Effect of reactor temperature and feeding ratio on fed-batch composting of household food waste and green wastes

Abstract

Currently, most regions of China still treat household food waste (HFW) in a centralized way, which increases the cost of collection and transportation. Therefore, it is necessary to develop a novel technology to treat HFW on site. In this study, a fed-batch reactor was designed to investigate the effect of reactor temperature and feeding ratio on the co-composting of HFW and green wastes (GW). The results showed that an increase in reactor temperature could promote composting efficiency and compost end-product maturity. When the reactor temperature was 50 °C, the moisture (4.1%), weight loss rate (87.3%), organic matter (OM) content (66.1%), and seed germination index (74.1%) of the compost reached the optimum. When the feeding ratio was 2:1, the decomposition rate of OM was the fastest, and the weight loss rate, OM content, and C/N ratio of the compost were 89.3%, 63.1%, and 12.6, respectively. According to the first-order kinetics, it was found that the reactor temperature had a greater impact on fed-batch composting than the feeding ratio. This study suggested that fed-batch composting is a promising technique for the utilization of HFW and GW and provided guidance for the scale-up application of bed-batch reactors.