Acta Scientiarum Naturalium Universitatis Pekinensis

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Separation of Pb2+ and Zn2+ by Using Polymer-Enhanced Ultrafilation

CAO Guangliang1, LI Zhenshan1,2, BAO Lichao1   

  1. 1. Shenzhen Key Laboratory for Heavy Metal Treatment and Reutilization, School of Environment and Energy, Peking University Shenzhen Graduate School, Shenzhen 518055; 2. Department of Environmental Engineering, Peking University, The Key Laboratory of Water and Sediment Sciences Ministry of Education, Beijing 100871;
  • Received:2013-04-24 Online:2014-05-20 Published:2014-05-20

丙烯酸-马来酸酐共聚物络合超滤分离水溶液中Pb2+和Zn2+的实验研究

曹光亮1,李振山1,2,包立超1   

  1. 1. 北京大学深圳研究生院环境与能源学院, 深圳市重金属污染控制与资源化重点实验室, 深圳 518055; 2. 北京大学环境工程系, 水沙科学教育部重点实验室, 北京 100871;

Abstract: Polyelectrolyte-enhanced ultrafiltration (PEUF) was investigated to separate Pb2+ and Zn2+ from aqueous solutions by PMA as a chalenting agent. Effects of pH, concentrations of PMA and the added sault on seperation rate (Sr) was studied. Sr inceased gradually before the PMA concentration reached 200 mg/L, and then it decreased, the best Sr value is 54.47%. At pH between 2 to 6, Sr increased gradually with pH reached a maxium value, and then deceased, It was preferable for the selective separation to control pH=4, and the Sr value is 71.34% at this time. PMA and pH play important roles in competitive complexation between Pb2+ and Zn2+, the increased concentration of PMA and pH enhanced the competitive complexation, when PH reached to 5, PMA concentration is 200 mg/L, the competitive complexation of Zn2+ was lowest. The concentration of the added sault have an important infect on Sr. The experiment was performed at pH=4 and PMA=200 mg/L, controlled the concentration of Sodium sulphate from 0.01 to 0.08 mol/L,When the concentration of sodium sulphate is 0.06 mol/L, Sr reached the best. The addition of Na2SO4 weakened the competitive complexation effect of Zn2+.

Key words: Pb2+, Zn2+, PMA, ultrafiltration, selective separation, competitive complexation

摘要: 采用丙烯酸-马来酸酐共聚物(PMA)为络合剂, 研究络合超滤技术对水溶液中Pb2+和Zn2+的分离效果、竞争络合效应以及外加盐对分离效果的影响。以两种金属离子截留率之差表示分离率, 以单一金属离子溶液中离子截留率与混合溶液中该离子的截留率之差表示金属离子间的竞争强度。结果表明: 随着PMA浓度增加, 两种金属离子的分离率先增大后减小, 当PMA浓度为200 mg/L时, 分离率达到最大值, 为54.47%。pH从2增加到6时, 分离率先增大后减小, 且在H=4时达到最大, 为71.34%。两种金属离子的竞争效应随pH及PMA浓度的增加先增强后减弱, 在pH=5, PMA浓度为200 mg/L时, 混合溶液中两种离子竞争效应最强。外加Na2SO4对分离率有较大影响, 随着 n(Na2SO4)增大分离率增加, 随后基本保持不变, 在n(Na2SO4)=0.06 mol/L时, 分离率达到最大值, 为97.677%。加入Na2SO4减弱了Zn2+的竞争络合能力, 有利于两种金属离子的分离。

关键词: Pb2+, Zn2+, 丙烯酸-马来酸酐共聚物, 超滤, 选择性分离, 竞争络合

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