Key Laboratory of Water Quality and Conservation in the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, China; Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510405, China.
Key Laboratory of Water Quality and Conservation in the Pearl River Delta, Ministry of Education, School of Environmental Science and Engineering, Guangzhou University, Guangzhou, China.
J Hazard Mater. 2021 Jun 5;411:125015. doi: 10.1016/j.jhazmat.2020.125015. Epub 2020 Dec 31.
Cadmium (Cd) is a toxic heavy metal pollutant. Various industrial activities, especially metal smelting, are the main sources of Cd pollution. Cd isotopes have exhibited the ability to be excellent source tracers and can be used to assess the pollution contributions from different sources. Herein, in a typical lead-zinc smelter, Shaoguan, China, significant Cd isotopic fractionation was found during the high temperature smelting process and followed a Rayleigh distillation model. The heavier Cd isotopes were concentrated in the slag, while the lighter Cd isotopes were concentrated in the dust. In the downstream sediment profile of the smelter, sediments have extremely high Cd concentrations that far exceed the Chinese background sediment, indicating severe pollution levels. The εCd of the sediment core, ranged from - 0.62 ± 0.5-1.73 ± 0.5, are found between slag (εCd=10.42) and dust (εCd=-5.68). The binary mixture model suggests that 88-93% of the Cd in sediment profile was derived from the slag, and 7-12% from the deposition of dust. The findings demonstrate the great potential to apply Cd isotopes as a new geochemical tool to distinguish anthropogenic sources and quantify the contribution from various sources in the environment.
镉（Cd）是一种有毒的重金属污染物。各种工业活动，尤其是金属冶炼，是镉污染的主要来源。镉同位素已表现出成为优秀的污染源示踪剂的能力，可用于评估来自不同来源的污染贡献。在此，在中国典型的铅锌冶炼厂——韶关，发现高温冶炼过程中存在显著的镉同位素分馏，遵循瑞利蒸馏模型。较重的镉同位素集中在炉渣中，而较轻的镉同位素则集中在粉尘中。在冶炼厂的下游沉积物剖面中，沉积物中的镉浓度极高，远远超过中国的背景沉积物，表明污染程度严重。沉积物芯的 εCd 值范围为-0.62±0.5 至 1.73±0.5，位于炉渣（εCd=10.42）和粉尘（εCd=-5.68）之间。二元混合模型表明，沉积物剖面中 88-93%的镉来自炉渣，7-12%来自粉尘的沉积。研究结果表明，镉同位素具有作为一种新的地球化学工具来区分人为来源并量化环境中各种来源贡献的巨大潜力。
