海底地下水排放对胶州湾碳酸盐系统的影响  

Effect of submarine groundwater discharge on the carbonate system in Jiaozhou bay

作　　者：高敏学 刘茜[1] 尹晓敏 马莉[1,2] 刘真松 张劲 赵化德 GAO Minxue;LIU Qian;YIN Xiaomin;MA Li;LIU Zhensong;ZHANG Jing;ZHAO Huade(Frontiers Science Center for Deep Ocean Multispheres and Earth System,and Key Laboratory of Marine Chemistry Theory and Technology,Ministry of Education,Ocean University of China,Qingdao 266100,China;College of Chemistry and Chemical Engineering,Ocean University of China,Qingdao 266100,China;National Marine Environment Monitoring Center,Dalian 116023,China;National Key Laboratory of Environmental Protection of Nearshore Aquatic Ecology and Environment,Dalian 116023,China)

机构地区：[1]中国海洋大学深海圈层与地球系统前沿科学中心/海洋化学理论与工程技术教育部重点实验室,山东青岛266100 [2]中国海洋大学化学化工学院,山东青岛266100 [3]国家海洋环境监测中心,辽宁大连116023 [4]国家环境保护近岸海域生态环境重点实验室,辽宁大连116023

出　　处：《海洋环境科学》2023年第6期901-911,972,共12页Marine Environmental Science

基　　金：国家自然科学基金面上基金项目(42276040);国家自然科学基金青年科学基金项目(41906038)。

摘　　要：海底地下水排放(submarine groundwater discharge,SGD)是陆地与海洋之间无机碳(DIC)、总碱度(TA)输送的重要途径,但是关于SGD在近海碳酸盐系统中的作用特别是对pH的影响,认识还十分有限。本文通过2021年1月和2021年4月胶州湾两个航次调查,结合7次不同季节地下水、污水处理厂的野外调查采样,评估了春季胶州湾SGD的流量及其输送的DIC和TA通量,探讨了SGD输入对胶州湾DIC收支及水体酸化的影响。研究结果表明,SGD的DIC、TA平均浓度为(5696±3528)μmol/kg和(4981±3359)μmol/kg,是胶州湾水体平均浓度的两倍左右。春季胶州湾SGD流量为(0.73±0.12)×10^(7)m^(3)/d, SGD输送的DIC和TA通量分别为(2.54±0.41)×10^(7)mol/d和(2.12±0.36)×10^(7)mol/d。SGD是胶州湾水体DIC的重要来源之一,其输送通量比污水高一个数量级。胶州湾SGD具有高DIC、低pH[平均值(7.09±0.46)]的特征,其输入会降低胶州湾海水的缓冲能力和pH。通过端元混合模型评估可得,陆源地下淡水(submarine fresh groundwater discharge,SFGD)输入会使胶州湾pH降低0.001~0.035,加剧胶州湾酸化。SGD是胶州湾DIC收支的重要组成部分,同时对近海酸化和海水缓冲能力的调节具有不可忽视的作用。Submarine Groundwater Discharge(SGD)is an important pathway for dissolved inorganic carbon(DIC)and total alkalinity(TA)transport from land to ocean.However,understanding of the role of SGD on carbonate systems in receiving waters,especially pH is very limited.In this study,to examine the effect of SGD on DIC budget and acidification,we investigate the distributions of carbonate system and radium in the seawater through two cruises in the Jiaozhou bay(January and April 2021),and in the groundwater,rivers and wastewater treatment plants during different seasons by seven field survey sampling.The results showed that the average values of DIC and TA in groundwater were(5696±3528)μmol/kg and(4981±3359)μmol/kg,respectively,about two-fold higher than that in seawater.The SGD flux in Jiaozhou Bay was estimated to be(0.73±0.12)×10^(7) m^(3)/d,and SGD transported DIC and TA fluxes were(2.54±0.41)×10^(7) mol/d and(2.12±0.36)×10^(7) mol/d,respectively.SGD is one of the major DIC sources in the Jiaozhou bay,and its transport flux is one order of magnitude higher than that from wastewater discharge.SGD is characteristic with high DIC and low pH[mean(7.09±0.46)]and input will thereby reduce the buffering capacity and pH of the baywater.Submarine Fresh Groundwater Discharge(SFGD)input to the Jiaozhou bay will lower the pH by 0.001~0.035 and aggravate ocean acidification by using a two end-member mixing model.SGD is an important component of the carbon balance in the Jiaozhou bay and plays an important role in the regulation of coastal ocean acidification and buffering capacity.

关 键 词：海底地下水排放 溶解无机碳 总碱度 海洋酸化 

分 类 号：P734[天文地球—海洋化学]