钛柱撑蒙脱石对镍离子和锰离子的吸附机理  

Adsorption Mechanism of Titanium Pillared Montmorillonite for Nickel and Manganese Ions

作　　者：宋祥 庹必阳[1,2,3] 赵徐霞 向海春 SONG Xiang;TUO Bi-yang;ZHAO Xu-xia;XIANG Hai-chun(Mining College of Guizhou University,Guiyang 550025,Guizhou,China;Guizhou Key Laboratory of Comprehensive Utilization of Non-metallic Mineral Resources,Guiyang 550025,Guizhou,China;National&Local Joint Laboratory of Engineering for Effective Utilization of Regional Mineral Resources from Karst Areas,Guiyang 550025,Guizhou,China)

机构地区：[1]贵州大学矿业学院,贵州贵阳550025 [2]贵州省非金属矿产资源综合利用重点实验室,贵州贵阳550025 [3]喀斯特地区优势矿产资源高效利用国家地方联合工程实验室,贵州贵阳550025

出　　处：《精细化工》2019年第12期2482-2490,共9页Fine Chemicals

基　　金：国家自然科学基金(51464007);贵州省科技厅联合资金项目(黔科合LH字[2015]7684);博士基金〔贵大人基合字(2013)51号〕

摘　　要：以钠基蒙脱石(Na-MMT)、钛酸四丁酯作基质材料,通过溶胶-凝胶法制备了钛柱撑蒙脱石(Ti-MMT)。利用XRD、FTIR及SEM对Ti-MMT进行了结构表征,考察了不同吸附条件对Ti-MMT吸附Ni^2+和Mn^2+的影响,并重点分析水溶液pH对Ti-MMT Zeta电位及吸附的影响,探究了Ti-MMT吸附Ni^2+和Mn^2+的机理。结果表明:Ti-MMT具有较大的晶面间距(d001=2.94 nm);pH对吸附Ni^2+与Mn^2+有较大影响,去除率随初始水溶液pH增加而提高。在pH=7,Ni^2+和Mn^2+初始质量浓度为50 mg/L,Ti-MMT投加量分别为5和9 g/L时,Ni^2+在318 K下吸附120 min,吸附量可达9.46 mg/g,去除率可达94.59%,Mn^2+在328 K下吸附180 min,吸附量可达4.82mg/g,去除率可达86.73%。此外,Ti-MMT对两种离子的吸附都更符合Temkin等温吸附模型及拟二级动力学模型,吸附过程受液膜扩散、颗粒内扩散等环节控制,且以离子交换的化学吸附为主。热力学分析表明,Ti-MMT对Ni^2+的吸附属于自发吸热熵增过程,而Mn^2+属于吸热熵增的非自发过程.Titanium pillared montmorillonite(Ti-MMT)was prepared by sol-gel method using sodium montmorillonite(Na-MMT)and tetrabutyl titanate as matrix materials.The Ti-MMT were characterized by XRD,FTIR and SEM.Then,the effects of different adsorption conditions on the adsorption of Ni^2+and Mn^2+on Ti-MMT were investigated,and the effect of pH on Zeta potential and adsorption was emphatically analyzed.The mechanism of Ti-MMT adsorption of Ni^2+and Mn^2+was investigated.The results show that Ti-MMT has a large interplanar spacing(d001=2.94 nm);pH has a great influence on adsorption,and the removal rate of Ni^2+and Mn^2+increases with the increase of initial pH.At pH=7,the dosage of Ti-MMT is 5 g/L,the initial mass concentration of Ni^2+is 50 mg/L,and the adsorption time is 120 min at 318 K,Ni^2+adsorption capacity can reach 9.46 mg/g,and the removal rate can reach 94.59%.At pH=7,the dosage of Ti-MMT is 9 g/L,the initial mass concentration of Mn^2+is 50 mg/L,and the adsorption time is 180 min at 318 K,Mn^2+adsorption capacity can reach 4.82 mg/g,and the removal rate can reach 86.73%.In addition,Ti-MMT adsorption of both ions is more consistent with Temkin isotherm adsorption,and the pseudosecond-order kinetics model.The adsorption process is controlled by liquid membrane diffusion and intra-particle diffusion,and ion exchange chemisorption is dominant.Thermodynamic analysis shows that the adsorption of Ni^2+by Ti-MMT belongs to the process of spontaneous endothermic entropy increase,while Mn^2+belongs to the non-spontaneous process of increasing endothermic entropy.

关 键 词：钛柱撑蒙脱石 吸附 二价镍离子 二价锰离子 水处理技术 

分 类 号：X703.5[环境科学与工程—环境工程]