Northwest Institute of Eco-Environment and Resources, Chinese Academy of Sciences, Lanzhou 730000, China.
Key Laboratory of Petroleum Resources, Lanzhou 730000, China.
Int J Environ Res Public Health. 2022 Jul 26;19(15):9140. doi: 10.3390/ijerph19159140.
Heavy metals are toxic, persistent, and non-degradable. After sedimentation and adsorption, they accumulate in water sediments. The aim of this study was to assess the extent of heavy metal pollution of Qinjiang River sediments and its effects on the ecological environment and apportioning sources. The mean total concentrations of Mn, Zn, Cr, Cu, and Pb are 3.14, 2.33, 1.39, 5.79, and 1.33 times higher than the background values, respectively. Co, Ni, and Cd concentrations are lower than the background values. Fe, Co, Ni, Cd, Cr, Cu, and Pb are all primarily in the residual state, while Mn and Zn are primarily in the acid-soluble and oxidizable states, respectively. Igeo, RI, SQGs, and RAC together indicate that the pollution status and ecological risk of heavy metals in Qinjiang River sediments are generally moderate; among them, Fe, Co, Ni, Cd, Cr, and Pb are not harmful to the ecological environment of the Qinjiang River. Cu is not readily released because of its higher residual composition, suggesting that Cu is less harmful to the ecological environment. Mn and Zn, as the primary pollution factors of the Qinjiang River, are harmful to the ecological environment. This heavy metal pollution in surface sediments of the Qinjiang River primarily comes from manganese and zinc ore mining. Manganese carbonate and its weathered secondary manganese oxide are frequently associated with a significant amount of residual copper and Cd, as a higher pH is suitable for the deposition and enrichment of these heavy metals. Lead-zinc ore and its weathering products form organic compounds with residual Fe, Co, Cr, and Ni, and their content is related to salinity. The risk assessment results of heavy metals in sediments provide an important theoretical basis for the prevention and control of heavy metal pollution in Qinjiang River.
重金属具有毒性、持久性和不可降解性。它们在沉降和吸附后会在水沉积物中积累。本研究旨在评估秦江沉积物中重金属污染的程度及其对生态环境的影响，并对其来源进行分配。Mn、Zn、Cr、Cu 和 Pb 的平均总浓度分别比背景值高出 3.14、2.33、1.39、5.79 和 1.33 倍。Co、Ni 和 Cd 的浓度低于背景值。Fe、Co、Ni、Cd、Cr、Cu 和 Pb 主要以残渣态为主，而 Mn 和 Zn 主要分别以酸可溶态和可氧化态为主。Igeo、RI、SQGs 和 RAC 共同表明，秦江沉积物中重金属的污染状况和生态风险总体上处于中等水平；其中，Fe、Co、Ni、Cd、Cr 和 Pb 对秦江的生态环境没有危害。Cu 由于其较高的残渣组成，不易释放，表明 Cu 对生态环境的危害较小。Mn 和 Zn 作为秦江的主要污染因素，对生态环境有害。秦江表层沉积物中的这种重金属污染主要来自锰锌矿开采。碳酸锰及其风化次生氧化锰经常与大量残余铜和 Cd 共生，因为较高的 pH 值有利于这些重金属的沉积和富集。铅锌矿及其风化产物与残余 Fe、Co、Cr 和 Ni 形成有机化合物，其含量与盐度有关。沉积物中重金属的风险评估结果为秦江重金属污染的防治提供了重要的理论依据。
