Li Jun, Gao Zhan-Dong, Ma Li-Bang, Ma Jing, Zhang Ming, Ma Xiao-Hong, Zang Fei, Li Xu
College of Urban Environment, Lanzhou City University, Lanzhou 730070, China.
College of Geography and Environmental Science, Northwest Normal University, Lanzhou 730070, China.
Huan Jing Ke Xue. 2024 Nov 8;45(11):6723-6733. doi: 10.13227/j.hjkx.202311243.
To elucidate the pollution characteristics and sources of heavy metals in the soil of drinking water sources in urban areas of the Yellow River Basin, the soil in the water source areas for urban drinking water in the Lanzhou section of the Yellow River was selected as the research object. The content characteristics of heavy metals, including As, Cd, Cr, Hg, and Pb, were analyzed. The pollution degree of heavy metals was quantified systematically using the geo-accumulation index, contamination factor, pollution load index, and improved Nemerow comprehensive pollution index. Correlation-clustering analysis, the positive matrix factorization （PMF） model, and the absolute principal component scores-multiple linear regression （APCS-MLR） model were jointly applied to quantitatively analyze the pollution sources and their contribution rates of heavy metals. The results indicated that： ① The soil in the water source areas for urban drinking water in Lanzhou was alkaline, and, with the exception of Cr, the average content of heavy metals in the soil, including As, Cd, Hg, and Pb, exceeded the background values of soil in Gansu Province. Particularly, Hg and Pb exhibited significant spatial distribution variations, indicative of strong anthropogenic influences. ② The overall pollution level of the water source area soil was mild, with Hg identified as the primary pollutant and localized pollution observed for As and Pb, whereas Cd and Cr showed no substantial contamination. ③ The enrichment of heavy metals in the water source area soil was influenced by a combination of industrial, traffic, coal combustion, and natural sources. The PMF model identified 41.40% as industrial-traffic sources, 32.92% as coal combustion sources, and 25.68% as natural-industrial sources. The APCS-MLR model distinguished 36.36% as industrial-traffic sources, 22.32% as coal-industrial sources, and 41.31% as natural sources. These findings provide a scientific basis for ensuring the health of soil in the water source areas and the safety of drinking water in the urban area of Lanzhou.
为阐明黄河流域城市饮用水源地土壤中重金属的污染特征及来源，选取黄河兰州段城市饮用水源地土壤作为研究对象，分析了砷（As）、镉（Cd）、铬（Cr）、汞（Hg）和铅（Pb）等重金属的含量特征，运用地累积指数、污染因子、污染负荷指数和改进的内梅罗综合污染指数对重金属污染程度进行系统量化，并联合应用相关性聚类分析、正定矩阵因子分解（PMF）模型和绝对主成分得分-多元线性回归（APCS-MLR）模型定量分析重金属污染源及其贡献率。结果表明：①兰州城市饮用水源地土壤呈碱性，除Cr外，土壤中As、Cd、Hg、Pb等重金属平均含量均超过甘肃省土壤背景值，其中Hg和Pb呈现出显著的空间分布差异，受人为影响较强。②水源地土壤总体污染水平为轻度，Hg为主要污染物，As和Pb存在局部污染，Cd和Cr无明显污染。③水源地土壤重金属富集受工业、交通、燃煤及自然源等多种因素共同影响。PMF模型识别出工业-交通源占41.40%，燃煤源占32.92%，自然-工业源占25.68%；APCS-MLR模型识别出工业-交通源占36%，燃煤-工业源占22.32%，自然源占41.31%。研究结果为保障兰州城市水源地土壤健康及饮用水安全提供了科学依据。
