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

•Field application potential of package system for black water treatment.•High removal efficiency for organic wastes as well as pathogenic microorganisms.•Significantly better effluent quality than the conventional septic tank.•Low cost, less maintenance, simple design, no electricity required.•Absolutely suitable for utilization in the developing countries like India.

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.