title: Impact of FeCl₃ dosing on AnMBR treatment of municipal wastewater.
abstract: The long-term (90 days) impact of dosing FeCl3 on bioprocess performance and membrane performance in a pilot AnMBR fed with authentic sewage was evaluated. The addition of 26 mg/L of FeCl3 enhanced the performance of the AnMBR with respect to removal efficiencies of COD and BOD5, but did not have a significant influence on the removal efficiencies of TKN and TP and the methane yield. The membrane was operated at a constant flux of 17 LMH and its performance was significantly improved by dosing FeCl3. This was demonstrated by a reduction in the fouling that withstood scouring stresses to values lower than 5 kPa and negligible reversible fouling for the first 75 days. The superior membrane performance was consistent with the shift of particle size distribution to the particulate fraction and the reduced colloidal and soluble substances in the sludge, especially the soluble protein, carbohydrate, Ca and S. CLSM tests showed that the addition of FeCl3 resulted in a thicker foulant layer and the deposition of protein and carbohydrate on the membrane surface was significantly reduced. Therefore a more porous foulant layer was formed and this prevented the development of a strongly-attached cake layer and pore blocking. A recovery cleaning study indicated FeCl3 dosing enhanced the efficiency of the recovery cleaning protocol. The foulants formed with the Fe-dosed sludge had greater inorganic content, as 75% of the foulant resistance was removed by citric acid. The superior membrane performance during the operation combined with enhanced cleaning efficiency by FeCl3 dosing would significantly improve the sustainability of AnMBR in municipal wastewater treatment.
authors.affiliation: Department of Civil and Environmental Engineering, University of Waterloo, 200 University Ave. West, N2L 3G1, Waterloo, Ontario, Canada. Electronic address: q5dong@uwaterloo.ca.
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; D057919:Biological Oxygen Demand Analysis; D019149:Bioreactors; D002118:Calcium / Q000737:chemistry / Q000378:metabolism; D002241:Carbohydrates / Q000737:chemistry; D002712:Chlorides / Q000737:chemistry* / Q000378:metabolism; D002947:Cities; D019343:Citric Acid / Q000737:chemistry; D005290:Ferric Compounds / Q000737:chemistry* / Q000378:metabolism; D007501:Iron / Q000737:chemistry / Q000378:metabolism; D008567:Membranes, Artificial; D018613:Microscopy, Confocal; D015203:Reproducibility of Results; D012722:Sewage / Q000737:chemistry* / Q000382:microbiology; D012972:Sodium Hydroxide / Q000737:chemistry; D013455:Sulfur / Q000737:chemistry / Q000378:metabolism; D062065:Wastewater / Q000737:chemistry / Q000382:microbiology; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
chemical_list: D002118:Calcium; D002241:Carbohydrates; D002712:Chlorides; D019343:Citric Acid; D005290:Ferric Compounds; D007501:Iron; D008567:Membranes, Artificial; D012722:Sewage; D012972:Sodium Hydroxide; D013455:Sulfur; D062065:Wastewater; C024555:ferric chloride
keywords: FeCl(3) as flux enhancer; Municipal wastewater; Pilot anaerobic membrane bioreactor; Porous cake layer