生物炭活化过一硫酸盐降解水中四环素的研究:表征、催化活性、反应条件优化和机理

Degradation of tetracycline by biochar activating peroxymonosulfate:Characterization,catalytic performance,process optimization and mechanism

采用椰壳、玉米芯和稻壳作为前驱体制备出3种生物炭,并将其用于活化过一硫酸盐(PMS)降解水中的四环素.结果表明,玉米芯生物炭(CC-BC)的催化活性最高,反应120 min,四环素的去除率高达71.2%.根据生物炭的表征结果可知,CC-BC优异的催化性能归因于其巨大的比表面积和较高的表面缺陷度.同时,对PMS用量、催化剂用量、溶液pH、反应温度和水质等影响四环素降解的因素进行了研究.自由基猝灭试验和电子顺磁共振测试(EPR)的结果表明,四环素的降解包括自由基和非自由基两种路径,CC-BC/PMS反应体系中产生了SO_(4)·^(-)、·OH、O_(2)·^(-)和^(1)O_(2)活性物种.最后,重复使用性试验证明CC-BC具有良好的稳定性.

Three biochars were prepared by using coconut shells,corn cores and rice hulls as precursors,and applied to activate peroxymonosulfate(PMS)for the degradation of tetracycline.The results indicated that corn cores biochar(CC-BC)showed the highest catalytic activity,allowing a tetracycline removal of 71.2%within 120 min.Based on the results of catalyst characterization,it was concluded that the superior catalytic performances of CC-BC was attributed to the high specific surface area and high defect degree of this carbon material.Factors affecting the degradation of tetracycline were investigated,including PMS concentration,catalyst dosage,and initial pH,reaction temperature and water matrices.The quenching experiments and electron paramagnetic resonance(EPR)measurements verified that the catalytic degradation of tetracycline occurred by both radical and non-radical pathways involving the generation of SO_(4)·^(-),·OH,O_(2)·^(-) and ^(1)O_(2) in the CC-BC/PMS system.Finally,the reusability experiments proved the good stability of CC-BC.