寒潮影响下北部湾研究海域颗粒态和溶解态^(210)Po的分布特征  

Distribution Features of Particulate and Dissolved ^(210)Po in Beibu Gulf Under the Influence of Cold Wave

作　　者：刘文靖 钟强强 王浩 陈随缘 黄德坤 刘进文 于涛 LIU Wenjing;ZHONG Qiangqiang;WANG Hao;CHEN Suiyuan;HUANG Dekun;LIU Jinwen;YU Tao(Third Institute of Oceanography,MNR,Xiamen 361000,China;Observation and Research Station of Coastal Wetland Ecosystem in Beibu Gulf,MNR,Beihai 536015,China)

机构地区：[1]自然资源部第三海洋研究所,福建厦门361000 [2]自然资源部北部湾滨海湿地生态系统野外科学观测研究站,广西北海536015

出　　处：《海洋科学进展》2024年第4期769-781,共13页Advances in Marine Science

基　　金：自然资源部第三海洋研究所基本科研业务费专项资金资助项目(2023007和2020017);国家自然科学基金项目(42206166);亚洲合作基金项目。

摘　　要：^(210)Po是天然放射性核素,具有较强的颗粒活性,可用于水体悬浮颗粒物来源及传输、污染物清除等过程的示踪研究。2021—2022年冬季寒潮过境期间北部湾研究海域不同形态^(210)Po的活度浓度分布及地球化学行为特征实测结果表明,表层水体中溶解态和颗粒态^(210)Po的活度浓度水平分别为0.36~1.39dpm·(100 L)^(-1)(1 Bq=60 dpm)和0.60~12.15 dpm·(100 L)^(-1);水体中^(210)Po主要以颗粒态形式存在。实测的颗粒态^(210)Po活度浓度和总悬浮颗粒物(TSM)质量浓度之间存在显著正相关性(R^(2)=0.968,P<0.01)表明,溶解态^(210)Po被颗粒物显著“清除”的现象;进一步分析发现北部湾寒潮期间水体中^(210)Po的分配系数(K_d值)为(1.16~17.95)×10^(5) mL·g^(-1),与其他海域相同TSM质量浓度条件下相比明显增加,再次表明溶解态^(210)Po在北部湾寒潮过境期间得到强化“清除”。原因可能是寒潮期间北部湾水体中的再悬浮过程和输送过程的加强促使水体TSM质量浓度增加,溶解态^(210)Po因被颗粒物吸附而被强化“清除”。冬季北部湾海域频发的寒潮等强对流天气过程导致水动力混合加剧,影响TSM分布的同时也改变了北部湾水体中^(210)Po的分布。这对认识寒潮、台风等强对流气象事件影响下近岸海域水体悬浮颗粒物及其携带的污染物质的传输过程具有重要的意义。^(210)Po is a natural radionuclide with strong particulate activity,which can be used as a tracer to investigate both the source and transportation of suspended particulate matter and the removal process of pollutants in the water column.The distribution of activity concentration and characteristics of geochemical behaviour of different forms of ^(210)Po in the study area of Beibu Gulf were investigated during the winter cold wave from 2021 to 2022.The results of actual measurement showed that the activity concentration levels of dissolved and particulate ^(210)Po in the surface water ranged from 0.36 to 1.39 dpm·(100 L)^(-1)(1 Bq=60 dpm)and from 0.60 to 12.15 dpm·(100 L)^(-1),respectively.The particulate phase was the main existence form of ^(210)Po.An excellent positive correlation(R^(2)=0.968,P<0.01)was observed between the activity concentration of ^(210)Po in the particulate phase and the mass concentration of total suspended particulate matter(TSM),suggesting the phenomenon of significant scavenging of dissolved ^(210)Po by particulate matter.Further analyses revealed that the distribution coefficients(Kd values)of ^(210)Po in the water column were from 1.16×105 mL·g^(-1) to 17.95×10^(5) mL·g^(-1) during the cold wave in Beibu Gulf,which was significantly increased compared with the same TSM mass concentration conditions in other sea areas,once again indicating that dissolved ^(210)Po was intensively scavenged during the transit of the cold wave in Beibu Gulf.This may be due to the increase of water mass concentration of TSM driven by the enhanced resuspension and transportation processes in the water column,and enhanced removal of dissolved ^(210)Po by adsorption to particulate matter in the water column after the cold wave transit in Beibu Gulf.Strong convective weather processes,such as cold waves,which occur frequently in the Beibu Gulf waters in winter,can make the hydrodynamic mixing intensify.Not only it can affect the distribution of TSM,but also change the distribution of ^(210)Po in the wate

关 键 词：溶解态^(210)Po 颗粒态^(210)Po 寒潮 总悬浮颗粒物 北部湾 

分 类 号：P734.2[天文地球—海洋化学]