Experimental Study On Optimization Of Key Process Parameters For Biological Treatment Of Kitchen Waste Reduction

Under the background of municipal solid waste classification,the research and development of kitchen waste treatment and disposal technology and equipment has received extensive attention and attention.Decentralized reduction of kitchen waste in situ is a clean,efficient and economical treatment method.The development of efficient compound microbial inoculum,the determination of equipment operation process parameters and pollution control conditions are the keys to efficient reduction of kitchen waste.In this paper,the high-efficiency degradation strains extracted and preserved in the laboratory were successfully prepared by solid-state fermentation process,which had a good effect on reducing kitchen waste.A reduced biological treatment device for kitchen waste with a daily treatment capacity of 200kg/d was designed and manufactured.The feasibility of the design and manufacturing scheme of the device was demonstrated through equipment debugging,reduction experiment and CFD simulation,and the key process parameters were determined.The main research results of this paper are as follows:（1）Bacillus paralicheniformis,bacillus thuringiensis,bacillus amyloliquefaciens and bacillus subtilis obtained by screening were inoculated into specific solid culture medium,and after solid fermentation for 24 hours in a fermentation container,the fermentation products were mixed in equal proportions according to weight ratio to prepare the composite microbial inoculum.Taking kitchen waste,Chinese cabbage and rice as treatment objects,the reduction experiment was carried out.The results showed that the reduction rates of kitchen waste,cabbage and rice were 84.46%,69.84%and 68.73%,respectively.The variation characteristics of temperature,p H and water content of each reaction system reflect that the reduction system of kitchen waste raw materials is relatively stable.The biological toxicity test of ryegrass seeds was carried out,and the results showed that the effluent from each reaction system had biological toxicity.（2）A 200kg/d kitchen waste treatment device was introduced.The air outlet structure of the equipment was optimized through CFD numerical simulation,and the pilot equipment was debugged and tested.The results show that the Z-shaped elbow of the outlet pipe is the main location where the fluid flow status changes and the pressure and energy are reduced.It has the greatest impact on the flow field of the elbow.Replacing the 90°elbow with a 45°elbow can reduce the outlet pipe.Fluid energy loss.With the cooperation of the loading lifting and turning device,the aerobic reduction reaction chamber,the screw stirring device,the discharging device,the hydraulic system,the PCL control system,etc.,the equipment realizes automatic feeding,intelligent control of aerobic reduction,and automatic discharge And other functions,its electrical protection test,emergency stop test,stirring load test,loading load lifting test and other related results meet the design requirements,and the average daily power consumption was 20.4kw·h without heating.（3）The pilot-scale kitchen waste biological treatment device was used to conduct reduction experiments on the market type waste to investigate the reduction rate and the effect of pollution discharge.The results show that when the process parameters of the treatment device are set at a stirring rate of 5rpm,a heating and holding temperature of 45℃,a stirring period of 45min/stop for 15min and an axial flow fan turned on,the 5-day reduction rate of bazaar waste is 72.59%,and at the same time The use of ozone generators to deodorize can significantly reduce the emission concentration of NH₃,H₂S and other odorous gases during the treatment process.