Independent and combined effects of sepiolite and palygorskite on humus spectral properties and heavy metal bioavailability during chicken manure composting. (July 2023)

• Record Type: Journal Article
• Authors: Wu, Shihang; Tursenjan, Dina; Sun, Yuebing
• Is Part Of: Chemosphere. Volume 329(2023)
• Publication Date: 2023-07
• Subjects: Composting -- Sepiolite -- Palygorskite -- Humification -- Heavy metal; Pollution -- Periodicals; Pollution -- Physiological effect -- Periodicals; Environmental sciences -- Periodicals; Atmospheric chemistry -- Periodicals; 551.511
• DOI: 10.1016/j.chemosphere.2023.138683
• Languages: English
• ISSNs: 0045-6535

Abstract

Abstract: The effects of the independent and combined addition strategies of sepiolite and palygorskite on humification and heavy metals (HMs) during chicken manure composting were evaluated. Results showed that clay mineral addition showed a favorable effect on composting, prolonged the duration of the thermophilic phase (5–9 d) and improved the TN content (14%–38%) compared to CK. Independent strategy enhanced the humification degree in equal measures with the combined strategy. Carbon nuclear magnetic resonance spectroscopy ( 13 C NMR) and fourier transform infrared spectroscopy (FTIR) confirmed that aromatic carbon species increased by 31%–33% during composting process. Excitation–emission matrix (EEM) fluorescence spectroscopy showed that humic acid–like compounds increased by 12%–15%. In addition, the maximum passivation rate of Cr, Mn, Cu, Zn, As, Cd, Pb and Ni were 51.35%, 35.98%, 30.39%, 32.46%, −87.02%, 36.61% and 27.62%, respectively. The independent addition of palygorskite exhibits the most potent effects for most HMs. Pearson correlation analysis indicated that pH and aromatic carbon were the key determinants of the HMs passivation. This study provided preliminary evidence and perspective of the application of clay minerals on the humification and safety of composting. Graphical abstract: Image 1 Highlights: Clay minerals prolonged the duration of the thermophilic phase and improved the total nitrogen content. Sepiolite and palygorskite increased the humification level of compost. Composting with sepiolite and palygorskite contributed to heavy metals immobilization and toxicity alleviation. Aromatic carbon and pH were likely the determinants in the passivation of heavy metals.