应用化学 ›› 2010, Vol. 27 ›› Issue (12): 1444-1450.DOI: 10.3724/SP.J.1095.2010.00115

• 研究论文 • 上一篇    下一篇

聚丙烯酸钠配合-超滤分离Hg(II)、Cu(II)和Cd(II)

曾坚贤*,贺勤程,孙霞辉,郑立锋   

  1. (湖南科技大学化学化工学院 湘潭 411201)
  • 收稿日期:2010-02-28 修回日期:2010-05-04 出版日期:2010-12-10 发布日期:2010-12-10
  • 通讯作者: 曾坚贤,男,副教授; E-mail:zengjianxian@163.com; 研究方向:膜分离
  • 基金资助:
    国家自然科学基金(20976040)湖南省科技计划(2009SK3036)资助项目

Separation of Hg(II), Cu(II) and Cd(II) by Complexation-ultrafiltration with Poly(acrylic acid) Sodium

ZENG Jian-Xian*, HE Qin-Cheng, SUN Xi-Hui, ZHENG Li-Feng   

  1. (College of Chemistry and Chemical Engineering,Hunan University of Science and Technology,Xiangtan 411201)
  • Received:2010-02-28 Revised:2010-05-04 Published:2010-12-10 Online:2010-12-10

摘要:

以聚丙烯酸钠为配合剂,研究了Hg(Ⅱ)、Cu(Ⅱ)和Cd(Ⅱ)混合溶液配合超滤分离行为。 考察了pH值和负载比LR对混合体系分离的影响,结果表明,pH=5适宜分离;当LR从0.01增大至2时,金属离子分离系数SHg-Cd和SHg-Cu逐渐增大,LR=2时达到最大值。 在pH=5、LR=2、体积浓缩因子为15和各金属离子的初始质量浓度为30 mg/L时,截留液中金属离子的质量浓度ρr,Hg、ρr,Cu和ρr,Cd分别为435.3、42.6和34.2 mg/L;SHg-Cd、SHg-Cu和SCu-Cd基本不变,依次为229.3、184.3和1.2,即Hg(Ⅱ)得到选择性浓缩。 浓缩液的洗涤研究结果表明,随着洗涤液体积增大,ρr,Hg基本不变,ρr,Cu 和ρr,Cd分别下降至12.54和4.73 mg/L。 收集含Cu(Ⅱ)和Cd(Ⅱ)的各渗透液,调节LR=0.033和pH=5,浓缩16倍时,ρr,Cu从27.34 mg/L升高至430.9 mg/L,ρr,Cd从27.83 mg/L仅升高至61.5 mg/L,SCu-Cd为95.8,Cu(Ⅱ)获得选择性浓缩。

关键词: Hg(II), Cu(II), Cd(II), 聚丙烯酸钠, 配合, 超滤

Abstract:

Complexationultrafiltration process was investigated for selective separation of Hg(Ⅱ), Cu(Ⅱ) and Cd(Ⅱ) from mixture aqueous solutions. This process included the addition of poly(acrylic acid) sodium salt as a water soluble polymer to selectively bind the metal cations, which was followed by an ultrafiltration operation. Effects of pH and loading ratio(LR) on the selective separation were investigated. It was found that controlling pH=5 was helpful to achieve the selective separation. When LR increased from 0.01 to 2, metal separation coefficients(SHg-Cd and SHg-Cu) increased gradually, and then reached maximum values at LR=2. A concentration experiment was carried out at pH=5 and LR=2. Initial mass concentrations for Hg(Ⅱ), Cu(Ⅱ) and Cd(Ⅱ) were all 30 mg/L. Result showed that, when volume concentration factor(VCF) reached 15, mercury mass concentration of mercury(ρr,Hg), copper(ρr,Cu) and cadmium(ρr,Cd) in the retentate were 435.3 mg/L, 42.6 mg/L and 34.2 mg/L, respectively. SHg-Cd, SHg-Cu and SCu-Cd did not change with VCF, and were 229.3, 184.3 and 1.2, respectively. This indicated that Hg(Ⅱ) was retained selectively in the retentate by the ultrafiltration operation while nearly all Cu(Ⅱ) and Cd(Ⅱ) passed through the membrane into the permeate. Then, the final concentrated solution was used to study the washing process. With increasing the washing water volume, ρr,Hg remained nearly constant while both ρr,Cu and ρr,Cd decreased rapidly. After doubling the washing water volume, ρr,Cu and ρr,Cd reached 12.54 mg/L and 4.73 mg/L respectively. Further, another concentration experiment was performed at LR=0.033 and pH=5 by using the permeate solutions containing Cu(Ⅱ) and Cd(Ⅱ). At VCF=16, ρr,Cu increased linearly from the beginning of 27.34 mg/L to the end of 430.9 mg/L, whereas ρr,Cd changed only from 27.83 mg/L to 61.5 mg/L. SCu-Cd was 95.8, therefore copper was selectively concentrated.

Key words: Mercury(II), Copper(II), Cadmium(II), Poly (acrylic acid) sodium salt, Complexation, Ultrafiltration

中图分类号: