不同季节下生物滞留系统中氮素迁移转化特性  

Migration and Transformation Characteristics of Nitrogen in Bioretention System under Different Seasons

作　　者：叶利兰 陈垚[1,2] 刘臻 陈人瑜 余雪花 袁绍春[1,2] YE Lilan;CHEN Yao;LIU Zhen;CHEN Renyu;YU Xuehua;YUAN Shaochun(School of River and Ocean Engineering,Chongqing Jiaotong University,Chongqing 400074,China;Engineering Laboratory of Environmental Hydraulic Engineering of Chongqing Municipal Development and Reform Commission,Chongqing Jiaotong University,Chongqing 400074,China)

机构地区：[1]重庆交通大学河海学院,重庆400074 [2]重庆交通大学环境水利工程重庆市工程实验室,重庆400074

出　　处：《环境科学与技术》2021年第12期90-98,共9页Environmental Science & Technology

基　　金：国家自然科学基金项目(51709024);重庆市建设科技计划项目(城科字2020第5-7);重庆市自然科学基金项目(cstc2020jcyj-msxmX1000);重庆市留创计划(cx2017065)。

摘　　要：生物滞留系统虽可有效削减降雨径流中氮素污染负荷,但其除氮能力呈现出季节性变化,而目前尚未掌握不同季节下生物滞留系统中氮素迁移转化规律。该研究考察了秋冬季、春季和夏季氮素在生物滞留系统孔隙水、植物、土壤等多介质中的赋存与分配情况,在此基础上分析了不同季节下氮素迁移转化规律与宏观收支平衡状况,进而探明了各介质对氮素归趋贡献的变化情况。结果表明,系统对NH_(4)^(+)-N和TN的去除受季节影响较大,而NO_(3)^(1)-N受季节影响较小。其中NH_(4)^(+)-N夏季去除率最高,而TN秋冬季去除率最高。秋冬季和春季各介质对氮素归趋的贡献大小为气态排放>土壤固持>出水排放>植物吸收,而夏季下出水排放对氮素归趋的贡献强于土壤固持。研究证实了不同季节下各介质对氮素归趋的贡献率会出现一定差异,但生物滞留系统对氮的去除主要以微生物硝化反硝化作用为主。Although bioretention systems can effectively reduce the nitrogen pollution load in rainfall runoff,their nitrogen removal capacity varies seasonally,and the nitrogen migration and transformation patterns in bioretention systems under different seasons are not yet known.The study investigated the nitrogen transport and transformation patterns and macro balance of nitrogen in the pore water,plants and soil of bioretention systems in autumn-winter,spring and summer,and then investigated the changes of the contribution of each medium to nitrogen fate.Results show that the removal of NH_(4)^(+)-N and TN is more affected by the season,while NO_(3)^(-)-N is less affected by the season.The highest removal rate of NH_(4)^(+)-N was observed in summer,while the highest removal rate of TN was observed in autumn-winter.The contribution of each medium to nitrogen fate in autumn,winter and spring was gaseous emission>soil sequestration>effluent emission>plant uptake,while effluent emission contributed more to nitrogen fate than soil sequestration in summer.This study confirms that the contribution of each media to nitrogen fractionation varies between seasons,but that nitrogen removal by bioretention systems is dominated by microbial nitrification and denitrification.

关 键 词：生物滞留 海绵城市 氮 季节性变化 归趋 固持 多介质 

分 类 号：X52[环境科学与工程—环境工程]