绿色合成纳米铁/铈催化剂联用过氧化氢降解甲氧苄啶的研究

Degradation of trimethoprim by green synthesized iron/cerium nanoparticles and H_(2)O_(2)

以抗生素中常见的磺胺增效剂甲氧苄啶(TMP)为目标污染物、葡萄籽提取液合成纳米铁铈(Fe/Ce-NPs)为催化剂,采用非均相类芬顿体系对甲氧苄啶的降解进行研究。利用SEM、FT-IR、XRD和XPS等对合成的催化剂进行表征。同时考察了反应温度、H_(2)O_(2)浓度、催化剂投加量、TMP初始质量浓度和溶液初始pH对降解甲氧苄啶的影响。结果表明,在TMP初始质量浓度为30 mg/L、Fe/Ce-NPs质量浓度为0.27 g/L、H_(2)O_(2)浓度为0.6 mol/L、35℃和pH 4.0的条件下反应50 min时,TMP的去除率可达100%。伪一级和伪二阶动力学模型均能有效拟合该类芬顿法对TMP的降解过程,但伪二级拟合效果更优,表明该反应过程以化学反应为主,且Ce^(3+)/Ce^(4+)催化还原体系以及CeO_(2)的氧空位作用会促进Fe-NPs/H_(2)O_(2)降解TMP。

Taking trimethoprim(TMP),a common sulfonamide synergist in antibiotics,as the target contaminant,the degradation of TMP by heterogeneous Fenton system is studied over nano-Fe/Ce-NPs catalyst that is synthesized from grape seed extracts.The synthesized catalyst is characterized by SEM,FT-IR,XRD and XPS.The effects of reaction temperature,H_(2)O_(2) concentration,catalyst dosage,TMP initial concentration and solution initial pH on the degradation are investigated.Results show that the removal rate of TMP can reach 100%as the initial concentration of TMP is 30 mg·L^(-1),the mass content of Fe/Ce-NPs is 0.27 g·L^(-1),H_(2)O_(2) concentration is 0.6 mol·L^(-1),reaction temperature remains at 35℃,the initial pH of the solution is 4.0 and the reaction has performed for 50 min.Both pseudo-first-order(0.9521-0.9800)and pseudo-second-order kinetics(0.9856-0.9980)models can effectively fit the degradation process of TMP by this Fenton method,but the latter fits better,which indicates that the reaction process is mainly chemical reaction.The Ce^(3+)/Ce^(4+)catalytic reduction system and the oxygen vacancy of CeO_(2) can promote the degradation of TMP by Fe/Ce-NPs/H_(2)O_(2).