Effect of Microbial Inoculum and Leachate Circulation on the Performance of Rotary Drum Composter Used for Household Wet Biodegradable Waste

Abstract

To reduce transportation costs and harmful environmental impacts, the household wet biodegradable waste (HWBW) should be segregated and processed at the source of generation. In the present study, the performance of a decentralized rotary drum composter (capacity = 160 L) was evaluated for the stabilization of HWBW. The system was divided into four compartments and approximately 2.5 kg of HWBW was added in each compartment for 10 days. Two sets of experimental runs were conducted to examine the effect of inoculum addition along with the leachate circulation on the biodegradation process and compost quality. The composting process was assumed to be over in ~ 40 days after the temperature reduced to the ambient level. The inoculum addition slightly improved the degradation rate while reducing the composting period though no considerable effect could be observed by leachate circulation. The compost yield (< 4 mm fraction) during both sets of studies was 15–18% and its quality satisfied the prescribed Indian standards. To ensure production of the good quality compost, germination and self-heating tests were also performed. The results revealed that mixing of compost (20%) with soil enhanced the growth of cress plants. Apart from this, the waste decomposition rate was also predicted using various kinetic models available in the literature.