Abstract：Polymer-enhanced ultrafiltration was investigated to separate selectively Hg2+ and Cd2+ from aqueous solutions by using poly (acrylic acid) sodium salt as a complexing agent. Effects of pH, loading ratio (LR) and the added salt on separation coefficient (S) were investigated. When pH increased from 5 to 7.5, S decreased gradually. Controlling pH=5 was helpful to achieve the selective separation. At LR between 0.01 and 2, S increased with LR, reached a maximum value, and then decreased rapidly. It was preferable for the selective separation to control LR=1.5. S changed in the present of sodium sulfate. A concentration experiment was carried out at pH=5 and LR=1.5. When volume concentration factor (VCF) reached 15, mercury concentration in the retentate (Cr, Hg) increased linearly from 30 mg/L to 444.9 mg/L, whereas cadmium concentration in the retentate (Cr, Cd) changed only from 30 mg/L to 35.4 mg/L. S was about 227. Then, the final concentrated solution was used to study the process of washing. With increasing the washing water volume, Cr, Hg did not change, but Cr, Cd decreased rapidly to 5.24 mg/L. Further, another concentration experiment was performed at pH=6 and LR=0.033 by using all permeate solutions. At VCF=13, Cr, Cd increased from 27.37 mg/L to 354.7 mg/L.
曾坚贤, 郑立锋, 孙霞辉, 贺勤程. 聚合物强化超滤技术分离Hg2+和Cd2+的研究[J]. 中国环境科学, 2010, 30(6): 780-785.
ZENG Jian-Xian, ZHENG Li-Feng, SUN Xia-Hui, HE Qin-Cheng. Separation of Hg2+ and Cd2+ by using polymer-enhanced ultrafiltration. CHINA ENVIRONMENTAL SCIENCECE, 2010, 30(6): 780-785.
