胞外聚合物对生物絮凝影响的研究龙腾锐

龙腾锐1,　龙向宇1,2,　唐　然2,　康　健1,　高绍双1(1.重庆大学三峡库区生态环境教育部重点实验室,重庆400045;2.解放军后勤工程学院营房管理与环境工程系,重庆400016)　　　:　采用超声波法与阳离子交换树脂法分别提取好氧活性污泥絮体外层的胞外聚合物(LEPS)与内层的胞外聚合物(TEPS),用LEPS与TEPS分别絮凝污泥悬浮液,考察它们对生物絮凝的影响。研究结果表明,增加LEPS投量不利于生物絮凝,并且LEPS表面负电荷的增大与疏水性的降低会导致絮凝效果变差;而提高TEPS投量能够促进生物絮凝,当TEPS投量60mg/gVSS时,其投量的增加对絮凝率的影响不大;泥龄为15d的TEPS较3d的TEPS具有更大的疏水性,表现出更强的絮凝性能。二价阳离子(如Ca2+)能有效降低颗粒物之间的静电斥力,促进生物絮凝;然而,三价阳离子(如Al3+)是生物絮凝中最重要的阳离子成分。　　:　胞外聚合物;　生物絮凝;　表面电荷;　疏水性;　超声波;　阳离子交换树脂:X703　　:A　　:1000-4602(2009)07-0030-06EffectofExtracellularPolymericSubstancesonBioflocculationLONGTeng-rui1,　LONGXiang-yu1,2,　TANGRan2,　KANGJian1,　GAOShao-shuang1(1.KeyLabofThreeGorgesReservoirRegion'sEco-EnvironmentMinistryofEducation,ChongqingUniversity,Chongqing400045,China;2.DepartmentofBarracksManagementandEnvironmentalEngineering,LogisticalEngineeringUniversityofPLA,Chongqing400016,China)　　Abstract:　LooselyboundEPS(LEPS)andtightlyboundEPS(TEPS)wereextractedbyultra-soundandcationexchangeresininturnfromaerobicactivatedsludgeflocs,andtheeffectofthetwoEPSonbioflocculationwasinvestigated.Theresultsareshownasfollows:thelargedosageofLEPShinderesbioflocculation,andtheincreaseinsurfacechargeandthedecreaseinhydrophobicitydonotbenefittheremovalofsuspendedsolid;however,theincreaseinTEPScanpromotebioflocculation.WhentheTEPSdosageismorethan60mg/gVSS,TEPShaslittleeffectontheflocculationrate.ComparedTEPSwithsludgeretentiontimeof3d,TEPSwithsludgeretentiontimeof15dexhibitstrongerhydrophobicityandflocculationcapability.Thebivalentcation,suchasCa2+,canreduceelectrostaticrepulsionbetweentheparticles,whichisimportanttobioflocculation.However,thetrivalentcation,suchasAl3+,isthemostimportantcationtobioflocculation.　　Keywords:　extracellularpolymericsubstances;　bioflocculation;　surfacecharge;　hydropho-bicity;　ultrasound;　cationexchangeresin　　(EPS),。2040,EPS[1～5],EPS,,。[6、7],·30·第25卷　第7期2009年4月　　　　　　　　　　　　中国给水排水CHINAWATERWASTEWATER　　　　　　　　　　　　　Vol.25No.7Apr.2009SRT3d15d(LEPS)(TEPS),EPS,EPS,EDTA,SRTLEPSTEPS。1　材料与方法1.1　EBA21,TGL-16G,CY-5D(24mm),NanoZS90Zeta,001×7,。1.2　EPSSBR,SBRSRT3d15d。,。,LEPS,21kHz、36W1min[7];LEPS2,TEPS[7],80g/gVSS,550r/min1.5h。6000r/min(4200g)15min,LEPSTEPS;8000r/min(6000g)30min,LEPSTEPS。[6、7]。1.3　LEPSTEPS(SRT3d),EPS。,(VSS4960mg/L)4TEPS。,,,Zeta。4,1.07mg/L;Zeta-38.1mV,[7]。Zeta1。1　ZetaTab.1　PolymerscontentinsupernatantandZetapotentialofsludgeduringcleaning/(mg·L-1)/(mg·L-1)/(mg·L-1)DNA/(mg·L-1)/(mg·L-1)Zeta/mV24.111.55.51.242.3-34.911.94.82.20.619.5-35.65.21.31.407.9-37.10.680.050.3501.07-38.11.4　,550nm0.960～1.000,VSS1200～1260mg/L。LEPSTEPS100mL,,200mL;,160r/min0.5min,40r/min5min,30min550nm。0.960～1.0001∶1,EPS。[6、7]。2　结果与分析2.1　EPSSRTLEPSTEPS2。2　EPSTab.2　QuantityandcharacteristicsofEPS　3dLEPS3dTEPS15dLEPS15dTEPS/(mg·g-1VSS)58.7±9.7102.3±5.128.6±4.681.9±4.8/(mmol·g-1EPS)-1.69±0.283＊-1.26±0.14-1.43±0.193＊-0.98±0.10/%8.9±1.73＊21.7±2.816.8±2.13＊40.4±5.8　:　＊LEPS。　　2,SRT3dSRT15dLEPS;TEPSLEPS;EPS:3dLEPS15dLEPS3dTEPS15dTEPS,。·31·龙腾锐,等:胞外聚合物对生物絮凝影响的研究第25卷　第7期PersonLEPSTEPSSS(FA),:LEPS,LEPSSS;TEPS,。2.2　LEPSEPS,[8]。Ca2+120mg/L(300mgCaCO3/L)Ca2+、Al3+80、6mg/L,EPS。Ca2+120mg/L,LEPS,120mg/gVSS,47%39%。Ca2+、Al3+80、6mg/L,,LEPS:SRT3dLEPS,71.5%48.5%;SRT15dLEPS,,,71.5%74.9%,57.9%。,LEPSPerson。Ca2+120mg/L,LEPS47%;Ca2+、Al3+80、6mg/L,71.5%,Al3+。Al3+,,。,Ca2+,LEPS;Al3+,LEPS,Al3+Ca2+LEPS。2.3　TEPS,TEPS,。Ca2+120mg/L,SRT3dTEPS60mg/gVSS,46.1%53.7%;,54%～55%。SRT15dTEPS40mg/gVSS,54.6%;,55%～56%。Ca2+、Al3+80、6mg/L,SRT3dTEPS40mg/gVSS,71.5%93.1%;,94%～95%。SRT15dTEPS20mg/gVSS,93.5%;,96%～97%。,TEPS,TEPS60mg/gVSS,;15dTEPS3dTEPS,,Person。,TEPSLEPS,。1,TEPS,[9],TEPSLEPS。,TEPS,TEPS;,15dTEPS3dTEPS。EPS,LEPS,,TEPS;,LEPS,,、。,LEPS,,。2.4　EPS80mg/gVSS、Ca2+80mg/L、Al3+6mg/L,EPS,,,1。1,15dTEPS,,97.5%96.1%。3dTEPS,1mol/L;1mol/L1.5mol/L,92.7%82.4%;2mol/L,78.2%。SRT15dLEPS3d,2mol/L,·32·第25卷　第7期　　　　　　　　　　　　　　中国给水排水　　　　　　　　　　　　。SRT3dLEPS,0.5mol/L1.5mol/L,69.8%48.3%;2mol/L,44.6%。,2mol/L[10]。,,:3dLEPS15dLEPS3dTEPS15dTEPS。,SRT,;,,。1　Fig.1　Effectofureaconcentrationonbioflocculation2.5　EDTAEDTAEPS,,,2。2　EDTAFig.2　EffectofEDTAconcentrationonbioflocculation2,EDTA,TEPS。EDTA300mg/L,15dTEPS97.1%96.3%,3dTEPS96.9%93.2%。LEPSEDTATEPS,81.4%、71.6%73.7%61.4%。EDTACa2+、Mg2+,Ca2+,;,EDTAAl3+,Al3+。,EDTACa2+。,EPSCa2+:3dLEPS15dLEPS3dTEPS15dTEPS。3　讨论3.1　。,K+、Ca2+、Al3+、,Zeta,(EPS80mg/gVSS)。3、4。3　Ca2+ZetaFig.3　EffectofCa2+concentrationonZetapotentialoffloc4　Al3+ZetaFig.4　EffectofAl3+concentrationonZetapotentialofflocK+468mg/L(12mmol/L),0.012(KCl),EPSZeta-27.8～·33·龙腾锐,等:胞外聚合物对生物絮凝影响的研究第25卷　第7期-29.3mV,,23%～27%。Ca2+Al3+K+Zeta。Ca2+60mg/L,Zeta-14～-15mV;Ca2+Zeta,-12.5～-14mV。EPSZetaAl3+,。Al3+18mg/L,3dLEPS、15dLEPS、3dTEPS15dTEPSZeta-12.2、-9.1、-4.9、-2mV。Al3+,Zeta,Al3+54mg/L,Zeta-7.7、-5.0、-2.7、1.1mV。,Al3+Ca2+K+,。K+20mg/L[11],K+。Ca2+,80～200mg/L[11],Ca2+40%～65%,,。Al3+Fe3+,,;Al3+Fe3+,Al3+Fe3+,,。,(Al3+)。3.2　EPSTEPSLEPS,TEPS,LEPS。,EPS,、EPS;,(EPS,LEPSTEPS),。TEPS,,。LEPS,;LEPS,,,。,SRTTEPSLEPS。SRT(15d)TEPSLEPS,SRT(3d)TEPSLEPS,,,,。,SRTTEPSLEPS,。4　结论①　LEPS,LEPS。TEPS,TEPS60mg/gVSS,;15dTEPS3dTEPS,。②　SRT(SRT=15d),Ca2+;,Ca2+,