title: Effect of aluminum speciation on fouling mechanisms by pre-coagulation/ultrafiltration process with different NOM fractions.
abstract: Ultrafiltration is an emerging technology for drinking water production, but the membrane fouling is still a challenge. This study was carried out to investigate the effect of aluminum speciation on UF membrane fouling behavior by different NOM fractions-humic substances and proteins, as represented by humic acid (HA) and bovine serum albumin (BSA), respectively. The interesting results showed that the total fouling resistance of the mixture of HA-BSA-kaolinite solution without coagulant demonstrated a slight decrease in comparison with those of the individually filtered substances, indicating a mitigatory fouling effect. The hydrolysis of aluminum products was various as pH and membrane fouling was related to aluminum speciation. The average size of flocs dramatically increased and fractal dimension of flocs decreased with the increasing of pH value independent on water quality, which indicated that aluminum speciation had a significant impact on floc properties. For the mixture of HA-BSA-kaolinte, the slightly larger of flocs average size in comparison with the individual organic fraction after coagulation was probably attributing that BSA was encapsulated by HA to enlarge the molecular length and floc size further increased. The membrane performance also showed that coagulation effluent of HA-BSA-kaolinite mitigated membrane fouling. The strong linear relationship was observed between flocs fractal dimension and final membrane flux in this research. From the results, the control of flocs fractal dimension should be considered as a new technique for traditional hybrid coagulation/ultrafiltration system, which resulted in minimized total and irreversible fouling and has a meaningful engineering application value.
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.|Heilongjiang Research Academy of Environmental Sciences, Harbin, 150056, People's Republic of China.
authors.forename: Weiguang
authors.initials: W
authors.lastname: Sun
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China. nanjun209@126.com.
authors.forename: Jun
authors.initials: J
authors.lastname: Nan
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.
authors.forename: Meng
authors.initials: M
authors.lastname: Yao
authors.affiliation: Heilongjiang Research Academy of Environmental Sciences, Harbin, 150056, People's Republic of China.
authors.forename: Jia
authors.initials: J
authors.lastname: Xing
authors.affiliation: State Key Laboratory of Urban Water Resource and Environment, School of Municipal and Environmental Engineering, Harbin Institute of Technology, Harbin, 150090, People's Republic of China.
authors.forename: Jiayu
authors.initials: J
authors.lastname: Tian
mesh_terms: D000535:Aluminum / Q000737:chemistry*; D000818:Animals; D002417:Cattle; D006863:Hydrogen-Ion Concentration; D012710:Serum Albumin, Bovine / Q000737:chemistry; D012996:Solutions; D014462:Ultrafiltration / Q000379:methods*
chemical_list: D012996:Solutions; D012710:Serum Albumin, Bovine; D000535:Aluminum
keywords: Aluminum speciation; Bovine serum albumin; Floc characteristics; Humic acid; Ultrafiltration membrane fouling; pH conditions