title: Effect of low dosage of coagulant on the ultrafiltration membrane performance in feedwater treatment.
abstract: One of the critical issues for the widely application of ultrafiltration (UF) in water treatment is membrane fouling owning to the dissolved organic matter. The aim of the present study is to explore the effect of various particle sizes caused by low dosages of coagulant with dissolved organic matter on the UF membrane performance. Aluminum chloride was added to the synthetic water with the hydrophobic humic acid (HA), the hydrophilic bovine serum albumin (BSA) - a protein- and their 1:1 (mass ratio) mixture. The results showed that there was a critical dose of Al that could cause dramatic flux reduction by blocking the membrane pores after coagulating with HA/BSA. For HA or BSA, the critical dose of Al was relatively lower at pH 6.0 than that at pH 8.0. After coagulation, the flux decline caused by HA was slightly varied as a function of pH while that caused by BSA was greatly affected by pH. The flux decline caused by the 1:1 (mass ratio) HA/BSA mixture after coagulation was similar to that caused by HA after coagulation because BSA could be encapsulated by HA. In addition, the peak value of the molecular weight (MW) distribution of HA coagulated with Al was changed more drastically compared to that of BSA after filtration.
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Baiwen
authors.initials: B
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Wenzheng
authors.initials: W
authors.lastname: Yu
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.
authors.forename: Huijuan
authors.initials: H
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Environmental Aquatic Chemistry, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China. Electronic address: jhqu@rcees.ac.cn.
authors.forename: Jiuhui
authors.initials: J
authors.lastname: Qu
mesh_terms: D000077410:Aluminum Chloride; D017607:Aluminum Compounds; D002712:Chlorides; D002850:Chromatography, Gel; D003029:Coagulants / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D008567:Membranes, Artificial; D008970:Molecular Weight; D010316:Particle Size; D012710:Serum Albumin, Bovine; D014462:Ultrafiltration / Q000295:instrumentation*; D018508:Water Purification / Q000295:instrumentation*
chemical_list: D017607:Aluminum Compounds; D002712:Chlorides; D003029:Coagulants; D006812:Humic Substances; D008567:Membranes, Artificial; D012710:Serum Albumin, Bovine; D000077410:Aluminum Chloride
keywords: Aluminum chloride; Critical dose; Flux decline; Low dosage; Ultrafiltration