Removal of cadmium ion from aqueous solutions by a complexation-ultrafiltration process
Complexation-ultrafiltration process was investigated for removal of cadmium ion. This process included the addition of poly (acrylic acid) sodium salt (PAASS) as a water soluble polymer to bind the metal ion, which was followed by an ultrafiltration operation. The kinetics of complexation reaction was investigated for PAASS with cadmium ion. Results showed that, under a large excess of PAASS and a constant pH 5.5, it takes 50 minutes for cadmium to get the complexation equilibrium, and the reaction kinetics can be described by a pseudo-first-order equation. Further, effects of loading ratio and pH value on the removal of cadmium ion were investigated. It was found that the binding capacity of PAASS to cadmium ion is 0.033 g cadmium/g PAASS.Cadmium complexation is sensitive with changing pH, and this sensitivity occurs mainly between pH 5 and 6. In the process of concentration, rejection coefficient of cadmium ion is about 1, and membrane flux declines slowly with increasing volume concentration factor. The concentrated retentate was used further for the decomplexation.The decomplexation ratio of cadmium-PAASS complex reaches 93.5%. After the decomplexation, the diafiltration experiment was carried out at pH 2.5. Cadmium can be diafiltrated satisfactorily from the retentate and a purified PAASS is obtained.
Complexation Ultrafiltration Poly (acrylic acid) sodium salt Cadmium
Jian-xian Zeng Hong-qi Ye Zhong-Yu Hu
College of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P R. China
国际会议
The 12th Asian Pacific Confederation of Chemical Engineering Congress(第十二届亚太化工联盟大会暨化工展览会)
大连
英文
2008-08-04（万方平台首次上网日期，不代表论文的发表时间）