白洋淀沉积物氮磷赋存特征及其内源负荷  

Occurrence and internal loadings of nitrogen and phosphorus in the sediment of Lake Baiyangdian

作　　者：杜奕衡 刘成[2] 陈开宁[2,3] 古小治 黄蔚[2] 韦众[1] DU Yiheng;LIU Cheng;CHEN Kaining;GU Xiaozhi;HUANG Wei;WEI Zhong(College of Animal Science and Technology,Anhui Agricultural University,Hefei 230036,P.R.China;State Key Laboratory of Lake Science and Environment,Nanjing Institute of Geography and Limnology,Chinese Academic of Sciences,Nanjing 210008,P.R.China;Collaborative Innovation Center of Water Treatment Technology&Material,Suzhou 215009,P.R.China)

机构地区：[1]安徽农业大学动物科技学院,合肥230036 [2]中国科学院南京地理与湖泊研究所,湖泊与环境国家重点实验室,南京210008 [3]江苏高校水处理技术与材料协同创新中心,苏州215009

出　　处：《湖泊科学》2018年第6期1537-1551,共15页Journal of Lake Sciences

基　　金：国家自然科学基金项目(41703078);南京科技计划项目(2017sb310016);江苏省太湖水环境综合治理科研课题(TH2016401)联合资助.

摘　　要：白洋淀环境整治对区域生态文明建设具有重要意义,然而,目前对加剧白洋淀富营养化的内源氮、磷污染负荷依然缺乏系统的研究.本研究以野外调研和室内培养实验相结合形式,在白洋淀主要水域内采集原位柱状沉积物样品,详细地研究了白洋淀沉积物中氮、磷赋存形态、间隙水中氮、磷剖面特征以及沉积物-水界面氮、磷交换特征.结果表明,白洋淀沉积物总氮、总磷含量分别为1230.8~9559.0 mg/kg(均值2379.5 mg/kg)和344.4~915.4 mg/kg(均值608.4 mg/kg),氮、磷累积污染量大.沉积物中铵态氮赋存量大(3.2~175.8 mg/kg),由此导致间隙水中铵态氮浓度较高,最高达到28.8 mg/L.沉积物磷形态以Ca-P和Fe-P为主,分别占总量的38.3%~76.1%和3.98%~18.0%,间隙水中磷酸盐浓度已接近甚至高于国内外典型富营养湖区.间隙水中高浓度的铵态氮和磷酸盐导致沉积物-水界面氮、磷交换通量较高,铵态氮平均释放和扩散通量分别为106.37和12.42 mg/(m2·d);磷酸盐平均释放和扩散通量分别为15.06和2.33 mg/(m2·d),沉积物内源氮、磷污染负荷较高,已严重威胁到白洋淀水环境质量,迫切需要整治.其中,北部河口区域以及中部府河入湖区和人口密集活动区沉积物氮、磷内源负荷尤为突出,应成为白洋淀沉积物内源污染整治的关键区域.The environmental restoration of Lake Baiyangdian is of great significance for regional construction of ecological civilization.However,information on the internal loadings of nitrogen and phosphorus,which aggravated the eutrophic status of Lake Baiyangdian,is still limited.In this study,a detailed field survey was carried out to investigate the occurrence and fractions of nitrogen and phosphorus in the sediment,the profiles of nitrogen and phosphorus in interstitial water,and the exchanges of nitrogen and phosphorus across the sediment-water interface.A series of in situ sediment core samples were collected in important water areas of Lake Baiyangdian for the study.Results showed that the contents of total nitrogen and total phosphorus in the sediments were in the range of 1230.8-9559.0 mg/kg(average:2379.5 mg/kg)and 344.4-915.4 mg/kg(average:608.4 mg/kg),respectively.A large quantity of the cumulative pollution of nitrogen and phosphorus was discovered.The high levels of ammonium nitrogen in the sediments(3.2-175.8 mg/kg)led to high concentrations of ammonium nitrogen in the interstitial water,with the highest concentration of 28.8 mg/L.The phosphorus forms in the sediments were largely Ca-P and Fe-P,accounting for 38.3%-76.1%and 3.98%-18.0%,respectively.The phosphate concentrations in the interstitial water were close to or even higher than those in typical eutrophic lakes around the world.The high levels of ammonium nitrogen and phosphate in the interstitial water resulted in high exchange fluxes of nitrogen and phosphorus across the sediment-water interface.The average release and diffusive fluxes of ammonium nitrogen were 106.37 mg/(m 2·d)and 12.42 mg/(m 2·d),respectively.The average release and diffusive fluxes of phosphate were 15.06 mg/(m 2·d)and 2.33 mg/(m 2·d),respectively.The high internal loadings of nitrogen and phosphorus in the sediments are now serious threat to the water environmental quality of Lake Baiyangdian.Urgent measures should be carried out to reduce the internal loadings.Especially

关 键 词：白洋淀 沉积物水界面 间隙水 扩散通量 释放通量 

分 类 号：X524[环境科学与工程—环境工程]