FEASIBILITY STUDY OF PROMOTIONWord格式.docx

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slivingstandard.

Modernfeedingtechnologiespromotedthedevelopmentoflivestockfeeding,butbecausethiscausedtheseparationoflivestockfarmsfromplantationresulted,thecentraldisposalofwasteshasharmfulimpacttotheenvironment.Basedonthelivestockproducedinintensivepig,chicken,andcowfarmsin1997,thetotalamountofmanureandsewageproducedoverayearcanbecalculatedtobemorethan1.7billiontons.Besides,alargeamountofwaterisusedtowashthefarm.Therefore,theactualsewagedisposalshouldbefarlargerthanthatnumber.Becausemostfarmsarelocatedinsuburb,itisdifficulttotreatsuchalargequantityofmanureandsewagebyreturningtothefield.Thus,itisinevitableofthewastestopollutepotablewater,agriculturalecology,andlivingenvironment.

Suchalargequantityofmanureandsewagehasbecomeabigpollutantsourcearoundeachcity.Accordingtothetestresultofsewageoflarge-scalelivestockfarmsbyenvironmentalprotectionsector,thecontentofCODexceedsstandardby50~60times,BODexceeding70~80times,SSexceeding12~20times.Theenvironmentofmostlivestockfarmsisabominable.Inregionswheretheintensivelivestockfarmsconcentrate,theproblemofpollutionoflivestockwastebecomesveryserious.BureauofEnvironmentalProtectionofShanghaistatedthat,contentofammoniaandnitrogeninwaterinDaliugangexceededthenationalstandard（1mg/l）by4~5times,oreven8~9timesasthehighest;

25.2%ofammoniaandnitrogenand47.7%ofCODinHuangpuRiverwasfrommorethan30large-andmedium-scalelivestockfarmslocatedinDaliugang.Table2showsthesituationofpollutionin

Disposaloflivestockmanurewithouttreatmentnotonlypollutesthesurroundingenvironmentbutalsothreatensthesustainableandhealthydevelopmentofthesefarmsthemselves.Untreatedmanurewillpolluteundergroundwater,andwilleventuallydecreasethequalityofwaterforlivestocktodrinkandwashingwater.Theviciouscyclehasseriouslythreatenedthefurtherdevelopmentoftheselivestockfarms.TheinvestigationofpigfarmsinBeijingandShanghaishowsthat,inrecentyears,thedeathrateofpigletandsowiskeptatahighlevel.Themajorreasonistheuseofundergroundwaterthathasbeenpolluted.Thesameresultcanbeseenintheinvestigationof6large-scalechickenfarmsinBeijing:

deathrateofchickenincreasesinrecentyears,whichhasrestrictedthedevelopmentofthesefarms.Inaddition,becausemanureandsewageseriouspollutedthesurroundingagriculturalfieldandwaterbody,peoplelivingaroundthefarmsarecontinuallycomplaining,andso-causedeconomicdisputesfrequentlyoccur.

Withthedeteriorationofenvironment,people'

sawarenessofenvironmentalprotectionisstrengthened.Localgovernmentshaveissuedregulationstolimitthedisposaloflivestockmanurebyidentifyingthedisposalstandard.Iftheproblemoflivestockmanurecannotbeproperlysolved,thedevelopmentof"

willbehampered,andthehealthydevelopmentofruraleconomicwillberestricted.

Atpresent,mostlivestockfarmsareinterestedin"

energy-environmentengineering"

inordertogetridofthedualrestrictionofmanurepollutionandrelativelawsandregulationsandthepredicamentthatfasterdevelopmentcausesmoreseriouspollution.Therecentsurveyshowsthat,80%ofthelivestockfarmsarewillingtoconstruct"

inthenearfuture,ifthefundisavailable;

16%ofthesurveyedfarmswillconstructthe"

before2010;

andonly4%willconstructtheengineeringafter2010.

II.CurrentSituationof"

Energy-EnvironmentEngineering"

ConstructioninChina

TheChineseGovernmentattachedmuchimportancetothedevelopmentof"

.TheMinistryofScienceandTechnologyandtheMinistryofAgricultureprovidespecialfundfortheprojectfromthe6thFive-Year-Planperiod（1981~1985）,andorganizedrelativeinstitutestoresearchonthisproject.Bytheendof8thFive-Year-Planperiod,seriestechnologiesofdifferenttypes,usage,andproductsconcerningtreatment,development,andutilizationofagriculturalwastessuchaslivestockmanureweredeveloped.Thesetechnologiesincludepre-treatment,anaerobicdigestion,biogastransfer,fertilizerproduction,post-treatmentofliquidafterdigestion,basedonthespecialtyofpigmanure,chickenmanure,andcowmanure.Someoftheindividualtechnologiesandcriteria,suchasresearchonbiologicalanaerobicfermentationmechanism,designoffermentationprocessofdifferentmanure,rationofbiogasproduction,ratioofCODremoval,havereachedtheinternationalleadinglevel.The"

energy-environmentalengineering"

technologyhasmulti-functions,i.e.environmentalprotection,energydevelopment,fertilizerproduction,andwatersaving.Thatistosay,thetechnologywillbringeconomicbenefitandsocialbenefit,andtheinvestmentislowerthanothercountries'

technologies.

Afewdemonstrativeprojectswerecarriedouttoassisttheresearchduringthe6th,7th,and8thFive-Year-Planperiod（1981~1995）,suchasinShanghaiXinhouFarm,ZhejiangFushanLivestockFarm,ShenyangMasanjiaPigFarm,andShanghaiJiadingBreedingFarm.Thesedemonstrativeproject,whichhavebeenconstructedindifferentregionsandunderdifferentnaturalcondition,havebeensuccessfullyoperatingformorethan5years.

Besides,onthebasisofcompletionof8thFive-Year-Planresearchproject,thedesignstandard,constructionandevaluationstandardfortreatmentandutilizationoflivestockmanurewereformulated.Thisshowsthatthetechnologieshavebeenmature,andthattheprimaryphaseofresearchonintegratedutilizationoflivestockmanureinChinahasended.

Becausetherawmaterialforfermentationinlivestockfarmsismainlylivestockmanure,andtheproportionsofsuspendingsubstanceandsolidsubstancearehigh,thecommontechnologicalprocessesarethefollowing:

first,full-mixingbiogasfermentationequipment,fermentedatnormaltemperature,therawmaterialiskeptforabout40days,andthebiogasproductionrateislow,approximately0.13~0.3m3/m3day;

second,塞流式fermentationprocesswithstirring,slurrycircling,andtemperaturepreservingequipment,thefermentationtemperatureisbetween15~32C,andthebiogasproductionrateus1.2~2.0m3/m3day;

third,up-flowslurrybed上流式污泥床反应器（UASB）reactororanaerobicfilter（AF）,ortheprocessthatcombinestheabovetwotogether,theadvantageofthisprocessisanaerobicmicroorganismcanbewelladheredtoimprovethereactionspeedandbiogasproductionquantity.

BiogastechnologyforlivestockfarmsinChinahasbeengraduallymaturesincethe1980s,andtheefficientengineeringandtechnologysystemwithmulti-functionshasbeenformed.Atpresent,thenormaltechnologicalprocessincludes:

1）pre-treatmentequipment,2）anaerobicdigester,3）equipmentforbiogascollection,storage,andtransfer,4）equipmentforpost-treatmentofliquidafterdigestion,and5）systemofsolidresiduetreatment.Theimprovementoftheseequipmentorsystemhasprovidedtechnologicalconditionsforincreaseofbiogasproductionrate,steadyoperationofsystem,decreaseofpollution,aswellasensuringtheefficientandsteadybiogassupplyforusers.

.

Biogasuse

Compostfromsolidresidue

Wastewater

Manurepool

Irrigationusingliquidafterdigestion

Full-mixingorimprovedanaerobicdigester

后沉池

Figure1isthetechnologicalprocessforanaerobictreatmentinpigfarms

Figure1

（1）Combinationofanaerobictreatmentandagriculturalutilization

Sandsedimentpool

Separatorofsolidandliquid

Adjustingpool

Biogas

Waterdisposal

Secondsandsedimentpool

Anaerobicdigester

Acidificationpool

曝气池

Partialcircling

Compost

Figure1

（2）Commontreatment

Biogas

Biogasdigester

Storagepool

Compoundfertilizerfromsolidresidue

Slurry

Feed

Fishfeedingpool

Aquaticplantpool

Irrigation

Liquidafterdigestion

Figure1（3）Ecologicaltreatmentandutilization

Generalspeaking,alarge-scalebiogasplantproducesbiogas1,000~2,000m3/day,andthetotalinvestmentis3~10millionRMByuan;

amedium-scalebiogasplantproducesbiogas50~1,000m3/day,andthetotalinvestmentis0.8~3.0millionRMByuan.Becausethelivestockfarmsaredevelopingtowardsmorecentralized,thedevelopmentofbiogasplantinthe21stcenturywillfocusonlarge-scalebiogasplant.

III.ExistingProblemsandBarriers

1.Conditionsfortechnologyindustrializationneedimproving

Intermsoftechnologyindustrialization,thecommercializationoflarge-andmedium-scalebiogasplantsisfacingthefollowingproblems:

✧Therearenostandardizedsystemofdesignandconstructionforlarge-andmedium-scalebiogasplants,andthestandardforqualificationappraisalofbiogasplantconstructionisinsufficient.

✧Automat