Ding Yuan, Xi Li, Wu Yujing, Chen Yihong, Guo Xiaoping, Shi Hong, Cai Shuo
National-Local Joint Engineering Research Center of Heavy Metals Pollutants Control and Resource Utilization, Nanchang Hangkong University, Nanchang 330063, China.
College of Environment and Chemical Engineering, Nanchang Hangkong University, Nanchang 330063, China.
Toxics. 2023 Jul 26;11(8):647. doi: 10.3390/toxics11080647.
To accurately evaluate the distribution and bioavailability of potentially toxic elements (PTEs) such as Cu and Cd in farmlands near a copper smelter, we determined the total concentrations (Cu-T and Cd-T), various speciation concentrations of Cu and Cd and physicochemical properties of 18 paddy soil (or colloid) samples in Guixi town, Jiangxi province, China. The results showed that the concentrations of Cu-T and Cd-T in the soil around the smelter far exceeded the standard limits. Specifically, Cu ranged from 97.47 to 1294.63 mg·kg, with a coefficient of variation (CV) of 0.95; Cd ranged from 0.14 to 9.06 mg·kg, and the CV was 1.68. Furthermore, the pollution of PTEs continued to accumulate, posing a significant risk to the environment and human health. The findings from the analysis of soil and colloid indicated that the distribution characteristics of Cu and Cd speciations did not align with the total concentrations. The highest pollution points were found to be shifted to the residual fraction of Cu, organic fraction, and crystalline iron oxide fraction of Cd in soil. The dominant fraction of Cu in colloid was the amorphous iron oxide fraction, whereas Cd was the crystalline iron oxide fraction. The assessment of Cu and Cd migration (M) revealed that Cd posed a greater ecological risk. Further examination of the properties of iron oxides in soil and colloid revealed that they played a crucial role in the migration and transformation of soil PTEs.
为了准确评估铜冶炼厂附近农田中铜（Cu）和镉（Cd）等潜在有毒元素（PTEs）的分布及生物有效性，我们测定了中国江西省贵溪市18个水稻土（或胶体）样品中铜和镉的总浓度（Cu-T和Cd-T）、各种形态浓度以及理化性质。结果表明，冶炼厂周边土壤中Cu-T和Cd-T的浓度远远超过标准限值。具体而言，Cu的含量范围为97.47至1294.63 mg·kg，变异系数（CV）为0.95；Cd的含量范围为0.14至9.06 mg·kg，CV为1.68。此外，PTEs的污染持续累积，对环境和人类健康构成重大风险。土壤和胶体分析结果表明，Cu和Cd形态的分布特征与总浓度不一致。污染最严重的点位发现转移到了土壤中Cu的残留态、有机态以及Cd的结晶铁氧化物态。胶体中Cu的主要形态为无定形铁氧化物态，而Cd为结晶铁氧化物态。对Cu和Cd迁移（M）的评估表明，Cd带来的生态风险更大。对土壤和胶体中铁氧化物性质的进一步研究表明，它们在土壤PTEs的迁移和转化中起着关键作用。
