再生水湿地中氮和多环芳烃污染特征及其耦合修复机制  

Pollution Features and Coupled Remediation Mechanisms of Nitrogen and Polycyclic Aromatic Hydrocarbons in Wetlands Recharged by Reclaimed Water

作　　者：谭丽琼 朱正 于亚男 索思雨 赵梦云 梁文艳[2] TAN Liqiong;ZHU Zheng;YU Yanan;SUO Siyu;ZHAO Mengyun;LIANG Wenyan(Yuanmingyuan Management Office,Beijing 100084,China;College of Environmental Science and Engineering,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京市海淀区圆明园管理处,北京100084 [2]北京林业大学环境科学与工程学院,北京100083

出　　处：《环境科学研究》2024年第12期2710-2721,共12页Research of Environmental Sciences

基　　金：国家自然科学基金项目(No.51672028);国家水体污染控制与治理科技重大专项(No.2018ZX07110-003)。

摘　　要：为了探究氮素和多环芳烃(PAHs)在再生水湿地中的迁移转化、空间分布、植物修复过程及其对植物修复措施的耦合响应机制,研究选取北京某处完全受再生水补给的城市湿地为典型案例。将研究区域划分为修复区、半修复区和非修复区,对其水体和沉积物中氮和PAHs的水平、空间分布、植物修复效能进行了系统性分析,并通过原位对比阐明了二者在不同植物修复程度下的响应机制。结果表明:①在湿地水体和沉积物中,ΣPAHs含量范围分别为10.6~326.3 ng/L和29.4~1245.9 ng/g,而平均总氮含量分别为6.09 mg/L和1250.4 mg/kg。②植物修复措施能有效去除湿地水体中的氮素,使水体平均TNw浓度从上游的8.87 mg/L降至下游的3.44 mg/L,且对水体中的中环PAHs和沉积物中的低环PAHs的有较好的修复效果。③植物修复改变了氮素和PAHs含量的耦合响应机制,在修复区湿地水体中氮素和PAHs的浓度表现为协同效应,非修复区中则因沉积物的截留作用表现为拮抗效应。④沉积物中,非修复区氮素和PAHs含量因其共同的来源表现为正相关,但植物修复使其之间的相关关系消失。研究显示,再生水会将氮素和PAHs污染输入受纳湿地中,但其中的水生植物能协同降解这两类污染物,且通过反硝化菌的介导作用相互促进,发生正向反馈机制。研究结果加深了对再生水湿地中氮素和PAHs演变规律的认识,可为同类型湿地的水环境保护提供参考。To investigate the migration and transformation,spatial distribution,phytoremediation process,and coupled response mechanisms of nitrogen and polycyclic aromatic hydrocarbons(PAHs)in reclaimed water wetlands,an urban wetland in Beijing that is completely recharged by reclaimed water was selected as a representative case study.The water area was divided into a phytoremediation area,a semi-phytoremediation area,and a non-phytoremediation area.A systematic analysis was conducted on the levels,spatial distribution,and phytoremediation efficiency of nitrogen and PAHs in the water and sediment.In-situ comparisons were made to elucidate the response mechanisms at different levels of phytoremediation.The results showed that:(1)ΣPAHs contents in the water column and sediment ranged from 10.6 to 326.3 ng/L and 29.4 to 1245.9 ng/g,respectively.The average contents of total nitrogen were 6.09 mg/L and 1250.4 mg/kg,respectively.(2)Phytoremediation proved to be an effective means of nitrogen removal from the water column,notably decreasing the average total nitrogen(TNw)concentration from 8.87 mg/L upstream to 3.44 mg/L downstream.Furthermore,phytoremediation was more effective in removing middle-ring PAHs from water and low-ring PAHs from sediment.(3)Phytoremediation altered the coupled response mechanisms between nitrogen and PAHs content.In the water column,the concentrations of nitrogen and PAHs in phytoremediation area exhibited a synergistic effect,while an antagonistic effect appeared in non-phytoremediation area due to the interception of sediment.(4)In the sediment,the non-phytoremediation zones displayed a positive correlation between nitrogen and PAHs content due to their shared source.However,aquatic plants caused the correlation between them to disappear.The research showed that reclaimed water inputs nitrogen and PAHs pollution into receiving wetlands.The hydrophytes can synergistically degrade these two types of water pollutants,and promote each other through the mediation of denitrifying bacteria,resulting in

关 键 词：再生水 城市湿地 植物修复 氮 多环芳烃(PAHs) 地统计分析 

分 类 号：X52[环境科学与工程—环境工程]