Decomposition and humification of dissolved organic matter in swine manure during housefly larvae composting

Housefly larvae (Musca domestica) composting has been increasingly adopted as an efficient practice to achieve value-added swine manure bioconversion, but few researches have evaluated the features of compost maturity by examining the biochemical compositions of dissolved organic matter (DOM) in compost. Here, we adopted spectrum fingerprint technologies to explore the related transformation mechanisms of DOM in compost by conducting field investigations in a full-scale housefly larvae composting farm. The 1-week composting with larvae significantly decreased DOM concentrations from 192.9 to 77.1 g kg(-1) The hydrolysis of proteins and lipids were enhanced during composting, as well as a build-up of aromatic substances, while contents of fulvic- and humic-like substances were augmented on Day 5 and Day 6 (ranged from 0.04 to 0.65 and 0.11 to 0.59 for Fmax, respectively). Compared with traditional composting without the aid of larvae, the stronger biodegradation of DOM and the subsequent formation of humus in compost, led to a higher level of aromaticity and humification under housefly larvae bioconversion, generating a more stable bio-product for downstream utilisation.