title: Operational factors of submerged inorganic membrane bioreactor for organic wastewater treatment: sludge concentration and aeration rate.
abstract: Various sludge concentrations and aeration rates were evaluated to find the optimal operation condition of a submerged ceramic membrane filtration system. 5.6 g/L of sludge was diluted with water to concentrations of 2.8 g/L and 1.4 g/L, and the three sludge concentrations were compared in terms of titration characteristics such as pressure and filtrate flux. Flux was at the highest value of about 30 L/m2 x hr at 50 kPa when sludge concentration was 1.4 g/L. In contrast, when sludge concentrations increased to 2.8 g/L and 5.6 g/L, the flux at 50 kPa decreased significantly to 18 L/m2 x hr and 10 L/m2 x hr, respectively. It was concluded that the sludge concentration directly affected the filtration efficiency, and low sludge concentration was suitable for improving filtration efficiency. Adjusting the aeration rate from 2 L/min to 4 L/min at 5.6 g/L of sludge and 50 kPa of pressure increased flux from 10 L/m2 x hr to 13 L/m2 x hr. It was obvious that the vigorous aeration improved the filtration efficiency, but the aeration rate did not seem to be high enough to maintain flux lower than critical flux.
authors.affiliation: Environmental Engineering Research Center, School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798.
authors.forename: E J
authors.initials: EJ
authors.lastname: Hwang
authors.forename: D D
authors.initials: DD
authors.lastname: Sun
authors.forename: J H
authors.initials: JH
authors.lastname: Tay
mesh_terms: D019149:Bioreactors; D002516:Ceramics; D005374:Filtration; D008567:Membranes, Artificial; D010100:Oxygen; D011312:Pressure; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D010100:Oxygen