Potential of using biological aerated filter as a post treatment for municipal wastewater

The main objective of this study was to assess and evaluate the performance of a packed bed up flow anaerobic sludge blanket reactor (P-UASB) followed by a biological aerated filter (BAF) for the treatment of municipial wastewater for reuse. The integrated pilot plant treatment system consisted of a UASB reactor packed with non-woven polyester fabric (NWPF) followed by BAF unit then inclined plate settler. The P-UASB was operated at two different organic loading rates (OLR) namely; 1.54 and 2.07 kg COD/m3/day with a corresponding HRT of 6 and 4 h. The results revealed that the system achieved sustainable and satisfactory reductions in total COD, BOD5 and TSS. Their corresponding residual values were 37.30 mgO2/l, 16.23 mgO2/l and 10.38 mg/l with average percentage removals of 89, 92 and 95%, respectively. Increasing the OLR from 1.54 to 2.07 kg COD/m3/day had a slight effect on the performance of the treatment system. Also, removal of 5 logs of total coliform, 4 logs of fecal coliform and 4 logs of fecal streptococci were obtained. Moreover, the treatment system had a small foot print, cost effective and can treat the wastewater of low to medium strength and produced an effluent suitable for reuse in unrestricted irrigation.