大冶湖沉积物-上覆水界面氮磷交换通量的冬夏对比  

Comparison of nitrogen and phosphorus exchange fluxes at the sedimentoverlying water interfaces of Daye Lake between winter and summer

作　　者：左韧 李海波[1] 刘芫 董浩 程艳 王临风 杨定炜 徐银 ZUO Ren;LI Haibo;LIU Yuan;DONG Hao;CHENG Yan;WANG Linfeng;YANG Dingwei;XU Yin(Faculty of Resources and Environmental Science,Hubei University,Wuhan 430062,China)

机构地区：[1]湖北大学资源环境学院,武汉430062

出　　处：《环境工程学报》2024年第6期1520-1530,共11页Chinese Journal of Environmental Engineering

基　　金：湖北省生态环境厅科技项目(2021HB-14);国家长江中心长江生态环境保护修复驻点跟踪研究(二期)项目(2022-LHYJ-02-0506-04)。

摘　　要：通过泥柱静态培养实验,对比探究大冶湖冬夏两季沉积物-上覆水界面氮磷交换通量的变化规律,估算界面交换对水体氮磷的潜在贡献率并探讨沉积物的“源”与“汇”作用,最后通过单因素控制法开展扰动、温度、溶解氧及水体pH等环境因子对氮磷释放的影响研究。结果表明,冬夏两季不同点位的交换通量和“源”、“汇”角色不同。冬季入湖处1~#点位氮磷交换通量最大,TN、NH_(4)^(+)-N、TP、PO_(4)^(3-)-P的平均交换通量分别为202.94、41.62、0.55、0.36 mg·(m^(2)·d)^(-1);夏季出湖处3~#点位氮磷交换通量最大,TN、NH_(4)^(+)-N、TP、PO_(4)^(3-)-P平均交换通量分别为389.27、89.54、1.79、1.18 mg·(m^(2)·d)^(-1)。冬季沉积物对上覆水中TN和NH_(4)^(+)-N整体上起“源”的作用,而对TP和PO_(4)^(3-)-P表现为“汇”;夏季沉积物对上覆水中TN、NH_(4)^(+)-N、TP、PO_(4)^(3-)-P均起“源”的作用。环境因子实验结果表明,水体扰动速率越大,沉积物氮磷的再悬浮通量越大;升温及厌氧条件均会促进沉积物氮磷的释放;水体pH对氮磷释放的影响规律不同,氮营养盐释放随着pH的升高而减少,而磷营养盐中性条件下释放强度最弱,偏酸或偏碱环境有助于磷的释放。本研究有助于厘清长江中下游城市浅水湖泊富营养化内源污染贡献,对设计湖泊内源负荷控制方案以及湖泊富营养化防控具有重要指导意义。In this work,the static incubation experiments of mud columns were used to compare the exchange fluxes of nitrogen and phosphorus at the sediment-overlying water interfaces of Daye Lake in winter and summer.The potential contribution of interfacial exchange to the nitrogen and phosphorus in the water body was then estimated,and the source or sink role of sediment was also discussed.Finally,the effects of disturbance,temperature,dissolved oxygen,and pH on the release of nitrogen and phosphorus were investigated through single-factor experiments.The results showed that the exchange fluxes and the source or sink role were different among the investigated sites between winter and summer.The exchange fluxes of nitrogen and phosphorus were the largest at point 1#of the lake in winter,and the average exchange fluxes of TN,NH_(4)^(+)-N,TP,and PO_(4)^(3−)-P were 202.94,41.62,0.55,and 0.36 mg·(m^(2)·d)^(−1),respectively.The maximum nitrogen and phosphorus exchange fluxes were observed at point 3#of the lake outlet in summer,the average exchange fluxes of TN,NH_(4)^(+)-N,TP,and PO_(4)^(3−)-P were 389.27,89.54,1.79,and 1.18 mg·(m^(2)·d)^(−1),respectively.In winter,the sediment acted as a source of TN and NH_(4)^(+)-N in the overlying water,and as a sink for TP and PO_(4)^(3−)-P in the overlying water.However,in summer the sediment acted as a source of TN,NH_(4)^(+)-N,TP,and PO_(4)^(3−)-P in the overlying water.Results of environmental factors analysis indicated that the resuspension fluxes of nitrogen and phosphorus increased with the increase of disturbance rate.High temperature and anaerobic conditions could promote the release of nitrogen and phosphorus from the sediment.The influence of water pH on nitrogen and phosphorus release was different,the release of nitrogen decreased with the increase of pH,while the release of phosphorus was the weakest at neutral pHs,but increased at acidic or alkaline pHs.This study is of great significance for clarifying the contribution of endogenous pollution to eutrophica

关 键 词：大冶湖 沉积物-上覆水 氮磷 交换通量 影响因素 

分 类 号：X703[环境科学与工程—环境工程]