我国中部水网区茭白潜流湿地进出水质和净化性能时变特征  

Time-varying characteristics of influent and effluent quality and purification performance of Zizania latifolia(Zl)subsurface flow wetland(SFW)in the water network area of central China

作　　者：马彦涛 曾志武 杜征宇 薛金凤[2] MA Yan-tao;ZENG Zhi-wu;DU Zheng-yu;XUE Jin-feng(Central Southern China Electric Power Design Institute Co.,Ltd.,of China Power Engineering Consulting Group,Wuhan 430071,China;School of Power&Mechanical Engineering,Wuhan University,Wuhan 430072,China)

机构地区：[1]中国电力工程顾问集团中南电力设计院有限公司,湖北武汉430071 [2]武汉大学动力与机械学院,湖北武汉430072

出　　处：《环境生态学》2024年第2期107-112,152,共7页Environmental Ecology

基　　金：中国电力工程顾问集团中南电力设计院有限公司科研项目(40-1A-KY202216-P301)资助。

摘　　要：本研究从小集水区角度研究了茭白潜流湿地进出水氮、磷、COD_(Cr)污染和净化性能的时变特征,结果表明,茭白潜流湿地进水氮、磷、COD_(Cr)季节波动大,其中春节期间湿地进水总氮(TN)和总磷(TP)最高,其次是农田施用化肥后产生地表径流的首月,中等降雨量下湿地进水COD_(Cr)浓度高于强暴雨下的浓度。受沉淀池的调节缓冲,湿地进水氨氮(NH_(3)-N)和硝态氮(NO_(x)^(-)-N)秋季最高,其次是春节后。湿地对小集水区氮、磷、COD_(Cr)冲击负荷均具有良好的缓冲能力和净化性能,TP、TN和COD_(Cr)平均去除率分别为(82.1±10.5)%、(72.9±8.1)%和(65.6±6.2)%;秋冬季过渡期间,因微生物降解和基质吸附的协同作用使得植物吸收氮磷的季节拐点不明显;冬季湿地具有耐受中部水网区低温的能力。不过冬季低温易于引起潜流湿地内有机氮分解转变为NH_(3)-N后被沸石等基质吸附而发生积聚,同时较长水力停留时间(HRT)下因有机质分解耗氧引起环境厌氧的加剧。此外,冬季出水溶解有机磷(DOP)比例增加。该潜流湿地可有效提升村镇面源污染排水水质,改善乡村水环境,但对上述受季节影响较大的时变因素应加强管控。The inflow time varying characteristics of nitrogen,phosphorus and COD_(Cr) pollution and the purification performance of Zl-SFW were studied from the angle of small catchment area in this study.The results showed that the inflow nitrogen,phosphorus and COD_(Cr) of Zl-SFW fluctuated greatly with season,in which TN and TP of the wetland inflow were the highest during the Spring Festival,followed by the first month of surface runoff generated after the application of fertilizer in the farmland,COD_(Cr) concentration in the wetland inflow under moderate rainfall was higher than that under heavy rainfall.Affected by the regulation and buffer of the sedimentation tank,NH_(3)-N and NO_(x)^(-)-N in the wetland inflow were the highest in autumn,followed by the date after the Spring Festival.Buffering capacity and purification performance of SFW were good for the shock loading of nitrogen,phosphorus and COD_(Cr) in the small basin,with(82.1±10.5)%、(72.9±8.1)%and(65.6±6.2)%of average removal efficiencies of TP,TN and COD_(Cr),respectively.During the transition period from autumn to winter,the seasonal inflection point of nitrogen and phosphorus uptaked by plants was not obvious due to the combined actions of microbial degradation and substrate adsorption.In winter,the wetland was of the ability to withstand low temperature in the water network area of central China.However,low temperature in winter was easy to cause the accumulation of NH_(3)-N from decomposed organic nitrogen as the result of adsorption by zeolite and other substrates in SFW,and at the same time,the oxygen consumption caused by degradation of organic matter could lead to aggravation of anaerobic environment under long hydraulic retention time(HRT).In addition,proportion of dissolved organic phosphorus(DOP)in effluent would increase in winter.In summary,this subsurface wetland can effectively improve the drainage quality polluted by non-point source in villages and towns,improve the rural water environment,but the management for the above time-varying

关 键 词：潜流湿地 茭白 氮磷 COD_(Cr) 降雨径流 季节变化 

分 类 号：TU992.3[建筑科学—市政工程] X703.1[环境科学与工程—环境工程]