Author(s)

S.I. ABOU-ELELA, M.E. FAWZY & W. ABDEL-HALIM

Abstract

There is a high potential for reuse of treated wastewater due to the shortage of renewable water resources for agricultural purposes in many countries of the world. To achieve this goal, an integrated anaerobic pilot plant treatment system treating almost 10 m3/day of wastewater was designed, manufactured and installed in a nearby wastewater treatment plant. The treatment scheme consists of a packed bed up-flow anaerobic sludge blanket (P-UASB) with corrugated lamella sheets, followed by inclined plate settler (IPS). However, to obtain a treated effluent amenable for reuse, post-treatment was carried out using a multi-stage roughing fine filtration unit (MSRFF). The pilot plant was operated at average hydraulic flow rate of 10 m3/day with average organic loading rate of 3.27 kg chemical oxygen demand (COD) m3/day. Two retention times in P-UASB namely, 4 and 6 h were investigated. The performance of the treatment scheme was monitored via physico-chemical as well as bacteriological and parasitological analysis. Treatment of wastewater by P-UASB followed by IPS produced a high quality effluent. Average removal rates of COD, biochemical oxygen demand (BOD) and total suspended solids (TSS) were 75, 70.6 and 91.3, respectively, with average corresponding residual values of 75, 58 and 18 mg/l. However, to obtain sustainable quality of treated effluent for reuse, post-treatment using MSRFF improved the quality of treated wastewater both chemically and biologically. The average residual concentrations of COD, BOD and TSS were 60, 34 and 10.9 mg/l, respectively, while almost complete removal of Fecal Coliforms was achieved. The treatment scheme proved to be a very promising approach for wastewater treatment for reuse in agricultural purposes.

Keywords

Anaerobic treatment, municipal wastewater, multi-stage sand roughing fine filtration, packed bed sludge blanket, reuse.