[The variation of inoculation complex microbial community in three stages MSW composting process controlled by...

Adding inoculation agent is one of the effective methods to accelerate the composting process of municipal solid wastes. However, because of the competing of indigenous microorganisms, high concentration of existing indigenous microorganisms could inhibit the prevalence of inoculating microorganisms. When indigenous microorganisms concentration in the raw material was 4 x 10(8) CFU/g, the microorganisms of inoculating did not grow up. With the process, the microbial population of inoculation declined rapidly and no-inoculating microbial population rose up quickly and reached a peak of 10(10) CFU/g. When indigenous microorganisms concentration was 4 x 10(5) CFU/g, the microorganisms of inoculation could inhibit the prevalence of the indigenous microorganisms and inoculating microbial population increased quickly and reached a peak of 10(11) CFU/g. Therefore, this paper introduces a method of three stages composting technology, which combined the heat produced from composting system and some extra energy, and heated up the composting temperature above 75 degrees C in 4 hours as well as maintaining for 8 hours. It well controlled the concentration of the indigenous microorganisms under 4 x 10(5) CFU/g and improve the structure of the compost media and make the remaining solids more amenable to biological attack. When composting materials temperature drops to 35 degrees C to 45 degrees C, add complex microorganisms in composting process. Then they develop more quickly than the others, the concentration of them rose up from 10(8) CFU/g to 10(11) CFU/g and lie in a preponderate position. So with this method, advanced the rate of organic degradation in municipal solid wastes (MSW) composting process, and enhanced the numbers of inoculation microorganisms in composting products. Therefore, they can be as inoculation agent for improving composting conditions, speedup the next composting process, cutting down the composting time, saving original inoculation agent and making composting more economic. But using compost products as inoculum, with the number of feedback increasing, the concentration ratio of inoculation microorganisms and no-inoculation microorganisms is around 1:3 (fifth feedback compost products). So, the number of feedback compost products should not be more than five.