Anaerobic onsite treatment of black water using filter-based packaged system as an alternative of conventional septic tank

Abstract

The present study investigates the efficiency and feasibility of an anaerobic packaged system for onsite treatment of source-separated black water from a residential school. The system consisted of a modified septic tank followed by an upflow anaerobic filter, both accommodated within a single unit. The present system achieved comparatively much higher removal efficiency than the existing conventional septic tank (CST) for CODtot, CODss, BOD and TSS as 72.6, 90.2, 78.4 and 83.2% respectively, which ranged between 30 and 50% for CST for all the parameters. Thermotolerant coliform removal was also quite good at about 2.84 logs. Therefore, the present system can be a promising alternative to the CST for the treatment of black water, particularly in the rural areas of the developing countries.