ABSTRACT
Traditional composting operation may take over 2 weeks for the primary stage. The enhancement of the composting process will shorten the operation time and thus reduce the composting space and production costs. In this work, a microbial inoculum originated from the MSW leachate was used for the enhancement of the biodegradation of organic fractions of MSW (namely OFMSW hereinafter) in the composting process. The leachate generated from OFMSW composting was cultivated in the presence of foreign nutritions of beef extract, peptone, K(2)HPO(4) and CaCO(3), respectively. The rough microbial inoculum was then harvested from the cultivated leachate and employed for the enhancement of OFMSW composting. One percent of the rough inoculum was mixed with 99% of the organic wastes (on wet basis). When the composting process proceeded at Day 7, the leachate thus generated was re-cultivated with the said nutrition and introduced into fresh organic wastes for another 7-day composting; repeating this step and the final generated leachate (namely final inoculum) was used for the fresh organic waste composting process. Seeding effects in terms of composting parameters (temperature, oxygen uptake rate, pH, cellulase, microbial numbers, moisture content, and nitrogen concentrations) were tested and the data were collected as reported in this paper. It was found that the temperature in the composting system seeded with the final inoculum could reach over 55 degrees C for the duration of over 96 h, and the numbers of thermophilic bacteria, actinomyces and molds in the refuse, increased by approximately 100%, 70% and 50%, respectively, after a 20-day primary composting. pH maintained at 7.0 with slight fluctuation, thus facilitating the microbial behaviors of cellulose depletion. Meanwhile, the oxygen uptake rate (OUR) and cellulase activity was observed to increase by some 50% and 26%, respectively. The development trend of nitrogen concentrations also indicated that the microorganisms in the final inoculum had the ability to endure the extreme temperature of 70 degrees C. Hence, it can be concluded that the final inoculum developed with leachate recirculated cultivation can work well, benefited from the indigenous communities present to efficiently accelerate the OFMSW composting process.
