Purification,characterization and application of dual coagulants containing chitosan and different Al species in coagulation and ultrafiltration process  

作　　者：Wenyu Wang Shuang Zhao Qinyan Yue Baoyu Gao Wen Song Lijuan Feng 

机构地区：[1]Shandong Provincial Key Laboratory of Water Pollution Control and Resource Reuse,School of Environmental Science and Engineering,Shandong University,Jinan 250100,China. [2]Key Laboratory of Inorganic Chemistry in Uniuersities of Shandong,Department of Chemistry and Chemical Engineering,Jining University,Shandong 273155,China

出　　处：《Journal of Environmental Sciences》2017年第1期214-221,共8页环境科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(No.21377071);the Tai Shan Scholar Foundation(No.ts201511003)

摘　　要：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.A1_a had better removal efficiency,as determined by UV_（254） and 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 4.0 mg/L with the CS concentration of 1.0 mg/L,by orthogonal coagulation experiments.Combining Al_a/A1_b/A1_c,with 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.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.A1_a had better removal efficiency,as determined by UV_（254） and 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 4.0 mg/L with the CS concentration of 1.0 mg/L,by orthogonal coagulation experiments.Combining Al_a/A1_b/A1_c,with 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.

关 键 词：Al species Chitosan Dual-coagulants Coagulation-ultrafiltration Floc-characteristics Membrane resistance 

分 类 号：X703[环境科学与工程—环境工程]