碘化阶层孔氧化硅纳米球对水中典型有机氯污染物的吸附性能研究

Highly efficient removal of organochlorine pollutants from aqueous solution by hierarchically porous silica nanospheres functionalized with iodine

采用共缩聚法,成功地原位合成了碘改性的阶层多孔氧化硅纳米球(SiO2-I),研究了其基于卤键作用对典型有机氯污染物六六六的吸附性能,并考察了改性剂I-硅烷含量和pH值对吸附效果的影响.实验结果表明,该纳米材料对六六六表现出优异的吸附富集性能,吸附速率快,60 min内对六六六的去除率为71.6%,240 min内达到吸附平衡,去除率可达98.3%,最大吸附量为178.6 mg·g^-1;吸附动力学符合拟二级动力学模型;碘物种的加入提高了阶层多孔氧化硅的吸附速率和吸附效率.另外,为了便于纳米吸附材料的分离,本研究对SiO2-I纳米球进行了磁性化.研究发现,磁性化修饰后,SiO2-I纳米材料仍然保留对六六六优异的吸附富集性能,240 min时的吸附去除率达90.3%.

In this study,hierarchically porous iodine-functionalized silica nanospheres(SiO2-I)were successfully synthesized by an in-situ copolycondensation method,and served as adsorbent materials for the removal of hexachlorocyclohexane(HCH)from aqueous solution.Effects of I-silane content and pH on the removal efficiency were investigated.The experimental results indicate the superior efficiency of SiO2-I for highly efficient and rapid removal of HCH.The adsorption is rapid,showing 71.6% removal of HCH in 1 h,and 98.3% removal in 8 h.The maximum adsorption capacity was calculated to be 178.6 mg·g^-1.The adsorption process fits well with the pseudo-second-order kinetic model.It has been confirmed that the introduction of iodine species led to the enhanced adsorption performance of porous silica nanospheres towards HCH.In addition,magnetic SiO2-I composites(Fe3O4@SiO2-I)were also synthesized for the convenient separation of adsorbents from aqueous solution.The adsorption experiments demonstrated the excellent adsorption performance of Fe3O4@SiO2-I for HCH uptake,90.3% of HCH could be captured in 4 h.More importantly,these Fe3O4@SiO2-I composites could be rapidly separated and collected using magnet.