镍渣表面理化特性及对Pb2+、Cu2+的吸附研究

利用多种表征手段对镍渣的组成和表面特性进行分析，证实了镍渣具备吸附废水中重金属的能力。本实验所采用的水淬二次镍渣中含有含量较高的SiO₂、Al₂O₃、CaO、MgO等活性成分，且具备由不同聚合度的Si-O四面体、Al-O四面体或Al-O八面体组成的岛状、链状或网状骨架结构，能够通过离子交换和专性吸附去除溶液中的重金属离子。此外，镍渣粉体表面的碱中心可以为金属阳离子提供有效的吸附位点，且表面在pH=4~12的范围内均带负电，这些都有利于金属阳离子的吸附。镍渣粉体对模拟废液中的Pb²⁺、Cu²⁺吸附实验结果显示，其对废液中的Pb²⁺、Cu²⁺均表现出较好的吸附效果，且对Pb²⁺表现出更好的选择性吸附效果。

A study on the surface physicochemical properties and removal of Pb2+ and Cu2+ from aqueous solution of nickel slag

The composition and surface properties of nickel slag was analysed through many characterization methods, which proved that nickel slag had the ability to absorb heavy metal from waste water. In this experiment, nickel slag had high content of active constituents, such as SiO₂, Al₂O₃, CaO, MgO, and it also contained the island, chain, or net skeletal structure that consisted of Si-O tetrahedron, Al-O tetrahedron or Al-O octahedron with different degrees of polymerization, which could remove heavy metal from aqueous solution through ion-exchange and specific adsorption. Moreover, surface base sites of nickel slag could provide effective adsorption sites and the surface was negatively charged within the range of pH=4~12, both of which benefited the absorption of metal cations. The results that nickel slag absorbed Pb²⁺ and Cu²⁺ from aqueous solution showed that nickel slag have a good effect on absorbing Pb²⁺ and Cu²⁺and better selective adsorption for Pb²⁺.