湖泊底泥氮磷污染特征与环境风险评估——以湖北省枝江市杨家垱湖和陶家湖为例  

Characteristics of Nitrogen-Phosphorus Pollution in Lake Sediments and Environmental Risk Evaluation——Case of Yangjiadang Lake and Taojia Lake in Zhijiang City,Hubei Province

作　　者：李博阳 徐浩阳 吴定 LI Boyang;XU Haoyang;WU Ding(School of Environmental Studies,China University of Geosciences(Wuhan),Wuhan 430078,China;Bogan Space Science and Technology Limited Company,Wuhan 430074,China)

机构地区：[1]中国地质大学(武汉)环境学院,湖北武汉430078 [2]武汉博感空间科技有限公司,湖北武汉430074

出　　处：《安全与环境工程》2023年第5期235-246,共12页Safety and Environmental Engineering

摘　　要：为推进区域性湖泊污染防控,有效改善湖泊富营养化问题,选取湖北省枝江市杨家垱湖和陶家湖两个典型湖泊为研究区,通过对湖泊底泥沉积物进行分层勘测并测定其氮磷含量,查明研究区典型湖泊底泥氮磷污染的特征,结合底泥氮磷释放试验,综合分析湖泊底泥污染程度及其潜在的环境风险,并提出底泥环保清淤建议。结果表明:(1)研究区典型湖泊底泥氮磷污染严重,是导致水体富营养化的重要因素;研究区湖泊表层底泥氮磷综合污染处于重度或严重污染状态(污染指数IN>2),以陶家湖东北部底泥氮磷污染最为严重;湖泊重度污染底泥总量分别达65.57万m^(3)(陶家湖)和12.05万m^(3)(杨家垱湖),其中杨家垱湖重度污染底泥的分布深度较陶家湖更深。(2)研究区典型湖泊底泥在氮磷释放试验中基本都能向上覆水体释放大量氮,尤以杨家垱湖底泥更甚;相较之下,底泥磷释放对湖水环境的影响相对较弱,深层底泥可反向吸附孔隙水中磷,有利于湖泊富营养化的控制。(3)基于研究区典型湖泊底泥氮磷污染特征提出湖泊清淤方案,建议湖泊清淤区域主要为重度污染底泥深度大于40 cm的湖域,清淤深度为50 cm,重点清淤区域位于杨家垱湖西部和陶家湖东北部。In order to promote the prevention of pollution and improve the eutrophication in regional lakes,taking typical lake sediments in Zhijiang city as research object,this study conducted stratified investiga-tion and measured the concentrations of nitrogen(N)and phosphorus(P).Combined with N and P release experiments for lake sediments,the study evaluated the contamination degree and environmental risk of lake sediments,and then proposed environment-friendly suggestions for dredging.The results are as fol-lows:Lake sediments of the study area are in seriously N and P pollution,which is also a crucial factor for eutrophication.N and P pollution in surface lake sediments are at a heavy to extreme levels(IN>2),with the most severe pollution in the northeast of Taojia Lake.The amounts of heavily polluted sediments reach 655700 m(Yangjiadang Lake-YJDL)and 120500 m'(Taojia Lake-TJL),respectively,and the depth of heavily polluted lake sediments in YJDL is deeper than that in TJL.@According to the results of N/P release experiments,lake sediments can release a large amount of N into the overlying water,especially for the sediments in YJDL.In contrast,the release of P from lake sediments has little influence on environment of lakes.The deep sediments can absorb P in pore water,which will be conducive to the control of lake eu-trophication.③Based on theN and P pollution characteristicsof lakesediments,weproposethedredging program for lake sediments.The suggested dredging area is mainly in the region where the depth of heavily polluted sediments is deeper than 40 cm,and the dredging depth is 50 cm.The key dredging areas are loca-ted in the west of YJDL and northeast of TJL.

关 键 词：湖泊底泥 氮磷污染 环境风险评估 清淤 杨家垱湖 陶家湖 

分 类 号：X51[环境科学与工程—环境工程] X820.4