The multi-media environmental behavior of heavy metals around tailings under the influence of precipitation

• Published in: Ecotoxicology and environmental safety 2023-11, Vol.266, p.115541-115541, Article 115541
• Main Authors: He, Yujie, Zhang, Qian, Wang, Wenjie, Hua, Jie, Li, Haisheng
• Format: Article
• Language: English
• Subjects: Fugacity model; Heavy metals; Leaching; Precipitation; Tailings
• ISSN: 0147-6513; 1090-2414
• DOI: 10.1016/j.ecoenv.2023.115541

Precipitation can lead to significant leaching of heavy metals from abandoned tailings，resulting in a decline in the quality of the surrounding environment. This study aimed to simulate and quantify the migration patterns and fate of heavy metals in tailings caused by precipitation in various environmental media (tailings, air, water, soil, and sediments) using leaching tests, source apportionment, and a fugacity model. Results revealed that the average contents of Cd, Cu, As, Pb, Zn, and Cr in the un-weathered tailings were 3.43, 495.56, 160.70, 138.94, 536.57, and 69.52 mg/kg, respectively. The ecological risk factors in the tailings as well as in sediments and soils, were in the following order: Cd >Cu >As >Pb >Zn >Cr. A fugacity model based on the mass-balance methods was established, achieving a good agreement between simulation and measured values. The total amounts of Cd, Cu, As, Pb, and Zn leached from abandoned tailings over the 30-year evaluation period were estimated to be 1.09, 62.44, 0.16, 0.94, and 102.12 t, respectively. Soil and sediments are important reservoirs for heavy metals. The sum of the As, Cd, Cu, Pb, and Zn storage capacities in the soil and sediment accounted for 77.28%, 75.63%, 73.94%, 69.39%, and 57.80% of the total storage capacity, respectively. This study could provide the means for the establishment of a targeted pollution control plan, a guide for restoration projects, and will aid in controlling pollution risk and improving the surrounding environment. •Heavy metal (HMs) leaching by precipitation degrades water, soil, and sediments.•A fugacity model was developed to simulate HMs migration in different environments.•HMs properties and environmental parameters determine HMs distribution and transport.•Our results can help establish a targeted pollution control plan.