微波辅助热解制备铁氮/生物炭及其芬顿催化活性

Preparation of Fe-N/biochar by microwave-assisted pyrolysis and its Fenton catalytic activity

以油菜秸秆为生物质原料,混入比例不同的硼酸(m(硼酸)∶m(秸秆)=1∶1和m(硼酸)∶m(秸秆)=2∶1),通过微波热解结合水热法制备铁氮/生物炭。采用XRD、SEM等技术对材料形貌及结构进行表征分析,研究不同硼酸比例制备的生物炭之间的性质差异。通过控制变量法对比分析不同H2O2浓度、环境温度下生物炭芬顿体系降解50 mg/L亚甲基蓝的降解效率,结果表明∶通过使用m(硼酸)∶m(秸秆)=2∶1混合进行热解的生物炭在各反应条件下的芬顿体系降解亚甲基蓝性能均优于使用m(硼酸)∶m(秸秆)=1∶1混合热解的生物炭。在25℃、pH=3的条件下,降解亚甲基蓝溶液的较优H2O2浓度为5 mmol/L;随着反应温度的升高,亚甲基蓝的降解效率逐步提高。

Fe-N/biochar was prepared by microwave pyrolysis combined with a hydrothermal method using rapeseed straw as biomass raw material mixed with different proportions of boric acid(m(boric acid)∶m(straw)=1∶1 and m(boric acid)∶m(straw)=2∶1).The morphology and structure of the materials were characterized by XRD and SEM,and the property differences of biochar prepared with different ratios of boric acid were studied.The degradation efficiency of 50 mg/L methylene blue by the Fenton system of biochar at different H2O2 concentrations and ambient temperatures was compared and analyzed by the control variates.The results showed that such degradation performance of biochar pyrolyzed by m(boric acid)∶m(straw)=2∶1 was better than that by m(boric acid)∶m(straw)=1∶1 under various reaction conditions.The optimal H2O2 concentration for degradating methylene blue solution was 5 mmol/L at 25℃and pH=3.With increasing reaction temperature,the degradation efficiency of methylene blue increased gradually.