华南中小型闸控入海河流DOM特征及藻源影响  

Characteristics and algal source effects of dissolved organic matter in small and medium-sized gate-controlled seagoing rivers in South China

作　　者：李丹 范中亚 罗千里 贾政博 陈钢 赵长进 曾凡棠 黄露 LI Dan;FAN Zhong-ya;LUO Qian-li;JIA Zheng-bo;CHEN Gang;ZHAO Chang-jin;ZENG Fan-tang;HUANG Lu(The Key Laboratory of Water and Air Pollution Control of Guangdong Province,South China Institute of Environmental Sciences,Ministry of Ecology and Environment,Guangzhou 510655,China)

机构地区：[1]生态环境部华南环境科学研究所,广东省水与大气污染防治重点实验室,广东广州510655

出　　处：《中国环境科学》2024年第2期911-922,共12页China Environmental Science

基　　金：中央级公益性科研院所基本科研业务专项(PM-zx703-202204-107);国家重点研发计划项目课题(2022YFC3202203);广东省重点领域研发计划项目(2020B1111350001)。

摘　　要：本研究以华南地区中小型闸控入海河流黄江河、东溪河和练江(三河)为研究对象,于2022年逐月持续监测三河DOM特征,探讨DOM浓度时空分布、来源和藻类大量增殖对其影响.结果表明:黄江河、东溪河和练江溶解有机碳(DOC)占总有机碳(TOC)比例分别为78.6%、81.3%和67.2%,DOC为三河有机碳主要存在形式;三河DOC年均浓度分别为2.6,4.3和5.1mg/L,低于世界河流平均浓度但高于华南地区大型河流.荧光参数结果表明三河DOM具有陆源内源双重特征,内源贡献更明显.利用吸光特征量化藻源DOC贡献,三河藻源DOC浓度分别为1.2,1.8和2.2mg/L,藻源DOC占比分别为49.6%、42.6%和48.0%,进一步表明藻类内源是三河DOM主要来源.平行因子解析出3种类蛋白组分和2种类腐殖质组分,其中,受藻类异常增殖影响,表征内源类蛋白组分C1和C3总荧光强度枯水期显著高于丰水期,表征来自陆源类腐殖质组分C2和C4总荧光强度呈练江>东溪河>黄江河.因此,藻类大量增殖是三河DOC浓度高于华南地区大型河流、枯水期类蛋白组分C1和C3显著高于丰水期的主要原因之一,外源输入及河流理化参数,包括降雨、温度、盐度和营养盐浓度以及人为干扰(闸控调度)共同影响三河DOM浓度和组分.Due to the influence of climate change and human activities,algal blooms frequent occurrences in rivers in South China.Evaluating the concentration,sources and composition of dissolved organic matter(DOM)is of great significance for regional carbon cycle.In this study,we focused on three typical small and medium-sized gate-controlled rivers(Huangjiang River,Dongxi River and Lianjiang River)in South China.From January to December of 2022,the DOM characteristics in these rivers were continuously monitored to investigate the spatial-temporal distribution of DOM concentrations,sources,and the effects of algal blooms.The results show that DOC accounted for 78.6%,81.3%,and 67.2%of the total organic carbon(TOC)in Huangjiang River,Dongxi River,and Lianjiang River,respectively,being the dominant form of organic carbon.The annual average DOC concentrations in these three rivers were 2.6mg/L,4.3mg/L,and 5.1mg/L,respectively,which were lower than the average concentration in all world rivers but higher than those in the large rivers in South China.The DOM in the three rivers exhibited characteristics of both terrestrial and endogenous sources,with a more pronounced contribution from endogenous sources.And the algal-derived DOC concentrations in Huangjiang River,Dongxi River,and Lianjiang River were determined to be 1.2mg/L,1.8mg/L,and 2.2mg/L,or proportionally accounted for 49.6%,42.6%,and 48.0%,respectively,further indicating that algal blooms were the main contributors to DOM in the three rivers.Fluorescence excitation-emission matrix-parallel factor analysis(EEM-PARAFAC)of DOM in the three rivers revealed three types of protein components and two types of humic substances.Among them,the fluorescence intensity of endogenous protein components C1 and C3 in the dry season was significantly higher than that in the wet season under the influence of algal blooms.The fluorescence intensity of humic substance components C2 and C4,originating from terrigenous humus,showed a pattern of Lianjiang River>Dongxi River>Huangjiang River.

关 键 词：溶解有机质(DOM) 闸控入海河流 藻类增殖 吸光特性 三维荧光 

分 类 号：X522[环境科学与工程—环境工程]