Desorption and migration behavior of beryllium from contaminated soils: insights for risk-based management

Abstract
Factors influencing the desorption, distribution, and vertical migration behavior of Be in contaminated soils are not fully understood. This study examined the desorption and migration of Be in a soil profile from a legacy radioactive waste disposal site using different batch leaching [monofilled waste extraction procedure (MWEP); synthetic precipitation leaching procedure (SPLP); simulated acid rain solution (SARS); and toxicity characteristic leaching procedure] and sequential leaching [community bureau of reference (BCR)] methods for insights relevant to the application of risk-based management. The results showed that Be desorption was higher in the presence of organic than the inorganic leachate composition (MWEP < SPLP < SARS < TCLP < BCR first-step). The desorption followed three diffusion control mechanisms, which resulted in three desorption rate constant estimates of 157, 87.1, and 40.4 Be/kg.h0.5, and the estimated desorption maximum was 556 μg/kg. The desorption process was, spontaneous (δG > 0), enthalpically and entropically influenced. Increasing the incubation period and heat treatment resulted in a decrease of Be desorption and migration. The soil clay content and pH were the primary factors influencing Be desorption, and the results suggested that Be was desorbed from metal oxyhydroxides and surfaces of silicates (e.g., reactive surfaces of clay minerals), organic matters, and soil pores. Because of high Kd values, the mobility of Be was limited, and no exceedances of ecological or human health risk index or guidelines were determined for the current contamination levels at the site. However, Be released from the waste trenches has the ongoing potential to increase Be concentration in the soil. © 2021 The Authors. Published by American Chemical Society. This publication is licensed under CC-BY-NC-ND 4.0.
Description
Keywords
Desorption, Migration, Beryllium, Contamination, Soils, Risk assessment, Organic matter, Heat treatments, Ecosystems, Leaching, Solid wastes, Acid rain
Citation
Islam, M. R., Sanderson, P., Payne, T. E., Johansen, M. P., & Naidu, R. (2021). Desorption and migration behavior of beryllium from contaminated soils: insights for risk-based mManagement. ACS Omega, 6(45), 30686-30697. doi:10.1021/acsomega.1c04572
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