含Cl^(-)/Br^(-)体系2,4,6-三氯苯酚的臭氧氧化处理效能及毒性变化研究  

Degradation Efficiency and Toxicity Variation in Ozonation of 2,4,6-trichlorophenol with Interference of Cl^(-)/Br^(-)

作　　者：徐冉云 姚鹏城 李菲菲[2] 陈吕军[2] Xu Ranyun;Yao Pengcheng;Li Feifei;Chen Lyujun(School of Engineering,Hangzhou Normal University,Hangzhou 310018,China;School of Environment,Tsinghua University,Beijing 100084,China;Zhejiang Institute of Hydraulics and Estuary,Hangzhou 310012,China)

机构地区：[1]杭州师范大学工学院,杭州310018 [2]清华大学环境学院,北京100084 [3]浙江省水利河口研究院,杭州310012

出　　处：《生态毒理学报》2024年第2期206-217,共12页Asian Journal of Ecotoxicology

基　　金：国家自然科学基金资助项目(52070111,52170181)。

摘　　要：2,4,6-三氯苯酚(2,4,6-trichlorophenol,2,4,6-TCP)作为典型的工业生产原料,常与无机卤素离子共存于工业废水中,然而目前少有实验报道后者对2,4,6-TCP氧化降解的影响机制。本文探究了在不同卤素离子条件下,2,4,6-TCP的臭氧氧化降解反应动力学及氧化效能变化,并通过模型预测和发光菌毒性实验评估了臭氧氧化处理过程中2,4,6-TCP降解中间体之间的毒性效应和溶液的毒性变化。结果表明,投加低浓度Cl^(-)(20 mmol·L^(-1))可使2,4,6-TCP的降解速率从0.234 mol·min^(-1)提升为0.237 mol·min^(-1),然而高浓度的Cl^(-)和Br^(-)会显著抑制2,4,6-TCP的降解。当体系中Cl^(-)和Br^(-)浓度分别从0 mmol·L^(-1)上升至300 mmol·L^(-1)和100 mmol·L^(-1)时,臭氧氧化2 h后2,4,6-TCP溶液的化学需氧量(chemical oxygen demand,COD)去除率下降了17%和18%,可吸附有机卤代物(adsorbable organic halides,AOX)去除率下降了15%和55%。研究表明2,4,6-TCP污染物主要在O_(3)、·OH和O_(2)^(-)·的共同作用下被降解,生成的2,6-二氯-1,4-苯二醇、2,6-二氯-1,4-苯醌和2,4,6-三溴苯酚的急性毒性和慢性毒性都比母体更高,且三元混合毒性实验表明降解中间体2,6-二氯-1,4-苯醌、2,6-二氯苯酚和2-氯苯酚之间存在协同毒性作用。整体上看,臭氧氧化处理过程中的AOX浓度与2,4,6-TCP溶液的毒性单位呈高度正相关关系,说明AOX物质对废水急性毒性的贡献较大,其对生态环境的潜在危害应引起更多关注。As a typical raw material for industrial production,2,4,6-trichlorophenol(2,4,6-TCP)commonly coexists with inorganic halogen ions in the industrial wastewater.However,little literature have reported the effect of halogen ions on the oxidative degradation of 2,4,6-TCP.In this paper,the ozonation degradation kinetics and oxidation efficiency of 2,4,6-TCP were investigated under varying halogen ion conditions.Additionally,the toxic effects between 2,4,6-TCP degradation intermediates as well as the alterations of solution toxicity were evaluated.The results showed that adding low concentration of Cl^(-)(20 mmol·L^(-1))could increase the degradation rate of 2,4,6-TCP from 0.234 mol·min^(-1)to 0.237 mol·min^(-1),while high concentration of Cl^(-)and Br^(-)significantly inhibited the degradation of 2,4,6-TCP.When the concentrations of Cl^(-)and Br^(-)respectively increased from 0 mmol·L^(-1)to 300 mmol·L^(-1)and 100 mmol·L^(-1),the chemical oxygen demand(COD)removal rate of 2,4,6-TCP solution decreased by 17%and 18%,and the adsorbable organic halides(AOX)removal rate decreased by 15%and 55%after 2 h of ozone oxidation.The results indicated that 2,4,6-TCP was mainly degraded by the co-oxidation of O_(3),·OH and O_(2)^(-)·.Notably,the intermediate 2,6-dichloro-1,4-benzohydroquinone,2,6-dichloro-1,4-benzoquinone and 2,4,6-tribromophenol exhibited higher acute and chronic toxicity than 2,4,6-TCP.The ternary mixed toxicity test showed a synergistic toxicity effect between 2,6-dichloro-1,4-benzoquinone,2,6-dichlorophenol and 2-chlorophenol.The concentration of AOX was highly positively correlated with the toxicity unit of the 2,4,6-TCP solution,indicating a substantial contribution of AOX substances to wastewater acute toxicity.Therefore,the potential ecological risks posed by AOX pollutants warrant further attention.

关 键 词：2 4 6-三氯苯酚 臭氧氧化 AOX COD 混合毒性 

分 类 号：X171.5[环境科学与工程—环境科学]