三阶段控温堆肥过程中接种复合微生物菌群的变化规律研究

接种复合微生物是提高堆肥效率的主要方法之一,但由于堆料中土生微生物的竞争,较高浓度的土生微生物浓度会抑制接种微生物的长生繁殖.实验表明:当堆料中土生微生物初始浓度为4×10⁸CFU/g时,所接种的微生物不增殖,且随着堆肥的进行,浓度下降很快;而非接种微生物增殖很快,最高浓度可达10¹⁰CFU/g.当土生微生物浓度降低至4×10⁵个/g,接种微生物增殖较快,最高达10¹¹CFU/g.因此,本文利用堆肥自身产热和少许外来热源加热的三阶段控温法进行堆肥.使堆温在4 h内迅速升到70℃以上,并维持8 h,从而使土生微生物浓度降至4×10⁵个/g以下,并起到软化堆料,便于微生物降解的目的.待温度冷却至35℃～45℃时,接种复合微生物,使其快速生长繁殖,数量从10⁸ CFU/g上升到10¹¹CFU/g(干样品),且接种微生物以非接种做生物保持优势地位,从而快速分解垃圾中的有机物.由于在最终产品中含有大量接种有益微生物,可利用其作为菌肥进行回流接种堆肥,以增加堆料中接种微生物数目、改善堆肥微环境、节约菌剂用量、缩短堆肥发酵周期和降低堆肥成本.但利用接种微生物堆肥产品作为菌肥反复接种时,随着反复次数的增加,非接种微生物高浓度繁殖;接种微生物和非接种微生物浓度比约为1:3(反复接种5次),浓度情况发生了逆变.因此,回流菌肥反复接种5次后,接种菌剂基本上就不再起作用了.

The Variation of Inoculation Complex Microbial Community in Three Stages MSW Composting Process Controlled by Temperature

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.