Investigation On The Change Of Material Properties During The Microbial Composting Of Stimulated Solid Waste

In order to deal with the solid organic waste in the controlled ecological life support system,this paper studies the change of the material properties in the process of microbiological treatment of solid waste.By analyzing the characteristics of solid waste composition in CELSS to make simulated solid waste,and study the changes of material properties during the aerobic composting of simulated solid waste,so that the elements to achieve a virtuous cycle in the system,and provide a reliable theoretical basis of scientific experiments.First,the simulated solid waste was aerobically composted with the modified reactor,and the initial moisture content was between 0.55 and 0.60.By adjusting different process parameters(ventilation,microbial agent,C/N),studying the effect of substance properties during composting process:During the experiment,the ventilation of the three groups of parallel experiments was 0;50 L/min,10 min/times;50 L/min,20 min/times.Research shows that the ventilation can make compost quickly into the high temperature stage,extended the high temperature period,and reduce the generation of organic acid during heating stage,promote the degradation of organic matter and maturity of composting product;the ventilation volume of 20 min/time is too large to maintenance of high temperature period.Ventilation quantity is 50 L/min 10 min/time has the best composting effect,the seed germination index reach to 116.59%.The experimental setup of aeration was 50L/min,10min/ times,adding VT-1000 fermentation bacteria,organic fertilizer fermentation bacteria and ecological toilet fermentation bacteria respectively.The results showed that the addition of exogenous microbial agents could prolong the high temperature period,improve the quality of compost products and shorten the time of composting.Compared with the three kinds of microbial agents,VT-1000 fermentation agent can effectively promote the degradation of simulated organic waste,promote the formation of humus,the germination index of seeds reached to 116.32%.The ecological toilet fermentation agent can effectively reduce the loss of nitrogen during composting,the effect of nitrogen retention is obvious,and the quality of the compost product is improved,and the germination index reaches 116.06%.The ventilation volume was 50 L/min,10 min/ times.Set the initial material C/N is 15,17,19,21.The results showed that the processing with the initial C/N was 15 has the higher removal rate of organic matter,and the experiment showed the phenomenon of secondary high temperature,which is more conducive to the degradation of the bottom material and promote the harmlessness of compost products.The initial C/N was 17,which was more conducive to the retention of nitrogen,the increment of total nitrogen content was up to 65.3096%,the quality of compost was better,and the germination rate was reach to 186.69%.Aiming at the above research results,the semi-automatic solid waste microbial aerobic compost reactor was used as the fermentation device to study the effect of compost reactor on physical and chemical properties,the material conversion characteristics,the gas release regularity and the microbial community succession of the simulated solid waste during the constant temperature composting.The simulated fecal and wheat straw were mixed at a ratio of 1: 3,and add the VT-1000 fermentation bacteria agent about 0.1% weight of dry material,the initial material had a moisture content of 0.55-0.60,the ventilation is 1 m3/min,and compost at a temperature of 35 oC ±2oC.The results are as follows:Comparing with the traditional way of compost,composting reactor can promote the realization of material homogenization and reduction,shorten the composting time,only 12 days to maturity,composting products has the best quality after 18 days of composting;In this experiment,the material is easy to form the anaerobic area,cause methane release was relatively high,the fast degradation of carbon accompanied with the amount of methane release increased during the composting process;Because composting period remains a large amount of ventilation,promote the release of NH3,the release of NH3 appeared two peaks in the middle and late stage.The diversity of bacteria is increased with composting,from low temperature bacteria like Leuconostocaceae and Enterobacteriaceae,which can degradation of carbohydrates and polyols substances,evaluated into thermophilic bacteria like Sphingolipid iaceae,Lactobacillaceae and Cytophagaceae,which is used to decompose the intermediate products such as sugar,glutamic acid,butyric acid,acetic acid,pyruvic acid,nitrate,methanol and other refractory materials like cellulose and lignose during the end period of composting.In the process of composting fungi mainly dominated by Ascomycota.The diversity of fungi is gradually decreased with compost,at the beginning of composting,Alternaria,Aspergillus and other fungi which were mainly used carbohydrate,protein and other organic carbon,promote the formation of humus.At the end of the composting,Chaetomiumkunze and Sordariathe are major fungi,which was mainly composed of the plant and animal residue as the nutrient substance.