水化氯铝酸钙脱氟的pH相关性研究  

Study on dependence between the pH value of the defluorination by hydrated calcium chloroaluminate

作　　者：张陆军 王宁宁 章兴华 曹建新[1,2] 易芸 许争[1] ZHANG Lu-jun;WANG Ning-ning;ZHANG Xing-hua;CAO Jian-xin;YI Yun;XU Zheng(School of Chemistry and Chemical Engineering,Guizhou University,Guiyang 550025,China;Key Laboratory for Green Chemical and Clean Energy Technology of Guizhou Province,Guiyang 550025,China)

机构地区：[1]贵州大学化学与化工学院,贵州贵阳550025 [2]贵州省绿色化工与清洁能源技术重点实验室,贵州贵阳550025

出　　处：《应用化工》2020年第6期1443-1447,1451,共6页Applied Chemical Industry

基　　金：贵州省省长专项资金项目(黔省专合(2009)72号);贵州省高层次人才特助经费资助(TZJF[2009]18号)。

摘　　要：以聚合氯化铝和石灰乳为原料合成了水化氯铝酸钙用于含氟水的处理。发现水化氯铝酸钙脱氟具有显著的pH相关性,脱氟效率最高的pH值在3~4区域、在pH值7~8区域的脱氟效率次之。对含氟絮体的的ζ电位、XRD、FTIR、XPS及SEM-EDS表征显示,溶解-再沉淀是水化氯铝酸钙脱氟的主要途径;但无论是在酸性、中性及碱性环境,水化氯铝酸钙对氟离子的去除始终存在着无定型Al(OH)3(am)絮体对CaF2的分子吸附;在酸性和碱性pH区域还分别存在着以新生态铝盐对氟离子的络合吸附以及水化氯铝酸钙层间的F-Cl离子交换,这些检测结果表明水化氯铝酸钙对溶液中氟离子吸收是一个复杂的过程。Hydrated calcium chloroaluminate was synthesized from polyaluminum and lime milk and used in the treatment of fluorine-containing water.It was found that the hydrated calcium chloroaluminate defluorination features a significant pH dependence,with the highest defluoridation efficiency in the pH region 3~4 and the second-best defluoridation in the pH region 7~8.The characterization results of theζpotential,XRD,FTIR,XPS and SEM-EDS of the fluorine-containing flocculants showed that dissolution-reprecipitation was the main way to defluorinate the hydrated calcium chloroaluminate.However,no matter in acidic,neutral and alkaline environment,the adsorption of amorphous Al(OH)3(am)flocs to CaF 2 molecules was always existed in the removal of fluorinios in hydrated calcium chloroaluminate.In the acidic and alkaline pH areas,it also exists complexing fluoride adsorption by new produced aluminium salt and F-Cl ion exchange among Friedel’s salt interlayers,respectively.These test results indicate that the absorption of fluoride ions in solution by calcium chloride hydrate was a complex process.

关 键 词：水化氯铝酸钙 除氟 pH相关性 溶解-再沉淀 络合吸附 

分 类 号：TQ085[化学工程] TQ326