摘要
为了解我国河流向海洋汞的输送通量,选取我国沿海10条大型河流的河口作为采样点,采集水体和沉积物,测定水中不同形态汞,包括总汞(THg)、溶解态汞(DHg)、颗粒态汞(PHg)、总氮(TN)、总磷(TP)和溶解有机碳(DOC)等,测定了沉积物THg和甲基汞(MeHg)等.结合河流的径流量,对陆地经河流向海洋汞的输入量进行了粗略的估算.结果显示:我国十条主要入海河流地表水THg含量为2.79~145.15 ng·L^(^(-1)),DHg含量为0.61~4.44 ng·L^(-1),PHg含量为1.28~143.54 ng·L^(-1).PHg约占THg含量的41%~99%,DHg约占THg含量的1%~35%.表层沉积物THg含量为0.02~0.3 mg·kg^(-1),MeHg含量为0.04~2.00μg·kg^(-1).MeHg百分含量为0.1%~1.2%.沉积物THg、MeHg和TOC之间呈显著相关性(p<0.01).我国主要河流经径流输入THg的入海通量为10.01~29.92 t·a^(-1),长江是我国河流向海洋汞输送通量的贡献量最大,约占到我国主要河流入海汞通量的58%~69%.本研究基于实测数据的估算值与前人的估算结果对比,我国主要河流的入海汞通量仅占全球入海汞通量0.2%~15%;对比前人对中国河流向海洋汞的输送通量实测结果以及模型模拟结果显示,实测结果在同一数量级,且实测结果比模拟结果更可靠.
In order to understand the distribution and flux of mercury from rivers to the ocean,surface water and sediment samples from the estuaries of 10 major rivers along the Chinese coasts were collected.Water samples were analyzed for the total mercury(THg)and dissolved mercury(DHg),particulate mercury(PHg),total nitrogen(TN),total phosphorus(TP),dissolved organic carbon(DOC),and sediments were analyzed for THg and methyl mercury(MeHg).The amount of mercury input from rivers to the ocean was estimated based on river runoff and Hg data.The results showed that THg concentrations in river water varied from 2.79 to 145.15 ng·L^(-1),DHg concentrations varied from 0.61 to 4.44 ng·L^(-1),and the PHg concentration varied from 1.28 to 143.54 ng·L^(-1).The PHg accounted for 41%~99%of THg,and DHg accounted for 1%~35%.The THg and MeHg concentrations in the surface sediments ranged from 0.02 to 0.3 mg·kg^(-1),and from 0.04 to 2.00μg·kg^(-1),respectively.The ratios of MeHg to THgin the sediments were 0.1%~1.2%.Total organic carbon(TOC)is significantly correlated with THg and MeHg contents in the sediments(p<0.01).The flux of THg input into the ocean through runoff of ten major rivers is about 10.01~29.92 t·a^(-1),and the Yangtze River is the major contributor accounting for 58%~69%.Based on our data and the previously published results,the mercury flux from Chinese major rivers is only accounting for 0.2%~15%of the global mercury flux into the ocean.This suggests that observation-based flux results were more reliable than model-based estimates.
作者
李毅欧
闫海鱼
戎钇锰
林晶
薛雯
LI Yiou;YAN Haiyu;RONG Yimeng;LIN Jing;XUE Wen(State Key Laboratory of Environmental Geochemistry,Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081;University of Chinese Academy of Sciences,Beijing 100049;School of Public Health,Guizhou Medical University,Guiyang 550025)
出处
《环境科学学报》
CAS
CSCD
北大核心
2022年第10期323-331,共9页
Acta Scientiae Circumstantiae
基金
贵州省科学技术基金项目(No.黔科合J字[2008]2242)
环境地球化学国家重点实验室开放课题(No.SKLEG2021206)。
关键词
河口
汞
分布特征
入海通量
estuaries
mercury
distribution
flux to the ocean
