餐厨垃圾厌氧发酵产挥发性脂肪酸的研究

哈尔滨工业大学工学硕士论文II光谱分析均显示优化条件提高了有机物的水解效率。并且发酵过程获得了较低的甲烷产量20.56ml/gVS，仅为理论产量的5.34%，说明此时产甲烷菌的活性被有效抑制。这主要归因于发酵过程中氨氮释放提供了较高的碱度，同时发酵液的定时输出和新鲜底物的定时输入中和了降低的pH，使其维持在5.2-6.4的范围，该pH范围被证实有利于有机物的水解酸化同时能抑制甲烷化的发生。碳平衡分析也表明，优化条件下有机底物能被充分和高效地转化为VFA，VFA的主要成分是乙酸、丙酸和正丁酸。关键词：餐厨垃圾；厌氧发酵；挥发性脂肪酸；超声；水解效率哈尔滨工业大学工学硕士论文IIIAbstractWiththeconstantlyimprovingofpopulationquantityandlivinglevel,high-yieldfoodwaste(FW)isproducedinevitably,whichcanseverelyharmenvironmentalsafetyandhumanhealthifthereisnotsuitabletreatmentanddisposal.Inaddition,theexcessiveexploitationandutilizationoffossilfuelscausedmoreandmoreprominentproblemsonenergycrisisandenvironmentpollution.Humanshowedunprecedentedenthusiasmanddesireforexploitingrenewableenergies.FWwasproventobeanidealsubstrateofanaerobicfermentation,andvolatilefattyacid(VFA)producedbyanaerobicfermentationshowedbroaduseofspaces.RecyclingVFAfromFWcansimultaneouslyrealizethedualgoalsofwastetreatmentandrenewableenergyproduction,whichisbeneficialforalleviatetheenvironmentpollutionandenergycrisisin21stcentury.However,thelowefficiencyofVFAproductionconstrainsthepracticalapplicationofthetechnology.Inthispaper,theproblemwassolvedbyimprovingthehydrolysisefficiencyofFW,inhibitingtheactivityofmethanogens,andoptimizingtheinfluencingfactorsofanaerobicacidificationprocess.Firstly,thehydrolysisefficiencywasimprovedbychoosingasuitablepretreatmentmethod.Theoperationconditionsofultrasonic,acidandultrasonic-acidpretreatmentswereoptimized,andtheireffectsonVFAproductionswereinvestigated.Theresultsshowedthat,theoptimizedultrasonicpretreatmentconditionswereenergydensityof1W/mLandtheprocessingtimeof20min,theoptimizedacidpretreatmentconditionswerepH2andprocessingtimeof20h,andultrasonic-acidpretreatmentconditionsobtainedbyresponsesurfacemethod(RSM)wereenergydensityof1.13W/mLandpHof1.43.Thedisgradationdegreesobtainedbythethreepretreatmentswere57.38%,46.90%and69.52%,respectively,andtheVFAproductionswere976.12、115.68and418.94mgCOD/gVS,respectively.Indicatingthatultrasonic-acidandacidpretreatme