Interactions between lead(Ⅱ) ions and dissolved organic matter derived from organic fertilizers incubated in the field

作者：Long Chen; Boling Li; Zhipeng Wu^*; Qingjie Zhao; Qiuyue Wang; Hailong Wang^*; Bhupinder Pal Singh; Weidong Wu; Chuanliang Fu

来源：Journal of Environmental Sciences, 2022, 121(11): 77-89.

This work was to study composition characteristics and the subsequent effect on the lead(Pb) binding properties of dissolved organic matter(DOM) derived from seaweed-based(SWOF) and chicken manure organic fertilizers(CMOF) during a one-year field incubation experiment using the excitation-emission matrix-parallel factor(EEM-PARAFAC) and twodimensional correlation spectroscopy(2DCOS) analysis. Results showed that high aromatic and hydrophobic fluorescent substances were enriched in CMOF-derived DOM and SWOFderived DOM and enhanced over time. And phenolic groups in the fulvic-like substances for SWOF-derived DOM and carboxyl groups in the humic-like substances for CMOF-derived DOM had the fastest responses over time, respectively. Moreover, both non-fluorescent polysaccharides and fluorescent humic-like substances or fulvic-like substances with aromatic(C=C) groups first participated in the binding process of Pb to SWOF-derived DOM on day 0 and 180 during the lead binding process. In contrast, humic-like substances associated with aromatic(C=C) and phenolic groups gave a faster response to Pb binding on day 360. Regarding CMOF-derived DOM, the fulvic-like substances associated with aromatic(C=C) and carboxylic groups displayed a faster response to Pb ions on day 0. Nonetheless,polysaccharides and humic-like associated with phenolic groups had a faster response on days 180 and 360. It is noteworthy that the polysaccharides, which participated in Pb binding to CMOF-derived DOM, posed a higher risk of Pb in the environment after 360 days. Therefore, these findings gave new insights into the long-term applications of commercial organic fertilizers for the amendment of soil.