New Insights into the Influence and Mechanism of Pb Adsorption on Clay Mediated by Dissolved Organic Matter in Composting Process
Dissolved organic matter (DOM) could affect the immobilization of heavy metals (HMs) in soil by interacting with HMs or clay minerals. Here, three kinds of DOM derived from fresh chicken manure (FDOM), immature compost (IDOM) and mature compost (MDOM) were used to compare their effects on the adsorption of Pb on montmorillonite, the variations in mineral structure and interfacial force were clarified, and the potential mechanism was revealed. Results demonstrated that the adsorption capacity (q max ) of Pb on clay was decreased by 14.3% and 29.8% in the presence of FDOM and IDOM, respectively, while promoted by 44.4% in the presence of MDOM. These phenomena were caused by the release or co-adsorption of DOM-Pb complexes and the discrepancies in molecular weight, hydrophilicity and bulk structure of DOM. Parallel factor (PARAFAC) further indicated that Pb mainly bound to protein-like substance in FDOM and IDOM, but fulvic-like in MDOM. The X-ray diffraction (XRD) analysis proved that DOM-Pb complexes could expand the d-spacing of clay from 1.33 nm to 1.42 nm-1.46 nm and MDOM-Pb complex had a stronger ability to enter into the interlayer of clay. The van der Waals force and Pb 2+ bridging dominated the adsorption of FDOM-Pb and IDOM-Pb, while ligand exchange was involved in the case of MDOM-Pb. This study provided a comprehensive insight into the geochemical behavior and the potential risk of HMs in soil applied with livestock manure and its compost
Year of publication: |
[2022]
|
---|---|
Authors: | Zhu, Yuanchen ; Guan, Qingkai ; Kong, Linghui ; Yang, Rui ; Tan, Wei ; Wang, Jingyi ; Jin, Yu ; Liu, Xuesheng ; QU, Juanjuan |
Publisher: |
[S.l.] : SSRN |
Saved in:
freely available
Saved in favorites
Similar items by person
-
An Exploratory Study of the Effectiveness of Mobile Advertising
Quan, Jing, (2017)
-
Liu, Jia, (2023)
-
Realization Utility with Path-Dependent Reference Points
Kong, Linghui, (2021)
- More ...