Effect of Compositional and Structural Evolution of Size-fractionated Dissolved Organic Matter on Electron Transfer Capacity During Composting

Abstract Ultrafiltration separation and spectrum analysis were employed to investigate the composition and structure evolution of size-fractionated dissolved organic matter (DOM) during chicken manure composting. Electrochemical method was applied to determine electron transfer capacity (ETC). The results showed that protein-like components, which were the main components at the initial stage of composting, were mainly observed in the DOM with molecule weight (MW) 1 kDa. Though humic-like components with different molecular weight changed differently during composting, their content at the end of composting was higher than that at the initial of composting. Electron donating capacity (EDC) was persistently reduced during composting, whereas electron accepting capacity (EAC) of the DOM with the MW 1 kDa was persistently increasing during the composting process, though the EAC of the fraction showed no system change. There was on irregular for the ETC of the DOM with the MW of 1–3 kDa and 3–5 kDa. The EAC value of the size-fractionation DOM was controlled by the content of the aromatic carbon which was derived from lignin degradation, while the EDC value of these DOM did not showed obvious relation with the spectrum parameter.