title: Recovery of small dye molecules from aqueous solutions using charged ultrafiltration membranes.
abstract: Recovery of reactive dyes from effluent streams is a growing environmental challenge. In this study, various charged regenerated cellulose (RC) ultrafiltration (UF) membranes were prepared and tested for removal of three model reactive dyes (reactive red ED-2B, reactive brilliant yellow K-6G, and reactive brilliant blue KN-R). Data were obtained with charged UF membranes having different spacer arm lengths between the base cellulose and the charge functionality. The effects of charge density of the dye molecules, ionic strength of the feed solution, spacer arm length of charged membranes and filtrate flux were studied. Results indicated that dye retention was greatest with the most negatively charged dye molecule. Higher rejection was also observed in low ionic strength solutions. Results were consistent with model calculations based on the partitioning of a charged sphere into a charged cylindrical pore. The membranes with longer spacer arm length had higher rejection coefficients, consistent with the greater negative charge on these membranes. This study confirms that charged UF membranes can effectively recover small reactive dye molecules at low pressures (below 100 kPa) under appropriate solution conditions due to the strong electrostatic repulsion from the membrane pores.
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
authors.forename: Xiuwen
authors.initials: X
authors.lastname: Chen
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
authors.forename: Yiru
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Chemical Engineering, Worcester Polytechnic Institute, Worcester, MA 01609, USA.
authors.forename: Jennifer
authors.initials: J
authors.lastname: Moutinho
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China. Electronic address: jhshao@sjtu.edu.cn.
authors.forename: Jiahui
authors.initials: J
authors.lastname: Shao
authors.affiliation: Department of Chemical Engineering, The Pennsylvania State University, University Park, PA 16802, USA.
authors.forename: Andrew L
authors.initials: AL
authors.lastname: Zydney
authors.affiliation: School of Environmental Science and Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, PR China.
authors.forename: Yiliang
authors.initials: Y
authors.lastname: He
mesh_terms: D002482:Cellulose / Q000737:chemistry; D004396:Coloring Agents / Q000737:chemistry*; D004573:Electrolytes; D007220:Industrial Waste; D007477:Ions; D008567:Membranes, Artificial; D009994:Osmolar Concentration; D011312:Pressure; D055672:Static Electricity; D013499:Surface Properties; D014462:Ultrafiltration; D014805:Vitamin B 12 / Q000737:chemistry; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D004396:Coloring Agents; D004573:Electrolytes; D007220:Industrial Waste; D007477:Ions; D008567:Membranes, Artificial; D014874:Water Pollutants, Chemical; D002482:Cellulose; D014805:Vitamin B 12
keywords: Charged membrane; Dye; Removal; Spacer arm length; Ultrafiltration