纳米二氧化钛对三价砷在大型蚤体内累积与毒性的影响  

Influence of Nano-TiO_2 on Accumulation and Toxicity of Arsenite in Daphnia magna

作　　者：王振红[1,2] 李金丽[2] 严雅萌 樊荣建 罗专溪[2] WANG Zhenhong;LI Jinli;YAN Yameng;FAN Rongjian;LUO Zhuanxi(Fujian Province Key Laboratory of Modern Analytical Science and Separation Technology,Pollution Monitoring and Control of Key Laboratoryof Universities in Fujian Province,College of Chemistry and Environment,Minnan Normal University,Zhangzhou 363000,China;Key Laboratory of Urban Environment and Health,Institute of Urban Environment,Chinese Academy of Sciences,Xiamen 361021,China3.Chongqing Yongsheng Huanbao Ltd.Co.,Chongqing 401147,China)

机构地区：[1]闽南师范大学化学与环境学院福建省现代分离分析科学与技术重点实验室污染监测与控制福建省高校重点实验室,福建漳州363000 [2]中国科学院城市环境研究所城市环境与健康重点实验室,福建厦门361021

出　　处：《环境科学研究》2018年第6期1123-1128,共6页Research of Environmental Sciences

基　　金：国家自然科学基金项目(No.41401552); 闽南师范大学新世纪优秀人才支持计划(No.MX14002); 福建省科技计划引导性(重点)项目(No.2017Y0081).

摘　　要：nTiO_2(纳米二氧化钛)可作为其吸附污染物的运输载体而影响污染物在生物体内的累积与毒性,为明晰nTiO_2吸附As(Ⅲ)(三价砷)后作为As的运输载体对水生物体内As累积与毒性的影响,以大型蚤(Daphnia magna)为受试生物,通过室内培养试验,研究了不同nTiO_2浓度、As(Ⅲ)不同暴露水平相互作用下蚤体中As与Ti的累积含量、毒性及其潜在作用机制.结果表明,nTiO_2可在30 min内吸附As(Ⅲ)至平衡,其中2、20 mg/L的nTiO_2对75μg/L As(Ⅲ)的吸附率分别可达31.38%、51.84%,蚤体内As的累积含量分别为对照组的2.9和3.8倍,表明nTiO_2可作为运输载体提高As(Ⅲ)在大型蚤体内的累积;但不同As暴露水平下蚤体As和Ti含量的相关关系表明,nTiO_2作为载体的运输作用可能会因As暴露水平的增加而减弱.另外,nTiO_2虽然作为运输载体提高了As(Ⅲ)在大型蚤体内的累积,但并未增加As(Ⅲ)对大型蚤的毒性.添加2、20 mg/L的nTiO_2后,As(Ⅲ)对大型蚤的24 h IC_(50)(半抑制浓度)分别从0.93 mg/L增至2.53和2.97 mg/L,表明nTiO_2降低了As(Ⅲ)对大型蚤的毒性.研究显示,nTiO_2虽增加了As(Ⅲ)在大型蚤体内的累积,但却降低了As(Ⅲ)对大型蚤的毒性,这有利于对nTiO_2及其复合重金属污染风险的深入认识.Titanium dioxide nanoparticles（nTiO2） have a higher capacity to adsorb contaminants,which in turn affects the biological accumulation and toxicity. To examine the toxicity and accumulation of arsenite（As（Ⅲ）） in Daphnia magna in the presence of nTiO2 as transport carriers,the half inhibitory concentration（IC（50））,and As and Ti accumulated levels were determined for different As concentrations（75 μg/L and IC（50）） in absence and presence of nTiO2 at 2 and 20 mg/L. Results showed that nTiO2 can adsorb As（Ⅲ） to be balanced after 30 min. Specifically,the adsorption rate of As（Ⅲ） was 31. 38% and 51. 84%,respectively at 2 and 20 mg/L nTiO2,and the amount of accumulated arsenic in D. magna was 2. 9 and 3. 8 times the amount accumulated in the control（without nTiO2）. This indicates that nTiO2 could function as carrier and enhance the accumulation of As（Ⅲ） in D. magna. Meanwhile,the amount of accumulated arsenic in D. magna transported by nTiO2 might decreased with increasing exposed As（Ⅲ） levels. The observation result issupported by the relationship between arsenic and titanium in D. magna for different As exposed levels. Furthermore,in spite of the increasing arsenic accumulation in D. magna with the nTiO2 concentration,the toxicity of As（Ⅲ） did not increase. Specifically,the 24 h IC（50） of As（Ⅲ） increased from 0. 93 mg/L in absence of nTiO2 to 2. 53 and 2. 97 mg/L at 2 and 20 mg/L of nTiO2,respectively,demonstrating that nTiO2 decreased the toxicity of As（Ⅲ） on D. magna. The study concluded that nTiO2 can enhance the accumulation of As（Ⅲ） in D. magna,but reduced its toxicity,which will be helpful of providing insights into ecological risks of combined pollution of nTiO2 with other heavy metals.

关 键 词：砷 纳米材料 吸附 毒性 累积 

分 类 号：X171.5[环境科学与工程—环境科学]