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Title:Odstranjevanje adsorbljivih organskih halogenov z ultrafiltracijo z micelarnim učinkom iz industrijske odpadne vode
Authors:Vinder, Aleksandra (Author)
Simonič, Marjana (Mentor) More about this mentor... New window
Novak Pintarič, Zorka (Co-mentor)
Files:.pdf DR_Vinder_Aleksandra_2013.pdf (2,49 MB)
 
Language:Slovenian
Work type:Dissertation (m)
Organization:FKKT - Faculty of Chemistry and Chemical Engineering
Abstract:Neočiščene odpadne vode so pretežni razlog onesnaženja tako površinskih kot podtalnih virov pitnih vod zaradi slabe biološke razgradljivosti, kopičenja v organizmih in sedimentih ter strupenosti za ljudi in okolje. Pri tem zavzemajo pomembno mesto detergenti in tista organska onesnažila, ki s klorom tvorijo adsorbljive organske halogene (AOX). Namen doktorske disertacije je odstranjevanje AOX iz industrijske odpadne vode, ki vsebuje tudi tenzide. Uporabili smo postopek koagulacije kot klasičen fizikalno kemijski postopek za odstranjevanje onesnažil iz odpadnih vod in ultrafiltracijo z micelarnim učinkom (MeUF) kot način čiščenja vod v skladu s smernicami trajnostnega razvoja. Tenzidi imajo namreč sposobnost tvorjenja večjih skupkov (micel) pri dovolj visokih koncentracijah, v katere se solubilizirajo organske molekule, kot so AOX, in se tako zadržijo na ultrafiltracijski membrani. Takšen način čiščenja industrijske odpadne vode je bolj učinkovit v primerjavi z drugimi separacijskimi procesi, ker je mogoče hkrati s tenzidi odstraniti tudi veliko količino organskih in anorganskih nečistoč, ne da bi bilo pri tem potrebno dodajati posebne kemikalije. Koagulacija je bila izvedena na realnih odpadnih vodah z različnimi kombinacijami kovinskih koagulantov in industrijskega flokulanta. Rezultati so pokazali, da je s to metodo mogoče očistiti odpadno vodo do določene stopnje. Tak postopek je ob uporabi klasičnih kovinskih koagulantov cenovno sorazmerno ugoden. Problem pa se pojavi zaradi problematike odlaganja oziroma možnosti uporabe velikih količin oborine, ki se tvori med procesom. V postopku ultrafiltracije je bila raziskava izvedena na modelnih in na realnih vodah, ki so vsebovale določene koncentracije tenzidov, soli, AOX in drugih organskih onesnažil, izraženih kot vrednost KPK. Določili smo korelacije med njimi in postavili matematični model, ki to zvezo zadovoljivo opisuje. Za preučevanje zvez med omenjenimi merjenimi parametri smo uporabili regresijsko analizo, s katero smo ugotavljali vpliv koncentracij anionskih tenzidov, neionskih tenzidov in elektrolitov na odstranjevanje AOX. Za vsako od komponent smo generirali zvezo, ki prikazuje odstranjevanje AOX kot linearno funkcijo koncentracije posamezne komponente. Validacijo enačb smo izvedli z analizo variance. Nazadnje smo generirali linearni model, ki vključuje koncentracije vseh treh komponent, z zaporednim dodajanjem ustreznih koncentracij v model. Rezultati so pokazali, da kaže MeUF velik potencial pri odstranjevanju tenzidov, posebno pa organskih onesnažil kot je AOX. Potrdili smo tezo, da je učinkovitost odstranjevanja AOX na membrani posledica solubilizacije le-teh v notranjost tenzidnih micel in je zato tvorba micel anionskih tenzidov bistvena za učinkovito odstranitev AOX. Z regresijsko analizo smo potrdili, da je nastajanje micel anionskih tenzidov odvisno od več dejavnikov. V linearnih modelih, ki smo jih izdelali za nizke in visoke koncentracije anionskih tenzidov, smo se omejili na dva dejavnika: prisotnost neionskih tenzidov in specifična prevodnost. Oba znižujeta kritično micelno koncentracijo (CMC) anionskih tenzidov, zato je njun vpliv opazen šele takrat, ko se koncentracija anionskih tenzidov približuje svoji vrednosti CMC, torej v modelu z visokimi koncentracijami tenzidov. Prav v tem pa se tudi oba modela med seboj razlikujeta. Zato je potrebno izdelati ločene modele, ki omogočajo napoved, do kolikšne mere je mogoče očistiti določeno odpadno vodo, saj so začetne koncentracije anionskih tenzidov v odpadni vodi najvplivnejše.
Keywords:tenzidi, ultrafiltracija z micelarnim učinkom, adsorbljivi organski halogeni, flokulacija/koagulacija, učinkovitost odstranjevanja, regresijska analiza
Year of publishing:2013
Source:Maribor
NUK URN:URN:SI:UM:DK:0PB54GWR
Views:2589
Downloads:260
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Categories:KTFMB - FKKT
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Secondary language

Language:English
Title:Removal of adsorbable organic halogens from industrial waste water by micellar-enhanced ultrafiltration
Abstract:Untreated wastewater is the main source of pollution of ground and underground drinking water sources. The characteristics of wastewater are poor biodegradability, accumulation in organisms and sediments as well as toxicity for people and the environment. Among pollutants, detergents are some of the most influential as well as organic pollutants, which form adsorbable organohalogens (AOX) together with chlorine. The purpose of this dissertation is the removal of AOX from industrial wastewaters, which also contain surfactants. We have used coagulation, a conventional physical and chemical process, to remove pollutants from wastewaters, and micellar-enhanced ultrafiltration (MeUF) to treat waters in accordance with the guidelines of sustainable development. In high concentrations, surfactants namely have the ability to form major clusters (micells), causing the solubilization of organic molecules, such as AOX, which then remain on the ultrafiltration membrane. This method of industrial wastewater treatment is much more effective than other separation processes, as it enables us to simultaneously remove a large amount of organic and inorganic pollutants using surfactants, without having to add special chemicals. The coagulation process was carried out directly on actual wastewaters using different combinations of metal coagulants and industrial flocculants. The results show that this method can effectively treat wastewater to a certain degree. Using conventional metal coagulants, this can be a relatively low-cost process. However, a problem arises with the disposal or the possibility of reusing large quantities of precipitate that forms during the process. Using the ultrafiltration process, the study was carried out on model and real waters, containing a certain concentration of surfactants, salt, AOX and other organic pollutants, recorded as values of Chemical Oxygen Demand (COD). We have determined the correlation between them and created a mathematical model, which sufficiently describes this correlation. Regression analysis was used to study the correlations between the mentioned measured parameters, enabling us to determine the impact of the concentrations of anionic surfactants, non-ionic surfactants and electrolytes on AOX removal. We created a correlation for each of the components, depicting AOX removal as a linear function of the concentration of individual components. The equations were validated using the analysis of variance. In the last step we created a linear model, which includes the concentrations of all three components, by successively adding the corresponding concentrations into the model. The results have demonstrated that MeUF shows great potential for removing surfactants and particularly organic pollutants such as AOX. We have confirmed our thesis, that the efficiency of AOX removal on the membrane is a result of AOX solubilization within the surfactant micells and therefore the formation of anionic surfactants is crucial for the effective removal of AOX. Regression analysis was used to effectively confirm that the creation of anionic surfactant micells depends on numerous factors. In the linear models, created for low and high concentrations of anionic surfactants, we focused solely on two factors: the presence of non-ionic surfactants and conductivity. Both factors lower critical micelle concentration (CMC) of anionic surfactants, which makes their influence noticeable only when the concentration of anionic surfactants approaches its CMC value, thus in the model with a high concentration of surfactants. However, this is also where the differences between both models become apparent. It is therefore important to create separate models, allowing us to predict to what extent different wastewaters can be treated, as it is the initial concentration levels of anionic surfactants in the wastewater that is the most influential.
Keywords:surfactants, micellar-enhanced ultrafiltration, adsorbable organic halogens, flocculation/coagulation, removal efficiency, regression analysis


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