Enhanced operation of the on-site garbage composting unit

Abstract

A study to suggest the technique for enhancing the performance of the on-site garbage composting was performed. The objectives included in this study were; i) to confirm the feasibility of the on-site garbage composting without compost removal, ii) to suggest the principles of the on-site garbage composting, iii) to estimate the effect and utility of seed inoculation on both batch and on-site garbage composting quantitatively, and iv) to investigate the efficacy of wasted scrap tire as a bulking agent for the on-site garbage composting units. The conclusions for detail research topics were summarized as follows; In order to evaluate the feasibility of the on-site garbage composting without compost removal, a continuous reactor of 30l size fed 1 kg of garbage per day was operated for 65 days. As a result, the operation technique suggested here could decrease the amounts of sawdust to add and compost to withdraw as compared with those of other batch operations. Most of the easily degradable organic matter (EDM) in garbage fed daily could be degraded within a day in view of CO2 gas evolution and changes of volatile matter (VM) content, temperature, and dry weight. Content of EDM decreased from 20% to 10% within three days and maintained at the constant level. Considering that the content in raw garbage was 43%, it could be assessed that the degradation efficiency of EDM in the reactor maintained about 70%. Degradation ratios of each EDM that meant degradation activity in continuous composting reactor were assessed as 75, 60, and 30% for lipids, sugar, and hemi-cellulose, respectively. Degradation ratio of EDM decreased from the range of 40-50% to the range of 10-40% by the intermittent garbage loading, which indicated that the idle period of the on-site composting unit should be controlled as short as possible, because it served to decrease of microbial activity though it reduced the aggregation among reaction particles. Final product had the low content of EDM. I...