Abstract
Feasibility of using up-flow anaerobic sludge blanket (UASB) reactor for the treatment of sewage water was studied. Three similar UASB reactors were operated at three different hydraulic retention time (HRT) of 6, 8 and 10 hrs. The reactors were operated with activated sludge inoculation in June 2011. Sample Collection was carried out after the steady state has been reached (around two months). The results showed that the efficiency of UASB reactors were comparable for the removal of chemical oxygen demand (COD), biological oxygen demand (BOD) and total suspended solids (TSS). On the other hand, the removal of fecal coliform (FC) did not exceed two log units in most cases. The results revealed that the quality of the effluent was not complying with WHO regulatory standards for reuse for irrigation. Consequently, post treatment step is of vital importance to protect the environment.