基于BC-BiOI/PMS的光催化体系降解恩诺沙星的研究

Degradation of Enrofloxacin by photocatalytic system based on BC-BiOI/PMS

通过水热法制备生物炭负载碘氧化铋光催化剂(BC-BiOI),并向体系中引入过一硫酸盐(PMS),将光催化和PMS高级氧化技术进行耦合。探讨了光/BC-BiOI/PMS复合体系对恩诺沙星(ENR)的降解效果,考察了反应条件对ENR去除的影响,并深入研究了光/BC-BiOI/PMS复合体系降解ENR的机理。研究表明,光/BC-BiOI/PMS体系对ENR的降解效果良好,在BC-BiOI投加量0.2 g/L、PMS投加量1.0 g/L、pH取7的条件下,ENR降解率可达76%。通过响应面法建模分析pH、BC-BiOI投加量、PMS投加量三因素之间的交互作用,结果表明,各因素对ENR降解的影响顺序为初始pH>PMS投加量>BC-BiOI投加量。根据自由基猝灭实验和电子顺磁共振(EPR)结果可知,体系中的主要活性氧物种为·OH、SO4·-和1O_(2),三者共同氧化降解ENR。重用性实验中,BC-BiOI光催化复合材料循环使用4次仍能保持65%以上的ENR去除率。

In this paper,biochar-supported bismuth iodide-oxidized composite catalyst(BC-BiOI)was prepared by hydrothermal method,and persulfate(PMS)was introduced into the system to couple photocatalysis and PMS ad-vanced oxidation technology.The degradation effect of Enrofloxacin(ENR)by the light/BC-BiOI/PMS composite system was investigated,and the effect of reaction conditions on the removal of ENR was examined.The mechanism of ENR degradation in light/BC-BIOI/PMS system was studied.The best degradation effect of typical antibiotic ENR was determined by light/BC-BiOI/PMS system.Under the conditions of BC-BiOI dosage of 0.2 g/L,PMS dos-age of 1.0 g/L,pH of 7,the degradation rate of ENR could reach 76%.The interaction among pH,BC-BiOI dosage and PMS dosage was analyzed by response surface methodology.The results indicated that the order of the effect of various factors on ENR degradation was initial pH>PMS dosage>BC-BiOI dosage.According to free radical quench-ing experiments and electron paramagnetic resonance(EPR),the main active oxidation species in the system were·OH,SO4·-,and 1O_(2),which jointly oxidized and degraded ENR.In the reusability test,BC-BiOI photocatalysis com-posite material could still remain more than 65%removal rate of ENR after four cycles.