Research On A New Aerobic Composting Of Rural Living Garbage Integrated With Solar Technology

With the development of economy and improvement of people's living standard, the quantity of the rural living garbage is steadily on the increase and its composition is complicated with each passing day, which gives enormous pressure on the rural environment.50%-65% components of the rural living garbage is made up of perishable organic waste, which is mainly compose of food remains, the food leftovers and wastes of food processing,this component of waste is a kind of typical high solid organic waste and is suitable for using composting processing to dispose. A series of experiments were carried out aiming at recycling organic solid waste from the rural,and a " new heat aerobic intermittent feeding compost reactor "which using solar to supply energy was designed.The restaurant-kitchen garbage,which is the main component of the rural living garbage ,was chosen as raw materials (the first and second composts ) in composting experiments, and In the experiments we also try to carry out the mixed composting of water hyacinth and restaurant-kitchen garbage ( the third batch ). This compost reactor is powered by solar system (the first batch) and first solar + auxiliary electrical heating fuel system (the second and third batch) respectively, and uses the way of spiral and intermittent forced ventilation ,control composting cycle process with piral propulsion, to control the composting. These experiments study the influence of different composting materials on the conventional physicochemical property, dynamic changes of biomass components, bio-chemical characteristics, humic characteristics, and evaluation index of compost rotten degree. The results are in below:1.Ambient temperature influences composting process directly: through energy supply system body temperature was improved at different degrees ,which made composting reaction initiate in the cold winter quickly. Body temperature is a direct parameters that reflects composting condition,and impact compost quality directly. The first batch is affected by the weather conditions largely, the pile is lasted in the mesophilic temperature condition during composting, while the second and third patch are actually realize harmless. The moisture content of raw compost materials influenced aerobic-compost reaction rates. With the high ambient temperature and ideal compost body oxygen concentration , the moisture content of compost materials are reduced from 86%,84% and 60% to 67%,59% and 51% respectly, which are in favour of secondary fermentation or save.2. During composting, the relative content of nutrient elements (C, N, P) in composting materials changed differently as dry matter decreased.The relative content of TOC and BDM,C/N ratio and content of organic matter presents the downward trend during composting, the content of TN shows different variation tendency based on different materials . The relative content of TP increased in different degrees respectively because of "enrichment" effect and basically no loss during composting.3. The pH value of compost decreased at the outset, and tended to increase in the following, leading to slight alkaline(7.0-7.5) finally , the pH value of raw materials are relatively low, and during composting pH value varies in small sector and keep at low level relatively; In the course of composting, EC value showed increased at first, and then tended to decrease(6.16 ms/cm) ;CEC value was growing gradually during composting, which were from 16.47 cmol/kg(organic matters),14.97 cmol/kg(organic matters),5.00 cmol/kg(organic matters)to 53.34 cmol/kg(organic matters),65.61 cmol/kg(organic matters),68.59 cmol/kg(organic matters)respectively.4.The content of total sugar, reducing sugar and starch decreased fastly primarily due to using by microorganisms firstly; then the contents were kept in a level because they were as intermediate product of complex organics'decomposition and transition. The fat content decreased as the composting beginning, while protein started to reduce at a high body tempreture.5.Raw material contains a large number of microorganisms in itself, initially, compost pile as body temperature rising, microbe growed and reproduced rapidly, especially the number of bacteria, the actinomycetes content were relatively few; During composting process, the number of bacteria, fungi, and actinomycete all appeared to increase at first, and then reduce;the third batch was lasted in high temperature longer,that leaded to more bacterias were dead and caused these quantity was less than the first sample at the final. Catalase activity, urine enzyme activity were relatively high initially, and decreased in the following and lasted at a low level in the final compost process, while protease activity is the decline at first, and then increased, and verged to stabilizing finally.6. After composting, the content of humic acid showed a rising trend, while fulvic acid declined; so HA/FA ratio shows a increased trend, humus quality; Humus content in compost present obvious increase tendency in the final process.7. From physical indicators, compost is loose granular particles, has a perfume of soil and no longer attracts mosquitoes and flies. C/N ratio, CEC value and CEC/TOC, HA/FA, seed germination rate, etc, can be chosen as indexes to reflect compost rotten degree. In addition, CEC value, conductivity value, seed germination rate reflect the quality of product, compost has no poisonous effect on crops already.To sum up, the composting technology and intermittent aerobic spiral mixing propulsion mode that the experiment used are feasible, solar aerobic high-temperature composting can achieve rural life rubbish and water hyacinth"reduction, harmless, and recycling"disposal requirements.