污水厂尾水补水对受纳水体氮磷形态与DOM时空分布特征的影响  

Effects of Replenishing with Effluent from Wastewater Plants on the Spatial and Temporal Characteristics of Nitrogen,Phosphorus and DOM in Receiving Water Body

作　　者：杨长明[1] 尉岚 杨阳 王育来 YANG Changming;YU Lan;YANG Yang;WANG Yulai(College of Environmental Science and Engineering,Tongji University,Shanghai 200092,China;College of Energy and Environment,Anhui University of Technology,Maanshan 243002,China)

机构地区：[1]同济大学环境科学与工程学院,上海200092 [2]安徽工业大学能源与环境学院,安徽马鞍山243002

出　　处：《环境科学研究》2023年第9期1705-1715,共11页Research of Environmental Sciences

基　　金：国家水体污染控制与治理科技重大专项(No.2017ZX07603-003)。

摘　　要：城镇污水厂尾水水量稳定、水质可控,是补给河湖水系生态基流的可靠水源.为保障污水厂尾水补水安全,以合肥市王建沟为研究对象,分别于枯水期、丰水期开展污水厂尾水回补河道氮、磷形态及溶解性有机质(dissolved organic matter,DOM)的时空分布特征研究,探明污水厂尾水对回补河流的影响.结果表明:①王建沟经尾水补水后水质明显改善,补水河段污染物浓度空间上沿程上升,时间上水质标识指数特征表现为丰水期>枯水期,总氮(total nitrogen,TN)为主要污染因子.②尾水回补河道中氮形态以溶解态为主,主要存在形式为溶解态无机氮(dissolved inorganic nitrogen,DIN,占60.9%),且以硝态氮(NO_(3)^(−)-N)为主.除溶解态有机氮(dissolved organic nitrogen,DON)和亚硝态氮(NO2−-N)以外,其余形态氮浓度均表现为丰水期>枯水期.③磷主要以溶解态无机磷(dissolved inorganic phosphorus,DIP,占80.3%)为主,各形态磷浓度均表现为丰水期>枯水期.④枯、丰水期尾水回补河道DOM均以类腐殖质为主,占68%以上,DOM具有较强自生源、低腐殖化特征;同时,较枯水期而言,丰水期DOM结构更为复杂,平均相对分子质量和含量升高.研究显示:污水厂尾水回补河流尽管会导致氮、磷等污染负荷的输入,但在丰富河流水动力、生态基流保障、河流生态恢复等方面具有积极的效应;同时建议丰水期强化入河城市面源污染管控.Wastewater treatment plant effluent is a reliable source of ecological flow for urban river and lake systems due to its stable quantity and controllable quality.In order to improve the environmental safety of replenishing water and explore its influence on the receiving water bodies,Wangjiangou River in Hefei City was taken as the research object.In this study,the water quality was monitored along the replenishing river during the dry and wet periods,and the spatial and temporal distribution characteristics of nitrogen and phosphorus forms and dissolved organic matter(DOM)in the receiving river were analyzed.The results showed that:(1)The water quality of Wangjiangou River was improved,and the concentration of pollutants increased along the river.The water quality index in the wet period was higher than that in the dry period,and total nitrogen(TN)was the main influencing factor.(2)The main form of nitrogen in the replenishing water was dissolved inorganic nitrogen(DIN,60.9%),of which nitrate was the main form.Except for dissolved organic nitrogen(DON)and nitrite(NO_(2)^(−)-N),the concentrations of other forms were higher in the wet period than those in the dry period.(3)Phosphorus was mainly in dissolved inorganic form(DIP,80.3%),and the concentrations of all forms of phosphorus were higher in the wet period than in the dry period.The concentrations of nitrogen and phosphorus increased along the replenishing river.(4)In both dry and wet periods,DOM was predominated by humic acid-like substances,accounting for more than 68%,with strong autogenous and low humification characteristics.The average relative molecular weight and content of DOM were higher in the wet period than in the dry period.These results suggests that the effluent of the wastewater treatment plant will result in increase in nitrogen and phosphorus loads of the replenishing river,which will play positive roles in enriching the river′s hydrodynamics,ensuring ecological flow and ecological restoration of urban rivers.Simultaneously,we should tak

关 键 词：尾水补水 受纳水体 氮磷形态 溶解性有机质(DOM) 时空变化 

分 类 号：X522[环境科学与工程—环境工程]