title: Long term performance of membranes in an anaerobic membrane bioreactor treating municipal wastewater.
abstract: The long term impact of SRT (100-40 days) and recovery cleaning on membrane performance of an AnMBR treating authentic municipal wastewater in a large pilot plant was assessed. Successful operation of the pilot plant at a flux of 17 LMH was maintained for a period of 536 days during which the longest period of operation without recovery cleaning or membrane replacement was 178 days. Lower SRT (40 days) reduced the fouling propensity of the mixed liquor in terms of TSS concentration and the dewaterability indicators including colloidal COD (cCOD) concentration and capillary suction time (CST). Critical fluxes ranged from 21 to 23 LMH to 25-27 LMH for SRTs of 70 and 40 days respectively and this was consistent with the reduced concentrations of TSS and improved dewaterability under the latter conditions. Recovery cleaning was found to result in substantial reduction of resistance as indicated by both pilot plant operation and clean water flux tests. The long-term fouling rate was observed to be higher with cleaned membranes as compared to virgin membranes. The lower membrane fouling with virgin membranes suggested that accumulation of foulants, which were resistant to cleaning, caused the higher fouling rates for the cleaned membranes.
authors.affiliation: Department of Civil and Environmental Engineering, University of Waterloo, 200 University Ave. West, N2L 3G1, Waterloo, Ontario, Canada. Electronic address: qirong.dong@gmail.com.
authors.forename: Qirong
authors.initials: Q
authors.lastname: Dong
authors.affiliation: Department of Civil and Environmental Engineering, University of Waterloo, 200 University Ave. West, N2L 3G1, Waterloo, Ontario, Canada.
authors.forename: Wayne
authors.initials: W
authors.lastname: Parker
authors.affiliation: GE Water & Process Technologies, 3239 Dundas Street West, L6M 4B2, Oakville, Ontario, Canada.
authors.forename: Martha
authors.initials: M
authors.lastname: Dagnew
mesh_terms: D000693:Anaerobiosis; D019149:Bioreactors; D008567:Membranes, Artificial; D009864:Ontario; D010865:Pilot Projects; D013997:Time Factors; D062065:Wastewater / Q000737:chemistry*; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D062065:Wastewater
keywords: Dewaterability; Irrecoverable foulants; Recovery cleaning; SRT