Treatment of domestic wastewater using modified septic tank

Abstract

AbstractThe treatment of domestic wastewater using conventional, single-baffle, two-baffle, and packed-type septic tanks was the main theme of the present study. The septic tanks were fed continuously with domestic wastewater at three hydraulic retention times (HRTs), ranging from 24 to 72 h. The average characteristics of raw domestic sewage investigated in this study in terms of chemical oxygen demand (COD), biochemical oxygen demand (BOD), and total suspended solids (TSS) were 960, 450, and 295 mg/l, respectively. The product quality of the treated domestic wastewater by the four types of septic tanks in terms of physicochemical and biological characteristics proved to be satisfactory. Comparison wise, better results were obtained using the packed-type septic tank for primary treatment. The average removal of pollutants for each type of septic tank in terms of COD, BOD, and TSS improved in direct proportion to HRT. The fecal coliform removal values were affected by the type of the septic tank and the H...