洱海沉积物溶解性有机氮释放及环境影响机制  

Releasing Characteristics of Sediment Dissolved Organic Nitrogen(DON) from Erhai Lake and its environmental impact mechanism

作　　者：史玲珑 张莉[2,3,4] 王圣瑞[2,3,4] 段昌群[1] 李文章[2,3] 席银 李秋才 许可宸 SHI Ling-long;ZHANG Li;WANG Sheng-rui;DUAN Chang-qun;LI Wen-zhang;XI Yin;LI Qiu-cai;Xu Ke-chen(College of Ecology and Environmental Sciences, Yunnan University, Kunming 650091, China;State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China;State Environmental Protection Key Laboratory for Lake Pollution Control, Research Center of Lake Eco-environment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China;Yunnan Key Laboratory of Pollution Process and Management of Plateau Lake-Watershed, Yunnan Kunming 650504, China)

机构地区：[1]云南大学生态学与环境学院,云南昆明650091 [2]中国环境科学研究院,环境基准与风险评估国家重点实验室,北京100012 [3]中国环境科学研究院,国家环境保护湖泊污染控制重点实验室,北京100012 [4]云南省高原湖泊流域污染过程与管理重点实验室,云南昆明650504

出　　处：《中国环境科学》2017年第7期2715-2722,共8页China Environmental Science

基　　金：国家自然科学基金(U1202235,41503113);国家水专项“十二五”课题“洱海湖泊生境改善关键技术与工程示范”(2012ZX07105-004);环境基准与风险评估国家重点实验室自由探索项目(2014-GOT-042-N-06)

摘　　要：通过模拟实验,结合紫外与荧光光谱技术,研究了洱海表层沉积物DON释放特征,并探讨其环境影响因素及环境学意义.结果表明:(1)一级动力学模型可很好地拟合洱海表层沉积物DON释放动力学过程,其最大释放量在24.387~46.949mg/kg之间,空间分布呈现北部>南部>中部;最先释放(10min内达到最大值)组分主要为类蛋白组分P_(Ⅰ+Ⅱ,n),而释放量最大的组分是类腐殖质组分P_(Ⅲ+Ⅳ,n),约占76%;(2)洱海沉积物DON在好氧(DO=8~10mg/L)和适中pH值(pH=8)的环境中释放量相对较小,pH值增加或DO含量降低均会促进其释放.(3)洱海沉积物DON组成特征参数与其释放量显著相关(r=0.813~0.919,P<0.01),随沉积物DON取代基增多,分子量增大,芳香性增强,释放量逐渐增大;类蛋白与类腐殖质组分比值P_(Ⅰ+Ⅱ,n)/P_(Ⅲ+Ⅳ,n)也可间接作为衡量沉积物DON释放量的指标,即沉积物DON结构组分特征参数可反映其释放特征,在一定程度上可用于指示洱海沉积物DON释放风险.The release characteristics of DON in the surface sediments of Erhai Lake were studied by simulation experiment combined with UV-Vis absorbance and fluorescence spectroscopy.Moreover,the environmental influence factors and environment implication of sediment DON were also discussed.The obtained results indicated that:(1)The release kinetics of DON in the surface sediment could be well simulated by first-order kinetics equation.The maximal DON release amount from each area followed the pattern:northern>southern>middle,ranging from24.387to46.949mg/kg.Moreover,the first(maximum within10min)and the largest releasing components were the protein-like component P(I+II,n)and humic-like component P(III+V,n)(accounting for approximately76%)respectively.(2)The DON release amount in sediments of Erhai Lake is relatively small under the overlying water conditions of aerobic(DO=8~10mg/L)and moderate pH(pH=8),and the obvious increase/decrease of pH/DO was considered to promote its releasing amount.(3)The compositional parameters of DON in Erhai sediments was positively correlated with its releasing amount(r=0.813~0.919,P<0.01).The more the substituent DON was contained in the sediment,the greater the molecular weight and aromaticity degree were,and the greater its release amount was.Moreover,the content ratio of protein-like to humic-like substances P(I+II,n)/P(III+V,n)can also be taken as the indirect indicator of the release amount of sediment DON.The compositional characteristic of sediment DON can reflect its releasing characteristics,that is,the DON release risk of from Erhai sediments can be reflected to some extent.

关 键 词：洱海 沉积物 溶解性有机氮释放 三维荧光光谱 FRI 

分 类 号：X524[环境科学与工程—环境工程]