长江重庆主城段地表水中有机锡赋存特征、时间变化及风险评估

Occurrence,temporal change and risk assessment of organotin in surface water of the Yangtze River in the urban section of Chongqing

为了解AFS公约执行10年后长江重庆主城段水环境中有机锡污染情况,以重庆主城段长江及其支流嘉陵江为研究区域,于2020年10月采集重庆主城段各码头水域地表水水样,采用固相微萃取-气相色谱-质谱法测定了地表水中丁基锡和苯基锡浓度,分析了水环境中三丁基锡(TBT)、三苯基锡(TPhT)及其降解产物的组成和分布特征.结果表明:研究区域地表水环境中同时检测到了TBT、TPhT及其降解产物一丁基锡(MBT)、二丁基锡(DBT)、一苯基锡(MPhT)和二苯基锡(DPhT);长江重庆主城段地表水中有机锡浓度近年来整体呈先下降后趋于平稳的趋势,尽管少数点位仍有新的TBT和TPhT输入,但绝大多数点位的TBT和TPhT已发生降解.生态风险评估结果表明,长江重庆主城段水环境中TBT和TPhT在部分水域可能会对水生生物产生生态风险.

In order to investigate the occurrence of organotin in the surface water of the Yangtze River after the implementation of the AFS Convention for ten years,surface water samples were collected in October 2020 at each wharf in the urban section of Chongqing to analyze the concentrations of butyltins and phenyltins by SPME-GC-MS.The results showed that tributyltin(TBT),triphenyltin(TPhT)and their metabolites(MBT,DBT,MPhT,and DPhT)were found in surface water.The concentration of organotins has shown a trend of first decreasing and then stabilizing in recent years.Although there were still new TBT and TPhT inputs at a few sites,TBT and TPhT degradation occurred at most of sites.The results of ecological risk assessment showed that TBT and TPhT in some sites of the urban section of Chongqing may pose ecological risks to aquatic organisms.