54 / 2021-06-30 09:08:14

Combination of biochar and Garbage enzyme improving the humification and succession of fungal community during sewage sludge composting

Garbage enzyme; Humification; Fungal community; EEM; Composting

To evaluate the effect of combination of biochar (BC) and garbage enzyme (GE) on total organic carbon (TOC) degradation, humification and the fungal succession during sewage sludge (SS) composting, three composting treatments, a control and a BC treatment, a combination addition of BC and GE treatment (BC+GE), were established. The results showed that the BC and BC+GE treatments significantly increased the enzyme activities of fluorescein diacetate hydrolase (FDA), thus improved the TOC degradation. In addition, the rate constants of TOC based on the first-order degradation kinetics for the three treatments were 0.0086, 0.0090, and 0.0097 day^-1, respectively. The excitation-emission matrix (EEM) combined with the percentage fluorescence response (Pi, n) also proved that the combination addition of BC and GE promoted the decomposition of TOC and the formation of humic-like substances, and thus increased humification. Furthermore, the combined addition of BC and GE significantly reduced the relative abundance of Unclassified _k_Fugni, while increased the abundance of Ascomycota and Basidiomycota. Comparatively, the combined addition of BC and GE showed the optimal performance for TOC degradation and humification during the SS composting.