城市污泥堆肥温度动态变化过程及层次效应

  • 格式:pdf
  • 大小:329.17 KB
  • 文档页数:6

第22卷第5期2002年5月生 态 学 报

ACTAECOLOGICASINICAVol.22,No.5May,2002

城市污泥堆肥温度动态变化过程及层次效应

陈同斌,黄启飞,高 定,黄泽春,郑玉琪,李艳霞

(中国科学院地理科学与资源研究所环境修复室,北京 100101)

基金项目:国家“九五”科技攻关资助项目(962909201205)收稿日期:2001209207;修订日期:2002203207作者简介:陈同斌(1963~),男,广西人,研究员。主要从事植物修复、废弃物资源化技术和土壤环境保护研究。E2mail:chentb@igsnrr.ac.cn摘要:对城市污泥强制通风静态垛堆肥的温度变化规律进行了研究。结果表明,当调理剂比例较低时,堆体升温速率和降温速率都较为缓慢,堆肥处理时间长,堆体温度较低。当调理剂比例较高时,堆体升温速率较快,堆肥温度将在较短时间内达到灭菌稳定化所要求的高温。堆体温度在高温阶段持续的时间与调理剂比例有着密切的联系,当调理剂比例太高时,高温持续时间短,如加入适当比例的回流污泥,堆温可以在50℃以上高温阶段持续足够的时间。当堆肥原料的起始温度高于15℃,堆体一般要经历升温阶段、高温持续阶段和降温阶段,但是当堆肥原料的起始温度很低时,堆体温度还要经历一个起爆阶段。堆体内不同层次的温度有着不同的变化趋势,堆肥初始阶段,堆体下层温度高于上层温度,随后上层温度逐渐高于下层温度。关键词:城市污泥;堆肥;温度;位置效应

TemperatureDynamicDuringtheSewageSludgeCompostingPro2

cess

CHENTong2Bin,HUANGQi2Fei,GAODing,HUANGZe2Chun,ZHENGYu2Qi,LI

Yan2Xia (LaboratoryofEnvironmentalRemediation,InstituteofGeographicSciencesandNaturalResourcesRe2

search,ChineseAcademyofSciences,Beijing 100101,China).ActaEcologicaSinica,2002,22(5):736~741.

Abstract:Itwaswellrecognizedthatmanyfactorsinfluencedthecompostingprocessandtheresulting

product.Temperaturewasthemostimportantecologicaldeterminantwithincomposingmaterial.Temper2

atureincreasewasafunctionofstartingpoints,metabolicheatevolutionandheatconservation,withthe

achievementofminimumtemperaturelevelsbeingessentialtoaneffectivecompostingprocessandcon2

tributingsubstantiallytothehighratesofdecompositionachievedduringprocessing.

Fewstudieshadbeenundertakentounderstandtheprocessesofmicrobes,heatlossesfromthemass,

andtheecologicalnature,includingmicrobialsuccession.

Thetemperatureofacompostingmassdependedlargelyonairflow.Thetemperaturebetweenthe

centerandthesurfaceofthecompostingmassvariedgreatlyinstaticpileslargelybecauseofairflow.

Turningofstacksorforcedaeration,asinenvironmentallycontrolledcomposting,couldcontroltempera2

tureeffectively.Terminationofsuchpracticesresultedinthetemperaturesoonreturningtotherangeof

70℃to80℃.

Theforcedaeratinginfluencedthetemperaturesatdifferentpositions,sothetemperaturechanges

weredifferent.Toknowthedifferencewasimportanttocontrolthecompostingprocess,improvethe

qualityofthecompostingproduct.

Thestudywascarriedouttoinvestigatethetemperaturedynamicduringthesewagesludgeaerobic

staticcomposting.Allexperimentedcompostingpileswereplacedinabuildingin116m×110mbayswithcement

floorsandwalls.Aerationboardswerelaidonthebottomofthebays.Thepilescontainedsewagesludge(moisturecontent=83%~85%,VolatileSolid=49%~58%),recycledcompostandbulkingagentwith

fiveproportions.Abulkingagentlayerontheaerationboardsdispersedairthroughthe110mhighmix

layer.Allpileswerecoveredwitha202cminsulatinglayerofrecycledcompost.Eachbayhadanaeratorto

supplyambientair.Sensorswereinsertedintothemiddlelayerandupperlayerofthepiles’geometrical

centerstodetectthetemperatures,andthedetectedvalueswerefedbacktothecomputerizedcontrolsys2

tem.Inordertostudythedifferenceamongthedifferentlayers,sixsensorswereinsertedintothepilesin

thetreatmentIIfromthebottomtothetop.Athree2stagecontrolalgorithmcontrolledthedamperduty

cycleofaerators.Thecontrolsoftwareloggedtemperaturesevery15minutesandgeneratedreports.

Thetemperatureincreasinganddecreasingspeedwasslow,lessthan417℃󰃗dand219℃󰃗drespec2

tively,andthecompostingdurationwaslongandthecompostingtemperaturewaslowerwhenthepropor2

tionofbulkingagentwaslower.Onthecontrary,whentheproportionofbulkingagentwashigh,the

temperaturedecreasingwasfaster,about12~1716℃󰃗d,andthecompostingtemperaturewashighe2

noughtodestroythepathogenicmicroorganisms.Thedurationinhightemperatureperiodrelatedtothe

proportionofbulkingagent:thedurationwasshorterwhenthelatterwashigher,butlongenoughtode2

stroythepathogenicmicroorganismswhentherecycledcompostwasadded.

Thecompostingprocesssuggestedbyearlierreportscouldbedividedintothreestages:temperature

increasingstage,hightemperaturestageandtemperaturedecreasingstage.Howeverourexperimentindi2

catedthatthecompostingprocessshouldbedividedintofourperiods:besidesthethreeperiodspreviously

stated,theperiodfromthelowtemperaturetothe15℃shouldbenoticedbecauseitwasimportantforthe

microorganismstoproliferateandthecompostingprocesstostart.

Thetemperaturechangingtrendsatthedifferentplacesinthecompostingpilesweredifferent.The

temperatureoftheupper2layerwaslowerthanthatoftheunder2layerintheearlystage,andthenthefor2

merwashigherwiththedevelopmentofcompostingprocess.

Thetemperatureofmiddle2layerwashigheratthehightemperaturestage,butthetemepratureofun2

der2layerwashigheratstartingstageanditshouldbestudiedinfuture.

Keywords:sewagesludge;composting;temperature;positioneffect文章编号:100020933(2002)0520736206 中图分类号:X705 文献标识码:A

在有机废弃物高温堆肥过程中,湿度、温度、pH、C󰃗N等许多因素均影响堆肥进程和最终产品的质

量[1~5]。在诸多因素中,温度是堆肥过程的核心参数[6,7],堆体一般要经历升温过程、高温持续过程和降温过

程[8]。国内外学者对于堆肥温度的研究主要集中于以下几个方面:堆肥升温过程的特点及堆肥所能达到的