ABSTRACT
One of environmental outcomes in industrial towns is developing environmental pollution such as production of industrial wastewaters. These industrial wastewaters should be appropriately treated before entering to receiving waters. However we can't solve environmental anxieties by establishing of wastewater treatment plants alone; but permanent and regular assessment of these treatment plants performance is necessary for achieving environmental standards. Thus, this research has been done in order to investigation of activated sludge performance in wastewater treatment of Agghala industrial town in Golestan province. This cross-sectional study implemented in sewage treatment plant laboratory of Agghala industrial town in Golestan within 12 months at 2007. Chemical Oxygen Demand [COD] parameter determined twice in week, But Biochemical Oxygen Demand [BOD] test accomplished weekly. pH measured by pH meter daily. Experiment of total suspended solids [TSS] and total dissolved solids [TDS] carried out every 10 days. All tests accomplished according to standard method for water and waste water examination [2005]. Then data analyzed using excel 2007. The average of BOD, COD and TSS in influent was 11196.17, 1854.58, 1232.25 mg/L respectively.Maximum influent organic loading rate was related to Shahrivar and Mehr months. The total average of removal efficiency for BOD, COD and TSS was calculated 99.66, 98.2, and 97.6% respectively. Quality of this treatment plant effluent was according to effluent disposal standards all over year. In sum, efficiency of this treatment plant [activated sludge system] was very good in influent pollutant removing. However occasionally effluent was not adapted with environmental standards but these deficiencies is solvable by accurate management and supervision on flow rate and influent organic loading rate easily