Self-circulating pulse alternating ventilation composting technology: Biotic and abiotic effects of mature compost on humification during food waste composting

Abstract

Traditional composting technology relies on external additives such as rice husks to optimize the moisture content and permeability of the pile, which increases transportation and economic costs. This study developed a self-circulating pulse alternating ventilation composting technology, which used mature compost as an additive and explored the optimal ratio and strengthening mechanism. Six composting experiments were set up with mature compost as additive and rice husk as control based on the self-made alternating ventilation composting reactor. The results showed that adding 10 % mature compost (wet weight) significantly extended the high-temperature phase (15 days). The total organic carbon degradation degree was 1.10 to 2.11 times higher, and the degree of directional humification was 1.56 to 3.39 times higher than those of the other groups. This may be due to the biological and non-biological effects of the mature compost. On one hand, adding mature compost increased the relative abundance of lignocellulose-degrading functional microbes, which enhanced the metabolic levels of xylanolysis and cellulolysis. On the other hand, it accelerated the dissolution and release of humus precursors, increasing the content of aromatic compounds such as phenyl-β-D-glucoside and indolizine, and thereby accelerating the condensation process. These results demonstrate that self-circulating pulse alternating ventilation composting technology is a low-cost green composting technology with the potential to achieve efficient treatment of food waste.