Study On The Resource Utilization Of Several Kinds Of Solid Organic Wastes

Resource and environment are two hot topics in21st century, of which thedisposal of solid organic waste is one of the most important tasks. With the rapiddevelopment of the economy and enlargement of city scale in China, solid organicwaste has been increasing rapidly. Wastes would become an effective energyresource with right disposition and the energy consumption stress would berelieved as a result. Therefore, it is of great practical significance in protection ofcity environment，development of national economy and adjustment of energystructure.Energy is one of the most sensitive problems for the sustainable developmentof society and economy worldwide. The rapid economic development of the world,especially in developing countries, is mostly based on the consumption of fossilfuel such as coal, oil, and natural gas. The development of clean energy couldreduce the emission of greenhouse gases and other pollutants, and would help toimprove the global environment.In this study, five types of common solid organic waste from rice straw, bluealgae, aquatic product waste, food wastes and peanut hull powder were investigatedwith the purpose of resource utilization and harmless treatment. Potentialities ofproducing biogas were studied in rice straws combined with blue algae, aquaticproduct waste combined with other solid organic waste as anaerobic fermentationmaterials respectively by using the different kinds of biogas slurry for inhibitingexperiment on Fusarium oxysporum f. sp. niveum. Fuel ethanol production fromfood waste was researched by mixed bacteria fermentation. This paper establishes astrategic framework for clean energy development in China with the expectationthat it would provide some theoretical and practical guidance.（1） Rice straws and rice straws mixed with blue algae were elected asanaerobic fermentation materials to produce biogas at the controlled temperature （35±1℃）. The result showed that the rice straws mixed with blue algae werethebetter raw material than the rice straws in the velocity and amount of biogasproduction. Two peaks of biogas production of experimental group B, the ricestraws mixed with blue algae at the ratio1:1, concentrated in the first16days of theanaerobic fermentation, while experimental group A only had one peak on the7thday of the anaerobic fermentation. The highest TS （Total solids，TS） daily biogasproduction, daily mean biogas production, accumulating amounts of biogasproduction, the potential of producing biogas of TS and the average content ofmethane of the former were20.21mL·g^-1，541.97mL，38480mL，456.09mL·g^-1and76.88%respectively, all of which were significantly more than the latter with4.57mL·g^-1，347mL，6940mL，42.03mL·g^-1and42.33%. Besides, the degradationratio of experimental group B is52.54%, which was more than5.52%ofexperimental group A. The effect of microchemical substances in anaerobicfermented liquid from rice straw and cyanobacteria（1:1）on Fusaruim oxysporum f.sp. niveum growth was also investigated,which including spore germination, sporenumber, and mycelial growth. The results showed that spore germination inhibitedby100%at40%concentration of biogas slurry. And the spore production could beinhibited by98.74%at20%concentration of biogas slurry. Moreover, the aerialmycelial growth could be almost inhibited at100%concentration of biogas slurry.Further analysis by gas chromatograph-mass spectrometer found that there aremany kinds of alkyl substances in the organic component from biogas liquid. Threemicrochemical substances, CCl₄, C₂Cl₆, CH₃CH（OCH₂CH₃）₂measured in biogasliquid by GC-MS analysis had distinct inhibition effects. The inhibition effects waspositive correlation with the concentrations, especially CH₃CH（OCH₂CH₃）₂. Thespore germination were inhibited by100%at the0.75%concentration of threechemicals; The numbers of producing-spore reduced5.67%，18.05%，8.72%respectively at the1%concentration of three chemicals. The inhibiting rate wouldget to90.4%when three chemicals at1.00%concentration were added in themedium.（2） The biogas production efficiency of aquatic product waste were researchedon the proportioning materials of weight ratio （9:1） of organic waste mixed withrice straws, peanut hull powder and food wastes respectively, together with control. These four treatments were analyzed to investigate their respective impacts on gasproduction from anaerobic fermentation. Results indicated that organic wastemixed with food wastes guaranteed quality and quantity of biogas production.Daily biggest biogas production, total biogas production and TS biogas productionrate were3870mL,38230mL,692.42mL g^-1respectively.And then use the biogasslurry of each treatment for inhibiting experiment on Fusarium oxysporum f. sp.niveum. Results indicated not only that organic waste mixed with food wastesguaranteed quality and quantity of biogas production, but also the unsterilizedbiogas slurry displayed strongly inhibiting effect on the mycelial growth ofFusarium oxysporum f. sp. niveum by78.17%.（3） In this experiment, ethanol was produced from food waste as raw material.The saccharification pretreatment of raw material was carried out by Rhizopus andBacillus subtilis, and then beer yeast was inoculated for ethanol fermentation. Thefermentation conditions for ethanol production were optimized by single factorexperiment. The results showed that the ethanol content could be up to6.67%under the optimum fermentation conditions （15%beer yeast inoculum,22.79%moisture content of material, and30℃for5d）.