Enhancing the decomposition and composting of food waste by in situ directional enzymatic hydrolysis: performance, ARGs removal and engineering application

Abstract

This research utilized food waste (FW) as substrate, innovatively developed a directional multienzyme applied for accelerating FW hydrolysis and composting, and an in situ enzymatic hydrolysis combining in composting has been developed to manage FW. Results showed that the composting was achieved at 4 days and the humification index was increased by 2.60 compared with that of without enzymatic hydrolysis. FTIR analysis revealed that following multienzyme pretreatment, the primary constituents of FW, including protein, starch and lipid, underwent structural breakdown, among which protein exhibited the higher susceptibility to multienzyme action and was the first to disintegrated, and the structure also became looser. Moreover, the total antibiotic resistance gene (ARGs) was reduced more than 90 % in the proposed composting process. Analysis of microbial communities and metagenomes showed that multienzyme pretreatment reshaped microbial communities towards favoring FW hydrolysis and humification. The engineering application analysis further implied that the proposed composting approach is scale flexible, engineering applicable, economic viability and environmentally sustainability. It was anticipated that this study has the potential to trigger a paradigm shift in future in-situ treatment of FW to achieve full resource recovery towards zero solid discharge.