文档名：黑曲霉菌对废旧电缆聚乙烯降解效果及反应机理研究
摘要：近年来,随着电缆批量退役,有机固体废物大量堆积,严重威胁环境清洁和人类生命健康.微生物降解废旧电缆比传统的焚烧填埋更为清洁、经济,因此可以采用菌群降解手段实现废旧电缆环保处理.为了研究微生物降解废弃聚乙烯(PE)组分的过程,该文选取黑曲霉菌对聚乙烯粉末进行降解处理,利用傅里叶红外光谱(FTIR)和X射线光电子能谱(XPS)进行官能团分析及样品表面碳、氧元素的含量分析,使用X射线衍射实验(XRD)进行样品的晶体结构分析,采用差示扫描量热-热重分析(DSC-TGA)联用热分析方法开展样品的变温热性能分析,同时基于扫描电子显微镜(SEM)进行10000～50000倍下样品的微观形貌观测.实验结果表明,在黑曲霉菌降解低密度聚乙烯的过程中发生了氧化反应,产生了羟基、羰基等亲水基团,在菌群处理聚乙烯天数为14天时,氧元素含量从1.38%增加至13.60%,同时聚乙烯结晶度从53.4%下降到34.18%,起始热解温度降低200℃,最终热解温度降低10℃,熔融峰降低0.87mW/mg,表面形貌出现明显的孔隙和沟壑.该文解析了黑曲霉菌降解低密度聚乙烯的化学机制为醇化、羰基化以及酶促氧化反应.
Abstract：Inrecentyears,theaccumulationoforganicsolidwaste,particularlyfromtheretirementofextensivecablesystems,posesasignificantthreattoenvironmentalcleanlinessandhumanhealth.However,traditionalincinerationmethodsonlyexacerbateenvironmentalpollution.Therefore,thereisanurgentneedforasafeandenvironmentallyfriendlydegradationmethodtoaddressthechallengeofmanagingdiscardedcables.Toinvestigatetheprocessofmicrobialdegradationofdiscardedpolyethylene(PE)components,thisstudyselectedAspergillusnigertotreatpolyethylenepowder.ThestudyexaminedtheeffectsandreactionmechanismsofAspergillusnigeronthedegradationofpolyethyleneindiscardedcablesbyanalyzingchangesinfunctionalgroups,crystallinity,elementalcomposition,andthemicroscopicmorphologyofthesamples.First,Fourier-transforminfraredanalysis(FTIR)wasusedtodetectchangesinthefunctionalgroupsofthesamplesaftertreatmentwithAspergillusniger.Newfunctionalgroups,suchashydroxylandcarbonylgroups,wereobserved.Subsequently,thepossibledegradationproducts,suchasalcoholsandaldehydes,wereanalyzedthroughthenewlyformedchemicalbonds.X-rayphotoelectronspectroscopy(XPS)wasemployedtoscanandanalyzethechangesinthecarbon-oxygenelementsonthesample'ssurface.Aftertwoweeksoftreatment,theatomicratioofoxygenelementsonthesurfaceincreasedfrom1.38%to13.6%.Furtheranalysisofthesample'scrystallinestructurethroughX-raydiffraction(XRD)experimentsrevealedadecreaseincrystallinityfrom53.4%to34.18%,indicatingthedisruptionoftheregularityofpolymermolecularchains.Inadditiontothesefindings,acombineddifferentialscanningcalorimetry-thermogravimetricanalysis(DSC-TGA)methodwasusedtoanalyzethesample'sthermalpropertiesatdifferenttemperatures.Theinitialdecompositiontemperaturedecreasedby200℃,andthefinaldecompositiontemperaturedeclinedby10℃.Thisphenomenonsuggestedthepresenceoflower-energycarbon-oxygenbondsduringthedegradationprocess,correspondingtothenewfunctionalgroupsobservedintheFTIRanalysis.Finally,scanningelectronmicroscopy(SEM)wasemployedtoobservethemicroscopicmorphologyofthesamplesatmagnificationsrangingfrom10000to50000times,revealingthepresenceofpores,grooves,cross-linkingfractures,andotherfeaturesonthesample'ssurface.ThisledtotheinferencethatthesampleshadbeenattackedbyextracellularenzymesproducedbytheAspergillusniger.Fromtheexperimentalresults,thefollowingconclusionscanbedrawn:(1)Aspergillusnigerproduceshydroxylgroupsduringthedegradationoflow-densitypolyethylenecablematerial.Subsequently,undertheactionofenzymessuchasalcoholdehydrogenaseandmonooxygenase,thesehydroxylgroupsareconvertedintocarbonylandC—O—Cgroups,promotingthedegradationprocess.(2)WithincreasingtreatmenttimebyAspergillusniger,thermaldecompositionandmeltingexperimentsindicatethepresenceoflower-energycarbon-oxygenbondsduringthedegradationprocess.ThisisconsistentwiththeappearanceofnewfunctionalgroupsinFTIRanalysisandtheincreaseintheatomicratioofoxygenelementsinXPS.(3)AfterbeingattackedbyAspergillusniger,therelativecrystallinityofpolyethylenesamplesdecreasedfrom53.4%to34.18%withprolongedtreatmenttime.ThisphenomenonindicatesthatAspergillusniger.canattackthepolymerchainsofpolyethylene,disruptingtheirregularityandsymmetry,leadingtoareductionincrystallinity.(4)Microscopicobservationsofthesample'smorphologyrevealedthepresenceofclearpores,grooves,andcross-linkingfractures.ThissuggeststhatAspergillusniger.cansecreteextracellularenzymestoattackthepolyethylenemolecularchains,causinglong-chainmoleculestobreakintosmallerchainsandpromotingdegradation.
作者：杨世芳 杨晓磊 谢军 侯前朋 刘云鹏Author：YangShifang YangXiaolei XieJun HouQianpeng LiuYunpeng
作者单位：华北电力大学电力工程系保定071003
刊名：电工技术学报
Journal：TransactionsofChinaElectrotechnicalSociety
年，卷(期)：2024, 39(1)
分类号：TM212X705
关键词：废旧电缆 微生物 聚乙烯 生物降解
Keywords：Obsoletecables microorganism polyethylene biodegradation
机标分类号：TQ203O641TQ325.12
在线出版日期：2024年1月18日
基金项目：国家自然科学基金，国家自然科学基金，河北省自然科学基金，中央高校基本科研业务费专项资金资助项目黑曲霉菌对废旧电缆聚乙烯降解效果及反应机理研究[
期刊论文] 电工技术学报--2024, 39(1)杨世芳 杨晓磊 谢军 侯前朋 刘云鹏近年来,随着电缆批量退役,有机固体废物大量堆积,严重威胁环境清洁和人类生命健康.微生物降解废旧电缆比传统的焚烧填埋更为清洁、经济,因此可以采用菌群降解手段实现废旧电缆环保处理.为了研究微生物降解废弃聚乙烯(PE)...参考文献和引证文献
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黑曲霉菌对废旧电缆聚乙烯降解效果及反应机理研究 Degradation Effect and Degradation Mechanism of Aspergillus Niger on Polyethylene Components of Waste Cables
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