Post-digestate composting benefits and the role of enzyme activity to predict trace element immobilization and compost maturity. (October 2021)

• Record Type: Journal Article
• Authors: Gurmessa, Biyensa; Cocco, Stefania; Ashworth, Amanda J.; Foppa Pedretti, Ester; Ilari, Alessio; Cardelli, Valeria; Fornasier, Flavio; Ruello, Maria Letizia; Corti, Giuseppe
• Is Part Of: Bioresource technology. Volume 338(2021)
• Publication Date: 2021-10
• Subjects: C/N ratio -- Compost maturity -- Food processing waste -- Maize silage -- Poultry litter; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2021.125550
• Languages: English
• ISSNs: 0960-8524

Abstract

Graphical abstract: Highlights: Pilot level aerobic co-composting of digestate and biogas feedstocks was conducted. Composting reduced C/N ratio, release of trace elements, and phytotoxicity. Enzyme activities were influenced by OM content and release of trace elements. Enzyme activities could be compost maturity indicators. Abstract: The current study evaluated the quality of agricultural waste digestate by composting or co-composting with biogas feedstock (maize silage, food processing waste, or poultry litter). Temperature, phytotoxicity, C/N ratio, water extractable trace elements, and 14 enzyme activities were monitored. Temperature dropped earlier in digestate and maize silage co-composting pile, reducing time to maturity by 20 days. Composting and co-composting reduced phytotoxicity and C/N ratio, but increased immobilization of Al, Ba, Fe, Zn, and Mn at least by 40% in all piles. All the enzyme activities, except arylsulfatase and α-glucosidase, increased at the maturity phase and negatively correlated with organic matter content and most of trace elements. Post-digestate composting or co-composting with biogas feedstock is a promising strategy to improve digestate quality for fertilizer use, and selected enzyme activities can be indicators of compost maturity and immobilization of trace elements.