国立台湾大学台大工程学刊

BulletinoftheCollegeofEngineering，N.T.U.，No.86，October2002，pp.103–112國立臺灣大學「台大工程」學刊第八十六期民國九十一年十月第103–112頁103廢水污泥於建築工程中之新應用POTENTIALREUSEOFWASTEWATERSLUDGEFORINNOVATIVEAPPLICATIONSINCONSTRUCTIONINDUSTRY鄭俊華*鄒光耀+方思韵†Joo-HwaTayKuan-YeowShowSze-YunnHong簡昭萸‡李篤中#Chao-YuChienDuu-JongLee*#教授+助理教授†研究助理‡碩士*+†新加坡南洋理工大學土木與結構工程學院‡#國立台灣大學化學工程學系*#Professor+AssistantProfessor†ProjectOfficer‡Master*+†SchoolofCivilandStructuralEngineering,NanyangTechnologicalUniversity,Singapore639798,R.O.S.‡#DepartmentofChemicalEngineering,NationalTaiwanUniversity,Taipei,Taiwan10617,R.O.C.AbstractThelargevolumeofwastewatersludgegeneratedrequiresenormouslandfillspacefordisposal.Divertingthewastewatersludgefromlandfillwouldalleviatetheshortageoflandfillsites.Thusalternativeapplicationshavetobeconsideredforthewastewatersludgedivertedawayfromthelandfills.Theuseofwastewatersludgefortheproductionofconstructionmaterialsisreviewedinthispaper.Wastewatersludgecanbeusedasrawmaterialsformakingbricks,concretefiller,concreteaggregatesandcement-likematerials.Upto40%ofsludgecanbemixedwithclayforstructuralbricksmaking.Foruseasconcretefiller,upto10%byweightofthecementcanbereplacedbysludgeashwithoutaffectingthestrengthproperty.Sludgeaggregatemadefrom100%sludgecanbeusedtoreplacegraniteinconcretewithoutanycompromiseincompressivestrength.Cement-likematerialsmadefromsludgecanbeusedtoreplaceordinaryPortlandcementforupto20%byweighttoproduceblendedcementswithoutaffectingthemortarstrength.Thestudyrevealsthatthereuseofwastewatersludgeasconstructionmaterialsoffersatechnicallyfeasiblealternativeforsludgedisposal.Thepropertiesofeachoftheproductsarereportedanddiscussed.Keywords:wastewatersludge,potentialapplications,constructionmaterials.ᄠॊ廢水處理程序所產生的大量污泥往往需要甚大面積的掩埋場進行處置，為因應目前掩埋場址日益短缺的問題，必須尋求掩埋之外的處置方式。本篇論文回顧將廢水污泥利用在製造建材原料的一系列研究，包括磚塊、混凝土填充物、混凝土骨材、與似水泥物質等。在混合污泥與黏土製磚時，污泥所佔比例可達重量分率40%；製造混凝土填充物時，重量分率10%的水泥成份可置換為污泥灰，而不影響其強度；污泥製成的骨材可以取代混凝土內的花崗岩材質，而不影響其壓縮強度；污泥製成的似水泥物質亦可取代重量分率20%的一般波特蘭水泥，而不影響製成混合水泥之灰泥強度。本研究顯示，將廢水污泥再利用於建築材料將提供掩埋處置以外的另一技術可行方案，在此也討論各種製品的物性。ᜮᗢພȆ廢水污泥、再利用、建築材料1.INTRODUCTIONSludgeisgenerallydisposedofthroughlandfillingandspreadingonreclaimedland.Incinerationcanreducethevolumeofsludgebuttheremainingresiduesstillrequiretobedisposedof.Allthesedisposal104BulletinoftheCollegeofEngineering,N.T.U.,No.86,October2002methodshavevaryingdegreesofenvironmentalimpact.Increasinglystringentenvironmentalregulationshavecausedmarkedincreaseinthewastedisposalrequirements.Thedisposalofsludgefromwastewatertreatmentisthusposingproblemsofhighcomplexitytoanymunicipality.Hence,thereisaneedforalternativemethodsofsludgedisposal,suchasreutilizationthatpossiblyexertslessharmfuleffectsontheenvironment.Studieshavebeencarriedoutbyvariousresearchersonpossibleapplicationsofsludgeandsludgeashasbuildingandconstructionmaterials.Thereuseofwastewatersludgeinthisaspectwouldprovidegoodpossibilitiesofalleviatingthewastewatersludgeinsignificantquantities.Thispaperprovidesareviewofstudiesofthewastewatersludgeforuseasbuildingandconstructionmaterials.2.BRICKSTheuseofmunicipalwastewatersludgemixedwithclaytoproducebrickshadbeenreportedbyTay[2~4].Amixtureofdriedsludgeandclaywasgroundandcrushedintofinepiecesbyacrushingmachine.Thecrushedmixturewasmixedwithwaterandextrudedintobricksamples.Thebricksweredriedandthenfiredinakilnatatemperatureof1080°Cforabout24h.Table1(a)showsthepropertiesofbrickmanufacturedfromsludge.Theresultsindicatedthatupto40%byweightofdriedsludgecouldbemixedwithclayinmakingbricks.Thesurfacetextureofthebrickswasuneven,mainlyduetotheorganiccomponentbeingburntoffduringthefiringprocess.Table1PropertiesofbrickusingsludgeandsludgeashShrinkage(%)%sludgebyweightSpecificgravityWaterabsorption%Lossonignition%BeforefiringAfterfiring(a)Sludge0.02.380.035.44.09.9110.02.320.7410.74.210.1520.02.241.3714.33.710.8430.02.172.5819.74.212.2640.01.983.6322.34.012.87(b)Industrialsludge302.903.30.4320.024.8402.891.30.3918.824.8502.9523.10.4513.5–11.2703.131.70.4516.146.3803.140.90.4516.541.1903.321.40.4113.843.51003.341.50.3212.048.4(c)Sludgeash0.02.380.035.44.09.9110.02.420.074.92.59.9520.02.460.114.82.59.1030.02.501.394.73.49.3640.02.551.524.73.29.7950.02.581.704.63.010.51Thepropertiesofbricksproducedfromindustrialsludgeandmarineclaysinteredatthetemperatureof1050°CaregiveninTable1(b)[1].Itwasfoundthat,bricksmadefrom100%sludgeand90%sludgewith10%clay,werepronetodevelopcracksduringfiring.Thespecificgravitydecreasedandwaterabsorptionincreasedwithincreasingproportionofclaymaterial,whichhasalowerspecificgravitycomparedtosludge.However,the50%claybricksamplehasasignificantlyhigherrateofwaterabsorption,whichcouldbeattributedtothehighporosityofthematerial.Bricksofallmixproportions,otherthan50%claycontent,conformedtothespecifiedwaterabsorptionlimitof7%.Shrinkageoccursduringtheprocessesofbothdryingandfiring.Thedryingshrinkageincreasedwithincreasingclaycontent,indicatingahighershrinkagerateastheclaycontentincreased.Thefiringshrinkageoncontraryreducedwithincreasingclaycontent.Significantexpansioncanbeobservedonthe50%claybricksampleasithasan