Fertilizer-induced manganese oxide formation enhances cadmium removal by paddy crusts from irrigation water

Xiaolin Kuang; Liang Peng; Ziyi Cheng; Siyan Zhou; Shaoning Chen; Cheng Peng; Huijuan Song; Changwu Li; Dan Li

doi:10.1016/j.jhazmat.2023.132030

Fertilizer-induced manganese oxide formation enhances cadmium removal by paddy crusts from irrigation water

J Hazard Mater. 2023 Sep 15:458:132030. doi: 10.1016/j.jhazmat.2023.132030. Epub 2023 Jul 10.

Authors

Xiaolin Kuang¹, Liang Peng², Ziyi Cheng¹, Siyan Zhou¹, Shaoning Chen¹, Cheng Peng¹, Huijuan Song¹, Changwu Li¹, Dan Li¹

Affiliations

¹ Department of Environmental Science & Engineering, Hunan Agricultural University, Changsha 410128, China.
² Department of Environmental Science & Engineering, Hunan Agricultural University, Changsha 410128, China. Electronic address: pengliang2004@126.com.

PMID: 37441865
DOI: 10.1016/j.jhazmat.2023.132030

Abstract

Fertilization is a crucial agrological measure for agricultural production that can significantly impact the removal of Cd from irrigation water by paddy crusts (PC). In this study, laboratory and field experiments were conducted to investigate the impact of fertilization at low, medium, and high concentrations on the accumulation of Cadmium (Cd) in PC and the underlying mechanisms involved. The results showed that only low fertilizer concentration could promote the removal of Cd by PC, which reduced the Cd concentration in irrigation water from 19.52 μg/L to 5.35 μg/L. Conversely, medium and high fertilizer concentrations reduced the accumulation of Cd by PC. After fertilizer addition, the proportion of Fe-Mn oxidizable-Cd in PC reached 55 % (with low concentration of fertilizer treatment). The application of low concentration of fertilizer was found to stimulate the growth of filamentous green algae, leading to a significant increase in the relative abundance of sphingomonadaceae (by 1.39 %) and comamonadaceae (by 1.29 %). The XRD, SEM and correlation analysis show that a large amount of manganese oxide is formed on the surface of PC, which increases the fixation of Cd. These findings provide a new perspective for the remediation of heavy metal contamination in paddy fields.

Keywords: Biological mineralization; Green algae; Heavy metal; Oxidizing bacteria; Paddy crusts.