Due to widespread of technical slaughterhouses of chicken; severe pollution caused by discharged wastewater from these areas, high values ​​of dissolved and suspended substances and values ​​of COD and BOD, has made treatment of wastewater an urgent necessity for protection of environment and water conservation in light of water deficit. Thus, researchers found it necessary to contribute by studying problems caused by these massacres for provision of appropriate practical solutions.

The study examined factors affecting efficiency of biological treatment of wastewater from technical chicken slaughterhouses. It concentrated on effect of both detention time and increase in organic load. Researchers noted that efficiency of treatment increased with an increase in detention time until reaching best time to meet specifications of treated effluent in accordance with standards for agricultural land irrigation, which is 7 hours, while efficiency of treatment decreased with an increase in organic load.