Effects of incubation time and filtration method on Kd of indigenous selenium and iodine in temperate soils

Al Mahayni, T.; Bailey, Elizabeth H.; Crout, Neil M.J.; Shaw, George

Abstract

In this study, the effects of incubation time and the method of soil solution extraction and filtration on the empirical distribution coefficient (Kd) obtained by de-sorbing indigenous selenium (Se) and iodine (I) from arable and woodland soils under temperate conditions were investigated.
Incubation time had a significant soil- and element- dependent effect on the Kd values, which tended to decrease with the incubation time. Generally, a four-week period was sufficient for the desorption Kd value to stabilise. Concurrent solubilisation of soil organic matter (OM) and release of organically-bound Se and I was probably responsible for the observed decrease in Kd with time. This contrasts with the conventional view of OM as a sink for Se and I in soils. Selenium and I Kd values were not significantly affected by the method of soil solution extraction and filtration.
The results suggest that incubation time is a key criterion when selecting Se and I Kd values from the literature for risk assessments. Values derived from desorption of indigenous soil Se and I might be most appropriate for long-term assessments since they reflect the quasi-equilibrium state of their partitioning in soils.

Citation

Al Mahayni, T., Bailey, E. H., Crout, N. M., & Shaw, G. (2017). Effects of incubation time and filtration method on Kd of indigenous selenium and iodine in temperate soils. Journal of Environmental Radioactivity, 177, 84-90. https://doi.org/10.1016/j.jenvrad.2017.06.004

• Journal Article Type: Article
• Acceptance Date: Jun 3, 2017
• Online Publication Date: Jun 17, 2017
• Publication Date: Oct 1, 2017
• Deposit Date: Aug 31, 2017
• Publicly Available Date: Aug 8, 2018
• Journal: Journal of Environmental Radioactivity
• Print ISSN: 0265-931X
• Electronic ISSN: 1879-1700
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 177
• Pages: 84-90
• DOI: https://doi.org/10.1016/j.jenvrad.2017.06.004
• Keywords: Soil indigenous selenium and iodine; Distribution coefficient (Kd); Incubation time; Soil solution = extraction; Rhizon soil moisture samplers
• Public URL: https://nottingham-repository.worktribe.com/output/965870
• Publisher URL: http://www.sciencedirect.com/science/article/pii/S0265931X17304216
• Contract Date: Aug 8, 2018