摘要
以水葫芦为原料,制备了负载纳米ZnO的生物炭材料(ZnO-BC),研究了单独光催化ZnO-BC和过硫酸钠(PS)协同ZnO-BC/UV体系氧化降解盐酸四环素(TC).结果表明,PS协同ZnO-BC/UV体系的降解反应速率比单独光催化ZnO-BC时有显著提高,120min后降解率达到89.48%.PS可作为强氧化剂,利用纳米ZnO的光生电子产生SO4-·和·OH协同光催化反应.TC的反应过程可分为两个阶段:暗吸附阶段和光催化反应阶段.影响因素和响应面试验结果得出的影响顺序为PS浓度>紫外灯功率>初始pH值>纳米ZnO质量浓度.猝灭试验表明,在TC的降解中,SO4-·和·OH是参与反应的主要自由基.起氧化作用的自由基一部分在溶液中产生,另一部分由生物炭材料表面含氧官能团的作用和紫外光激发纳米ZnO产生.在此基础上,探讨了在TC降解过程中,PS与ZnO-BC的协同机理和协同作用的规律.
In this paper,biochar loaded with nano-ZnO(ZnO-BC)was prepared from water hyacinth.The degradation performance of tetracycline hydrochloride(TC)in two systems,one referred to UV/ZnO-BC system and the other to UV/ZnO-BC/sodium persulfate(PS),were comparatively studied.The results showed that the degradation efficiency of ZnO-BC/UV system alongside PS was significantly higher than that of ZnO-BC alone,and the efficiency reached 89.48%after 120min.PS could be used as a strong oxidant that could use photogenerated electrons of nano-ZnO to produce SO4-·and·OH,achieving synergistic photocatalytic effects.The oxidation process of TC could be divided into two stages:dark adsorption and photocatalysis.The order of influence factors obtained by response surface methodology was PS concentration>UV power>initial pH value>nano-ZnO mass concentration.The quenching test suggested that SO4-·and·OH were the main free radicals in the degradation of TC.One part of the oxidizing free radicals were generated in the solution,the others from some kind of oxygen-containing functional groups on the biochar surface and the excitation of nano-ZnO by UV.On this basis,the synergistic mechanism and principle of PS and ZnO-BC during TC degradation were discussed.
作者
翟文琰
李孟
张倩
ZHAI Wen-yan;LI Meng;ZHANG Qian(School of Civil Engineering and Architecture,Wuhan University of Technology,Wuhan 430070,China)
出处
《中国环境科学》
EI
CAS
CSCD
北大核心
2020年第6期2483-2492,共10页
China Environmental Science
基金
海绵城市建设水系统科学湖北省重点实验室开放基金资助(2019-06)。
关键词
纳米ZNO
过硫酸盐
紫外光
生物炭
盐酸四环素
降解机理
nano-ZnO
persulfate
ultraviolet light
biochar
tetracycline hydrochloride
degradation mechanism
