海洋学研究 ›› 2022, Vol. 40 ›› Issue (3): 120-131.DOI: 10.3969-j.issn.1001-909X.2022.03.011

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广西北部湾北部近海水体中不同形态210Po的分布及地球化学行为

  

  1. 1.北部湾大学 广西北部湾海洋环境变化与灾害研究重点实验室,广西 钦州 535011; 
    2.中国医学科学院和北京协和医院放射医学研究所 天津市放射医学与分子核医学重点实验室,天津 300192; 
    3.自然资源部第三海洋研究所,福建 厦门 361000; 
    4.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
  • 出版日期:2022-09-15 发布日期:2022-09-15
  • 通讯作者: 苏锴骏(1989—),男,助理研究员,主要从事放射化学方面的研究,E-mail:sukaijun@irmcams.ac.cn。
  • 作者简介:王希龙(1989—),女,山东省聊城市人,讲师,主要从事同位素海洋学方面的研究,E-mail:xlwang@bbgu.edu.cn。
  • 基金资助:
    国家自然科学基金(41906150);广西科技计划项目(桂科AD19245147);自然资源部第三海洋研究所基本科研业务费(海三科2020017);自然资源部海洋大气化学与全球变化重点实验室开放基金项目(GCMAC2208)

Distribution and geochemical behavior of different phases for 210Po in offshore water of the northern Beibu Gulf, Guangxi


  • Online:2022-09-15 Published:2022-09-15

摘要:

210Po是典型的颗粒活性核素,可作为大气气溶胶沉降动力学过程、海洋颗粒态物质输运过程研究的示踪剂。本文研究了北部湾近海水域6个离岸断面的水质参数和不同形态210Po的比活度分布及行为特征。结果表明溶解态、颗粒态和总210Po的比活度变化范围分别为0.16~2.78、0.14~2.43和0.51~3.94 mBq/L,溶解态210Po的比活度与水质参数无明显相关性,但颗粒态210Po的比活度与水温、盐度和TSM质量浓度之间以及总210Po的比活度与水温和TSM质量浓度之间呈显著相关关系。210Po比活度的分布趋势在不同断面表现并不一致,但整体上近海水体中210Po以颗粒态为主要存在形式,离岸水体中则主要以溶解态为主。进一步分析发现210Po在固液两相中的分配系数与悬浮颗粒物质量浓度呈负相关关系;一维稳态不可逆清除模型的计算结果表明溶解态210Po比颗粒态210Po的停留时间更长,说明大气或河流输入北部湾近海的210Po进入海水后会部分进入溶解相,使其在水中的停留时间加长。

关键词: 210Po, 分布特征, 分配系数, 停留时间, 北部湾

Abstract: 210Po is a typical natural particle active radionuclide, which can be used as a tracer for the study of atmospheric aerosol deposition dynamics and particle dynamics in marine environment. In this study, the water quality parameters and the specific activities distributions and behavior of different phases for 210Po in six offshore sections of the north coastal Beibu Gulf were investigated. Results showed that the specific activities of dissolved, particulate and total 210Po were 0.16-2.78 mBq/L, 0.14-2.43 mBq/L and 0.51-3.94 mBq/L, respectively. There was no significant correlation between the specific activities of dissolved 210Po and the water quality parameters, but the specific activities of particulate 210Po showed significant correlation with water temperature, salinity and mass concentrations of TSM, respectively. At the same time, the specific activities of total 210Po were significantly correlated with water temperature and mass concentrations of TSM, respectively. The distribution trends of 210Po in different sections were not consistent, but in general, the particulate phase was the main existence form of 210Po in the nearshore water, and the offshore 210Po was confirmed mainly in the form of dissolved phase. Further analysis showed a negative correlation between the distribution coefficients of 210Po in the solid-liquid phase and the mass concentrations of total suspended particulate matter. Based on the one-dimensional steady-state irreversible removal model, a longer residence time of dissolved 210Po relative to particulate 210Po was obtained, indicating that the atmospheric deposition and riverine input of 210Po into the coastal Beibu Gulf would partially enter the dissolved phase after entering the seawater, so that its residence time in the water was prolonged.


Key words: 210Po, distribution characteristics, distribution coefficient, residence time, Beibu Gulf

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