碳羟基磷灰石/钾长石复合材料对镍的吸附性能研究

以钾长石为原料,用液相合成法制备碳羟基磷灰石/钾长石吸附剂（CHAK）去除水中的重金属镍,用静态吸附实验考察了CHAK添加量、溶液初始pH、吸附时间、镍初始浓度等因素对镍去除效果的影响,并结合动力学及热力学拟合探究吸附机理。结果表明：随着CHAK量的增加,对Ni ²⁺的去除率增加,但吸附量会降低;溶液pH=6时吸附效果达到最佳;吸附时间为10 h时吸附达到平衡;Ni ²⁺溶液的初始质量浓度为50~4 000 mg/L时,CHAK对Ni ²⁺的吸附量呈先增长后平稳趋势,饱和吸附量与原材料相比增大7.1倍。动力学及热力学拟合结果显示：准二级模型更符合描述该吸附行为。ΔH>0,表明该吸附过程为吸热反应,升温有利于吸附。ΔG<0,表明该反应能自发进行。

Research on adsorption of Ni 2+ by carbonated hydroxyapatite/potash feldspar composite materials

The carbonated hydroxyapatite/potash feldspar composite adsorbent（CHAK） used to remove heavy metal nickel in water were prepared by liquid method with potash feldspar as the raw material.The effects of the adsorbent amount,initial so-lution pH,adsorption time and initial concentration of Ni ²⁺ on the adsorbability were investigated by static adsorption test.In addition,kinetics and thermodynamic were used to explore the adsorption mechanism.Results showed that with the increase of CHAK,the removal rate of Ni ²⁺ was increased,while the adsorption capacity of Ni ²⁺ was decreased.The optimal adsorption effect was obtained with the pH of 6.The adsorption equilibrium obtained with the adsorption time of 10 h.The adsorption ability of CHAK to Ni ²⁺ increased with the initial mass concentration of Ni ²⁺ at 50~4 000 mg/L,and then it reached stabilized. The saturated adsorption capacity of the CHAK was 7.1 times than that of the raw material.The kinetic and thermodynamic fitting results showed that the pseudo second order kinetic model more fitting the adsorption process.ΔH>0,it showed that the adsorption of Ni ²⁺ on CHAK was an endothermic process and raising the temperature was benefit to the adsorption process,ΔG<0 indicated that the adsorption was a spontaneous process.