富营养化底泥氮磷在电动导排孔隙水过程中的响应特征  

Response Characteristics of Nitrogen and Phosphorus in Eutrophic Sediment During Electrokinetic Drainage of Pore Water

作　　者：于滨养 黎睿[2,3] 汤显强 肖尚斌[1] 胡艳平 郭栋帆[2] 陈明鉴[1] YU Binyang;LI Rui;TANG Xianqiang;XIAO Shangbin;HU Yanping;GUO Dongfan;CHEN Mingjian(College of Hydraulic&Environmental Engineering,China Three Gorges University,Yichang 443002,China;Basin Water Environmental Department,Changjiang River Scientific Research Institute,Wuhan 430010,China;Key Laboratory of Basin Water Resource and Eco-environmental Science in Hubei Province,Wuhan 430010,China)

机构地区：[1]三峡大学水利与环境学院,湖北宜昌443002 [2]长江科学院流域水环境研究所,湖北武汉430010 [3]流域水资源与生态环境科学湖北省重点实验室,湖北武汉430010

出　　处：《环境科学与技术》2025年第2期31-39,共9页Environmental Science & Technology

基　　金：湖北省自然科学基金重点项目(2024AFD349);中央级公益性科研院所基本科研业务费专项项目(CKSF2024327/SH);国家自然科学基金面上项目(51979006);上海水环境模拟与水生态修复工程技术研究中心资助项目(WESER-202204)。

摘　　要：在外源污染负荷得到有效治理后,来自底泥的内源污染成为影响水环境改善的主要障碍。针对氮磷污染底泥,该研究采用新型电动土工布材料柱状电极,在上覆水深度为80 cm、底泥为120 cm的条件下开展电动导排孔隙水实验。作者共设置对照组、重力排水(0 V/cm电压梯度)和间歇通电实验(分别为0.5、1.0、1.5 V/cm电压梯度,4 h开-4 h关)5组实验,监测不同电压梯度下导排水中氮磷浓度的变化特征,分析底泥中氮磷的去除量及氮磷各赋存形态的去除率,评估修复后泥-水界面(SWI)氮磷释放通量的特征及影响因素。结果表明:电动导排孔隙水可以有效降低底泥中氮磷污染物的负荷,0.5 V/cm实验组共脱除氮素11071.01 mg,1.5 V/cm实验组脱共除磷128.85 mg。底泥中弱酸可提取态氮的去除率最高,达到了40.03%,阳极有机磷在0~5 cm去除率最高达45.65%。采用薄膜梯度扩散技术,在0.5 V/cm电压梯度下NH_(4)^(+)-N和NO_(3)^(-)-N的释放通量分别为-0.0799和0.0412 mg/(m^(2)·d),SWI界面通量主要受孔隙水中氮浓度的影响。对于溶解性总磷,1.0 V/cm实验组和1.5 V/cm实验组均表现为营养盐向上覆水中释放,1.5 V/cm实验组扩散通量是1.0 V/cm实验组通量的5.27倍,更高的电压梯度可能会导致泥水界面释放通量的升高。After the external pollution load has been effectively controlled,the internal pollution from sediment has become the main obstacle to the improvement of water environment.A novel electrodynamic geotextile columnar electrode was used to conduct an electrodynamic pore water drainage experiment under the condition that the overlay water depth was 80 cm and the bottom mud was 120 cm.A total of 5 groups of experiments were set up:control group,gravity drainage(0 V/cm voltage gradient)and intermittent power supply(0.5,1.0,1.5 V/cm voltage gradient,4 h ON-4 h OFF).The variation charac-teristics of nitrogen and phosphorus concentration in drainage under different voltage gradients were monitored,the removal amount of nitrogen and phosphorus in the sediment and the removal rates of each occurrence form of nitrogen and phosphorus were analyzed,and the characteristics and influencing factors of nitrogen and phosphorus release flux at the mud-water inter-face(SWI)after restoration were evaluated.The results show that the electric drainage of pore water can effectively reduce the load of nitrogen and phosphorus pollutants in the sediment.In the experimental group of 0.5 V/cm,the nitrogen removal was 11071.01 mg,and in the experimental group of 1.5 V/cm,the phosphorus removal was 128.85 mg.The removal rate of weak acid extractable nitrogen(WAFE-N)was the highest,reaching 40.03%,and the removal rate of anodic organophosphate(OP)at 0~5 cm was the highest,reaching 45.65%.Using thin film gradient diffusion technology,the release fluxes of NH_(4)^(+)-N and NO_(3)^(-)-N at 0.5 V/cm voltage gradient are-0.0799 mg/(m^(2)·d)and 0.0412 mg/(m^(2)·d),respectively,and the SWI interface fluxes are mainly affected by the nitrogen concentration in pore water.For DTP,both the 1.0 V/cm experimental group and the 1.5 V/cm experimental group showed that nutrients were released upward from the overhanging water,and the diffusion flux of the 1.5 V/cm experimental group was 5.27 times that of the 1.0 V/cm experimental group.The higher voltage gra

关 键 词：电动修复 间隙水 污染底泥 释放通量 

分 类 号：X53[环境科学与工程—环境工程]