近岸海域溶解有机质与金属离子的配位机制及溶解氧的影响特性  

Coordination mechanism of dissolved organic matter and metal ions in coastal waters and the influence characteristics of dissolved oxygen

作　　者：徐啸 章天晏 夏功伟 李宏亮 陈建芳 郑豪[1] XU Xiao;ZHANG Tianyan;XIA Gongwei;LI Hongliang;CHEN Jianfang;ZHENG Hao(Institute of Marine Chemistry and Environment,Ocean Academy,Zhejiang University,Zhoushan 316021,China;Key Laboratory of Marine Ecosystems and Dynamics,Second Institute of Oceanography,Ministry of Natural Resources,Hangzhou 310012,China)

机构地区：[1]浙江大学海洋学院海洋化学与环境研究所,浙江舟山316021 [2]自然资源部第二海洋研究所海洋生态系统与动力学重点实验室,浙江杭州310012

出　　处：《海洋科学》2024年第7期57-67,共11页Marine Sciences

基　　金：“浙江省‘尖兵’研发攻关计划资助”(2022C03044);浙江省自然科学基金(LY20D060007)。

摘　　要：溶解有机质(DOM)能与金属离子配位,从而影响金属离子的毒性、迁移转化以及生物可利用性,对近岸养殖区的生态环境产生深远的影响。本文利用三维荧光光谱结合平行因子法研究了舟山近岸海域DOM的组成,采用荧光猝灭滴定并运用修正Stern-Volmer模型系统研究了DOM各荧光组分与典型的过渡金属离子Cu^(2+)、Fe^(3+)和Pb^(2+)的配位机制,并进一步研究了海水溶解氧对DOM与Cu^(2+)、Fe^(3+)和Pb^(2+)配位作用的影响。结果表明:舟山近岸海域DOM的4种荧光组分,两种类腐殖质组分(C1、C2)明显比2种类蛋白质组分(C3、C4)更易与金属离子配位;DOM与金属离子配位化合物稳定性大小依次是:Cu-DOM>Fe-DOM>Pb-DOM;此外,缺氧环境明显抑制了溶解有机质与Fe^(3+)的配位能力,但Cu^(2+)、Pb^(2+)的配位能力则几乎不受溶解氧浓度的影响。这些结果将为海水养殖水体的调控、恢复提供科学依据。Dissolved organic matter(DOM)plays a pivotal role in coordinating with metal ions,thereby affecting their toxicity,migration,transformation,and bioavailability of metal ions,factors that significantly impact the eco-logical environment of nearshore aquaculture areas.This study delves into the composition and molecular structure of DOM in the coastal waters of Zhoushan through the use of three-dimensional fluorescence spectroscopy com-bined with parallel factor analysis and fluorescence quenching titration.The coordination mechanisms between various fluorescence components of DOM and typical transition metal ions Cu^(2+),Fe^(3+),and Pb^(2+)were examined using a modified Stern–Volmer model.Furthermore,the study explored how dissolved oxygen in seawater affects the coordination of DOM with these metal ions.The results identified two humic-like components(C1 and C2)and two protein-like components(C3 and C4)within the DOM of Zhoushan’s coastal waters.It was observed that the humic-like components(C1 and C2)exhibited a higher propensity for coordinating with metal ions compared to the two protein-like components(C3 and C4).The stability of the coordination followed the order:Cu-DOM>Fe-DOM>Pb-DOM.In addition,an anoxic environment significantly inhibited the coordination ability of DOM with Fe^(3+),while the coordination ability of Cu^(2+)ions was almost unaffected by dissolved oxygen concentration.These findings provide a scientific foundation for regulating and restoring seawater aquaculture systems.

关 键 词：海洋溶解有机质 金属离子 溶解氧 配位 

分 类 号：X145[环境科学与工程—环境科学]