Zn/Al双金属氧化物对水中硫酸根离子的吸附性能  

Adsorptive removal of sulfate from water by Zn/Al layered double oxide

作　　者：程珺煜 岳秀萍[1] 曹岳[1] 张悦[1] 

机构地区：[1]太原理工大学环境科学与工程学院,太原030024

出　　处：《环境工程学报》2014年第1期131-137,共7页Chinese Journal of Environmental Engineering

基　　金：山西省科技攻关项目(20120311008-01);山西省高等学校教学改革项目(2011年)

摘　　要：研究了用Zn/Al水滑石制得的Zn/Al双金属氧化物(Zn/Al-300)吸附剂对水中硫酸根离子的吸附,考查了吸附剂投加量、初始pH等因素对硫酸根离子吸附的影响。结果表明,Zn/Al-300对水中硫酸根离子的吸附符合Langmuir吸附等温方程,理论最大吸附量为62.5 mg/g。运用动力学方程进行拟合,吸附过程符合准二级动力学方程;溶液的pH影响吸附剂对硫酸根的吸附,在pH=5.5时硫酸根的去除率最大;X射线衍射结果显示,水滑石经过焙烧后丧失了原有的构形,并在吸附硫酸根离子后重新恢复水滑石的部分层状结构。吸附机制主要为Zn/Al-300从溶液中获取阴离子以重建水滑石的晶体结构,即"记忆效应"。对吸附后的双金属氧化循环应用4此后,吸附容量几乎不变,说明双金属氧化物具有可循环型。通过将Zn/Al-300与其他几种吸附剂的经济性分析,表明此吸附剂在使用过程中具有一定优势。The adsorption characteristics of sulfate from aqueous solution by the Zn/Al layered double oxide （Zn/Al-300） and its influencing factors, such as the pH of aqueous solution, dosage of Zn/Al-300, equilibrium i- sotherm and adsorption kinetic were studied. The results showed that the adsorption of sulfate on Zn/Al-300 was conformed to the Langmuir isotherm equation and the maximum adsorption capacity of Zn/Al-300 for sulfate was 62.5mg/g which was close to the stoichiometric adsorption. Three kinetic models were used to fit the experimen- tal data, indicating that the pseudo-second-order kinetics model could better describe the adsorption process. The adsorption of sulfate with the maximum removal rate was found at pH = 5.5. The results by X-ray diffraction （ XRD） showed that the reconstruction of its original layered structure in the presence of appropriate anions is mainly attributed to the removal sulfate mechanism of Zn/Al-300. Zn/Al-300 has a good desorption and it can be regenerated by calcination. Through the economical analysis and comparison, it was found that the Zn/Al-300 could be used to remove sulfate at the lowest costs.

关 键 词：双金属氧化物 硫酸根 吸附机理 经济性分析 

分 类 号：X523[环境科学与工程—环境工程]