Comparison of efficiencies of Escherichia Coli (E.Coli) removal in sewage treatment plant with different treatment system

Abstract

Two sewage treatment plants (STP) were investigated over a 2 months period in order to measure the microbiological load of untreated municipal wastewater and to evaluate the removal efficiencies of different treatment systems. The STP investigated can be classified into smaller plants with enhanced secondary treatment. The plants studied had a considerable quantitative impact on the marine of the area. Consequently, it was anticipated that the microbiological load of the effluent would also be significant and also the e-coli that achieved the highest exceeding value for Perlis. Sixteen samples were taken from the influent and effluent of the STP, regardless of weather conditions, and e-coli was analyzed. The average microbiological reduction of each STP was dependent on its treatment procedures or treatment system. Extended Aeration (EA) system is more effective in removing microbiological and e-coli compared to Hi-Kleen (HK) system. Efficiency of the HK system and EA system is almost same but from the study it shows that EA system having a more average performances compared to HK system. HK system has a higher tendency to tilt and flow short-circuiting especially from aeration tank to clarifier due to minor land movement or settlement. During the study period, biochemical oxygen demand and e-coli are affected by the temperature. High temperature will increase the photosynthesis but will kill the e-coli. Conclusion for the study is EA system is more effective than HK system.