The Study Of Test On Shortening Of High Oil And Salt Kitchen Wastes In Aerobic Composting Cycle

In the study, urban kitchen waste was set as the research object, based on the influenceindexes of kitchen waste aerobic composting that former researchers had reported, and C/Nand moisture content were fixed as main influence factors of kitchen waste aerobiccomposting and the level values were determined (C/N:25:1,30:1,35:1; moisture content:55%,60%,65%). Component analysis on kitchen waste, straw and bean dregs were carriedout, the test combined separately of each level of two factors was operated according to thelevel values of C/N and moisture content, then test was used to determine the best ratio ofkitchen waste and straw. The change of temperature, moisture content, organic matter content,pH, conductivity, ammonia nitrogen and TN throughout the whole aerobic compostingprocess was determined, and C/N and seeds germination index were used to evaluate aerobiccomposting maturity of kitchen waste. The results of the study showed that when C/N contentand moisture content were at30:1and60%, the period of the experiment was shortest in allthe experiments which was25days.According to the change of composting temperature gradient, bacteria strains werescreened from the heating, high temperature and cooling stages of the experiment. Aftergenetic sequencing identification, five kinds of predominant bacteria were obtained at lastwhich were respective No.1: Proteus mirabilis strain-singular Proteus strains, No.2:Bacillus methylotrophicus strain-methyl nutrition Bacillus, No.3: Bacillus amyloliquefaciensstrain-solution starch Bacillus, No.4: Uncultured compost bsacterium clone-compostbacteria and No.5: Ornithinibacillus-ornithine Bacillus SPP. Then two kinds ofpredominant bacteria including No.1and No.2were added into the aerobic composting againwith the reactor volume quantity of1.5%, according to the different ratio of1:1,1:2,2:1,1:3,3:1. Compared to the control test, the results showed that the composting effect of kitchenwaste was the best for the ratio of2:1, and C/N and the seeds germination rate were4.89and95.9%respectively. The aerobic composting period of kitchen waste and straw was shorted at22days, and compared with the control test, moisture content, the organic matter and TNwere reduced respectively by1.90%,4.27%and11.96%. The change regularity of pH valueand ammonia showed increase at first and then decrease, while the electrical conductivity wasincreased at first and then stabilized. The fertilizer made by kitchen waste and straw had thestabilization of plants, and met the harmless requirements of fully maturity.