【摘要】 考察了不同反应时间及硅源前驱体添加量对纳米零价铁@介孔氧化硅（NZVI@mSiO₂）结构的影响。采用以1,1,1-TCA为模式氯代烃的模拟污染地下水,考察了铁剂量与有机质（NOM）含量对NZVI@mSiO₂吸附去除和吸附-降解去除氯代烃行为的影响。结果表明:加入正硅酸乙酯（TEOS）后,以300 r/min速度搅拌4 h便可获得结构稳定的NZVI@mSiO₂;不同TEOS添加量可调控NZVI@mSiO₂的mSiO₂壳层厚度;铁剂量的升高促进NZVI@mSiO₂对1,1,1-TCA的吸附-降解去除;NOM通过吸附桥连和网捕卷扫作用降低mSiO₂悬浮液的稳定性,但因其引入的新的吸附位点及降低体系pH,从而促进对氯代烃的吸附去除与吸附-降解去除。更多还原

【Abstract】 Nanoscale zerovalent iron@mesoporous silica（NZVI@mSiO₂） can effectively remove chlorinated hydrocarbons in groundwater. The effects of the reaction time after adding silicon source and the amount of silicon source added in the structure of NZVI@mSiO₂ were studied. 1,1,1-TCA was used as a model chlorinated hydrocarbon to study the effects of NZVI@mSiO₂ amount and natural organic matter（NOM） on the removal of chlorinated hydrocarbons via the adsorption and adsorptiondegradation by NZVI@mSiO₂. The results show: the stable structure of NZVI@mSiO₂ can be obtained after adding tetraethoxysilane（TEOS） and stirring at 300 r/min for 4 h; the thickness of the mSiO₂ shell can be controlled by adding different amount of TEOS; higher NZVI@mSiO₂ dosage provides more active sites for the reaction, which is beneficial to the removal of chlorinated hydrocarbons via the adsorption-degradation; NOM can reduce the stability of mSiO₂ suspension through bridging and trapping mSiO₂ particles, while the introduced new sites and the reduced pH value of the solution finally promote the removal of chlorinated hydrocarbons via the adsorption and adsorption-degradation.更多还原