摘要
溶解性有机质(DOM)广泛分布于土壤和水环境中,沉积物中DOM的释放是水体DOM的重要来源,探明沉积物中DOM的释放规律,可为水体重金属污染和有机物污染治理提供理论支撑。该文以鄱阳湖湿地沉积物为研究对象,探讨了时间以及溶解氧水平对沉积物中DOM释放的影响,运用三维荧光光谱法对不同溶解氧水平下上覆水中DOM进行了光谱分析,并结合荧光指数、生物源指数和荧光区域积分法对DOM进行了性质和来源的分析。结果表明,随着时间的增加,DOM的累积释放量逐渐增加,在240 h时达到最大值并稳定。随着溶解氧水平的增加,DOM的累积释放量先减小后增加,在溶解氧为0%和100%时,累积释放量较大。不同溶解氧水平下,吴城沉积物释放到上覆水中DOM的荧光峰为C峰和T峰,湖口沉积物释放到上覆水中DOM的荧光峰为C峰、T峰和B峰,梅溪沉积物释放到上覆水中DOM的荧光峰为A峰、C峰和T1峰。除梅溪采样点外,缺氧条件下,释放出来的DOM主要来源于陆源输入,有氧条件下,释放出来的DOM既有陆源输入,又有内源产生的新生源DOM。因此,溶解氧水平对沉积物中DOM的释放有显著影响。
Dissolved organic matter(DOM)is widely distributed in soil and water environment,and can be complexed with heavy metals and organic pollutants.The release of DOM in sediments is an important source of DOM in water body.Explor⁃ing the release rule of DOM in sediments can provide certain theoretical support for the treatment of heavy metal pollution and organic pollution in water.The effects of time and dissolved oxygen(DO)level on DOM release in Poyang Lake wetland sediments were investigated.The DOM in the overlying water at different dissolved oxygen levels was analyzed by using three-dimensional fluorescence spectroscopy,and the properties and sources of DOM were analyzed by combining fluores⁃cence index,biosource index and fluorescence regional integration.The results indicated that the release amount of DOM gradually increased with the increase of time,which was reached the maximum and stable value at 240 h.However,as the DO level increases,the release of DOM first decreased and then increased.The release of DOM reached maximum in the 0%and 100%of DO level.Under different DO levels,the fluorescence peaks of DOM released by Wucheng sediments into overlying water were mainly peak C and peak T,while peak C,peak T and peak B were the main peaks in Hukou sediments.The fluorescence peaks of DOM released by Wucheng sediments into overlying water were mainly peak A,peak C and peak T1.Except for Meixi sampling site,the release of DOM under hypoxia is mainly derived from land source input.Both land source input and endogenously generated were found from the release of DOM under aerobic condition.Therefore,the level of DO has a significant impact on the release of DOM in sediments.
作者
孙玉恒
弓晓峰
李远航
熊捷迁
舒瑶
牛丹妮
吴莉
林媛
SUN Yuheng;GONG Xiaofeng;LI Yuanhang;XIONG Jieqian;SHU Yao;NIU Danni;WU Li;LIN Yuan(Key Laboratory of Poyang Lake Environment and Resource Utilization of Ministry of Education,School of Resources Environmental and Chemical Engineering,Nanchang University,Nanchang 330031,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2021年第3期110-119,共10页
Environmental Science & Technology
基金
国家自然科学基金(41761095)。
关键词
溶解性有机质
沉积物
鄱阳湖
溶解氧
三维荧光
区域积分
dissolved organic matter
sediment
Poyang Lake
dissolved oxygen
three-dimensional fluorescence
regional integration
