• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 25
  • 5
  • 3
  • 3
  • 2
  • 2
  • Tagged with
  • 41
  • 41
  • 15
  • 12
  • 9
  • 9
  • 8
  • 6
  • 6
  • 6
  • 6
  • 5
  • 5
  • 5
  • 5
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The effect of water chemistry and fibre-size distribution on dissolved air flotation efficiency

Sjölander, Anna January 2009 (has links)
The purpose of this diploma work was to investigate the problem of insufficient fibre recovery in the dissolved air flotation-cell at the new thermomechanical pulping-line at Braviken Paper Mill. An investigation of the effect of process parameters on the removal efficiency in the micro-flotation process was undertaken. The experiments were carried out for two setups at the Noss pilot plant with a small-scale flotation unit. Factorial design helped plan the experiments and four factors were controlled; temperature, fibre-size distribution, water quality and feed concentration. Three samples, feed, overflow and filtrate, were taken from each experiment and concentration measurements were made. The results were analyzed using the software MODDE. The results from showed an influence from the fibre-size distribution. To see if the fibre-size distribution really had an effect on the results, follow-up experiments were carried out. These experiments showed no influence from temperature, fibre-size distribution or water quality. This concludes that none of those three factors influenced the results significantly. Additional experiments were done to examine the influence from concentration and fibre-size distribution on the flotation efficiency and these showed an influence from the feed concentration. When increasing the feed concentration the efficiency of the flotation process decreased.
22

An investigation of the Mechanisms Behind the Pharmaceutical Removal in Ekeby Wetland WWTP

Luu, Paula January 2020 (has links)
Pharmaceutical residues are being released into the aquatic environment through domestic wastewater effluents all around the world. Ekeby wetland located in Eskilstuna has been shown to degrade pharmaceutical residues in wastewater but the mechanism of how and where in the wetland these substances are removed were not known. The aim of this Master’s thesis was to study the mechanism behind the pharmaceutical removal in Ekeby wetland. The presence of 22 selected pharmaceuticals were examined in water-, sediment- and plant samples collected from the wetland. Additionally, the concentration of nutrients’, pH and temperature of the water were examined. With this data, the correlations between the concentration of pharmaceuticals in the water and the concentration of selected nutrients could be determined. Nine out of 22 substances were detected in the sediment samples and 10 out of 22 was detected in the plant sample. The five pharmaceutical substances that required additional removal were citalopram, diclofenac, erythromycin, oxazepam and sertraline. Citalopram, diclofenac and sertraline were found in the sediment and plant samples. A significant negative correlation was found between the concentration of pharmaceuticals in water samples and total suspended solids (TSS) indicating that an increase of TSS, decreases the pharmaceutical concentration in the water. The main mechanism behind the pharmaceutical removal in Ekeby wetland was determined to be by sedimentation and plant uptake, mainly by Phragmites australis. The wetland system could also remove metoprolol, propranolol, tramadol, trimethoprim, naproxen, venlafaxine and carbamazepine. Hence, to increase the pharmaceutical removal in the wetland it’s recommended to increase the amount of plants, mainly P. australis. Thus, wetland systems could be of great advantage in the development of sustainable wastewater management. / Via avloppsvattnet släpps mängder av läkemedelsrester ut i vårt vatten. Ekeby våtmark i Eskilstuna har visat sig bryta ner läkemedelsrester från avloppsvatten, men mekanismen för hur och vart dessa ämnen tas bort är sedan tidigare okänt. Målet med detta examensarbete var att studera mekanismerna bakom läkemedelsnedbrytningen i Ekebys våtmark. Halterna av 22 läkemedelssubstanser i vatten-, sediment-och växtprover tagna från våtmarken undersöktes. Även koncentrationen av näringsämnen, pH och temperatur bestämdes i vattenprover tagna från våtmarken. Utifrån detta kunde sambanden mellan läkemedelskoncentrationerna och halterna av tidigare nämnda ämnen i vattnet studeras. Nio av 22 substanser uppmättes i sedimentproverna och 10 av 22 uppmättes i växtprovet. De fem läkemedel som krävde ytterligare rening var citalopram, diclofenac, erythromycin, oxazepam, och sertraline. Citalopram, diclofenac och sertraline uppmättes i sediment och växtproverna. I vattnet erhölls ett signifikant negativ samband mellan koncentration av läkemedel och suspenderade ämnen. Detta indikerar på att en ökning av suspenderade ämnen minskar läkemedelskoncentrationen i vattnet. Mekanismen bakom läkemedelsnedbrytningen i Ekebys våtmark fastställdes till sedimentation och växtupptag, främst av växten Phragmites australis. Våtmarken kunde även avlägsna metoprolol, propranolol, tramadol, trimetroprim, naproxen venlafaxin och carbamazapine. För att öka nedbrytningen av läkemedel i våtmarken är det därför rekommenderat att öka mängden växter. Våtmarkssystem kan därmed vara till stor fördel när man utvecklar reningsprocesser för läkemedel av avloppsvatten som är miljömässigt hållbara.
23

Reningsfunktion i svenska spillvattenvåtmarker : En studie av avskiljningseffektiviteten av kväve, fosfor och läkemedelsrester / Functionality of constructed wetlands for wastewater treatment in Sweden : A study of the removal efficiency of nitrogen, phosphorus, and pharmaceutical residues

Nyholm, Emma January 2023 (has links)
Utsläpp av orenat spillvatten till de naturliga vattendragen kan ge stora negativa effekter på det akvatiska ekosystemet och på människans hälsa genom exempelvis övergödning, toxisk påverkan på vattenlevande organismer, sjukdomsspridning och antibiotikaresistens. Reningsverk i större tätorter är idag anpassade för att rena spillvatten från kväve och fosfor, men de flesta reningsverk i Sverige saknar kväverening och är i låg grad anpassade för att rena avloppsvattnet från organiska mikroföroreningar. För att minska belastningen på recipienten krävs extra rening, och ett alternativ till mer traditionella reningstekniker är genom system som våtmarker för spillvattenrening, så kallade spillvattenvåtmarker.  Syftet med denna studie är att undersöka reningsfunktionen i spillvattenvåtmarker för att höja kunskapen kring spillvattenvåtmarkers funktion för avskiljning av kväve, fosfor och läkemedelsrester. Genom en datainsamling från befintliga provtagningar, beräknades avskiljningseffektiviten för kväve och fosfor i sju våtmarker och för läkemedel i fem våtmarker. Även ingående och utgående halter av föroreningar analyserades. Efter analys och jämförelse av reningsresultat, togs parametrar som påverkar avskiljningseffektiviten inom och emellan olika våtmarker fram baserat på hur anläggningen och driften ser ut för respektive våtmark. Även en regressionsanalys gjordes.  I spillvattenvåtmarker kan en kväveavskiljning i medeltal mellan 500 och 1600 kg/(ha·år) motsvarande 14 till 64 % och fosforavskiljning mellan 14 och 68 kg/(ha·år) motsvarande mellan 44 och 85 % väntas. I medeltal har kvävehalterna minskat från 20 mg/l till 13 mg/l, och fosforhalter från 0,27 mg/l till 0,13 mg/l. Resultatet av läkemedelsavskiljning delades in i säsonger, där halterna sommartid minskat från 1500 ng/l till 390 ng/l motsvarande 80 %, och vintertid från 500 ng/l till 315 ng/l motsvarande 21 %. Några läkemedelssubstanser med stor avskiljning var Diklofenak, Furosemid, Ibuprofen och Naproxen. Avskiljningen påverkas till stor del av belastning, som varierar mellan våtmarker och tider på året. Andra parametrar som kunde visas påverka avskiljningen är temperatur och syresättning för kväveavskiljning och mängden fosforsläpp, som i sin tur kan undvikas genom en jämn belastning och torrlagda våtmarkssystem, för fosforavskiljning. Kväve- och fosforavskiljning påverkas dessutom av växtlighet. Läkemedelsavskiljnigen gynnas främst av hög temperatur, solinstrålning och växtlighet. Slutligen kunde konstateras att goda förutsättningar finns för vattenrening i våtmarker, under förutsättning att våtmarken planeras och drivs utifrån en processidé om vad man vill att våtmarken ska åstadkomma. / Discharges of pollutants through wastewater into natural waterways may cause major negative effects on the aquatic ecosystem and human health, where nitrogen, phosphorus and pharmaceutical residues are some of the pollutants found in wastewater. Treatment plants in larger urban areas are today built to reduce nitrogen and phosphorus, but most treatment plants in Sweden lack nitrogen removal and are to a low degree adapted to remove organic micro pollutions. To reduce the load on the recipient, additional treatment is required, and an alternative to more traditional treatment techniques is through systems such as constructed wetlands for wastewater treatment.  The purpose of this study is to investigate the function of constructed wetlands for water treatment to increase knowledge about the function of reducing nitrogen, phosphorus and pharmaceutical residues. Through existing monitoring data, the treatment efficiency of nitrogen and phosphorus from seven wetlands and of pharmaceuticals from five wetlands were calculated. Also, incoming and outgoing concentrations of the pollutants were analyzed. After analysis and comparison of treatment results, parameters that affects removal efficiency within and between different wetlands were obtained based on the facility and operation for each wetland. Also, a regression analysis was made.  In a wetland for wastewater treatment, a nitrogen removal between 500 to 1600 kg/(ha·year) (14 to 64 %) and a phosphorus removal between 14 to 68 kg/(ha·year) (44 to 88 %) can be expected. On average, nitrogen concentrations have decreased from 20 mg/l to 13 mg/l, and phosphorus concentrations from 0,27 mg/l to 0,13 mg/l. The result of pharmaceutical removal was divided into seasons, where the concentrations in summer decreased from 1500 ng/l to 390 ng/l corresponding to 80%, and in winter from 500 ng/l to 315 ng/l corresponding to 21%. Pharmaceuticals with greater removal efficiencies were Diclofenac, Furosemide, Ibuprofen and Naproxen. Conclusions that were drawn is that removal is largely influenced by load, which varies between wetlands and seasons. Other parameters that could be proved is temperature and oxygenation for nitrogen removal and the amount of phosphorous released from the sediment, which for example could be avoided through a constant load, for phosphorous removal. Removal of nitrogen and phosphorus is also affected by vegetation. Removal of pharmaceuticals is mainly benefited by high temperature, solar radiation, and vegetation. / <p>Rättelse angående Tot-N Alhagen våtmark finns i bifogad fil.</p>
24

Efficiency of soil aquifer treatment in the removal of wastewater contaminants and endocrine disruptors : a study on the removal of triclocarban and estrogens and the effect of chemical oxygen demand and hydraulic loading rates on the reduction of organics and nutrients in the unsaturated and saturated zones of the aquifer

Essandoh, Helen Michelle Korkor January 2011 (has links)
This study was carried out to evaluate the performance of Soil Aquifer Treatment (SAT) under different loading regimes, using wastewater of much higher strength than usually encountered in SAT systems, and also to investigate the removal of the endocrine disruptors triclocarban (TCC), estrone (E1), 17β-estradiol (E2) and 17α-ethinylestradiol (EE2). SAT was simulated in the laboratory using a series of soil columns under saturated and unsaturated conditions. Investigation of the removal of Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Dissolved Organic Carbon (DOC), nitrogen and phosphate in a 2 meter long saturated soil column under a combination of constant hydraulic loading rates (HLRs) and variable COD concentrations as well as variable HLR under constant COD showed that at fixed HLR, a decrease in the influent concentrations of DOC, BOD, total nitrogen and phosphate improved their removal efficiencies. It was found that COD mass loading applied as low COD wastewater infiltrated over short residence times would provide better effluent quality than the same mass applied as a COD with higher concentration at long residence times. On the other hand relatively high concentrations coupled with long residence time gave better removal efficiency for organic nitrogen. Phosphate removal though poor under all experimental conditions, was better at low HLRs. In 1 meter saturated and unsaturated soil columns, E2 was the most easily removed estrogen, while EE2 was the least removed. Reducing the thickness of the unsaturated zone had a negative impact on removal efficiencies of the estrogens whereas increased DOC improved the removal in the saturated columns. Better removal efficiencies were also obtained at lower HLRs and in the presence of silt and clay. Sorption and biodegradation were found to be responsible for TCC removal in a 300 mm long saturated soil column, the latter mechanism however being unsustainable. TCC removal efficiency was dependent on the applied concentration and decreased over time and increased with column depth. Within the duration of the experimental run, TCC negatively impacted on treatment performance, possibly due to its antibacterial property, as evidenced by a reduction in COD removals in the column. COD in the 2 meter column under saturated conditions was modelled successfully with the advection dispersion equation with coupled Monod kinetics. Empirical models were also developed for the removal of TCC and EE2 under saturated and unsaturated conditions respectively. The empirical models predicted the TCC and EE2 removal profiles well. There is however the need for validation of the models developed
25

Amélioration de l’élimination des micropolluants organiques des eaux usées par traitements secondaire et tertiaire / Enhancement of the elimination of organic micropollutants from wastewater at secondary and tertiary stage

Tahar, Alexandre 12 July 2013 (has links)
La présence de micropolluants dans tous les milieux aquatiques est aujourd'hui une préoccupation importante. La réduction des émissions de micropolluants organiques vers le milieu aquatique par les stations d'épuration (STEP) domestiques est donc un enjeu important. Ce travail porte sur l'amélioration du traitement de ces substances par les traitements secondaires et tertiaires des STEP. En premier lieu, l'objectif a été de mieux comprendre les processus d'élimination des micropolluants organiques lors de leur passage au sein d'un procédé de type boues activées aération prolongée (BA-AP). Notre travail a consisté à proposer un outil permettant de prévoir a priori le comportement de substances organiques en BA-AP par rapport à certaines de leurs propriétés physico-chimiques (i.e. constante de Henry, log Dow, structure moléculaire). La démarche adoptée a consisté à sélectionner des données de rendements d'élimination fiables et robustes, puis à les associer aux caractéristiques physico-chimiques des substances. La méthode développée est simple ; elle nécessite de connaitre uniquement des paramètres physico-chimiques facilement accessibles et la structure moléculaire des substances. Elle constitue donc une alternative crédible aux méthodes faisant intervenir la modélisation. Cette méthode permet une prédiction a priori du niveau de traitement d'une substance (rendement supérieur ou inférieur à 70%) par les traitements secondaires existants. Dans un second temps, l'objectif a été de proposer une étape de traitement tertiaire, spécifique à l'élimination de micropolluants organiques réfractaires aux traitements secondaires. Le procédé proposé est une filtration sur support fin spécifique capable de retenir par des processus d'adsorption les substances ciblés (i.e. phytosanitaires et substances pharmaceutiques dont l'élimination est insuffisante en traitement secondaire conventionnel). Une étude bibliographique a permis tout d'abord de dresser un état des lieux sur les adsorbants utilisés et leur capacité d'adsorption. Suite à cette étude, la zéolite et l'argile expansée ont été retenus ; les potentialités d'adsorption de ces deux matériaux ont été étudiées à l'échelle laboratoire (tests en réacteur fermé) et à l'échelle pilote (suivi des performances de réacteurs à garnissage drainé à écoulement horizontal). Les tests d'adsorption en réacteur fermé montrent que les matériaux choisis (argile expansée et zéolite) possèdent une potentialité pour adsorber les substances étudiées (14 substances soient 10 pharmaceutiques et 4 pesticides). Le suivi des réacteurs ouvert confortent les résultats obtenus en réacteur fermé et démontrent que les matériaux étudiés possèdent un potentiel pour l'adsorption des substances ciblées, et ce y compris dans des conditions de filtration lente, proches des conditions réelles. Les résultats obtenus démontrent le potentiel de matériaux minéraux microporeux à éliminer des micropolluants organiques de la phase dissoute et ainsi à se substituer au charbon actif, matériau onéreux et peu adapté aux petites collectivités. / The aim of the present work was to propose solutions to reduce organic micropollutants emissions by wastewater treatment plants (WWTP). First, the objective was to improve the comprehension of micropollutants behaviour in nitrifying activated sludge process. The use of a reliable removal efficiency dataset allowed setting up a removal efficiency prediction method only from the micropollutants physico-chemical characteristics (i.e. log Kow, Henry constant and molecular structure). This method represents a first progress through a better micropollutants removal by the existing secondary WWTP. Second, the aim was to set up a tertiary stage process to enhance the removal of micropollutants refractory to conventional WWTP. This tertiary stage process is a filtration of the secondary effluent by adsorbent materials that could represent a credible alternative to expensive materials such as activated carbons. Experimental approaches at different scales (lab and pilot) demonstrated that some alternative materials such as expanded clay and zeolite have the potential to adsorb refractory substances (e.g. pesticids and pharmaceuticals) and thus to decrease the concentration of organic micropollutants in effluent.
26

Sedimentprovtagning av dagvattendammar som ett alternativ till flödesproportionell vattenprovtagning / Sediment sampling in stormwater ponds as an alternative to flow-weighted water sampling

Persson, Annika January 2010 (has links)
<p>Stormwater run-off from surfaces such as roads or rooftops is often polluted with heavy metals and nutrients. Many of these substances can cause great damage in biota if they end up in the recipient. In Sweden constructed wetlands and ponds for treatment of stormwater are frequently used, since research has shown that these treatment ponds are reducing stormwater pollution considerably to a low cost. The knowledge of these pollutant removal mechanisms and how follow-up and assessment of the ponds should be performed is still limited.</p><p>To determine the pollutant removal efficiency of the stormwater ponds it is recommended that flow-weighted water samples are collected from both the inflow and the outflow of the pond. This method demands considerable resources of time and money for installations and analysis. Alternative methods for assessing pollutant removal are requested, methods with lower costs but relevant results. This thesis is investigating whether sediment sampling could be such an alternative.</p><p>Sediment core samples were taken in four stormwater ponds where flow-weighted water sampling has been performed as well. This makes it possible to compare the two methods. A method of sampling recently sedimented material was also tried out by constructing and placing sediment traps on the pond floor. Analysis of concentration of six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and phosphorus were carried out.</p><p>The results show i.e. that the concentrations of heavy metals and phosphorus in the pond sediments decrease as the distance from the pond inlet increase. Comparing the two methods shows that the results from the sediment sampling are in the same order of magnitude as the results from the water sampling. Consequently, the conclusion states that a well executed sediment sampling may be an alternative to flow-weighted water sampling.</p> / NOS dagvatten
27

Sedimentprovtagning av dagvattendammar som ett alternativ till flödesproportionell vattenprovtagning / Sediment sampling in stormwater ponds as an alternative to flow-weighted water sampling

Persson, Annika January 2010 (has links)
Stormwater run-off from surfaces such as roads or rooftops is often polluted with heavy metals and nutrients. Many of these substances can cause great damage in biota if they end up in the recipient. In Sweden constructed wetlands and ponds for treatment of stormwater are frequently used, since research has shown that these treatment ponds are reducing stormwater pollution considerably to a low cost. The knowledge of these pollutant removal mechanisms and how follow-up and assessment of the ponds should be performed is still limited. To determine the pollutant removal efficiency of the stormwater ponds it is recommended that flow-weighted water samples are collected from both the inflow and the outflow of the pond. This method demands considerable resources of time and money for installations and analysis. Alternative methods for assessing pollutant removal are requested, methods with lower costs but relevant results. This thesis is investigating whether sediment sampling could be such an alternative. Sediment core samples were taken in four stormwater ponds where flow-weighted water sampling has been performed as well. This makes it possible to compare the two methods. A method of sampling recently sedimented material was also tried out by constructing and placing sediment traps on the pond floor. Analysis of concentration of six heavy metals (Cd, Cr, Cu, Ni, Pb and Zn) and phosphorus were carried out. The results show i.e. that the concentrations of heavy metals and phosphorus in the pond sediments decrease as the distance from the pond inlet increase. Comparing the two methods shows that the results from the sediment sampling are in the same order of magnitude as the results from the water sampling. Consequently, the conclusion states that a well executed sediment sampling may be an alternative to flow-weighted water sampling. / NOS dagvatten
28

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 jonbytarmassa

Lindegren, 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 (&gt;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 (&gt;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
29

Účinnost technologie ČOV České Budějovice pro eliminaci farmak / Efficiency of the technology of WWTP České Budějovice for the elimination of pharmaceuticals

BARTOŇ, Jiří January 2013 (has links)
The main aim of this study was to investigate the efficiency of wastewater treatment plant (WWTP) in České Budějovice for the elimination of selected pharmaceuticals (carbamazepine, diclofenac, atenolol, metoprolol, sotalol, bisoprolol, valsartan, verapamil and tramadol) over a long time period (March 2011 - February 2012). Time-proportional 24 hours pooled samples of wastewater from influent and effluent of the WWTP were used to assess the efficiency of WWTP. The concentrations of target compounds were determined by using in line SPE/LC-MS/MS analysis. The average annual concentrations in the effluent of WTP were in the range of 0,019 microgram/l (verapamil) to 1,00 microgram/l (atenolol). Average annual efficiencies of pharmaceutical elimination in WWTP based on pooled samples were found in the case of carbamazepine (-22 %), tramadol (-15 %), sotalol (-1 %), diclofenac (15 %), metoprolol (16 %), verapamil (43 %), bisoprolol (48 %) and valsartan (85 %). The statistical analysis of daily results in the winter and in the summer period showed significantly higher efficiency of the WWTP in the summer for 5 target compounds (diclofenac, atenolol, valsartan, sotalol and bisoprolol). Removal efficiency for the rest of pharmaceuticals did not show significant differences. Elevated temperature and longer irradiation period in summer can positively affect biodegradation or increased photolysis respectively.
30

Extra??o do corante reactive blue 19 utilizando tensoativo n?o i?nico / Extraction of Reactive Blue 19 dye using nonionic surfactant

Melo, Ricardo Paulo Fonseca 20 July 2012 (has links)
Made available in DSpace on 2014-12-17T15:01:28Z (GMT). No. of bitstreams: 1 RicardoPFM_DISSERT.pdf: 809568 bytes, checksum: 0179539902298813dbee39bd2859650c (MD5) Previous issue date: 2012-07-20 / The generation of effluent from the finishing process in textile industry is a serious environmental problem and turned into an object of study in several scientific papers. Contamination with dyes and the presences of substances that are toxic to the environment characterize this difficult treatment effluent. Several processes have already been evaluated to remove and even degrade such pollutants are examples: coagulation-flocculation, biological treatment and advanced oxidative processes, but not yet sufficient to enable the recovery of dye or at least of the recovery agent. An alternative to this problem is the cloud point extraction that involves the application of nonionic surfactants at temperatures above the cloud point, making the water a weak solvent to the surfactant, providing the agglomeration of those molecules around the dyes molecules by affinity with the organic phase. After that, the formation of two phases occurred: the diluted one, poor in dye and surfactant, and the other one, coacervate, with higher concentrations of dye and surfactants than the other one. The later use of the coacervate as a dye and surfactant recycle shows the technical and economic viability of this process. In this paper, the cloud point extraction is used to remove the dye Reactive Blue from the water, using nonionic surfactant nonyl phenol with 9,5 etoxilations. The aim is to solubilize the dye molecules in surfactant, varying the concentration and temperature to study its effects. Evaluating the dye concentration in dilute phase after extraction, it is possible to analyze thermodynamic variables, build Langmuir isotherms, determine the behavior of the coacervate volume for a surfactant concentration and temperature, the distribution coefficient and the dye removal efficiency. The concentration of surfactant proved itself to be crucial to the success of the treatment. The results of removal efficiency reached values of 91,38%, 90,69%, 89,58%, 87,22% and 84,18% to temperatures of 65,0, 67,5, 70,0, 72,5 and 75,0?C, respectively, showing that the cloud point extraction is an efficient alternative for the treatment of wastewater containing Reactive Blue / A gera??o de efluente proveniente do processo de acabamento na industria t?xtil ? um grave problema ambiental e se transformou em objeto de estudo em diversos trabalhos cient?ficos. A contamina??o por corantes e a presen?a de subst?ncias que s?o t?xicas ao meio ambiente caracterizam este efluente de dif?cil tratamento. V?rios processos j? foram avaliados para remover e at? degradar tais poluentes s?o exemplos: a coagula??o-flocula??o, tratamento biol?gico e processos oxidativos avan?ados, mas ainda n?o foram suficientes para possibilitar a recupera??o do corante ou pelo menos do agente separador. Uma alternativa para este problema ? a extra??o por ponto nuvem que envolve a aplica??o de tensoativos n?o i?nicos a temperaturas acima do ponto de nuvem, tornando a ?gua um solvente fraco para o tensoativo, proporcionando a aglomera??o destas mol?culas ao redor do corante por afinidade a fase org?nica. Depois disso ocorre a forma??o de duas fases: uma chamada de dilu?da pobre em corante e tensoativo e a coacervato com concentra??o de corante e tensoativo bem maior que a outra fase. A utiliza??o posterior do coacervato como reciclo de corante e tensoativo mostra a viabilidade t?cnica e econ?mica do processo. Neste trabalho a extra??o por ponto nuvem ? utilizada para remover o corante Reactive Blue da ?gua utilizando tensoativo n?o-i?nico nonil fenol com 9,5 etoxila??es. O objetivo ? solubilizar as mol?culas de corante no tensoativo, variando-se a concentra??o deste e a temperatura para estudar seus efeitos. Avaliando a concentra??o de corante na fase dilu?da ap?s a extra??o ? poss?vel analisar vari?veis termodin?micas, construir isotermas de Langmuir, determinar o comportamento do volume de coacervato para uma concentra??o de tensoativo e temperatura, o coeficiente de distribui??o e a efici?ncia de remo??o de corante. A concentra??o de tensoativo mostrou-se fundamental para o sucesso do tratamento. Os resultados de efici?ncia de remo??o alcan?aram valores de 91,38%, 90,69%, 89,58%, 87,22% e 84,18% para temperaturas de 65,0, 67,5, 70,0, 72,5 e 75,0?C, respectivamente, mostrando que a extra??o por ponto nuvem ? uma alternativa eficiente para o tratamento de efluentes contendo Reactive Blue

Page generated in 0.6289 seconds