李晋鹏,成登苗,赵爱东,董世魁,尤晓光.澜沧江梯级水坝库区沉积物重金属和营养盐污染特征及评价[J].环境科学学报,2019,39(8):2791-2799
澜沧江梯级水坝库区沉积物重金属和营养盐污染特征及评价
- The characteristics and the assessment of heavy metal and nutrient pollution in sediments of cascading hydropower dams in Lancang River
- 基金项目：国家自然科学基金（No.51509116，31772395）
- 李晋鹏
- 交通运输部水运科学研究所, 北京 100088
- 成登苗
- 东莞理工学院生态环境工程技术研发中心, 东莞 523808
- 赵爱东
- 河北师范大学分析测试中心, 石家庄 050024
- 尤晓光
- 交通运输部水运科学研究所, 北京 100088
- 摘要：为研究梯级水坝运行条件下沉积物中重金属和营养盐的污染状况，于2016年对澜沧江漫湾和大朝山梯级水坝库区表层沉积物中重金属（As、Cd、Cr、Cu、Pb和Zn）和营养盐（总有机碳TOC、总氮TN）的污染特征展开了调查，并采用潜在生态风险指数（RI）、有机指数（OI）、有机氮百分数（ONP）、TOC/TN和Pearson相关分析评价了梯级水坝库区沉积物污染状况及空间分布特征.结果表明，沿着库区河流纵向梯度，重金属和营养盐污染均表现为坝前静水区相对较高的空间分布格局.重金属潜在生态风险指数（RI）评价结果表明，上游漫湾库区重金属生态风险（I~Ⅲ级）总体高于下游大朝山库区（I~Ⅱ级）；而营养盐污染程度则表现为下游大朝山库区高于上游漫湾库区的分布格局.两库区沉积物有机质主要由水库水体产生，漫湾库区坝前静水区雨季有机质来源主要为陆源.Pearson相关分析表明，沉积物重金属生态风险与营养盐污染的来源具有一定的空间差异性.梯级水坝工程对沉积物的重金属和营养盐污染具有显著的累积和拦截效应.
- Abstract：The contamination of heavy metals (As, Cd, Cr, Cu, Pb and Zn), total organic carbon (TOC) and total nitrogen (TN) were investigated in the surface sediments of the cascading hydropower dams of Lancang River including Manwan and Dachaoshan in 2016. The potential ecological risk index (RI), organic index (OI), organic nitrogen percentage (ONP), TOC/TN were calculated and Pearson correlation analysis were performed to evaluate the contamination status of sediments in various spatial zones of cascading hydropower dams. The results indicate that the contents of heavy metals and nutrients in the lacustrine zone were relative higher than those of transitional and riverine zone along the longitudinal gradient of this river. The RI of heavy metals at the upstream of Manwan (level I~Ⅲ) was higher than that at the downstream Dachaoshan dam (level I~Ⅱ). The nutrient pollution at the downstream Dachaoshan was higher than that at the upstream Manwan dam. In these cascading hydropower dams, organic matter in the sediment was mainly originated from water, but was mainly derived from land source in the lacustrine zone of Manwan dam in rainy season. Pearson correlation analysis shows that there was spatial difference of pollution sources for ecological risk of heavy metals and nutrients in sediments. Cascading hydropower dams showed significant accumulation and interception effects on heavy metals and nutrients pollution in sediments.
