摘要
为确定长荡湖环保清淤范围,通过对表层沉积物TN、TP和8种重金属的监测来确定空间分布差异及高污染区域,并结合实际操作情况确定具体清淤范围。结果表明,研究区域TN为419~2 920 mg·kg^(-1),均值为1 186mg·kg^(-1),无明显空间差异和分层差异。长荡湖表层(0~15 cm)沉积物TP均值为499 mg·kg^(-1),上层0~5 cm的TP略高于底层。沉积物TP具有一定的空间差异性,不同深度的TP空间差异性相似,均为北部中间湖区、西部湖区、南部及东侧湖区较高。长荡湖表层沉积物Cr、Cu、Ni、Zn、As、Cd、Pb和Hg的平均质量分数分别为:53.3、26.1、30.6、88.4、6.20、0.467、18.3、0.050 mg·kg^(-1)。其中,Cd污染较为严重,平均值为背景值的3.71倍,其余重金属污染较轻。8种重金属在表层沉积物0~5 cm质量分数明显高于底部,高质量分数区域主要集中在大浦港、新河港入湖湖区。通过对TN、TP、重金属进行污染评价,以TN>1 627 mg·kg^(-1),TP>625 mg·kg^(-1),RI>300为清淤界限并扣除沉积物小于10 cm的区域和鱼类养殖区,确定主要清淤区域为西部、东南部及部分东北部、南部中心湖区。该研究结果可为类似环保清淤工程的清淤区域确定提供参考。
In order to determine the scope of environmental dredging in Changdang Lake,this study identified the spatial distribution differences and areas of high pollution by surveying Total Nitrogen(TN),Total Phosphorus(TP)and eight heavy metals in surface sediments.The specific dredging range was then determined in conjunction with actual operational circumstances.The results are as follows:TN ranged from 419 to 2920 mg·kg^(-1),with an average value of 1186 mg·kg^(-1),and showed no obvious spatial or stratified difference.The average value of TP in the surface sediments of Changdang Lake was 499 mg·kg^(-1),and the upper 0~5 cm slightly higher than the lower layer(average of 523 mg·kg^(-1)).The mass fraction of sedimentary TP exhibited certain spatial difference,with similar spatial variability at different depths,primarily in the higher content areas in the central northern,western,southern,and eastern lake regions.The average levels of Cr,Cu,Ni,Zn,As,Cd,Pb and Hg in surface sediments were 53.3,26.1,30.6,88.4,6.20,0.467,18.3,0.050 mg·kg^(-1).Among them,Cd pollution was relatively severe,with an average value 3.71 times the background value,while the other heavy metals were less polluted.The contents of these eight heavy metals in the 0~5 cm surface sediments were significantly higher than that at the bottom,with high concentrations area mainly observed in the lake areas where Dapu Port and Xinhe Port enter.Through the pollution evaluation of TN,TP,heavy metals,using thresholds of TN>1627 mg·kg^(-1),TP>625 mg·kg^(-1),RI>300 for the dredging boundaries,and excluding areas with sediments less than 10 cm and fish farming areas,it was found that the western,southwestern,southeastern and eastern parts of the lake were more severely polluted.These regions have been identified as the primary dredging areas.
作者
吉心怡
陆海明
史佳莹
陈辉
唐文忠
李红静
梁庆华
张洪
JI Xinyi;LU Haiming;SHI Jiaying;CHEN Hui;TANG Wenzhong;LI Hongjing;LIANG Qinghua;ZHANG Hong(State Key Laboratory of Environmental Aquatic Chemistry,Research Center for Eco-environmental Sciences,Chinese Academy of Sciences,Beijing 100085,China;Nanjing Hydraulic Research Institute,Research center on hydrology and water resources of Ministry of water resources,Nanjing 210029,China;School of Environmental Studies,China University of Geosciences(Wuhan),Wuhan 430074,China;Jiangsu Jintan Changdang Lake Tourism Resort Management Office,Changzhou 213022,China;University of Chinese Academy of Sciences,Beijing 100049,China;Jiangsu Taihu Lake Water Conservancy Planning and Design Institute Co.,Ltd.,Suzhou 215103,China)
出处
《环境工程学报》
CAS
CSCD
北大核心
2023年第12期3870-3879,共10页
Chinese Journal of Environmental Engineering
基金
国家自然科学基金资助项目(52270202,41877471)
江苏省水利科技项目(2019033,2021013)。
关键词
长荡湖
环保清淤
营养盐
重金属
Changdang Lake
environmental dredging
nutrient salt
heavy metal
