Efficiency Evaluation of a wastewater Treatment Plant by Activated Sludge

Abstract: Performance of El-Agamyeen Plant for wastewater treatment (WWTP) by activated sludge was studied over a period of 20 weeks. Results showed that chemical oxygen demand; COD, biochemical oxygen demand; BOD, total suspended solids; TSS and ammonia decreased through stages of treatment process. The percentage removal of these parameters during studied period ranged 86-95, 91-96, 90-94 and 71-85 % respectively. Dissolved oxygen; DO in aeration tank was not less than 1.2 mg/L during study. Of microfauna, amoebae and flagellates appeared at low DO and high organic load, dominancy of crawling and stalked ciliates affected efficiency of treatment. Rotifers count ranged from 1.3x10 3 to 9x10 4 indicating good sludge quality.High toxicity could be obtained with the inlet wastewater and decreased with mixed liquor; the outlet water has been shown the least average toxic effects (<10% mortality) on the test organism. The results indicated that wastewater treatment in this Plant during the study period reduced pollution significantly and effluent water can be left for discharge into water bodies