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Unit16AnaerobicBiologicalTreatmentImportantWordsandExpressions•oxygen-freeadj.无氧气的•undergovt.经受；遭受；忍受•microorganismn.微生物•consumevt.消耗,消费,耗尽•biodegradableadj.可生物降解的•sludgen.下水道的污泥•anaerobicdigestion厌氧消化•leftoveradj.剩下的，多余的•initialstages初级阶段•ammonian.氨•hydrogenn.氢，氢气•carbondioxide二氧化碳•methanogenn.产烷生物•biogasn..生物气，沼气•methanen.甲烷•greenhousegas温室气体•postulatevt.假定,假设•controversyn.争议•fossilfuel矿物燃料•carbohydrate碳水化合物•fat脂肪•proteinadj.蛋白质•fattyacid脂肪酸•aminoacid氨基酸•carbonicacid碳酸•aceticacid醋酸•hydrolysisn.水解作用•acidogenesisn.酸化•acetogenesis（乙）酸化•methanogenesis甲烷生成Text•Anaerobicbiologicaltreatmentisaseriesofprocessesinwhichmicroorganismsbreakdownbiodegradablematerialintheabsenceofoxygen.•Afterundergoingsuchatreatment,watercanbesafelyreleasedbackintotheenvironment.•Thebiologicalagentsusedintheprocessareanaerobicmicroorganismsthatconsumeorbreakdownbiodegradablematerialsinsludge,orthesolidportionofwastewaterfollowingitsfiltrationfrompollutedwater.•厌氧生物处理是一系列过程，其中微生物在缺少氧的条件分解可生物降解材料（物质）。•接受这样的处理后，水可以安全地释放到环境中。•在这个过程中使用的生物制剂是厌氧微生物消耗或分解污泥中生物可降解材料,或受污染的水过滤后污水的固体部分。•Anaerobicbiologicaltreatmentisusedforindustrialordomesticpurposestomanagewasteortoreleaseenergy.•Anaerobicbiologicaltreatmentisalsoknownasanaerobicdigestionduetotheactionofthemicroorganisms.Thatis,theyareessentiallydigestingthepollutedpartsofthewater.•Anexcellentwaytodecreasetheamountoforganicmatterleftoverinthingssuchassewageandleftoverfood,anaerobicdigestionistypicallyacomponentofanybiologicalwastewatertreatmentsystem.•厌氧生物处理被用于工业或民用目的来管理废弃物或释放能量。•厌氧生物处理也被称为由于微生物作用的厌氧消化。也就是说（即），它们基本上是“消化”水的污染部分。•减少在诸如污水和吃剩的食物中有机物残留量的一个好方法，厌氧消化通常是任何废水生物处理系统的一个组成部分。•Usually,theanaerobicprocesstakesplaceinsealedtanks,locatedeitheraboveorbelowtheground.•Thedigestionprocessbeginswithbacterialhydrolysisoftheinputmaterialstobreakdowninsolubleorganicpolymers,suchascarbonhydrates,andmakethemavailableforotherbacteria.•Acidogenicbacteriathenconvertthesugarsandaminoacidsintocarbondioxide,hydrogen,ammoniaandorganicacids.•通常，厌氧过程发生在密封罐，位于地面上方或下方。•消化过程始于细菌水解输入材料并分解不溶性有机聚合物,如糖类、并使其可用于其他细菌。•然后，引起酸化的细菌将糖类和氨基酸转化为二氧化碳、氢气、氨和有机酸。•Finally,methanogensconverttheseproductstomethaneandcarbondioxide.Themethanogenicarchaeapopulationsplayanindispensableroleinanaerobicwastewatertreatments(seeFigure16.1).•最后，产甲烷菌将这些产物转化为甲烷和二氧化碳。产甲烷古菌种群在厌氧废水处理中发挥着不可或缺的作用（见图16.1）。•Therearefourkeybiologicalandchemicalstagesofanaerobicbiologicaltreatment:1.Hydrolysis2.Acidogenesis3.Acetogenesis4.Methanogenesis•Inmostcases,biomassismadeupoflargeorganicpolymers.Forthebacteriainanaerobicdigesterstoaccesstheenergypotentialofthematerial,thesechainsmustfirstbebrokendownintotheirsmallerconstituentparts.•在厌氧生物处理的四个关键的生物和化学过程：1、水解；2、酸化；3、产乙酸；4、产甲烷•在厌氧消化中，细菌接近物质（材料）的潜在能量，这些链首先必须被分解成更小的组成部分。•Theseconstituentparts,ormonomers,suchassugars,arereadilyavailabletootherbacteria.•Theprocessofbreakingthesechainsanddissolvingthesmallermoleculesintosolutioniscalledhydrolysis.•Therefore,hydrolysisofthesehigh-molecular-weightpolymericcomponentsisthenecessaryfirststepinanaerobicdigestion.•Throughhydrolysisthecomplexorganicmoleculesarebrokendownintosimplesugars,aminoacids,andfattyacids.•单体，诸如糖的这些构成部分，对于其他细菌是很容易利用的。•因此，这些高分子量的聚合成分的水解是厌氧消化中必要的第一步。•通过水解，复杂的有机分子分解成简单的糖，氨基酸，脂肪酸。•Acetateandhydrogenproducedinthefirststagescanbeuseddirectlybymethanogens.Othermolecules,suchasvolatilefattyacids(VFAs)withachainlengthgreaterthanthatofacetatemustfirstbecatabolisedintocompoundsthatcanbedirectlyusedbymethanogens.•Thebiologicalprocessofacidogenesisresultsinfurtherbreakdownoftheremainingcomponentsbyacidogenic(fermentative)bacteria.•Here,VFAsarecreated,alongwithammonia,carbondioxide,andhydrogensulfide,aswellasotherbyproducts.•Theprocessofacidogenesisissimilartothewaymilksours.•其他分子，如链长度大于乙酸的挥发性脂肪酸（VFAs）首先必须分解代谢成可直接能被甲烷菌利用的化合物。•酸化的生物过程引起剩余组分由产酸（发酵）细菌的进一步分解。•在这里，挥发性脂肪酸产生，伴随着氨气，二氧化碳，硫化氢，以及其他副产品。酸化的过程类似于使牛奶变酸。•Thethirdstageofanaerobicdigestionisacetogenesis.Here,simplemoleculescreatedthroughtheacidogenesisphasearefurtherdigestedbyacetogenstoproducelargelyaceticacid,aswellascarbondioxideandhydrogen.•Theterminalstageofanaerobicdigestionisthebiologicalprocessofmethanogenesis.•Here,methanogensusetheintermediateproductsoftheprecedingstagesandconvertthemintomethane,carbondioxide,andwater.•厌氧消化过程的第三阶段是产乙酸。在这里，通过酸化阶段产生的简单分子进一步经乙酸菌产生大量的乙酸，以及二氧化碳和氢气。•厌氧消化的最终阶段是产甲烷的生物过程。•在这里，产甲烷菌利用前一阶段的中间产物并将其转化为甲烷，二氧化碳和水。•Thesecomponentsmakeupthemajorityofthebiogasemittedfromthesystem.MethanogenesisissensitivetobothhighandlowpHsandoccursbetweenpH6.5andpH8.•Theremaining,indigestiblematerialthemicrobescannotuseandanydeadbacterialremainsconstitutethedigestate.•Asimplifiedgenericchemicalequationfortheoverallprocessesoutlinedaboveisasfollows:•这些组分构成了系统中发出的沼气的主体。甲烷生成对高和低pH值敏感，发生在pH值6.5和8之间。•剩下的，无法消化的物质微生物不能利用，任何死细菌菌体构成了沼肥。•对于上述全过程的简化通用的化学方程式如下：•C6H12O6→3CO2+3CH4(seeFigure16.2)•WecangetfromtheFigure16.2thatduringtheinitialstagesofthesludgebreakdown,themicroorganisms,whicharemostlybacteria,convertthewasteintoorganicacids,ammonia,hydrogenandcarbondioxide.•从图16.2中我们可以得到，在污泥分解的初始阶段，微生物，大部分是细菌，将废成有机酸，氨，氢和二氧化碳。•Inthef