摘要
洋河流域是北京官厅水库重要的入库水源,通过对洋河流域万全段采集地表水和沉积物样品,研究重金属空间特征及其生态风险,结果表明,地表水中所监测的Cu、Ni、Cd、Zn、Cr、Pb、Hg、As含量分别为1.28~24.13、1.13~16.84、0.08~0.11、1.80~10.65、1.40~19.12、0.13~2.05、0.06~0.99、0.46~4.22μg·L-1,不同点位各重金属含量均低于国家Ⅳ类水质标准,仅满足一般工业用水和农业灌溉用水要求.沉积物中Cu、Ni、Cd、Zn、Cr、Pb、Hg、As含量分别为5.90~110.11、17.34~56.04、0.07~0.31、38.71~116.74、40.39~85.77、18.65~22.74、nd^0.047、0.85~9.98 mg·kg-1.沉积物中各重金属平均潜在生态风险均表现为轻微等级,但有部分点位Cd、Hg的潜在生态危害指数达到中等,危害指数由高到低分别为Cd>Cu>Hg>Ni>As>Pb>Cr>Zn.监测点重金属的累积生态风险由高到低分别为:YH-07>YH-03>YH-09>YH-02>YH-06>YH-04>YH-05>YH-01,平均潜在生态危害累积指数处于轻微级别,但点位YH-07潜在生态风险累积指数已达到中等级别.整个万全河段区域中,风险较高区域集中在农业耕作较密集的YH-02~YH-03点位和人工化程度较高的YH-07~YH-09点位.基于研究结果,提出了具体的重金属生态风险管理对策及建议,并明确了农业耕作控制区、河道改造控制区以及洋河水源保护缓冲区等3个污染风险调控功能区.
In order to investigate heavy metals contamination status in Wanquan segment of Yanghe River, Zhangjiakou, 9 water and sediments samples were collected respectively for analyzing Cu, Ni, Cd, Zn, Cr, Pb, Hg and As, with water quality indicators determined at the same time. The potential ecological risk index （PERI） was then employed to evaluate potential ecological risk of heavy metals in sediments. Results indicated that the concentrations of Cu, Ni, Cd, Zn, Cr, Pb, Hg and As in water samples ranged from 1.28-24. 13, 1.13-16.84, 0.08-0.11, 1.80-10.65, 1.40-19.12, 0.13-2.05, 0.06-0.99, 0.46-4.22 μg-L-1, respectively, which are all below the national water quality standard for the demands of industrial use and agricultural irrigation. Principal component analysis （PCA） was conducted to reveal the relationship between water quality indicators and heavy metals pollution in water samples. Concentrations of Cu, Ni, Cd, Zn, Cr, Pb, Hg and As in sediments ranged from 5.90-110. 11, 17.34-56. 04, 0.07-0. 31, 38.71- 116.74, 40.39-85.77, 18.65-22.74, nd-0. 047, 0. 85-9.98 mg· kg - 1, respectively. The descending order of potential ecological risk intensity caused by different heavy metals was ： Cd 〉 Cu 〉 Hg 〉 Ni 〉 As 〉 Pb 〉 Cr 〉 Zn, and the average value of each heavy metal was low, while middle-grade risk level of Cd and Hg were also found in several sites. Among all monitoring sites, the descending order of PERI of all target heavy metals was： YH-07 〉 YH-03 〉 YH-09 〉 YH-02 〉 YH-06 〉 YH-04 〉 YH-05 〉 YH-01, and the average value reached slight grade, while middle-grade risk level was detected in YH-07. Sampling locations in YH-02-YH-03 and YH-07-YH-09 were found with relatively high ecological risk level because of agricultural and anthropogenic activities, respectively. Finally, three risk management regions were figured out and corresponding countermeasures for improving the environmental quality of the watershed were orooosed based on the research results.
出处
《环境科学》
EI
CAS
CSCD
北大核心
2014年第2期719-726,共8页
Environmental Science
基金
国家自然科学基金项目(41171394)
国家科技基础性工作专项重点项目(2013FY111100)
中国科学院重点部署项目(KZZD-EW-TZ-12)
关键词
水体
沉积物
洋河流域
潜在生态危害指数
风险管理
surface water
surface sediment
Yanghe River Watershed
potential ecological risk index
risk management
