含氟Fe-MCM-48的制备及其在饮用水处理中抑制臭氧氧化生成溴酸盐机制  

Preparation of fluorinated Fe-MCM-48 and its mechanism for inhibiting ozone oxidation to bromate in drinking water treatment

作　　者：周毅 黄武林 谭冠新 张晓霞 陈敏 林文轩 林明富 ZHOU Yi;HUANG Wulin;TAN Guanxin;ZHANG Xiaoxia;CHEN Min;LIN Wenxuan;LIN Mingfu(Guangzhou Jinghai Oily Water Treatment Co.,Ltd.)

机构地区：[1]广州净海油污水工程有限公司

出　　处：《环境工程技术学报》2025年第2期572-583,共12页Journal of Environmental Engineering Technology

基　　金：广东省科技攻关项目(2014B090901038)。

摘　　要：饮用水厂的臭氧氧化过程中会产生溴酸盐(BrO_(3)^(-))等毒性副产物,对人体健康造成较大威胁。非均相催化臭氧氧化技术可以抑制BrO_(3)^(-)的生成。Fe-MCM-48介孔分子筛具有独特的三维立方孔道结构,常作为催化剂用于催化臭氧氧化过程。但Fe-MCM-48存在表面酸性位点不足、传质效果差等缺点,这限制了其应用和推广。以FeF_(3)为铁源和氟源,通过一步合成法制备了不同F-Fe-MCM-48并将其用于控制臭氧氧化过程BrO_(3)的产生;利用XRD、TEM和红外光谱等手段研究了F-Fe-MCM-48比表面积和酸性位点等理化性质,考察了F-Fe-MCM-48、溶液pH、叔丁醇(TBA)等因素对BrO_(3)产生情况的影响,同时结合电子顺磁共振等技术揭示催化剂作用机制。结果表明:1)F-Fe-MCM-48具有良好的三维立体介孔结构和较大的比表面积(1487m^(2)/g)。在水热反应中,铁原子能够通过替代硅氧四面体中的硅原子,成功地进入分子筛的骨架结构;同时,氟原子也通过取代分子筛表面的Si—OH基团,形成了具疏水性的Si—F基团。2)在臭氧(O_(3))产量为100 mg/h,Br^(-)投加量为1000μg/L条件下,反应60 min后,F-Fe-MCM-48/O_(3)体系中BrO_(3)^(-)产生量为70.3μg/L,抑制率达78.9%,抑制效果是Fe-MCM-48/O_(3)的1.4倍。且在pH为5~9的范围内,F-Fe-MCM-48/O_(3)均保持良好的BrO_(3)^(-)抑制效果。3)F-Fe-MCM-48具有丰富的Lewis酸位点,能有效吸附并分解O_(3),降低溶液中O_(3)浓度,从而抑制了O_(3)对Br的直接氧化作用。反应过程中产生的·O_(2)^(-)和H_(2)O_(2)等活性物种能还原BrO_(3)、·Br_(2)^(-)和·Br_(3)^(-)等中间产物,进一步抑制F-Fe-MCM-48/O_(3)过程中BrO_(3)^(-)的产生。本研究可为臭氧氧化中BrO_(3)^(-)的控制提供理论依据。The ozonation process in drinking water plant will generate toxic by-products such as bromate(BrO_(3)^(-)),which pose significant threats to human health.Heterogeneous catalytic ozonation process can inhibit the formation BrO_(3)^(-)of.Fe-MCM-48 mesoporous molecular sieves,with their unique three-dimensional cubic pore structures,are often used as catalyst for catalytic ozonation.However,the insufficient surface acidic sites and poor mass transfer effects of Fe-MCM-48 limit its application and popularization.In this study,F-Fe-MCM-48 was prepared using BrO_(3)^(-)FeF_(3)as the iron and fluoride source via a one-step synthesis method.It was applied to inhibit production during the catalytic ozonation process.XRD,TEM and FTIR were used to study the physicochemical properties like specific surface area and acid sites.The influence of F-Fe-MCM-48,solution pH and tert-Butanol(TBA)addition on BrO_(3)^(-)formation were investigated and the functional mechanism of catalyst was revealed by electron paramagnetic resonance(EPR).Results showed that:1)F-Fe-MCM-48 possessed a good three-dimensional mesoporous structure and a large specific surface area(1487 m^(2)/g).During hydrothermal reactions,iron atoms replaced silicon atoms in the siloxane tetrahedra to enter the framework of the molecular sieve,and F replaced the Si—OH on the surface to form the hydrophobic Si—F group.2)With an ozone production of 100 mg/h and a Br^(-)addition of 1000μg/L,the BrO_(3)^(-)concentration of in the F-Fe-MCM-48/O_(3)system after 60 min was 70.3μg/L,with an inhibition rate of 78.9%,which was 1.4 times of that in Fe-MCM-48/O_(3).Within a pH range of 5-9,the F-Fe-MCM-48/O_(3)system maintained BrO_(3)^(-)good inhibition.3)F-Fe-MCM-48 was enriched with Lewis acid sites,which could effectively adsorb and decompose O_(3),thereby reducing its concentration and inhibiting the direct oxidation of Br^(-).The active species such·O_(2)^(-)BrO_(3)^(-)·Br_(2)^(-)·Br_(3)^(-)as and H_(2)O_(2)generated during the reaction process could further reduce i

关 键 词：F-Fe-MCM-48 催化臭氧氧化 溴酸5盐(BrO_(3)^(-)) 羟基自由基 Lewis酸性位点 机理 

分 类 号：X703[环境科学与工程—环境工程]