物理化学学报 >> 2013, Vol. 29 >> Issue (09): 2019-2026.doi: 10.3866/PKU.WHXB201306271

催化和表面科学 上一篇    下一篇

Co(Ⅱ)和Ni(Ⅱ)在北山花岗岩上的吸附:表面配位模型及线性自由能关系

陈宗元1, 张瑞1, 杨兴龙1, 吴王锁1, 郭治军1, 刘春立2   

  1. 1 兰州大学核科学与技术学院, 兰州 730000;
    2 北京大学化学与分子工程学院, 放射化学与辐射化学重点学科实验室, 北京分子科学国家实验室, 北京 100871
  • 收稿日期:2013-03-29 修回日期:2013-03-29 发布日期:2013-08-28
  • 通讯作者: 郭治军, 刘春立 E-mail:guozhj@lzu.edu.cn;liucl@pku.edu.cn
  • 基金资助:

    国家自然科学基金(91226113, 11075006, 91026010);核设施退役和放射性废物治理科研专项(科工计[2012]494号, [2007]840号, [2012]851号)

Adsorption of Co(Ⅱ) and Ni(Ⅱ) on Beishan Granite:Surface Complexation Model and Linear Free Energy Relationship

CHEN Zong-Yuan1, ZHANG Rui1, YANG Xing-Long1, WU Wang-Suo1, GUO Zhi-Jun1, LIU Chun-Li2   

  1. 1 School of Nuclear Science and Technology, Lanzhou University, Lanzhou 730000, P. R. China;
    2 Beijing National Laboratory for Molecular Sciences, Radiochemistry & Radiation Chemistry Key Laboratory for Fundamental Science, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, P. R. China
  • Received:2013-03-29 Revised:2013-03-29 Published:2013-08-28
  • Contact: GUO Zhi-Jun, LIU Chun-Li E-mail:guozhj@lzu.edu.cn;liucl@pku.edu.cn
  • Supported by:

    The project was supported by the National Natural Science Foundation of China (91226113, 11075006, 91026010) and Special Foundation for High Level Waste Disposal, China ([2012]494, [2007]840, [2012]851).

摘要:

用批式法研究了Co(Ⅱ)和Ni(Ⅱ)在北山花岗岩(BS03, 600 m)上的吸附. Co(Ⅱ)和Ni(Ⅱ)在北山花岗岩上的吸附分配比(Kd)均随pH值、离子强度和吸附质浓度的变化而变化; 在低pH值范围, Co(Ⅱ)和Ni(Ⅱ)的Kd 值随离子强度的增大显著减小, 而在高pH值范围,离子强度对Kd的影响较小; Co(Ⅱ)和Ni(Ⅱ)在北山花岗岩上的吸附作用可以分别用1个离子交换反应和2个内层表面配位反应进行定量描述. 建立了表面配位反应平衡常数(K)与过渡金属二价离子水解常数(OHK)之间的线性自由能关系(LFER),据此对Pb(Ⅱ)和Cu(Ⅱ)在花岗岩上的吸附进行了预测,并与实验结果进行了对比,获得了较好的一致性.

关键词: 北山花岗岩, 吸附, Co(Ⅱ), Ni(Ⅱ), 表面配位模型, 线性自由能关系

Abstract:

The adsorption of Co(Ⅱ) and Ni(Ⅱ) on crushed Beishan granite (BS03, 600 m) was studied by a batch experimental method. The distribution coefficient (Kd) was found to vary as a function of the pH, ionic strength, and the initial concentrations of Co(Ⅱ) and Ni(Ⅱ). In the low pH range, the Kd values of Co(Ⅱ) and Ni(Ⅱ) decreased significantly as the ionic strength increased, whereas the effect of the ionic strength was weak in the high pH range. The adsorption of Co(Ⅱ) and Ni(Ⅱ) on granite was quantitatively interpreted by a model with one cation exchange reaction and two inner-sphere surface complexation reactions. A linear free energy relationship (LFER) between the equilibrium constants (K) of the surface complexation reactions and the hydrolysis stability constants of the divalent transition metals (OHK) was established. Predictions based on the LFER are in good agreement with the experimental results for the adsorption of Pb(Ⅱ) and Cu(Ⅱ) on granite.

Key words: Beishan granite, Adsorption, Co(Ⅱ), Ni(Ⅱ), Surface complexation model, Linear free energy relationship

MSC2000: 

  • O647.32