An alternative for pre‐treatment of high‐strength raw whey wastewaters: submerged membrane bioreactors

Abstract

AbstractThe direct treatment of whey wastewater at various sludge ages (10–75 days) and high biomass concentration (above 50 g mixed liquor suspended solid (MLSS) dm−3) in a submerged membrane bioreactor (sMBR) is described. The chemical oxygen demand (COD) of raw whey varied in the range of 60 and 90 g dm−3. After feeding the sMBR with raw whey, effluent COD reduced to about 20 g dm−3. The effluent was free of suspended solids and total coliform bacteria. Total phosphorus (TP) and orthophosphate (Ortho‐P) in the influent varied between 204 and 880 mg dm−3 and between 180 and 620 mg dm−3, and effluent TP and Ortho‐P reduced to 113 and 109 mg dm−3, respectively. The ammonium and nitrate concentrations in the influent were in the ranges of 3.4 and 120 mg dm−3 and 10 and 503 mg dm−3, respectively. The effluent ammonium concentration varied between 17.6 and 198 mg dm−3 and nitrate concentrations varied between 0.9 and 69 mg dm−3. Effluent turbidity varied between 23 and 111 FAU (Formazin Attenuation Unit). The results show that sMBR is an effective pre‐treatment system for high‐strength agro‐wastewaters because of its ability to reduce the pollution load. Copyright © 2004 Society of Chemical Industry