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为研究ZnxCa(2-x)-Fe系LDHs(层状双金属氢氧化物)对P的吸附去除特性,在室温下采用化学共沉淀法制备一系列不同配比的ZnxCa(2-x)-Fe系LDHs,通过XRD(X射线衍射)、FTIR(傅里叶变换红外光谱)、Zeta电位测试对吸附剂的微观结构和表面电荷进行分析,采用静态吸附试验考察了投加量、接触时间及溶液初始p H对ZnxCa(2-x)-Fe系LDHs除P性能的影响.结果表明:ZnxCa(2-x)-Fe系LDHs与含P水接触4 h后,达到吸附平衡;其中0~1 h为快速吸附阶段,之后为缓慢吸附阶段,吸附过程符合准二级动力学方程.Ca2.0-Fe、Zn2.0-Fe对P的吸附符合Langmuir等温吸附模型,经计算所得理论最大吸附量分别为228.31和95.23 mg/g.结合Zeta电位与FTIR的测试结果,推测ZnxCa(2-x)-Fe系LDHs主要通过静电吸引、离子交换、配位交换及化学沉淀的协同作用实现水中P的去除.ZnxCa(2-x)-Fe系LDHs的饱和吸附量均高于同类吸附剂,能有效去除自然水体和市政污水中的P.
In order to study the adsorption and desorption properties of Zn on ZnxCa (2-x) -Fe LDHs (layered double hydroxide), a series of ZnxCa (2-x) Fe-based LDHs. The microstructures and surface charges of the adsorbents were analyzed by XRD, FTIR and Zeta potential tests. The static adsorption experiments were carried out to investigate the effects of dosage, contact time and The effect of initial pH of solution on the performance of ZnxCa (2-x) -Fe LDHs in addition to P was studied. The results showed that the adsorption equilibrium of ZnxCa (2-x) -Fe LDHs was reached after contact with P-containing water for 4 h, 1 h for the fast adsorption stage, followed by a slow adsorption stage, the adsorption process in line with quasi-second-order kinetic equation.Ca2.0-Fe, Zn2.0-Fe adsorption of P in line Langmuir isothermal adsorption model, the calculated maximum theoretical adsorption The results showed that ZnxCa (2-x) -Fe-based LDHs could achieve the synergistic effect of P (superscript +) in water by electrostatic attraction, ion exchange, coordination exchange and chemical precipitation . The saturated adsorption capacity of ZnxCa (2-x) -Fe series LDHs is higher than that of the same kind of adsorbent, which can effectively remove the natural water and the city P