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On-Site Regeneration of Granular Activated Carbon : A literature study, comparison and assessment of different regeneration methods to find potential on-site regeneration method in Sweden / Regenerering av Granulärt Aktivtkol : En litteraturstudie, jämförelse och bedömning av olika regenereringsmetoder för att hitta potentiell regenereringsmetod på plats i SverigeMishra, Chinmay January 2021 (has links)
In this thesis project, different existing granular activated carbon regeneration methods/technologies are assessed based on existing literature. The project aims to identify and analyse the method with the highest on-site regeneration potential by using the Himmerfjärdsverket wastewater treatment plant as a reference and performing a cost estimation analysis. Information is gathered about different methods from the literature study and then sorted into the following parts: working principle, technology readiness and cost, advantages and disadvantages, and references (case studies). The methods are then assessed and compared by a scoring and weightage system, where the factors which are regeneration efficiency, ease of implementation, sustainability, cost, and reliability are weighted and then scored for each method. Furthermore, the highest scoring method is then compared to the proposed regeneration method at Himmerfjärdsverket. The results from my comparison and assessment show that chemical regeneration is the highest scored method, followed by microwave and wet-oxidation regeneration methods. On applying chemical regeneration at Himmerfjärdsverket, it is found out that it may indeed be cheaper and more sustainable than the proposed off-site regeneration method. However, thermal and biological regeneration are better alternatives at Himmerfjärdsverket than microwave and wet- oxidation. From the above results, chemical regeneration has the highest potential for on-site regeneration of granular activated carbon in Sweden. / Läkemedel i vatten är ett stort hot mot miljö och hälsa. Kommunalt avloppsvatten består av avloppsvatten från hushåll, privata och offentliga institutioner och dagvattenavrinning. En viktig läkemedelskälla i avloppsvatten är ett läkemedel som kommer in via urin och / eller avföring. Olika tekniker finns för avlägsnande av farmaceutiska rester och andra mikroföroreningar från avloppsvatten. En sådan teknik är adsorptionen av dessa rester med hjälp av Granulärt Aktivtkor (GAC). Aktivtkor (AC) är ett kolhaltigt material med liten pordiameter, stora porvolymer och hög specifik yta rea vid bearbetning. Det anses vara det bästa adsorptionsmedlet för att adsorbera organiska, oorganiska och giftiga metalljoner som finns i avloppsvattnet. Det finns två typer av aktivtkol som används för att avlägsna farmaceutiska rester: Granulärt aktivtkol och pulveriserat aktivt kol. Denna forskning syftar till att identifiera, jämföra och bedöma befintlig regenereringsteknik för att hitta den teknik som har störst potential och använda den på ett referensavloppsreningsverk. Det finns olika metoder för regenerering av använt aktivt kol (SAC). Dessa är termisk regenerering, kemisk regenerering, biologisk regenerering, elektrokemisk regenerering, mikrovågsregenerering och våt-oxidationsregenerering. Metoderna listas och förklaras med hjälp av deras arbetsprincip, beredskap, kostnad, fördelar, nackdelar och referenser till studier där de har använts. Flera kriterier / faktorer beaktas för bedömning och jämförelse av olika regenereringsmetoder. Faktorerna poängsätts sedan med hjälp av ett viktat poängsystem. Var och en av de ovannämnda faktorerna görs mellan 0–5 och tilldelas en vikt mellan 1–3. En högre poäng betyder bättre prestanda i den givna faktorn. Medan en högre vikt betyder betydelsen av faktorn. Från bedömningen visar sig kemisk regenerering vara den mest lämpliga metoden för regenerering av GAC på plats. Den minst lämpliga metoden är biologisk regenerering med en total poäng på 39. De två bästa regenereringsmetoderna på plats är kemisk och mikrovågsregenerering. I procent har kemisk regenerering och mikrovågsregenerering en rating på 93,3% och 90%. För att validera resultatet av bedömningen används Himmerfjärdsverket som referensavloppsverk. Himmerfjärdsverket bygger om och expanderar till en högteknologisk anläggning. Den nya anläggningen kommer att bestå av modern reningsteknik och hög reningskapacitet. Den planerade nya anläggningen förväntas vara klar 2025, medan byggandet påbörjades i januari 2020. I en studie genomförd av Syvab i samarbete med Ramboll, IVL och SU anges att det skulle behövas kolförbrukning på 15–20 g / m3 vatten. Den totala kostnaden per behandlat avloppsvatten skulle sannolikt öka med 20–30% till 2027 om läkemedelsreningen genomförs på Himmerfjärdsverket med hjälp av GAC och av regenereringsmetoden utanför anläggningen. Himmerfjärdsverket kommer att konsumera 3,92 ton kol dagligen eller 27,56 ton varje vecka. Detta kommer att kosta 28,7 miljoner SEK / år för 20 000 EBV (i värsta fall) och 11,5 miljoner SEK / år för 50 000 EBV. Medan kostnaden för kemisk regenerering av GAC med högsta regenereringseffektivitet uppskattas till 27,4 miljoner SEK / år för användning av flytande NaOH-lösning och 17,7 miljoner SEK / år för användning av fast NaOH för 20 000 EBV. För mängden 573 t / år kol kommer NaOH-förbrukningen att vara 2083,5 t / år, vilket kommer att kosta 7,1 och 10,9 miljoner SEK / år för 50 000 EBV. Eftersom kostnad är en av de viktigaste faktorerna som motverkar tillämpningen av metoder som är lika tillförlitliga som termisk regenerering. Om termisk regenerering implementeras på Himmerfjärdsverket kan installationen användas för att regenerera GAC från andra reningsverk från Stockholm. 2 GAC-bio filter i serieskapare bättre förutsättningar för biologisk regenerering av GAC samt ger låga föroreningskoncentrationer och höga syrekoncentrationer. För att lägga till det producerar Himmerfjärdsverket biogas som kan användas för att uppnå höga temperaturer som krävs enligt denna metod eller generera den erforderliga elen eller båda. I alla tre fall kommer kostnaden att minskas ytterligare. Avslutningsvis har kemisk regenerering den högsta regenereringspotentialen på plats bland alla andra studerade metoder. Medan termisk regenerering är nära den andra på grund av kolförlusten. En pilotstudie krävs för att validera de regenereringseffektivitet som nämns i litteraturen och bearbetningsförhållandena och typerna av adsorbera vid Himmerfjärdsverket behöver utvärderas liksom behandlingsförhållandena.
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Producing carotenoid-rich powder from Gac fruitTran, Thao Hoang, University of Western Sydney, College of Health and Science, Centre for Plant and Food Science January 2007 (has links)
Gac (Momordica Cochinchinensis Spreng or Muricia Cochinchinensis Spreng) is an indigenous fruit of Vietnam, commonly used as a colourant in traditional dishes. Recent studies showed that this fruit had a high carotenoid content, especially lycopene and β-carotene. These carotenoids are currently in high demand as they are natural antioxidants to prevent and treat cancers. Over the last ten years some new products from Gac fruit have been found on the market but the cultivation and consumption of the fruit is still limited. Gac is harvested seasonally and the post harvest processing has not been well developed. To make the best use of the valuable substances in Gac, this project investigated some processing methods to make Gac powder and developed the product quality analyses, potentially applicable to local small-scale manufacture. In order to evaluate the efficiency of the Gac powder process and some of the most important qualities of the Gac powder products, the analytical methods to determine lycopene and β-carotene were developed and validated in this project. The new HPLC-based method included a liquid-liquid extraction, followed by a solid phase extraction before the analysis. Both newly- developed HPLC and SP methods exhibited a high extraction yield, good recovery and reproducibility. Compared with the HPLC, the SP method gives higher mean values and standard deviations, but it is quicker, simpler, less expensive and still reliable for industrial applications due to the use of less toxic solvents. The production of powder from Gac fruit included two main stages: seed removal and aril dehydration. Derived from the same drying operation, the enzymatic-treated Gac powder had a lower carotenoid content compared to the heat-treated powder. The Gac powder produced by the freeze-drying method had the highest carotenoid level and brightest colour. Finally the orange-red Gac powder with high carotenoid content was added to some foods as a colorant and nutrient supplement to illustrate its applications. The colours of foods were significantly improved and the carotenoid contents were increased after processing, indicating a potential market for the Gac powder. / Master of Science (Hons)
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Optimization of an Advanced Water Treatment Plant: Bromate Control and Biofiltration ImprovementBales, Dustin William 01 January 2012 (has links)
The David L. Tippin Water Treatment Facility (DLTWTF) serving the city of Tampa, Florida is an advanced drinking water treatment facility consisting of coagulation/flocculation, ozonation, granular activated carbon biofiltration, and disinfection by chloramine. New regulations and the recent economic crisis pushed the facility to investigate methods to decrease costs and meet regulatory requirements easier.
The two major issues identified as priorities for investigation were the optimization of the biofiltration system and the use of a novel process to reduce the formation of bromate during ozonation.
Optimization of the biofiltration system is needed to remove more of the assorted particles that cause biofilms, nitrification in the distribution system, and high chloramine demand. Previous work improved the removal of particles that cause biofilms and nitrification, but was not able address the removal of particles that cause high chloramine demand to a satisfactory degree. Possible factors affecting this high chloramine decay were identified and evaluated at the pilot scale, including filter depth, chloramination of filter backwash water, media material, and nutrient addition. Non-chlorinated backwash water reduced chloramine demand by approximately 30% for GAC filters, and by approximately 50% for anthracite. Generally, anthracite performed slightly worse than GAC. Nutrient addition showed no effect. Filter depth improved chloramine decay, but not significantly enough to warrant the increased material required
Bromate control is necessary to prevent the formation of bromate, a regulated carcinogen. Traditional bromate control methods use pH depression. While effective, at the DLTWTF, this forces the increased use of more expensive caustic soda over lime for raising the pH of process water. A novel process known as the chlorine-ammonia process was investigated at the bench scale to identify the ideal ratio of chlorine and ammonia to decrease the formation of bromate to ensure regulatory compliance and allow greater use of lime to decrease costs. The best ratio in this study is 0.45 mg/L NH3 to 0.75 mg/L Cl2 which produced 1.09 ppb bromate at a CT of 6.8 min*mg/L, representing a 84% improvement over the control.
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PFAS in a Swedish wastewater treatment plant : An analysis of the effectiveness of major treatment steps on 33 PFASForsberg, Jonatan January 2022 (has links)
Wastewater treatment plants (WWTP) are known spreaders of per- and polyfluoroalkyl substances (PFAS) into the environment. Luleå University of Technology is conducting a yearlong study in which PFAS concentrations in the different treatment steps are measured at Uddebo treatment plant. This report covers the first four months of the year-long study. The aims of this study are to see what happens with the PFAS concentrations in the treatment processes, if they are above regulated limits, and to see if concentrations at Uddebo are comparable toreference concentrations in Sweden. Sampled PFAS concentrations were taken once per fortnight in incoming wastewater, after primary sedimentation, after Moving Bed Biofilm Reactor (MBBR), after secondary sedimentation and after the pilot treatment plant containing granulated active carbon (GAC) filter when it was in use. Precursors in incoming wastewater and PFAS in sludge were measured in samples taken once per month. Comparing the 33 analysed PFAS in wastewater at each sampling point, 30 analysed precursors for PFAS in incoming wastewater and 30 analysed PFAS in sludge, only PFOS and PFOA wereregularly found in both wastewater and in outgoing sludge. This indicates a separation of PFAS in the different medium, with sludge having PFAS where the perfluorinated carbon chain length is grater than 6. Out of the analysed 33 PFAS in wastewater PFOA had the highest median concentration of about 7 ng/l with no significant variation between the wastewater sample points. Similarly, the median concentration of total detected 33 PFAS was around 35 ng/l with no significant variation between the wastewater sample points, indicating no significant treatment of measured PFAS during WWTP. This was also comparable to other WWTP in Sweden. PFBA, PFHxA and PFPeA precursors had the highest concentration of the measured 30 PFAS precursors, however, except for one sampling occasion, no significant deviation in precursor PFAS could be detected during the sampling period. Out of the 30 analysed PFAS in outgoing sludge, PFOS had the highest concentration of 6.8 μg/kg dry weight (dw), but no discernible pattern could be identified between sampling dates due to too few samples. PFOS was foundabove the recommended concentration for sensitive land use (3.0 μg/kg dw), but still within recommendations for less sensitive land use (20.0 μg/kg dw) in Sweden. The median concentration of 13.6 μg/kg dw measured PFAS in sludge makes it well below median Swedish concentration. However, all comparisons to other Swedish WWTPs and background concentrations in Sweden were based on a few studies with few samples, potentially increasing or decreasing the median concentration as more research is conducted.
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Using Rapid Small Scale Column Testing to Evaluate Granular Activated Carbon Adsorption of Cyanotoxins from Drinking WaterKelley, Thomas M. January 2017 (has links)
No description available.
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Sorption and desorption of the industrial chemical MCHM into polymer pipes, liners and activated carbonAhart, Megan Leanne 21 May 2015 (has links)
Polyethylene pipes and epoxy or polyurethane linings are increasingly used in drinking water infrastructure. As a recent introduction to the water industry, there are still many unknowns about how polymers will behave in the distribution system specifically relating to sorption and desorption of chemical contaminants. This study is in response to a spill of 4-methylcyclohexane methanol (MCHM) that occurred in January 2014 contaminating the drinking water of nine counties in West Virginia. This study investigated sorption and desorption of the odorous chemical MCHM into polymer drinking water infrastructure and granular activated carbon (GAC). Experiments for sorption of non-polar toluene and polar 1-butanol were conducted as a comparison for MCHM sorption. Additionally, a brief odor analysis was done on the ability of activated carbon to remove odor from contaminated water and on leaching of MCHM from pipe material into clean water. The results show that MCHM diffusion and solubility in polyethylene pipe materials is low. Solubility in polyethylene ranged from 0.003-0.008 g/cm3 and was more similar to the polar contaminant n-butanol than the non-polar contaminant toluene. Desorption experiments indicated that MCHM sorbed to polyethylene diffused back into water at levels that produced odor. MCHM diffused very quickly into epoxy; its solubility was similar to polyethylene pipe. MCHM caused the polyurethane lining to swell and deform. Granular activated carbon effectively sorbed MCHM to below its odor threshold. The sorption properties of MCHM indicate the potential for contamination of infrastructure and the desorption indicates subsequent recontamination of drinking water. / Master of Science
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Role d' ARN non codants régulateurs dans l' adaptation de Pseudomonas brassicacearum à la rhizosphère et aux fluctuations de l' environnement. / Role of non-coding regulatory RNAs on the adaptative response of speudomonas brassicacearum to the rhizosphere and changing environmentsLalaouna, David 09 March 2012 (has links)
Pseudomonas brassicacearum a la particularité de générer une diversité intraclonale aussi bien in vitro qu'en conditions naturelles dans la rhizosphère de plantes. Ce phénomène de variation phénotypique commun chez les bactéries est un processus d'adaptation aux environnements changeants. Des données de transcriptomique issues de puces à ADN, contenant aussi bien des séquences codantes que non codantes, nous ont permis d'identifier les gènes dont l'expression est altérée et surtout de relier ce phénomène à l'expression d'ARN non codants régulateurs (ARNnc) de type Rsm qui sont sous le contrôle du système à deux composants GacS/GacA. Nous avons montré que des mutations ponctuelles dans les gènes gacS ou gacA sont à l'origine de cette variation phénotypique et que l'expression de l'un des trois gènes rsmX, rsmY ou rsmZ permet de restaurer le phénotype de la souche sauvage. L'importance de ces ARNnc dans la survie de la bactérie aux fluctuations de son environnement est dénotée par la duplication de rsmX en un gène que nous avons nommé rsmX-2, dont la fonction a été validée. Nos données suggèrent une activation exclusive des gènes rsmX-1 et rsmX-2 par GacA et l'intervention de régulateurs additionnels dans le cas de rsmY et rsmZ. Au vu de la redondance fonctionnelle de ces quatre ARNnc, nous avons investigué leur niveau d'expression et leur stabilité dans différentes conditions de culture et montré des différences pour les quatre ARNnc. En réponse à une carence en nutriments, l'expression des ARNnc Rsm est fortement activée et atteint son maximum quand le ppGpp est détecté dans le milieu, suggérant un lien entre le système Gac/Rsm et la réponse « stringente ». / The plant-beneficial bacterium Pseudomonas brassicacearum forms phenotypic variants in vitro as well as in planta during root colonisation under natural conditions. Transcriptome analysis of typical phenotypic variants using microarrays containing coding as well as non-coding DNA fragments showed differential expression of several genes relevant to secondary metabolism and of the small non-coding RNA (ncRNA) genes rsmX, rsmY and rsmZ, which was characterized by down-regulation. Naturally occurring mutations in the GacS/GacA two-component system accounted for phenotypic switching. The importance of these ncRNAs in the survival of the bacteria to changing environments is denoted by the duplication of rsmX gene, which we called rsmX-2 and whose function has been validated. Our data suggest an exclusive activation of rsmX-1 and rsmX-2 genes by GacA and the involvement of additional regulators in the case of rsmY and rsmZ. Given the functional redundancy of these ncRNAs, we investigated their expression level and stability in different culture conditions and showed differences for the four ncRNAs. In response to nutrient depletion, the four ncRNAs expression is strongly activated and reaches its maximum when the ppGpp is detected in bacterial cells, suggesting a link between the Gac/Rsm system and the "stringent" response. Determining the level of each Rsm ncRNA, which is defined by a balance between synthesis and degradation of each transcript, shows the maintenance of a very important pool of RsmZ compared to other ncRNAs.
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Étude du métabolisme de la glutamine dans les leucémies aiguës myéloïdes / Glutamine metabolism in acute myeloid leukemiaJacque, Nathalie 05 March 2015 (has links)
La survie des cellules cancéreuses dépend d’une activité énergétique et biosynthétique accrue et la glutamine participe à de nombreux processus nécessaires à cette adaptation métabolique. Dans les leucémies aiguës myéloïdes (LAM), la croissance et la prolifération sont favorisées par l’activation anormale de plusieurs voies de signalisation, et notamment par la voie mTORC1. Les acides aminés essentiels, et en particulier la leucine, sont indispensables à l’activation de mTORC1. La glutamine est captée par la cellule via le transporteur SLC1A5 et permet ensuite l’entrée de la leucine via le transporteur bidirectionnel SLC7A5. La concentration en glutamine est donc une étape limitante dans l’activation de mTORC1 par la leucine. Nous avons étudié les effets de la privation en glutamine dans les LAM à l’aide de différents outils (milieu sans glutamine, shARN inhibant l’expression du transporteur de la glutamine SLC1A5 et la drogue L-asparaginase, qui a une activité de glutaminase extracellulaire), et observé une inhibition de mTORC1 et de la synthèse protéique. L’inhibition du transporteur SLC1A5 inhibe la pousse tumorale dans un modèle de xénotransplantation. La L-asparaginase inhibe mTORC1 et induit une apoptose de façon proportionnelle à son activité glutaminase et complètement indépendante de la concentration en asparagine. La privation en glutamine induit l’expression de la glutamine synthase et l’autophagie, et ces deux processus peuvent être des mécanismes de résistance intrinsèques ou acquis dans certaines lignées leucémiques. L’apoptose induite par la privation en glutamine n’est cependant pas liée à l’inhibition de mTORC1, puisqu’elle n’est pas diminuée par l’utilisation d’un mutant de mTOR non inhibé par la privation en glutamine. Nous nous sommes donc intéressés à une autre voie dépendante de la glutamine dans de nombreux cancers, la phosphorylation oxydative. L’étape initiale du catabolisme intracellulaire de la glutamine est la conversion de la glutamine en glutamate par des enzymes appelées glutaminases. Différentes isoformes des glutaminases existent qui sont codées chez l’homme par les gènes GLS1 et GLS2. Le glutamate est ensuite transformé en α-cétoglutarate, intermédiaire du cycle TCA. Dans les lignées de LAM, la privation en glutamine inhibe la phosphorylation oxydative mitochondriale. Nous avons observé que la protéine glutaminase C (GAC), une des isoformes de GLS1, est constamment exprimée dans les LAM mais aussi dans les progéniteurs hématopoïétiques CD34+ normaux. L’inhibition d’expression de la GLS1 par des shARN inductibles ou bien par le composé CB-839 réduit la phosphorylation oxydative, conduisant à une inhibition de prolifération et à une induction d’apoptose des cellules leucémiques. L’invalidation génétique de la GLS1 inhibe la formation de tumeur et améliore la survie des souris dans un modèle de xénotransplantation. A l’inverse, le ciblage de la GLS1 n’a pas d’effets cytotoxiques ni cytostatiques sur les progéniteurs hématopoïétiques normaux. Ces effets anti-leucémiques sont inhibés par l’adjonction d’α-cétoglutarate, et ceux induit par le CB-839 sont abrogés lorsqu’est exprimé de façon ectopique un mutant GACK320A hyperactif, attestant du rôle essentiel du maintien d’un cycle TCA actif dans les cellules de LAM. Enfin, nous montrons que l’inhibition de la glutaminolyse active la voie d’apoptose mitochondriale intrinsèque et agit en synergie avec l’inhibition spécifique de BCL-2 par l’ABT-199. Ces résultats démontrent que le ciblage spécifique de la glutaminolyse est une autre façon d’exploiter l’addiction à la glutamine des cellules leucémiques de LAM et que le maintien d’un cycle TCA actif est essentiel à la survie de ces cellules. / Cancer cells survival is dependent on high energetic and biosynthetic activity, and glutamine is involved in many metabolic processes necessary for this adaptation. In acute myeloid leukemia (AML), growth and proliferation are promoted by activation of several signaling pathways, including mTORC1. Essential amino acids, in particular leucine, are required for mTORC1 activation. Glutamine enters into the cell via the SLC1A5 transporter and then allows the input of leucine via the bidirectional SLC7A5 transporter. Therefore, the intracellular glutamine concentration is a limiting step in the activation of mTORC1 by leucine. We studied the effects of glutamine deprivation in AML using different tools (medium without glutamine, shRNA against the SLC1A5 glutamine transporter and the drug L-asparaginase, which has an extracellular glutaminase activity) and observed mTORC1 and protein synthesis inhibition. SLC1A5 transporter knockdown inhibits tumor growth in a xenotransplantation model. L-asparaginase inhibits mTORC1 and induces apoptosis in proportion to its glutaminase activity and independently of asparagine concentration. Glutamine privation induces the expression of glutamine synthase and autophagy, and these two processes are involved in the resistance to glutamine privation in some leukemic cell lines. However, apoptosis induced by glutamine privation is not related to the inhibition of mTORC1, since it is not modified in the presence of a constitutively active mutant of mTOR. We next focused on the oxidative phosphorylation, another glutamine dependent pathway in many cancers. The initial step of the intracellular catabolism of glutamine is the conversion of glutamine to glutamate by enzymes called glutaminases. Different glutaminases isoforms exist that are encoded by the GLS1 and GLS2 genes. Glutamate is then converted to α-ketoglutarate, an essential TCA cycle intermediate. In AML cell lines, we observed that glutamine privation inhibits mitochondrial oxidative phosphorylation. The protein glutaminase C (GAC), an isoform of GLS1, is constantly expressed in AML but also in normal CD34 + hematopoietic progenitors. The knockdown of GLS1 by inducible shRNA or by the CB-839 compound reduced oxidative phosphorylation, leading to proliferation inhibition and apoptosis induction in leukemia cells. Genetic invalidation of GLS1 inhibits tumor formation and improves survival of mice in a xenograft model. Conversely, the targeting of GLS1 has no cytotoxic or cytostatic effects on normal hematopoietic progenitors. These anti-leukemic effects are inhibited by the addition of α-ketoglutarate, and those induced by the CB-839 are suppressed in the presence of an ectopically expressed GACK320A hyperactive mutant, confirming the essential role of maintaining an active TCA cycle in AML cells. Finally, we showed that glutaminolysis inhibition induces the intrinsic mitochondrial pathway of apoptosis and acts synergistically with the specific inhibition of BCL-2 by ABT-199. These results demonstrate that specific targeting of glutaminolysis is another way to exploit glutamine addiction in AML and that an active TCA cycle in essential for AML cell survival.
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Evaluation of the Removal Efficiency of Per- and Polyfluoroalkyl Substances in Drinking Water using Nanofiltration Membranes, Active Carbon and Anion Exchange / Utvärdering av reningseffektiviteten av per- och polyfluorerade alkylsubstanser i dricksvatten med nanofiltrering, aktivt kol och jonbytarmassaLindegren, Klara January 2015 (has links)
Per- and polyfluoroalkyl substances (PFASs) is a group of man-made, highly persistent chemicals. Due to the specific surface-active attributes of these molecules, applications are numerous and feed an economically important industry. During the last decade, PFASs have been detected globally in the environment, living organisms and tap water. The combination of toxic properties and high bioaccumulative potential, together with the discovery that conventional water treatment methods do not remove PFAS, renders further research on purification methods highly needed. Three techniques of purifying water from PFASs were examined. Nanofiltration technology (NF) is a membrane filtration technique, which produces a purified product (the permeate) by generating an effluent of high contaminant concentration (the reject water). To decontaminate the reject water, adsorption by granular activated carbon (GAC) or anion exchange (AE) have been proposed. The efficiency of these three technologies was studied at Bäcklösa drinking water treatment plant (DWTP) in Uppsala. A nanofiltration pilot with two 270NF membranes (Dow Filmtech™), connected in series, was used. A high removal efficiency (>90%) was found for all PFASs. Furthermore, it was confirmed that the concentration in the permeate water was a function of the concentration in the incoming raw water; increased PFAS raw water concentration resulted in increased PFAS permeate concentration. Size-exclusion and electrostatic repulsion were deemed important mechanisms. For the comparison of GAC (Filtrasorb 400®) and AE (Purolite® A-600), a column experiment was set up. The perfluoroalkane (-alkyl) sulfonic acids (PFSAs) and perfluorooctanesulfonamide (FOSA) had similar removal efficiencies using both GAC and AE, and the efficiency increased with increasing chain length. AE was found to have a higher average removal efficiency of perfluoroalkyl carboxylic acid (PFCAs) (62-95%) than GAC (49-81%). In conclusion, longer chain length PFASs were removed more effectively than shorter-chained, and the PFSAs and FOSA showed higher removal efficiency compared to the PFCAs. Furthermore, linear isomers were removed more effectively than branched for GAC and AE. In contrast, the opposite was found for the NF membrane, where branched isomers were better retained. / Per- och polyfluorerade alkylsubstanser (PFAS) är en grupp syntetiska, ytterst persistenta kemikalier. På grund av deras ytaktiva egenskaper är de lämpliga för användning i många produkter och tillverkningsprocesser, och är således viktiga för en ekonomiskt betydande industri. Under det senaste årtiondet har PFAS påträffats i miljön, levande organismer och kranvatten världen över. Kombinationen av toxiska egenskaper, en hög bioackumuleringspotential och upptäckten att konventionella reningsmetoder inte avlägsnar substanserna från vatten, gör att vidare forskning av reningsmetoder för PFAS är mycket angelägen. Tre reningsteknikers förmåga att rena vatten från PFAS undersöktes. Nanofiltrering (NF) är en membranfiltreringsteknik som utöver den renade produkten, permeatet, även framställer en biprodukt av hög föroreningsgrad, rententatet. För att rena rententatet har adsorption till granulärt aktivt kol (GAC) eller jonbytarmassa (AE) föreslagits. Teknikerna utvärderades på Bäcklösa Vattenverk i Uppsala. Nanofiltreringen undersöktes i en pilotanläggning där två 270NF (Dow Filmtech™) membran var seriekopplade. En hög reningsgrad (>90%) konstaterades för alla typer av PFAS. Vidare visades PFAS-koncentrationen i permeatet vara en funktion av PFAS-koncentrationen i råvattnet; en ökad råvattenkoncentration gav en ökad permeatkoncentration. Storleksseparation och elektrostatisk repulsion befanns vara viktiga mekanismer som påverkade reningsgraden. För att undersöka de mekanismer som påverkar PFAS-adsorption jämfördes GAC (Filtrasorb 400®) och AE (Purolite® A-600) i ett kolonnexperiment. Reningsgraden för GAC och AE av perfluorerade sulfonsyror (PFSA) och perfluorooktan sulfonamider (FOSA) var lika hög och reningseffektiviteten ökade med ökande kolkedjelängd. AE återfanns ha en högre genomsnittlig reningsgrad av perfluorkarboxylsyror (PFCA) (62-95%) än GAC (49-81%). Sammanfattningsvis avlägsnades PFAS av längre kolkedjelängd mer effektivt än kortare kolkedjor, och PFAS med sulfonsyror och sulfonamider som funktionella grupper uppvisade en högre reningsgrad än karboxylsyrorna. Vidare renades linjära isomerer mer effektivt än grenade både genom GAC och AE. Däremot konstaterades det motsatta för NF-membranen, där grenade isomerer renades mer effektivt. / SafeDrink
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Carbon Filters for Drinking Water Treatment – How Flow Rate and Empty Bed Contact Time Influence the Performance / Kolfilter för dricksvattenrening - Hur flödeshastighet och uppehållstid påverkar reningenBäckström Nilsson, Wilma January 2021 (has links)
Dricksvatten är en essentiell del av ett hållbart samhälle. Därför är det viktigt att säkerställa säkert dricksvatten genom fungerande vattenreningsverk. En viktig förorening att behandla är NOM, som i sig är ofarligt men som kan producera farliga föroreningar. En teknik som används för behandling av NOM är kolfiltrering. Hur ökad flödeshastighet och ökad kontakttid påverkade kolfiltrens effektivitet undersöktes vid dricksvattenreningsverket Norrvatten. De undersökta parametrarna var partiklar, ultraviolett absorbans vid 254 nm, turbiditet, konduktivitet, fluorescent löst organiskt material, totalt organiskt kol, kemisk syreförbrukning, odlingsbara mikroorganismer och lukt. Tre kolfilter studerades vid olika flödeshastigheter; 190, 220, 250 och 280 L/s under ett dygn var. Samtidigt hade två filter ökad kontakttid på 60 och 76 % under sex veckor, medan ett filter fortsatte med den vanliga flödeshastigheten på 190 L/s. Utgående vatten från filtren analyserades för att se om dessa ändringar hade någon effekt på vattenreningen. Denna preliminära studie fann ingen signifikant effekt på kolfiltreringens rening på grund av ökad flödeshastighet eller uppehållstid. Detta kan vara en indikation på att kolfiltreringen kan hantera en framtida flödesökning och därmed vara en väsentlig del av en framtida expansionen av vattenreningsverket. De tecken som visade på att kolfiltren påverkades av ökningen av flödeshastigheter kunde förklaras av fluktuationer i inkommande vatten och skillnader mellan de olika filtren. I framtiden bör effekten av inkommande vatten studeras i detalj. En mer ingående analys av både inkommande och utgående vatten till kolfiltren bör utföras, där provtagning sker oftare för att bättre förstå fluktuationerna i inkommande föroreningskoncentrationer. Dessutom bör testerna upprepas för att se hur reningen skiljer sig från dag till dag. Hur kolfiltren hanterar ökade flödeshastigheter över längre tidsperioder bör också undersökas vidare. / Drinking water is an essential part of a sustainable society. In the future, the demand for drinking water will increase and contaminants in the water sources are also predicted to increase. Therefore, it is essential to ensure safe drinking water through functioning drinking water treatment plants (DWTPs). One important contaminant to treat is natural organic matter (NOM), which is harmless in itself but can produce harmful products. One technique to use for treating NOM is carbon filters (CFs). The effect of increased flow rate and increased empty bed contact time (EBCT) on the CF efficiency was investigated at a DWTP. The investigated parameters were particles, ultraviolet absorbance at 254 nm, turbidity, conductivity, cultivable microorganisms, fluorescent dissolved organic matter, total organic carbon, chemical oxygen demand, and odour. Three CFs were studied at different flow rates; 190, 220, 250, and 280 L/s for 24 hours each. Additionally, two filters had increased EBCT of 60 and 76 %, while one filter continued with the regular flow rate of 190 L/s for six weeks. Outgoing water from the filters was analysed to see if the change had any effect on the DWTP. This preliminary study did not find any significant effect on the CF treatment caused by increased flow rate or EBCT. This could be an indication that the CFs can handle a future increase in flow rate and thus be an essential part of a future expansion of the DWTP. The indications of CFs being affected by the increase in flow rates for some of the parameters could be explained by fluctuations in incoming water or differences between the separate filters. In the future, a more thorough analysis of both incoming and outgoing water to the CFs should be done, where sampling occurs more frequently to better understand the fluctuations in incoming contaminant concentrations. The measurements should also be repeated to see how the treatment differs from day to day. How the CFs handle increased flow rates over longer time periods should also be investigated further.
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