水污染处理文献综述英文

1、Applicationofmulti-soil-layersystem(MSL)inruralwastewatertreatmentAbstract:withthecontinuousimprovementoflivinginruralfarmers,thewaterconsumptionofresidentsisincreasing,ruralsewageemissionswillcontinuetoincrease,ifnottreateffectively,thewaterenvironmentinruralareaswillbeseriousdeteriorated,andinflue

2、ncethelifequalityofruralresidents.Inthiscasethispaperpresentsadecentralizedsewagetreatmentsystem,multi-soil-layersystemtechnology(MSL)applicationintheruralsewagetreatment,thispapersummarizesthenewtechnology,youcanbetterunderstandandpractice,especiallyinthedevelopingcountrieswhereisinneedofthistechno

3、logy.Intheforeseeablefuture,itcanprotectpublichealthandthesustainabledevelopmentoftheenvironment,anditalsoprovidesanewwayforruralsewagetreatment.Keywords:ruralsewage;mult-soil-layeringsystem;distributed1.IntroductionInrecentyears,withthecontinuousdevelopmentofeconomy,people'slivingstandardsconti

4、nuetoimprove,ruraleconomicdevelopmentisalsoveryrapid,buttheruraleconomicdevelopmentandenvironmentaldevelopmentisnotsynchronized,seriousruralwaterpollution.Whilehightechnicalsewagetreatmentplants,suchascentralizedsewagetreatmentplantsareinvoIvedinlargeinvestmentcosts,highoperatingcosts,Becauseofecono

5、micconstraints,suchsystemsarelesssuitableforlivestockfarmsandsmallcommunitiesinruralareas.Whilethemulti-media-soillayersystem(MSL)sewagetreatmentsystem,thisdecentralizedsewagetreatmentsystem,ithaslessinvestment,lowoperatingcosts,highhandlingload.Besides,theutilitymodelovercomesthedefectsofthepriorso

6、ilpercolationwhichiseasytobeblockedfromthespacestructure.ThesewagetreatmentsystemisonekindofthepurificationtechnologyofseweragetreatmentsoildevelopedinJapanintwentiethCentury,thesoilsystemwillbemodularized,andthemoduleissetuparoundthewaterinthesoillayertoavoidclogging,andaddingnaturalorganicmaterial

7、stosoilmodulescanimprovethepurificationabilityofthesystem.TheMSLsystemconsistsofaPermeablelayer(PL)andasoilmixinglayerblock(SMB),ThePermeablelayerisusuallycomposedoflargerparticlesfillerssuchasgravel,pumice,perliteandzeolite.Higherporositycaneffectivelypreventcloggingofthesoilwaterlayer.Atthesametim

8、e,theformationofaerobicenvironmentisconducivetoorganicdegradation.Themixedlayersoilismainlypackingsoilmixedwithother20%-30%othermaterialssuchasactivatedcarbon,wood,ironandothermaterialorsoilwithlocalresources.Theorganicmaterialaddedinthesoilmixedlayercanimprovethebiologicaldecompositionandadsorption

9、capacityofthesystem,andcanalsoimprovethesupplyofhydrogenintheprocessofnitrogenremovalandpromotetheremovalofnitrogen.TherearemanyresearchesonMSLsystemtreatingurbansewage,livestockwastewaterandriverwaterathomeandabroad.ResearchersinChina,YeHaietalstudiedtheeffectofsurfaceloadonpollutedriverwatertreate

10、dbymulti-soil-layersystem.SongYing2hadstudiedthetreatmenteffectofmultimediumsoilinfiltrationsystemforturtlebreedingwastewater.ZouJud3alsopointedoutthatmulti-soil-layermaterialselectionwillhaveacertainimpactonthedomesticsewagetreatmentefficiency.Inforeigncountries,especiallyinJapan,ThailandandIndones

11、ia,MSLsystemshavebeenusedtohandlevarioustypesofwastewater,butthedomesticofthistechnologyinsewagetreatmentinruralareasthereisnocomprehensivestudy,ThisarticlethroughtotheMSLsystemtechnologyprocessingruraldomesticsewageresearch,inordertoprovidesometechnicalsupportfortheMSLsysteminthepracticalapplicatio

12、nofruralsewagetreatment.2.1characteristicsofruralsewageForalongtime,China'spollutioncontrolonruralattentionandinvestmentfarlessthanthecity,96%ofthevillageswithoutdrainagepipenetworkandsewagetreatmentsystem,Therandomdischargeofdomesticsewagehasbecomeoneofthemainreasonsforthedeteriorationofwaterqu

13、alityinthebasin,andisalsoanimportantfactorcausingtheruralwaterenvironmentpollutionandlakeeutrophication.Atthesametime,itseriouslyaffectsthesafetyofproductionandlivingintheruralareas,andseriouslyaffectstheeconomicdevelopmeiThemainfeaturesofruralsewageinChinaare:(1) Theamountishugeandincreasesyearbyye

14、ar.Statisticsshowthatin2OO2.Thereare3.205milliontonsofnationalruraldomesticsewagedailyemissions.Thetotalnitrogenemissionisabout283.1t,totalphosphorusdailyemissionisabout56.6t,basicallywithoutanytreatmentdirectlydischarged.(2) Waterqualityandwaterquantityfluctuationarehuge.Ruralsewagewaterisnotstable

15、,differentperiodshavedifferentwaterquality,generallydonotcontainheavymetalsandtoxicandharmfulsubstances,butcontainsmoresyntheticdetergentandbacteria,viruses.(3) Moresources.Inadditiontohumanfeces,kitchengeneratedsewage,therearehouseholdcleaning,domesticwasteIandfillleachategeneratedsewage,whichwillt

16、henentertheriverpartofthesewage,willcausegreaterpollution.(4) Lowtreatmentrate.Partofthesystemcannotrunlowtemperature,ruralsewagedailyvariationcoefficientandseasonalvariationcoefficient,thesystemafewtimehighloadoperation,ifthereislittlesewage,itwillstoprunning.(5) Wideandscattered.Scatteredgeographi

17、caldistributionofvillagescausedsewagedispersionanditisdifficulttocollect.2.2themainsourceofruralsewageRuralsewagereferstotheformationofsewageoftheruralareasinthelifeandproductionprocess,includingruralproductionwastewaterandruraldomesticsewagetwoaspects.Ruraldomesticsewagereferstotheresidentslivingin

18、theprocessoftoiletdischargeofsewage,bath,laundryandkitchensewage,etc.Ruralproductionsewagereferstolivestockandpoultrybreeding,aquaculture,agriculturalproductsprocessingandotherhighconcentrationoforganicwastewater.BecauseChina'srurallivingisscattered,ruraldomesticsewageshowedasmallamountandwidedi

19、spersion.Lackofappropriatesewagecollection,treatmentfacilities,domesticsewagewithouttreatmentwillbefreetodischarge,thehealthofruralresidentstobringgreaterharmAtthesametime,ruralsewageproductionalsoposesagreaterthreattotheruralecologicalenvironment.2.3maintechnologiesofdecentralizeddomesticsewagetrea

20、tmentBeginningin1970s,Japan,theUnitedStates,Europeandotherdevelopedcountriesontheuseofdecentralizedsewagetreatmentofruralsewagetreatment,hasaccumulatedalotofexperienee,achievedgoodresults.TheUnitedStatessineethemid-20thcenturybegantheconstructionofruralsewagetreatmentfacilities,in1972promulgatedthef

21、irstcompletecleanwater,thenaccordingtothedistributedprocessingtechnologyin2002promulgatedthedecentralizedsewagetreatmentsystemapplicationmanual.1987,InDenmarkpromulgatedadecentralizedsewagetreatmentguidelines.Germanyfrom2003toimplementthedecentralizedneedleinfrastructuresystemprojectresearch,usememb

22、ranebioreactorpurificationtotreatremoteruralsewage.Australiaproposedasewagetreatmentlandusesystem.WhileresearchandapplicationofruralsewagedecentralizedtreatmentinChinabeganinlate1980s,Comparedwithdevelopedcountriesandregions,therearestillmanygapsinlawsandregulationssystem,technicalstandardsystemandm

23、anagementandservicesystemLnrecentyears,domesticscholarshavedonealotofresearchonruraldomesticsewage,andputsforwardsomematureprocessingtechnology,includingaerobicbiologicaltreatment,anaerobicbiologicaltreatmenttechnology,soilinfiltrationtechniqueandphysicalandchemicalprocessingtechnologyetc.Therearema

24、nyscholarsinthemulti-soil-layersystemimprovementandapplicationdevelopmentoftheJapanese,ithasalsodonealotofresearch,somescholarsfoundthroughexperiments:toearthwormsoilinfiltrationlayercanalsosolvetheproblemofblockageofMSLsystem,butalsocanguaranteethewinteroperationeffectinwinter9-10.Multi-soil-layert

25、reatment(MSL)systemisakindoflandsewagetreatmentsystem.MainlycomposedofPermeablelayer(PL)andasoilmixinglayerblock(SMB),Fromtoptobottomarewaterprooflayer,gravellayer,soillayerandmixedlayer(twoalternatelyarranged),inaddition,theMSLtechnologyhasacertainterrainfallfromtheinlettotheoutlet,mainlybythedropl

26、etwatercanautomaticallyflowinthesystem,atthesametimetopurity11】.WastewatercontainshighconcentrationsofBOD,COD,ammonianitrogen,phosphateionsandorganicmatter.WhenthewastewaterintotheMSLsystem,theorganicmatterinwastewatercanbeadsorbedonthesurfaceofzeoliteandsoilthroughphysicalandchemicaleffects,followe

27、dbydecompositionofsoillayerinmicroorganism,andphosphorusremovalismainlythroughthesoillayerofironisoxidizedtoferrichydroxideaftertheformationofinsolubleiron,thenadsorptioninwastewatertheformationofphosphatecoprecipitation.Nitrogenremovalismainlythroughnitrificationanddenitrificationbyammoniaion,andfi

28、nallyreducedtonitrogendischargesystem.Multi-media-soillayersystemisusedtotreatwastewaterfromtraditionalsoilinfiltrationsystem.Ithasthedisadvantagesoflowtreatmentload,largeground,easytoblocknitrogenandphosphorusremovalandothershortcomingd12.TheMSLsystemwith"soilmodular"asthecoreconcept,itsu

29、niquebricktypeinternalstructurecanformapluralityofaerobicandanaerobicenvironmentinordertopromotetheremovalofpollutants,Amongthem,thepermeablelayergreatlyimprovesthewaterpermeabilityofthesystemtopreventclogging,addingnaturalmaterialsinthesoilincreasesthepurificationcapacityofthesystem.3. ConclusionsW

30、iththeeconomicreformanddevelopment,China'senvironmentalawarenessisalsoimproving,waterpollutioninruralareashavealsoobtainedmoreandmoreattention,TheMSLsystemapplicabletothesmallpopulation,scatteredinruralareas,thedecentralizedsewagetreatmentsystemcanbewidelyinstalledandusedintheruralsociety,especi

31、allyinruralareasofdevelopingcountriessuchasChinese,Chineseisinneedofsuchtechnology,sustainabledevelopmentcanprotectthepublichealthandtheenvironment.4. ReferenceYeHaiYeetal.EffectofsurfaceloadonpollutedriverwatertreatedbymultisoillayersystemJ.Chinawatersupplyanddrainage,2012,28(19):747YingSongetal.Tr

32、eatmentofturtleaquacultureeffluentbyanmulti-soil-layersystemJ.JournalofZhejiangUniversityScieneeB.2015,16(2):145154ZouJun,ChenXinetal.Effectofmaterialselectionofmulti-soil-layersystemondomesticwastewatertreatmentefficiencyJ.Journalofecologyandruralenvironment,2010,26(1):14181 ZhangKeqiangetal.RuralsewagetreatmenttechnologyMBeijing:ChinatreatmentsystemsintheUnitedStatesJ.Chinawatersupplyanddrainage,2004,2