有机改性伊利石负载纳米零价铁类芬顿降解废水中头孢哌酮

Fenton-like degradation of cefoperazone in water by organic modified illite supported nano-zero-valent iron

为提高纳米零价铁(nZVI)在类芬顿体系中的催化效能,将液相还原法生成的纳米零价铁负载在经十六烷基三甲基溴化铵(CTAB)改性后的伊利石上,制备成类芬顿催化剂(It/CTAB@nZVI);采用XRD、SEM及FTIR等方法对催化剂(It/CTAB@nZVI)的形貌和结构进行了表征,并以头孢哌酮(CPZ)为目标污染物,分别考察了H_(2)O_(2)浓度、催化剂投加量及pH对CPZ去除效果的影响,初步探究了It/CTAB@nZVI类芬顿体系降解废水中头孢哌酮的机理。结果表明,nZVI已成功地附着在改性后的伊利石表面,能有效防止纳米零价铁的团聚,提高了其在类芬顿体系中的催化效能;在H_(2)O_(2)浓度为3.2 mmol·L^(-1)、It/CTAB@nZVI投加量为0.03 g·L^(-1)、初始pH为2的条件下,CPZ的最大去除率可达99.4%。CPZ中β-内酰胺环结构被羟基自由破坏,先分解成具有苯环的中间产物,随后中间产物被进一步氧化分解为小分子的有机酸及醇类,最终被彻底降解为CO_(2)、H_(2)O、NO_(3)^(-)、NH_(4)^(+)、SO_(4)^(2-)等无机物。以上研究结果可为类芬顿催化剂的制备和类芬顿技术处理难生物降解有机废水提供参考。

In order to improve the catalytic performance of nano-zero-valent iron(nZVI)in Fenton-like system,the nano-zero-valent iron(nZVI)generated by liquid phase reduction method was supported on illite modified by cetyltrimethyl ammonium bromide(CTAB),and a Fenton-like catalyst of It/CTAB@nZVI was prepared.The morphology and structure of It/CTAB@nZVI were characterized by XRD,SEM and FTIR.Cefoperazone(CPZ)was taken as the target pollutant,and the effects of H_(2)O_(2) concentration,catalyst dosage and pH on CPZ removal were investigated.The mechanism of cefoperazone degradation in water by It/CTAB@nZVI-like Fenton system was preliminary studied.The results show that nZVI successfully adhered to the surface of modified illite,which could effectively reduce the agglomeration of nanometer zero-valent iron and improve its catalytic efficiency in Fenton-like system.Under the conditions of 3.2 mmol·L^(-1) H_(2)O_(2) concentration,0.03 g·L^(-1)It/CTAB@nZVI dosage and initial pH 2,the maximum CPZ removal rate could reach 99.4%.Theβ--lactam ring structure in CPZ was freely destroyed by hydroxyl group,it was decomposed into intermediate products with benzene ring first,and then these intermediate products were further decomposed into organic acids and alcohols with small molecules,and finally completely degraded into inorganic substances such as CO_(2),H_(2)O,NO_(3)^(-),NH_(4)^(+),SO_(4)^(2-).This study can provide a reference for the preparation of Fenton-like catalysts and refractory organics treatment by Fenton-like technology.