considerations for selecting biological treatment processes for industrial wastewaters have been discussed. A simplified diagram summarizing these considerations is presented, and it is believed that the diagram developed herein could help the practicing engineer in arriving at a rational process selection for any particular case.