-.z---.--總結(jié)資料綜合厭氧處理乳品工業(yè)廢水和污泥摘要：人們研究了一個(gè)替代的乳品污水處理系統(tǒng)的性能參數(shù)，該系統(tǒng)包括兩個(gè)厭氧污泥反響器，均安排向上流動(dòng)，內(nèi)部脂肪別離浮選，外部板定居和浮動(dòng)材料沼氣池。反響器最初接種高負(fù)荷的絮狀和粒狀污泥。使用負(fù)荷率最高達(dá)5.5kgCOD/m3.d，水力停留時(shí)間17小時(shí)，發(fā)現(xiàn)反響器仍能穩(wěn)定去除90%的COD。長(zhǎng)鏈脂肪酸的測(cè)定使用抑制棕櫚酸脂，然而現(xiàn)在發(fā)現(xiàn)不僅取決于棕櫚酸酯的濃度，而且還跟棕櫚酸酯的生物量濃度比有關(guān)。導(dǎo)言生產(chǎn)產(chǎn)品的不同，以及在生產(chǎn)以奶制品為原料的產(chǎn)品使用的設(shè)備和工藝的不同，不同的工廠污水特征可能大不一樣。因此，每一個(gè)種情況，都必須單獨(dú)考慮，以確保適宜的處理方案〔德米雷爾等al.2005〕。盡管如此，由于生產(chǎn)過(guò)程中奶類(lèi)或以奶類(lèi)為原料的產(chǎn)品泄漏，一些成分有規(guī)律地在乳品工業(yè)廢水中檢測(cè)出來(lái)：乳糖，血脂，酪蛋白和其他蛋白質(zhì)。由甘油三酯組成的脂質(zhì)，主要出現(xiàn)在乳液最初的均質(zhì)過(guò)程。此外，廢水將根據(jù)在任何的進(jìn)程中所使用的化學(xué)洗滌劑呈現(xiàn)酸性或堿性。在處理乳品廢水以及其他復(fù)雜的廢水中，上流式厭氧污泥反響器取得的效果很小，這是因?yàn)橄喈?dāng)數(shù)量的有機(jī)物質(zhì)水解率或降低率過(guò)于低，而通常導(dǎo)致污泥床內(nèi)的卷吸或吸附。其結(jié)果只是稀釋生物量，偽裝了傳質(zhì)性能和損害污泥沉降能力。污泥活性因此降低，污泥可能從反響器中流出〔賽義德1984;賽義德1987年;Rinzema1993年;胡等al.1998〕。一批研究選用不適應(yīng)降解脂肪的生物且在基底負(fù)荷高達(dá)每克VSS中既有脂肪12.6克〔Petruy＆拉丁格1997年〕，這些研究說(shuō)明了奶制品脂肪乳劑的快速吸附和顯著退化。2000年維達(dá)爾等報(bào)告說(shuō)，脂肪豐富的乳品廢水的生物降解率局限于脂肪水解。他們分批進(jìn)展檢測(cè)不適應(yīng)的生物。然而，使用適合的載體和與底物適應(yīng)的微生物，水解可能無(wú)法成為總處理過(guò)程的速率限制因素。不受限于水解，總處理率可能會(huì)受限于由于長(zhǎng)鏈脂肪酸吸附污泥而降低的質(zhì)量傳輸速率〔佩雷拉等al.2003;佩雷拉等al.2004〕，或者是長(zhǎng)鏈脂肪酸對(duì)產(chǎn)甲烷物種的抑制作用〔佩雷拉等al.2005;胡等al.1996〕。根據(jù)1998年胡等人的研究報(bào)告，在上流式厭氧污泥反響器中由于長(zhǎng)鏈脂肪酸的吸附而產(chǎn)生的污泥上浮，可能會(huì)比那些產(chǎn)生抑制作用的出現(xiàn)在更低的長(zhǎng)鏈脂肪酸的濃度。為了研究上流式厭氧污泥床反響器前階段的脂肪吸附和長(zhǎng)鏈脂肪酸降解性能，假設(shè)干項(xiàng)研究采用間歇污水排放，取得了令人振奮的成果〔賽義德1984年;Nadais等al.2006〕。卡瓦萊魯?shù)热嗽?008年報(bào)告說(shuō)使用脈沖控制來(lái)提高產(chǎn)甲烷菌對(duì)長(zhǎng)鏈脂肪酸的降解，并建議連續(xù)操作的預(yù)期效果可能是下一階段的由脈沖喂養(yǎng)得到的生物馴化。幾項(xiàng)研究說(shuō)明，使用絮狀污泥而不是顆粒狀污泥，在去除長(zhǎng)鏈脂肪酸〔Nadais等al.2003〕和處理復(fù)雜的廢水〔賽義德1987年〕上會(huì)取得更好的效果。相比之下，絮狀污泥似乎受長(zhǎng)鏈脂肪酸抑制較少〔胡等al.1996〕。由于污泥反響器很難處理復(fù)雜的廢水，所以常會(huì)使用預(yù)處理，如利用氣浮進(jìn)展脂肪別離。為了省去前期的油質(zhì)別離獲得一個(gè)緊湊的系統(tǒng)，兩個(gè)上流式厭氧污泥床反響器進(jìn)展了修改，引入一個(gè)新的理念：上流式厭氧污泥床通過(guò)沉降使得內(nèi)部進(jìn)展油脂別離，外部進(jìn)展污泥再生。懸浮材料的使用完成了該系統(tǒng)，其目的是防止污泥處置。烏拉圭〔合作社Lecheria日達(dá)拉梅洛〕在本文提出，對(duì)這種替代污水處理系統(tǒng)的分析在達(dá)拉梅洛市的奶業(yè)中形成了真正的規(guī)模。乳制品工業(yè)廢水脂肪含量已經(jīng)高于40％的總化學(xué)需氧量，平均流量約100m3/d。材料和方法系統(tǒng)設(shè)計(jì)和運(yùn)行鑒于重大的負(fù)載和流量波開(kāi)工廠的污水流，緩沖罐〔平均水力停留時(shí)間為12小時(shí)〕安裝了上流式厭氧反響器。表1描述了緩沖池的出水特性，圖1顯示了完整的處理系統(tǒng)布局，其中包括緩沖池，兩個(gè)40立方米的厭氧反響器〔R1和R2〕，一個(gè)固定板和一個(gè)片浮動(dòng)材料的五立方米沼氣池。兩個(gè)厭氧反響器排水到一個(gè)帶著傾斜60°的金屬片、間隔5厘米的固定板上，并且利用污泥泵是局部污泥回流，返回到供應(yīng)槽。固定板要滿(mǎn)負(fù)荷地運(yùn)行15分鐘時(shí)間。沉淀池的出口直接排放到市政污水管道。一個(gè)用來(lái)提取浮動(dòng)脂肪的漏斗狀水槽被安裝在兩個(gè)反響器的廢氣罐內(nèi)并且要低于液位2cm。在每一個(gè)反響堆里，脂肪由水泵從一個(gè)作為脂肪手機(jī)接收水槽的外部空間提取的，其中漂浮材料被保存下來(lái)，順著流出的水流被返回給反響器。反響器從一個(gè)專(zhuān)門(mén)處理活性0.12gCH4-COD/gVSS.d甲烷的厭氧處理塘接種絮狀污泥。間歇和替代的提供速率被用來(lái)啟動(dòng)和逐步提速的過(guò)程中。連續(xù)供應(yīng)速度被用在120天的運(yùn)行之后，并且到達(dá)污水廠所產(chǎn)生的160天之后的總共速率。造粒工藝依據(jù)Jeison和Chamy〔1998〕技術(shù)進(jìn)展了分析，然后使用UTHSCA圖像工具軟件固定化顆粒瓊脂。浮動(dòng)污泥沼氣池在290天投入使用，以便從反響器穩(wěn)定地提取浮泥。固體沼氣池是接種污泥來(lái)自同一瀉湖所使用的反響堆，并采用條件下充分混合污泥回流泵的工作方式。該沼氣池支持每天再循環(huán)8次。該沼氣池出口流排入R1和R2以保持該系統(tǒng)的生物量穩(wěn)定。產(chǎn)生的沼氣除了用來(lái)保持沼氣池內(nèi)容在溫度32℃和38℃以外，還被用來(lái)增加3-4℃的流反響器進(jìn)水溫度。一個(gè)不銹鋼材料的同心管用于增加進(jìn)水和沼氣池的溫度。通過(guò)以監(jiān)測(cè)有機(jī)物去除的COD和脂肪和油的根底的數(shù)據(jù)記錄和系統(tǒng)運(yùn)行分析，對(duì)反響器的性能進(jìn)展了評(píng)價(jià)。鑒于廢水波動(dòng)，每周用冷凍24小時(shí)采集的樣本對(duì)R1和R2進(jìn)水和污水流進(jìn)展分析。COD為聯(lián)合確定的所有樣品。參照該階段之前使用的分析，以便確定可溶性化學(xué)需氧量COD和膠體化學(xué)需氧量，防止造成扭曲測(cè)量變量污泥結(jié)轉(zhuǎn)。油脂分析每月使用相結(jié)合的樣品進(jìn)水和污水流〔標(biāo)準(zhǔn)方法，APHA，AWWA，世界經(jīng)濟(jì)論壇1995年〕。每日針對(duì)進(jìn)水和污水流樣本點(diǎn)進(jìn)展溫度和pH測(cè)量記錄;并且每周三次采用總堿度，重碳酸鹽堿度和揮發(fā)性脂肪酸的滴定法測(cè)定根底樣品點(diǎn)。每天監(jiān)測(cè)數(shù)米外連接到的反響堆產(chǎn)生的沼氣。固定板執(zhí)行每日測(cè)量settleable固體30分鐘后的進(jìn)水和出水流樣本。利用監(jiān)測(cè)率和揮發(fā)性固體去除率的脂肪和除油，對(duì)沼氣池的性能進(jìn)展了評(píng)價(jià)。交易量測(cè)量浮動(dòng)了污泥提取的反響堆和美聯(lián)儲(chǔ)的沼氣池;和沼氣池進(jìn)，出口樣品分析了每周的總固體，揮發(fā)性固體和油脂。沼氣池溫度測(cè)量一天兩次，開(kāi)場(chǎng)和完畢時(shí)的采暖期。長(zhǎng)鏈脂肪酸含量反映了長(zhǎng)鏈脂肪酸的抑制效果，一批試驗(yàn)進(jìn)展了不同關(guān)系的長(zhǎng)鏈脂肪酸/的VSS。長(zhǎng)鏈脂肪酸抑制測(cè)定分批運(yùn)行使用鈉棕櫚酸酯，最豐富的牛奶甘油三酯和引物較小的長(zhǎng)鏈脂肪酸存在于牛奶。上流式厭氧污泥床反響器是用來(lái)進(jìn)展顆粒污泥測(cè)試的。三份測(cè)量是在150mL瓶不同濃度的生物量〔表示的VSS〕和棕櫚酸，而醋酸濃度顯示表保持不變。結(jié)果與討論污泥床反響堆圖2顯示反響器的COD去除率〔每周平均〕。去除效率保持在90％左右的COD負(fù)荷值增加的最多，為5.5kg/m3.d;水力停留時(shí)間在最大負(fù)荷時(shí)保持有效時(shí)間約17小時(shí)。在整個(gè)實(shí)驗(yàn)過(guò)程中，反響器的溫度波動(dòng)*圍為20℃至30℃，并且對(duì)COD去除率沒(méi)有產(chǎn)生太大影響。運(yùn)行的反響堆R1和R2分別開(kāi)場(chǎng)使用440和400kgVSS〔平均濃度值的11和10kgVSS/m3〕。圖3顯示的VSS演變。初期減少的5克/LVSS濃度是由于結(jié)轉(zhuǎn)。兩個(gè)反響堆之間又增加了約290kgVSS污泥，250天恢復(fù)了初始濃度的污泥。R2的和R1分別在于肉芽開(kāi)場(chǎng)在350天還是400天;R2的和R1分別還在于被測(cè)量的400天的小顆粒的平均粒徑為0.57毫米還是0.45毫米。造粒導(dǎo)致減少污泥結(jié)轉(zhuǎn)，也會(huì)導(dǎo)致增加VSS濃度，上述的20克/L的污泥容積指數(shù)從在inoculums的37mL/克以12mL/克下降完成。盡管在絮狀污泥據(jù)報(bào)告中，有更有效治療廢水高長(zhǎng)鏈脂肪酸濃度〔佩雷拉等人。2002年;Nadais，等al.2003〕，以及復(fù)雜的廢水〔賽義德1987年〕，然而顆粒污泥已自發(fā)在較高的有機(jī)負(fù)荷的階段，從而提高了污泥停留能力。結(jié)果是，微生物生長(zhǎng)，反響器運(yùn)轉(zhuǎn)過(guò)程中經(jīng)過(guò)消解和遺留的污泥可以順利流出，從而防止了污泥的突然暴增。IntegratedanaerobictreatmentofdairyindustrialwastewaterandsludgeABSTRACTPerformanceparameterwerestudiedinanalternativefull-scaledairyeffluencetreatmentsystemprisingtwoanaerobicsludge-blanketreactorsinparallelarrangementwithupwardflow，internalfat-separationbyflotation，e*ternallamellasettlerandfloatedmaterialdigester.Reactorswereinitiallyinoculatedsludgeandgranulatedinahigh-loadstage.Usingloadingratesuptoama*imum5.5kgCOD/m3.d-hydraulicresidencetimeof17hours-reactorefficiencywasfoundtoremainstablearound90%ofCOD.Averagesludgedigesterefficiencyusingaloadingrateof3.5kgVS/m3．dwithalipidcontentof47%ofCODamountedto78%ofVS〔87%oflipidremoval〕．LCFAinhibitionasassayedusingpalmitatewasfoundtodependnotonlyonthepalmitateconcentrationbutalsoonthepalmitate-to-biomassconcentrationratio.INTRODUCTIONDependingonthetypeofproduct,equipmentandunitprocessesentailedinprocessingofdairy-basedproducts,effluentcharacteristicsmayvarywidelyaccordingtoindustrialplant.Thus,everyindividualsituationmustbeconsideredseparatelywithaviewtoensuringappropriatetreatmentdesign(Demireletal.2005).Nonetheless,onaccountofprocessleakageofmilkormilk-basedproducts,anumberofconstituentsaresystematicallyfoundindairyindustrialwastewater:lactose,lipids,caseinandotherproteins.Lipids,posedoftriglycerides,arefoundmainlyinemulsionsresultingfrominitialprocessstageofhomogenization.Inaddition,effluentswillbeacidicorbasicaccordingtochemicalcleaningasusedatanytimeofprocess.TheuseofUASBreactorsindairywastewatertreatment-aswellasinthetreatmentofotherple*effluents-hasfoundlimitedsuccessinviewofthefactthataconsiderableamountoforganicmaterialhydrolyzesordegradesatane*cessivelylowrate,whilenormallybuildingupwithinthesludgeblanketbyentrainmentoradsorption.Theresultisthedilutionofbiomass,theaffectationofmasstransferpropertiesandtheimpairmentofsludgesettlingcapacity.Sludgeactivityisthereforereducedandsludgewashedoutfromthereactorintheoutletstreamcouldoccur(Sayed1984;Sayed1987;Rinzema1993;Hwuetal.1998).Rapidadsorptionandsignificantlyslowdegradationofdairyfatemulsionswerereportedforbatchstudiesusingbiomassthatwasnotadaptedtodegradingfatsandasubstrateloadashighas12.6gramsoffatpergramofVSS(Petruy&Lettinga1997).Vidaletal.(2000)reportedthatfat-richdairywastewaterbiodegradabilityrateislimitedbyfatshydrolysis.Theyperformedbatchassayswithnon-adaptedbiomass.However,usingmoderateloadsandsubstrate-adaptedmicroorganisms,hydrolysismaynotbetheratelimitingstageoftotaltreatmentprocess.Notlimitedbyhydrolysis,totalprocessratemaybelimitedbyareducedmasstransferrateduetoLCFAadsorptionontosludge(Pereiraetal.2003;Pereiraetal.2004),orbytheinhibitoryeffectofLCFAonacetotrophicmethanogenicpopulations(Pereiraetal.2005;Hwuetal.1996).AccordingtoresearchreportedbyHwuetal.(1998),sludgeflotationinUASBreactorsduetoLCFAadsorptionmayoccuratlowerLCFAconcentrationthanthosethatproduceinhibitoryeffect.Withaviewtostudyingtheinfluenceofthestageofadsorptionprecedinglipid–andLCFA-degradationontheperformanceofUASBreactors,severalstudiesweremadeusinganintermittenteffluentfeed,leadingtoencouragingresults(Sayed1984;Nadaisetal.2006).Cavaleiroetal.(2008)reportedthatuseofpulse-feedsresultsinincreasedtoleranceofacetotrophicmethanogenstoLCFA,andsuggestthatsatisfactoryresultsforcontinuousoperationmaybeobtainedfollowingastageofbiomassacclimatizationbymeansofpulse-feed.Severalstudiesdemonstratedthattheuseofflocculentsludge–ratherthangranular-resultsinahigherefficiencyinremovingLCFA(Nadaisetal.2003)andtreatingple*effluents(Sayed1987).Incontrast,flocculentsludgeappearstobelessresistanttoLCFAinhibition(Hwuetal.1996).Asaresultofdifficultiesintreatingple*effluentsinsludge-blanketreactors,pre-treatmentmethodsarenormallyused,suchasfatseparationbymeansofflotationbydissolvedair.Inordertoobtainapactsystemwithouttheneedofpreviousfatsseparation,twoUASBreactorsweremodifiedtointroduceanovelconcept:UpflowAnaerobicSludgeBlanketwithinternalfatseparatorande*ternalsludgerecoverybysettling.Thesystemispletedbyafloatedmaterialdigesterwiththeobjectiveofavoidsludgedisposal.AnanalysisofthisalternativewastewatertreatmentsystemconstructedatrealscaleinadairyindustryinMeloCity,Uruguay(CooperativadeLecheriadeMelo)ispresentedinthispaper.Thisdairyindustrialwastewaterhaslipidcontenthigherthan40%oftotalCOD,andthemeanflowisabout100m3/d.MATERIALSANDMETHODSSystemdesignandoperationInviewofsignificantloadandflow-ratefluctuationsintheplant’seffluentstream，abuffertank〔averagehydraulicresidencetimeof12hours〕wasinstalledupstreamoftheanaerobicreactors.Table1depictstheeffluentcharacteristicsoutletthebuffertank,andFigure1showsthepletetreatmentsystemlay-out,prisingthebuffertank,two40m3anaerobicreactors(R1andR2),alamellasettleranda5m3digesteroffloatedmaterial.Outleteffluentsofbothanaerobicreactorsdischargetoalamellasettlerwithplatestilted60°andspacedat5cm,retainingpartofthesludgecarry-overfromthereactors,returningittothefeedbo*bymeansofpumpingequipment.Thelamellasettleroperatesataresidencetimeof15minutesatfull-load.Thesettlingtankoutletisdischargedtomunicipalsewer.Afunnel-shapedsinkfore*tractionoffloatingfatwasinstalledinbothreactors,insideoftheoff-gasheaderandtwocentimeters,belowliquidlevel.Ateachreactor,fate*tractionwasperformedbypumpingfromane*ternalchamber-actingasfattrap-receivingthedischargeofthesink,wherebyfloatmaterialisretained,returningtheoutletstreamofthischambertothereactor.ThereactorswereinoculatedwithflocculentsludgefromananaerobictreatmentlagoonofanabattoirwithSpecificMethanogenicActivityof0.12gCH4-COD/gVSS.d.Intermittentandalternatefeedrateswereusedatstart-up,withrateincreasinggradually.Continuousfeedratewasusedafter120dayoperation,reachingthetotalrateofwastewatergeneratedbytheplant160daysafterstart-up.GranulationprocesswasanalysedfollowingtheJeisonandChamy(1998)technique,immobilizinggranulesinagarandthenusingUTHSCAImageToolsoftware.Thefloatsludgedigesterwasputinoperationonday290inordertostabilizefloatingsludgee*tractedfromthereactors.Soliddigesterwasinoculatedwithsludgefromthesamelagoonasusedforthereactors,andoperatedunderfullmi*ingconditionswithsludgerecirculationbymeansofpumping.Thedigesterhold-upwasrecirculated8timesperday.ThedigesteroutletstreamwasdischargedintoR1andR2inordertoretainthesystem’sbiomasshold-up.Generatedbiogaswasusedtoincreasereactorinfluentstreamtemperatureby3-4℃,inadditiontokeepingthedigestercontentsatatemperaturebetween32℃and38℃.Aconcentrictubese*changerconstructedinstainlesssteelwasusedtoincreasethetemperatureoftheinfluentandofthedigestercontent.DatarecordingandsystemoperationanalysisReactorperformancewasevaluatedbymonitoringtheorganicmatterremovalonaCODandafat-and-oilbasis.Inviewofwastewaterfluctuations,R1andR2influentandeffluentstreamswereanalyzedweeklyusingrefrigerated24-hoursamplescollecteddaily.CODwasdeterminedforallbinedsamples.Asettingstagewasusedpriortoanalysis,sothatCODdeterminationsincludesolubleCODandcolloidalCOD,avoidingdistortedmeasurementresultingfromvariablesludgecarry-over.Fatsandoilswereanalyzedmonthlyusingbinedsamplesofinfluentandeffluentstreams(StandardMethods,APHA,AWWA,WEF1995).TemperatureandPHmeasurementswererecordeddailyforpointsamplesoftheinfluentandeffluentstreams;andtotalalkalinity,bicarbonatealkalinityandvolatilefattyacidsweredeterminedbytitrationforpointsamplesonathree-per-weekbasis.Generatedbiogaswasmonitoreddailybymetersconnectedtoeitherreactor.Lamellasettlerperformancewasevaluatedbydailymeasurementofsettleablesolidsinafter30minutes,forbothinfluentandeffluentstreamsamples.Digesterperformancewasevaluatedbymonitoringtherateofvolatilesolidremovalandtherateoffat-and-oilremoval.Dailyvolumemeasurementweremadeoffloatedsludgee*tractedfromthereactorsandfedtothedigester;anddigesterinletandoutletsampleswereanalysedonaweeklybasisforTotalSolids,VolatileSolidsandFatsandOils.Digestertemperaturewasmeasuredtwiceaday,atthebeginningandendoftheheatingperiod.AssayingLCFAinhibitionToevaluatetheeffectofLCFAinhibition,batchtestswerecarriedoutwithdifferentrelationshipsofLCFA/VSS.LCFAinhibitionwasassayedinbatchrunsusingsodiumpalmitate-thelargestabundantofmilktriglyceridesandprimerofsmallerLCFApresentinthemilk.GranularadaptedsludgefromtheUASBreactorswasusedtoperformthetests.Triplicatemeasurementsweremadein150mLvialswithvaryingconcentrationofbiomass(e*pressedasVSS)andpalmitate,whiletheacetateconcentrationwaskeptconstantasshowninTable2.RESULTSANDDISCUSSIONSludgeblanketreactorsFigure2showsreactorfeedloadsandremovalefficiencyinCOD(weeklyaverage).Removalefficiencyremainedatavaluearound90%ofCODforloadvaluesincreasingupto5.5kg/m3.d;thehydraulicresidencetimerema