title: Purification, characterization and application of dual coagulants containing chitosan and different Al species in coagulation and ultrafiltration process.
abstract: The objective of this study was to investigate the effect of different Al species and chitosan (CS) dosages on coagulation performance, floc characteristics (floc sizes, strength and regrowth ability and fractal dimension) and membrane resistance in a coagulation-ultrafiltration hybrid process. Results showed that different Al species combined with humic acid in diverse ways. Alahad better removal efficiency, as determined by UV254and dissolved organic carbon, which could be further improved by the addition of CS. In addition, the optimal dosage of different Al species was determined to be 4.0mg/L with the CS concentration of 1.0mg/L, by orthogonal coagulation experiments. Combining Ala/Alb/Alcwith CS resulted in larger flocs, higher recovery, and higher fractal dimension values corresponding to denser flocs; in particular, the floc size at the steady state stage was four times larger than that obtained with Al species coagulants alone. The results of ultrafiltration experiments indicated that the external fouling percentage was significantly higher than that of internal fouling, at around 85% and 15%, respectively. In addition, the total membrane resistance was significantly decreased due to CS addition.
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China. Electronic address: sduwenyuwang@foxmail.com.
authors.forename: Wenyu
authors.initials: W
authors.lastname: Wang
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
authors.forename: Shuang
authors.initials: S
authors.lastname: Zhao
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China. Electronic address: qyyue58@aliyun.com.
authors.forename: Qinyan
authors.initials: Q
authors.lastname: Yue
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
authors.forename: Baoyu
authors.initials: B
authors.lastname: Gao
authors.affiliation: Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse, School of Environmental Science and Engineering, Shandong University, Jinan 250100, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Song
authors.affiliation: Key Laboratory of Inorganic Chemistry in Universities of Shandong, Department of Chemistry and Chemical Engineering, Jining University, Shandong 273155, China.
authors.forename: Lijuan
authors.initials: L
authors.lastname: Feng
mesh_terms: D000535:Aluminum / Q000032:analysis / Q000737:chemistry*; D048271:Chitosan / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis; D014462:Ultrafiltration; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification
chemical_list: D006812:Humic Substances; D014874:Water Pollutants, Chemical; D048271:Chitosan; D000535:Aluminum
keywords: Al species; Chitosan; Coagulation–ultrafiltration; Dual-coagulants; Floc characteristics; Membrane resistance