Abstract
Chemical speciation of soil cadmium (Cd) dictates its mobility and potential toxicity in the environment. Our objective was to compare temporal changes in speciation of Cd(II) reacted with samples from six Brazilian soils having varying Cd(II) sorption capacities. Cadmium L-edge X-ray absorption near edge structure (XANES) analysis showed there were short-term changes in speciation after reaction with 4.45 mmol Cd kg for 0.5 and 6 h. Chemical fractionation evaluated changes in Cd extractability after reaction with 89 μmol Cd kg for up to 4 mo. The XANES spectral fits suggested that Cd(II) bound with organic matter was a dominant species in all samples, along with Cd(II) bound with iron and aluminum oxides or montmorillonite. In several samples, CdCl apparently precipitated from aqueous Cd(II) during drying. The XANES spectral fits typically showed <25% change in speciation between 0.5 and 6 h of reaction, and chemical fractionation showed significant ( < 0.05) temporal changes in Cd extractability over time in two samples. Our results suggest that Cd(II) discharged into these soils, such as that occurring as a release into the environment, would bind with soil organic matter and oxide minerals or remain dissolved, with little change in speciation in the months following release.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
