实验室模拟制备环境持久性自由基及其生物毒性研究  

Generation and toxicity of environmental persistent free radicals

作　　者：郭溪 张瑛 孟甜甜 杨瑞新 司小会 周集体 GUO Xi ZHANG Ying MENG Tiantian YANG Ruixin SI Xiaohui ZHOU Jiti(Laboratory of Industrial Ecology and Environmental Engineering （ MOE ）, School of Environmental Science and Technology, Dalian University of Technology, Dalian, 116024, China)

机构地区：[1]大连理工大学化工与环境生命学部环境学院,工业生态与环境工程教育部重点实验室,大连116024

出　　处：《环境化学》2018年第10期2095-2102,共8页Environmental Chemistry

基　　金：国家自然科学基金(21477014,21261140334)的资助

摘　　要：一些表面吸附有机物的颗粒物在不完全燃烧的过程中会产生环境持久性自由基(EPFRs),但是目前关于这些EPFRs的水生生物毒性的报道还很有限.为了更好地了解EPFRs对水生生物的毒性作用,采用邻苯二酚-二氧化硅(CT-SiO_2)模拟体系在限氧条件下制备EPFRs,考察金属离子(Fe、Cu、Ni、Zn)及其氧化物、热解温度和CT/SiO_2质量比对颗粒物表面EPFRs生成的影响,并对EPFRs悬浮液中·OH的产生以及对发光细菌的急性毒性进行了测定.采用电子顺磁共振(EPR)对制备的EPFRs进行表征的结果表明,金属氧化物能够促进EPFRs的生成,而金属离子则恰好相反;热解温度以及CT/SiO_2质量比是EPFRs的生成过程的重要影响因素,对CT-SiO_2热解体系中EPFRs的生成浓度和类型具有至关重要的影响,EPFRs的生成浓度在热解温度为400℃且CT/SiO_2质量比为0.032时,达到最高值5.04×10^(15)spins·g^(-1).本研究所制备的EPFRs在环境空气中的半衰期,能够达到18—80 d,这可能是因为其与颗粒物的结合增加了其稳定性;发光细菌(P.phosphoreum T3spp.)的急性毒性结果表明,含有EPFRs的颗粒物对发光细菌的发光具有明显的抑制作用,发光抑制率与EPFRs浓度呈明显的剂量-效应关系,并推测可能与EPFRs悬浮液中活性氧物种(ROS)的产生有关.该结果为研究EPFRs在环境过程中的形成因素及其生物毒性提供了基础,为研究EPFRs的潜在环境风险提供了基础数据.Environmental persistent free radicals（EPFRs）can be formed during incomplete combustion of particles with some organic substances adsorbed on the surface.However,the current study on the toxicity of these EPFRs is still limited.To better understand the effect of EPFRs on aquatic organisms,we simulated the generation process of EPFRs in the lab using catechol-silica（CT-SiO2）as model substrate with pyrolysis under oxygen-limited environment.We investigated the effects of metal ions（Fe,Cu,Ni,Zn）and their metal oxides,pyrolysis temperature and CT/SiO2 mass ratio on the formation of EPFRs.In addition,the generation of·OH in the suspension and the toxicity of synthesized EPFRs were also examined.Our results showed that the addition of metal oxides in matrix increased the formation of EPFRs,while metal ions inhibited it.The pyrolysis temperature and mass ratio of CT/SiO2significantly affected the concentration and types of EPFRs formed in the pyrolysis system,where the highest concentration of EPFRs reached 5.04×10^（15）spins·g^（-1）at 400℃and CT/SiO2mass ratio of 0.032.Half-lives of EPFRs reached 18—80 days at ambient air.Toxicity tests revealed that EPFRs significantly inhibited the luminescence of P.phosphoreum T3spp.with dose-response dependence,which may be contributed to the generation of reactive oxygen species（ROS）in the suspension.Our results provided information for the formation of EPFRs and their biotoxicity in environmental processes,which will be further necessary for the potential environmental risk of EPFRs.

关 键 词：环境持久性自由基 影响因素 半衰期 发光细菌 水生生物毒性 

分 类 号：X592[环境科学与工程—环境工程] X171.5