植物分布对洱海沉积物间隙水DOM光谱特征及对氮磷释放影响研究  

The effects of plant distribution on DOM spectroscopic characteristics and nitrogen and phosphorus release in sediment pore water of Erhai Lake

作　　者：周帅帅 吕志伟 马煜 倪兆奎 王圣瑞 刘哲哲 ZHOU Shuaishuai;LÜZhiwei;MA Yu;NI Zhaokui;WANG Shengrui;LIU Zhezhe(School of Energy and Environmental Engineering,Hebei University of Technology,Handan 056000;Hong Kong-Guangdong Joint Laboratory of Water Security,Water Science Research Center,Zhuhai Campus,Beijing Normal University,Zhuhai 519087;Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake Watershed,Kunming 650034;College of Resources,Environment and Tourism,Capital Normal University,Beijing 100084)

机构地区：[1]河北工程大学,能源与环境工程学院,邯郸056000 [2]粤港水安全保障联合实验室,北京师范大学珠海校区水科学研究中心,珠海519087 [3]云南省高原湖泊流域污染过程与管理重点实验室,昆明650034 [4]首都师范大学资源环境与旅游学院,北京100084

出　　处：《环境科学学报》2024年第2期203-213,共11页Acta Scientiae Circumstantiae

基　　金：云南省高原湖泊流域污染过程与管理重点实验室开放基金(No.2023PL00X);国家自然科学基金联合基金项目(No.U1902207)。

摘　　要：沉水植物分解导致大量溶解性有机质(DOM)进入水环境,进而对水质产生重要影响.然而,关于沉水植物分布对沉积物间隙水DOM的变化特征及其对氮磷释放的影响研究较少.本研究利用紫外-可见吸收光谱(UV-vis)和三维荧光光谱结合平行因子(EEMs-PARAFAC)技术对比研究了洱海沉水植物分布/非分布区沉积物间隙水DOM组分变化特征,并探讨DOM变化对氮磷释放的影响.结果表明,沉水植物分布区沉积物间隙水DOM主要以富里酸为主,而沉水植物非分布区DOM则以腐殖酸为主.通过UV-vis分析发现,沉水植物分布区沉积物间隙水DOM a_(355)、a_(440)、SUVA_(254)、A_(253)/A_(203)、S_(R)平均值高于植物非分布区,这表明沉水植物分解作用能够促进沉积物间隙水DOM含量、芳香性、分子量、以及取代基数量增加.沉水植物分布区上覆水和间隙水氮磷浓度均高于沉水植物非分布区,这主要是由于沉水植物衰亡期腐烂分解释放氮磷.此外,DOM中的羟基和羧基能够与磷酸盐竞争沉积物颗粒上的吸附位点,有利于磷酸盐从沉积物颗粒表面解吸和释放,进而促进沉积物磷酸盐向上覆水释放.本研究为增强沉水植物对沉积物DOM特征和氮磷释放机制理解提供有价值的信息,并为通过沉水植物修复和控制湖泊沉积物内源污染提供科学指导.Decomposition of submerged plants would cause the release of dissolved organic matter(DOM),which may adversely affect water quality.However,effects of submerged plants on characteristic DOM in sediment porewater and the release of nitrogen and phosphorus remain unclear.Herein,ultraviolet-visible spectroscopy(UV-vis)and three-dimensional fluorescence spectroscopy techniques combined with parallel factor(EEMs-PARAFAC)methods were used to compare the characteristics of sediment porewater DOM components in plant distributed and non-plant distributed regions from Lake Erhai.The effects of DOM on nitrogen and phosphorus release were also explored.The results showed that sediment porewater DOM was mainly composed of fulvic acid in submerged plant regions,while humic acid mainly exists in non-submerged plant regions.UV-vis spectra analysis showed that the average values of a_(355),a_(440),SUVA_(254),A_(253)/A_(203) and S_(R) were higher in submerged plant regions,indicating that the sediments porewater DOM have higher content,aromaticity,molecular weight and substituent groups,which largely attributed to the decomposition of submerged plants.The concentration of nitrogen and phosphorus in overlying water and porewater from submerged plant regions was higher than that of non-submerged plant regions,which also effected by the decay and decomposition of submerged plants.Furthermore,abundant hydroxyl and carboxyl groups in DOM would compete with phosphate for adsorption sites,benefitting from phosphate release and desorption from sediments,thereby promoting the release of phosphate towards overlying water.The results from this study provide valuable information to enhance the understanding of nitrogen and phosphorus release mechanism affected by submerged plants,and provide scientific guidance for the restoration and control endogenous pollution in lake sediments.

关 键 词：DOM 沉水植物 沉积物间隙水 氮磷 

分 类 号：X522[环境科学与工程—环境工程]