The stabilizing mechanism of cadmium in contaminated soil using green synthesized iron oxide nanoparticles under long-term incubation
Date
2019
Authors
Lin, J.
He, F.
Su, B.
Sun, M.
Owens, G.
Chen, Z.
Editors
Advisors
Journal Title
Journal ISSN
Volume Title
Type:
Journal article
Citation
Journal of Hazardous Materials, 2019; 379(120832)
Statement of Responsibility
Conference Name
Abstract
Despite numerous studies having been conducted on the stabilization of heavy metal contaminated soil, our understanding of the mechanisms involved remains limited. Here green synthesized iron oxide nanoparticles (GION) were applied to stabilize cadmium (Cd) in a contaminated soil. GION not only stabilized soil Cd, but also improved soil properties within one year of incubation. After GION application both the exchangeable and carbonate bound Cd fractions decreased by 14.2-83.5% and 18.3-85.8% respectively, and most of the Cd was translocated to the residual Cd fraction. The application of GION also strongly altered soil bacterial communities. In GION treatments, the abundance of Gemmatimonadetes, Proteobacteria, and Saccharibacteria increased which led to a shift in the dominant bacterial genera from Bacillus to Candidatus koribacter. The variation in bacteria confirmed the restoration of the contaminated soil. The most abundant bacterial genus and species found in GION treatments were related to (i) plant derived biomass decomposition; (ii) ammoxidation and denitrification; and (iii) Fe oxidation. GION application may enhance the formation of larger soil aggregates with anaerobic centers and coprecipitation coupled Fe (II) oxidization, ammoxidation and nitrite reduction followed by Fe mineral ripening may be involved in Cd stabilization. The predominant stabilization mechanism was thus coprecipitation-ripening-stabilization.
School/Discipline
Dissertation Note
Provenance
Description
Access Status
Rights
Copyright 2019 Elsevier BV
Access Condition Notes: Accepted manuscript available after 1 July 2021