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Simultaneous remediation and fertility improvement of heavy metals contaminated soil by a novel composite hydrogel synthesized from food waste.

Authors :
Zhou T
Zhao M
Zhao X
Guo Y
Zhao Y
Source :
Chemosphere [Chemosphere] 2021 Jul; Vol. 275, pp. 129984. Date of Electronic Publication: 2021 Feb 20.
Publication Year :
2021

Abstract

Soil contamination by heavy metals constitutes a serious global environmental problem, and numerous remediation technologies have been developed. In this study, a novel soil remediation agent, namely composite hydrogel (leftover rice-g-poly(acrylic acid)/montmorillonite/Urea, LR-g-PAA/MMT/urea), was prepared based on free radical polymerization cross-linking technology. Experimental results indicated that the LR-g-PAA/MMT/urea dosage increased from 0% to 10%, the oxidizable state proportions of Cd, Cu, Pb and Zn in contaminated soil increased from 8.3%, 23.7%, 54.0% and 11.4%-71.3%, 61.0%, 76.5%, and 27.9%, respectively. Compared with control experiment, the residue state growth rate were 56.6%, 23.4% and 39.8% for Cu, Pb and Zn respectively with 10% dosage of composite hydrogel. Simultaneously, the LR-g-PAA/MMT/urea was also seen to enhance soil fertility, including organic matter content, cation exchange capacity, and N and P contents. Pot experiments for biological toxicity suggested that the addition of hydrogel weakened the toxic effect of heavy metals on cotton seeds, and the action effect was increasingly visible with the increase of hydrogel dosage. The analysis of the mechanism involved suggested that the organic matter and its possessed characteristic functional groups could weaken the biological toxicity via complexation, adsorption, and ion exchange. Overall, the synthesized composite hydrogel exhibits great potential for the simultaneous remediation and fertility improvement of heavy metal contaminated soil.<br />Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.<br /> (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Details

Language :
English
ISSN :
1879-1298
Volume :
275
Database :
MEDLINE
Journal :
Chemosphere
Publication Type :
Academic Journal
Accession number :
33984900
Full Text :
https://doi.org/10.1016/j.chemosphere.2021.129984