On-site treatment of source separated domestic wastewater employing anaerobic package system

On-site treatment of black water generated at a residential school was investigated by employing an upgraded two-stage package system: a modified septic tank followed by an anaerobic filter. The findings revealed that the average removal efficiency for CODtot, CODss, BOD and TSS were 72.6, 90.2, 78.4 and 83.2%, respectively. Monthly septage characterization revealed a declining trend in VSS/TSS ratio, which indicated the progressive hydrolysis as well as stabilization of the sludge. The interrelationship between physico-chemical and microbial parameters revealed a linear relationship between the data with a good coefficient of correlation. High methanogenic activity of 0.386 g CH4/g VSS. D was observed within the developed sludge. Thus the studied package system can be a suitable alternative to the conventional septic tank for on-site treatment of black water in the rural areas of developing regions.