Spatial distribution and solubilization characteristics of metal(loid)s in riparian soils within reservoirs along the middle Jinsha River

• Published in: Journal of soils and sediments Vol. 21; no. 10; pp. 3515 - 3527
• Main Authors: Yuan, Qiusheng, Wang, Peifang, Wang, Chao, Chen, Juan, Wang, Xun, Liu, Sheng
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.10.2021; Springer Nature B.V
• Subjects: Cadmium; Carbonates; Chemical precipitation; Chromium; Copper; Dam construction; Distribution; Drought; Earth and Environmental Science; Environment; Environmental management; Environmental Physics; Heavy metals; Industrial pollution; Iron; Lithology; Manganese; Metal concentrations; Nickel; Ores; Oxidation; Oxidation-reduction potential; pH effects; Principal components analysis; Redox potential; Reservoir management; Reservoirs; Rivers; Sediment Environment and Pollution Control 2020; Soil; Soil analysis; Soil contamination; Soil pollution; Soil Science & Conservation; Soils; Solid suspensions; Solubilization; Spatial distribution; Submergence; Suspended particulate matter; Suspended solids; Water pollution; Water quality; Wetting; Jinsha River; Riparian soils; Reservoirs; Spatial distribution; Metals and metalloids; Solubilization characteristics; Water submergence
• ISSN: 1439-0108; 1614-7480
• DOI: 10.1007/s11368-021-02921-2

Purpose The construction of large dams submerges riparian soils within reservoirs. However, little is known about the influence of water submergence on metal(loid) solubilization from polluted soils. In this study, the spatial distribution and solubilization characteristics of soil-associated metal(loid)s within reservoirs along the middle Jinsha River were evaluated. Methods Concentrations of soil-associated metal(loid)s were determined and principal component analysis was performed to evaluate the metal(loid) spatial distribution. Then, metal(loid) chemical fractions of highly contaminated soils were analyzed. Finally, ex situ experiments of metal(loid) solubilization were conducted under the influence of changing pH, suspended solid concentration (SSC), and oxidation-reduction potential (ORP) conditions as well as successive drought-wetting cycles. Results Within the LY, AH, and LKK reservoirs, the soil-associated Ni and Cr originated from specific metal(loid) ores, and Cd and Cu remained from historical industrial pollution posed potential risks to water quality. Water submergence changed pH, SSC, and ORP conditions, which affected metal(loid) solubilization through dissolution-precipitation and sorption-desorption processes. The low SSC variables contributed to over 20% solubilization of total Cd, Cu, and As. Moreover, the neutral-alkaline conditions due to carbonate-dominated lithology limited metal(loid) release from soils. Finally, the decreased ORP promoted solubilization of metal(loid)s bound to Fe-Mn oxyhydroxides. Generally, the solubilization levels of metal(loid)s were dependent on the chemical fractions. Conclusion Water submergence could induce potential solubilization of metal(loid)s, especially for Cd from historical industrial pollution. Thus, this study highlighted that the investigation on both spatial distribution and solubilization characteristics of metal(loid)s in riparian soils is important for future environmental management of reservoirs.