Дисертації з теми "Sorbent material"
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Chigome, Samuel, and Samuel Chigome. "Electrospun nanofibers : an alternative sorbent material for solid phase extraction." Thesis, Rhodes University, 2012. http://hdl.handle.net/10962/d1004972.
Fontenot, Sean, and Sean Fontenot. "Supramolecular Modification of Mesoscale Materials." Thesis, University of Oregon, 2012. http://hdl.handle.net/1794/12356.
Brun, Raphaël. "Understanding the behavior of inorganic matrix-based construction materials for Indoor Air Quality improvement." Electronic Thesis or Diss., Ecole nationale supérieure Mines-Télécom Lille Douai, 2022. http://www.theses.fr/2022MTLD0009.
Use of sorptive construction materials to mitigate VOC concentrations indoors appears as a promising alternative to conventional solutions responsible for energy consumption and potential harmful by-products release. In this PhD, the VOC uptake properties of gypsum boards and lime-cement plasters enriched in VOC sorbents, activated carbons (AC), are investigated. Three-scale reactors have been deployed to complementarily assess the behavior of the materials regarding indoor Volatiles Organic Compounds (VOCs). Selected powder sorbents, exposed to single VOC (toluene and formaldehyde), are characterized using a U-shape reactor under mild conditions (50% RH and 23 °C). AC surface chemistry and morphology are correlated with VOC uptake capacities. The fate of taken up VOCs on AC surface is investigated at ambient temperature and under typical indoor heat events. Results lead to the definition of guidelines for AC selection. Fully processed board samples, exposed to an 18-VOC mix, representative of indoor pollutant diversity, are studied using FLEC reactors. The uptake capacities of sorptive materials are assessed using a continuous 42-day exposure to the VOC mix. Key parameters are proposed to discriminate materials according to their impact on IAQ. The introduction of ACs remarkably enhances the VOC removal ability of construction materials on short and long term. Additionally, experiments dedicated to HCHO evidence a reactive uptake on lime-cement plaster matrix: Cannizzaro reaction leads to the formation of gaseous methanol and adsorbed formates. At real scale, using the 40-m3 IRINA experimental room, lime-cement plaster matrix and a lime-cement plaster enriched in AC are exposed to selected pollutants (ozone, toluene, decane, limonene, acetone, ethanol and formaldehyde) at typical indoor level. The effectiveness of the AC-enriched plaster to mitigate pollution episodes is evidenced and quantified for all investigated compounds. Real scale results emphasize that sorptive construction materials can perform as well as widespread active and oxidative air treatment devices
Campos, Lopez F. (Felipe). "Evaluating the effectivity of peat as sorbent material for mining water purification in pilot scale systems." Master's thesis, University of Oulu, 2018. http://urn.fi/URN:NBN:fi:oulu-201805091619.
Albrecht, Karl Oscar. "Development and testing of a combined catalyst/sorbent core-in-shell material for the production of high concentration hydrogen." [Ames, Iowa : Iowa State University], 2008.
Jones, Michael T. "The disposal of spilled oils and sorbent materials." Thesis, Springfield, Va. : : Available from National Technical Information Service, 2001. University of Florida, 2001. http://handle.dtic.mil/100.2/ADA393129.
Ding, Kaijie. "Arsenite removal from contaminated water by different sorbent materials." Thesis, KTH, Hållbar utveckling, miljövetenskap och teknik, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-273970.
Alltför höga halter av arsenik (As) i vatten är ett världsomspännande problem som orsakar hälsoproblem för miljontals människor. Det finns två huvudsakliga oorganiska former av As i vatten: arsenat(V) och arsenit(III), och adsorption till ett material (s.k. ”sorbent”) kan vara eneffektiv metod för att avlägsna dem från vatten. I denna studie fokuserade vi på arsenit(III), den mer giftiga formen, vilken dominerar under reducerande förhållanden. Vi undersökte adsorptionsegenskaperna för arsenit(III) för fyra sorbentmaterial som kan vara tänkbara när det gäller arsenikrening av förorenade vatten: hydrotalkit, s.k. Mg-Al LDH (Mg-Al-skiktad dubbelhydroxid), am-Al(OH)3 (amorf aluminiumhydroxid), och am-TiO2 (amorf titandioxid). Dessa material undersöktes när det gäller följande: adsorption av arsenit(III) som funktion av pH,betydelsen av sorbentkoncentration, adsorption som funktion av löst arsenit(III) (”isoterm”), och konkurrens från samexisterande anjoner (HCO3− och PO43−). Den maximala adsorptionen av As (III) till HT (0,1 mmol As(III)/g sorbent), Mg-Al LDH (0,1 mmol As(III)/g sorbent), am-Al(OH)3 (0,22 mmol As(III)/g sorbent) och am-TiO2(0,21 mmol As(III)/g sorbent) inträffade vid pH 7,5, 7, 7, respektive 8. Vid dessa pH-värden adsorberades ungefär 20%, 62%, 35% respektive 98,3% tillsatt As(III). När kvoten mellan As(III) till sorbent ökades blev adsorptionen istället cirka 7% till am-Al(OH)3 (2,2 mmol As(III)/g sorbent) och 46,3% till am-Ti02(2,1mmol As(III)/g sorbent). Dock var adsorptionsmängden per viktsenhetsorbenthögre över hela pH-området. Dessa siffror visar att am-TiO2 är det mest effektiva av de fyra testade materialen för As(III)-adsorption, Mg-Al LDH det näst bästa, medan HT och am-Al(OH)3 är olämpliga för detta ändamål. Adsorptionen av As(III) till Mg-Al LDH som funktion av löst As(III) kunde beskrivas väl med en linjär ekvation, vilket antyder att adsorptionen av As(III) till Mg-Al LDH styrdes av anjonbyte. I konsekvens med detta hade de samexisterande anjonerna (HCO3- och PO43-) ett betydande inflytande på As(III)-adsorptionen till Mg-Al LDH. För am-TiO2 påverkade HCO3− inte As(III)-adsorptionen, medan PO43- orsakade en liten men tydlig konkurrenseffekt. Sammantaget är am-TiO2 det bästa valet av dessa fyra material i kontakt med As- kontaminerat grundvatten på grund av dess betydligt bättre förmåga att avskilja arsenit(III) och den förhållandevis blygsamma konkurrensen från andra anjoner.
Brown, Veronica M. "Development of improved methods for the characterisation of organic chemicals emitted into indoor air by building and furnishing products." Thesis, Cranfield University, 2013. http://dspace.lib.cranfield.ac.uk/handle/1826/8078.
Carmody, Onuma. "Development and evaluation of hydrocarbon sorbent materials with the aid of chemometrics." Thesis, Queensland University of Technology, 2006. https://eprints.qut.edu.au/37169/1/Onuma_Carmody_Thesis.pdf.
Soo, Haw Yun. "Commercialization of cryptomelane-type manganese oxide (OMS-2) nanowire paper oil sorbent." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/42158.
Includes bibliographical references (leaf 36).
Cryptomelane-type Manganese oxide (OMS-2, a group of Octahedral Molecular Sieves) nanowire paper exhibits interesting properties: reversible wettability, oleophilic while being hydrophobic, and high thermal stability. These properties open up possible markets for commercialization. This thesis reviews the market potential of each of these properties and explores the competitiveness of the nanowire paper in the proposed markets. The proposed values of this technology are in its high selective absorbency towards oil, high performance over cost metric and its high thermal stability. Its thermal stability enables a thermal desorption type process to regenerate and recycle the sorbent for reuse. This translates into further differentiation and provides greater value for the users.
by Haw Yun Soo.
M.Eng.
Biasin, Alberto. "CO2 capture with solid sorbents: materials characterization and reaction kinetics." Doctoral thesis, Università degli studi di Padova, 2015. http://hdl.handle.net/11577/3424135.
Negli ultimi anni, l’interesse riguardo al problema del riscaldamento globale è cresciuto notevolmente. La comunità scientifica è concorde sul fatto che i cambiamenti climatici osservati nel mondo sono correlati alle emissioni di gas serra, in modo particolare quelle di biossido di carbonio, che sono incrementate rapidamente in seguito allo sviluppo tecnologico ed industriale ([1], [2], [3]). Il settore principalmente coinvolto nelle emissioni di CO2 è l’industria per la generazione di energia, dove gli impianti di combustione e gassificazione che sfruttano combustibili fossili sono predominanti e contano ancora oggi per più di un terzo di tutte le emissioni antropogeniche di CO2. Se si considera la continua e progressiva crescita nell’utilizzo di questi combustibili in tale settore, lo sviluppo e l’implementazione di processi caratterizzati da ridotte (se non assenti) emissioni di CO2 sono questioni che devono essere urgentemente affrontate. La cattura e lo stoccaggio dell’anidride carbonica, comunemente denominato CCS (dall’inglese Carbon dioxide Capture and Storage), rappresenta l’insieme delle tecnologie orientate appunto a separare l’anidride carbonica dalle correnti gassose industriali (oltre che al trasporto e allo stoccaggio della stessa in formazioni geologiche o nel fondo degli oceani in modo tale da isolarla dall’atmosfera a lungo termine) in modo efficiente ed economicamente conveniente, e rappresenta una possibile soluzione a breve termine per mitigare le emissioni di CO2 nell’atmosfera ([1], [4]). Tuttavia, i costi associati alle tecniche di cattura della CO2 ad oggi disponibili (come ad esempio i processi basati su lavaggi con solventi amminici) sono proibitivamente alti (soprattutto in termini di penalizzazioni nell’efficienza energetica degli impianti di produzione di energia), e rendono quindi lo sviluppo di nuovi sorbenti per la cattura del biossido di carbonio una sfida molto importante nel panorama della ricerca scientifica. Tra le diverse strategie attualmente investigate, l’ossido di calcio (CaO), facilmente ottenuto attraverso trattamenti termici di calcinazione del carbonato di calcio ampiamente disponibile e diffuso in natura, si presta come un sorbente solido particolarmente interessante/promettente che potrebbe ridurre in modo significativo i costi associati ai processi di cattura dell’anidride carbonica. La tecnica della cattura della CO2 attraverso sorbenti solidi a base di ossido di calcio è ampiamente discussa in letteratura e recentemente è stata riassunta da alcuni autori ([5], [6], [7], [8]). Essa fa riferimento alla reazione reversibile CaO (s) + CO2 (g) ↔ CaCO3 (s) e dovrebbe essere applicata attraverso cicli di calcinazione e carbonatazione, offrendo diversi vantaggi. Tuttavia, alcune problematiche, tra cui il progressivo declino nella capacità di cattura che tali sorbenti evidenziano all’aumentare del numero di cicli di assorbimento/desorbimento, ne mettono ancora in discussione l’utilizzo diffuso in applicazioni di scala industriale. La ricerca di miglioramenti e lo sviluppo di nuovi sorbenti solidi sono quindi una materia di studio attuale e, nonostante l’apparente semplicità della reazione chimica coinvolta, diversi aspetti riguardanti la carbonatazione del CaO non sono stati definitivamente chiariti. La determinazione dei parametri cinetici intrinseci della reazione di carbonatazione è una delle questioni aperte. La qualità della stima della costante cinetica della reazione superficiale (necessaria per progettare i reattori per la carbonatazione) dipende dall’accuratezza dei dati sperimentali (nello specifico delle curve di conversione vs. tempo) i quali, in tutti i contributi disponibili in letteratura, sono ottenuti (al meglio delle conoscenze dell’autore) tramite un approccio termo-gravimetrico ([15], [11], [12], [9], [10], o [21]). Tuttavia, è noto che misure TGA possono essere affette da limitazioni legate a resistenze al mass transfer, specialmente per quanto riguarda la diffusione esterna, per cui è ragionevolmente discutibile se i risultati finora riportati in letteratura siano realmente espressione della cinetica intrinseca oppure, diversamente, riproducano soltanto una cinetica di assorbimento della CO2 apparente. Un altro aspetto rilevante è la dipendenza della reazione di carbonatazione dalle proprietà strutturali del sorbente. Finora, diverse ricerche hanno focalizzato l’attenzione sull’impatto della porosità e della superficie specifica, o ancora sull’impatto della distribuzione della dimensione dei pori rispetto la reazione di carbonatazione e alla sua cinetica ([15], [17], [10], [13], [18], o [19]). Anche se la superficie specifica e la distribuzione della dimensione dei pori sono parametri probabilmente rilevanti nella determinazione della cinetica di una tipica reazione gas-solido come la carbonatazione del CaO, l’impatto delle dimensioni dei domini cristallini che formano le fasi di ossido di calcio e di carbonato sulle prestazioni dei sorbenti sono informazioni non ancora disponibili in letteratura quando ci si riferisce alla reazione di carbonatazione. Il progetto di ricerca riassunto in questo lavoro di tesi è stato quindi focalizzato sullo studio della reazione di carbonatazione del CaO e sulla caratterizzazione dei sorbenti a base di ossido di calcio, con l’obiettivo di chiarire questi aspetti emersi dalla letteratura, ancora poco risolti. Dopo avere affrontato il problema del surriscaldamento globale e aver riassunto le inequivocabili evidenze scientifiche riguardanti i cambiamenti climatici già discusse in dettaglio nei report dell’Intergovernmental Panel of Climate Change (IPCC) ([1], [2], [3] ), nel Capitolo 1 sono delineate le cause di tali cambiamenti ed la CCS viene presentata come una delle possibili strategie di mitigazione delle emissioni di CO2, focalizzando l’attenzione sullo stato dell’arte in merito alle tecnologie CCS attualmente investigate. Successivamente, viene presentata la tecnologia della cattura dell’anidride carbonica realizzata attraverso l’utilizzo di sorbenti solidi a base di ossido di calcio. Nel Capitolo 2 vengono quindi discussi gli aspetti fondamentali riguardanti la reazione di carbonatazione del CaO, descrivendo la sua termodinamica e il tipico comportamento caratterizzato da due differenti fasi di reazione ovvero, una parte iniziale veloce, controllata nei primi istanti dalla reazione chimica alla superficie, seguita da una seconda fase più lenta, controllata dalla diffusione della CO2 attraverso lo strato di carbonato di calcio prodotto. Altresì, nel capitolo sono riportate considerazioni sugli aspetti irrisolti riguardanti la reazione di carbonatazione riscontrati in letteratura, come la caratterizzazione/misura del critical product layer thickness, il quale determina la transizione tra i due regimi di reazione menzionati, ed il problema della stima dei parametri cinetici intrinseci della carbonatazione. Infine, sono proposti i principali risultati dell’investigazione preliminare condotta attraverso l’applicazione dell’approccio termo-gravimetrico. Campioni di sorbente (i.e. particelle di ossido di calcio) direttamente prodotti in TGA tramite decomposizioni termiche di CaCO3 commerciale, in atmosfera di N2 (range di temperatura tra i 650°C e i 900°C), sono state testate per analizzare la loro reattività nella fase di cattura del biossido di carbonio, con l’obiettivo di identificare le velocità di assorbimento specifiche e confermare come i tradizionali esperimenti in TGA siano affetti da limitazioni fisiche, specialmente resistenze legate a fenomeni di mass transfer. Questi esperimenti sono stati condotti alimentando un classico strumento TGA sia con CO2 pura, sia con miscele N2/CO2 in modo da variare la pressione parziale di anidride carbonica in un intervallo compreso tra 0.05 bar e 1 bar, e imponendo isoterme a diverse temperature di carbonatazione, fissate tra i 450°C e i 650°C. Alcuni campioni di sorbente sono stati anche preparati attraverso fasi di calcinazione realizzate separatamente in un forno a muffola. Diverse condizioni operative sono state utilizzate in termini di temperature di calcinazione (principalmente 900°C) e tempi di residenza a tali temperature (da pochi secondi a qualche ora), in modo da produrre particelle di ossido di calcio caratterizzate da differenti proprietà strutturali, specialmente in termini di porosità e superficie specifica. Infatti, tali fattori, che sono strettamente legati alle modificazioni strutturali alle quali questi sorbenti sono soggetti per effetto dei trattamenti termici ad alta temperatura, ragionevolmente influenzano la reazione di carbonatazione. Per completare la caratterizzazione dei sorbenti così prodotti si sono eseguite dapprima misure di superficie specifica attraverso adsorbimento di N2 e analisi BET, e in seguito se n’è testata la capacità di assorbimento di CO2 in TGA con flussi di anidride carbonica (pressione totale di 1 bar). Sulla base dei profili di conversione e delle corrispondenti velocità di reazione, un semplice modello cinetico ([9]) è stato utilizzato per determinare i parametri della cinetica intrinseca. Anche se ragionevolmente associabile ad una cinetica di reazione apparente, un’energia di attivazione di circa 45 kJ/mol è stata stimata. A seguito dell’incertezza sui dati sperimentali ottenuti e connessi a limitazioni legate a fenomeni di mass transfer, la tecnica di diffrazione ai raggi X su polveri è stata quindi applicata come metodo alternativo all’analisi termo-gravimetrica nello studio della reazione tra CaO e CO2. In particolare, nel Capitolo 3 è riportata una piccola descrizione dei principali fondamenti teorici alla base di questa tecnica; successivamente sono discussi i principali risultati raccolti durante una fase di studio realizzata in collaborazione con il dipartimento di Geoscienze dell’Università di Padova. Esperimenti di diffrazione in–situ sono stati condotti per determinare le variazioni strutturali che interessano i sorbenti solidi (in modo particolare, l’evoluzione nel tempo delle fasi cristalline (i.e. composizione) e le variazioni nelle dimensioni dei domini cristallini che caratterizzano le fasi stesse) in funzione della temperatura e della pressione parziale di anidride carbonica. Diversi esperimenti sono stati eseguiti usando una camera di reazione, applicata ad un diffrattometro da laboratorio, che ha permesso di controllare la composizione gassosa del sistema sia durante la fase di decomposizione/rigenerazione, sia durante il processo di assorbimento, nonché la temperatura del materiale testato. Esperimenti di calcinazione sono stati condotti anche qui in atmosfera di N2 (pressione totale di 1 bar) e in un intervallo di temperature tra i 650°C e i 950°C, ed hanno permesso di osservare che dopo la decomposizione completa del carbonato di calcio usato come precursore le dimensioni medie dei domini cristallini di CaO di neo formazione (approssimativamente nell’ordine dei 40 nm) cambiano considerevolmente quando il materiale è mantenuto ad alte temperature per lunghi tempi di permanenza. Inoltre, si è verificato che anche piccole concentrazioni di CO2 nell’atmosfera nella quale è condotta la fase di decomposizione favoriscono l’accrescimento dei cristalliti di ossido di calcio, tanto che le dimensioni dei nascenti domini cristallini di CaO risultano notevolmente aumentate rispetto al caso di calcinazioni condotte in atmosfera inerte. Prove di carbonatazione hanno invece evidenziato che differenze nella dimensione iniziale (ovvero, all’inizio della carbonatazione) dei domini cristallini di ossido di calcio apparentemente sembrano influenzare la reattività del campione di sorbente solido durante il processo di assorbimento della CO2: a parità d’isoterma di carbonatazione (temperature tra i 450°C e i 650°C), con pressioni parziali di CO2 di 1 bar, campioni costituiti da cristalliti più grandi hanno infatti mostrato una capacità di assorbimento della CO2 più bassa raggiungendo, al termine di esperimenti di carbonatazione nell’ordine dei 120 min, conversioni inferiori. Altresì, questa evidenza rimane confermata anche all’aumentare del numero di cicli di calcinazione/carbonatazione. Purtroppo, la bassa risoluzione temporale caratterizzante la strumentazione di laboratorio disponibile non è stata sufficiente per ottenere informazioni dettagliate sulle trasformazioni che avvengono nella struttura cristallina delle particelle di sorbente, soprattutto durante la fase iniziale (molto veloce) della carbonatazione laddove la reazione alla superficie (i.e. cinetica intrinseca) ragionevolmente ha luogo con trascurabili effetti di diffusione attraverso il product layer di carbonato. Per approfondire la caratterizzazione della carbonatazione del CaO attraverso la diffrazione dei raggi X si è pertanto scelto di incrementare le potenzialità della tecnica con l’utilizzo della radiazione da sincrotrone. Nel Capitolo 4 sono presentati i risultati sulla caratterizzazione della reazione tra CaO e CO2 ottenuti da esperimenti di diffrazione ai raggi X in-situ condotti in collaborazione con le strutture dell’Advanced Photon Source (APS) presso l’Argonne National Laboratory (Argonnne, IL, U.S.A). Un set di esperimenti di cattura della CO2 è stato completato utilizzando un sistema con capillare riscaldato appositamente sviluppato ([20]) per condurre prove di diffrazione da polveri controllando l’atmosfera di reazione (pressioni parziali di CO2 di 1 bar) e la temperatura (tra i 450°C e i 750°C), per seguire l’evoluzione delle fasi cristalline di CaO e CaCO3 durante il processo di carbonatazione di particelle di ossido di calcio prodotte per decomposizione termica di carbonato di calcio commerciale. Il metodo di raffinamento Rietveld è stato poi applicato sia per quantificare la conversione dell’ossido di calcio durante il procedere della reazione, sia per stimare la dimensione media dei domini cristallini di CaO all’inizio della carbonatazione. Dai profili di conversione è stata valutata una velocità media iniziale della carbonatazione (espressa in termini di derivata della conversione rispetto al tempo) pari a 0.280 s-1 (deviazione standard di ± 13.2%) che è risultata significativamente più alta rispetto ai valori ottenuti da analisi termo-gravimetriche e riportati finora in letteratura ([9], [15] o [12]). E’ stata inoltre osservata una dipendenza dei profili di conversione rispetto al tempo dalla dimensione iniziale dei cristalliti di ossido di calcio, come pure è stata identificata una relazione lineare tra questa grandezza e la conversione finale. Analogamente, anche l’evoluzione del carbonato di calcio durante la fase di assorbimento della CO2 è stata monitorata: dimensioni massime dei domini cristallini di CaCO3 sono state osservate nei profili del crystallite size del carbonato in funzione del tempo (in particolare durante la prima rapida fase della reazione), e sono state identificate come i valori medi del critical product layer thickness. Una relazione tra questo parametro e le corrispondenti conversioni dell’ossido di calcio, alle quali si può ragionevolmente associare la transizione alla seconda fase caratteristica della carbonatazione (i.e. regime controllato dalla diffusione della CO2 attraverso lo strato di prodotto), è stata individuata, come anche tra il critical product layer thickness e la porosità iniziale delle particelle di sorbente. Infine, i valori individuati sono stati usati per stimare la superficie specifica iniziale delle particelle di CaO utilizzate negli esperimenti di carbonatazione; tali superfici sono quindi state usate nella stima dei parametri cinetici intrinseci della reazione di carbonatazione, ottenendo una costante di reazione pari a circa 1.89 × 10-3 mol/m2 s, con energia di attivazione nulla.
Zhao, Qichao. "Ionic Liquid Materials as Gas Chromatography Stationary Phases and Sorbent Coatings in Solid-Phase Microextraction." University of Toledo / OhioLINK, 2011. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1320963975.
Fayemi, Omolola Esther. "The development of platinum and palladium-selective polymeric materials." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1002964.
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Hellman, Oskar. "Synthesis of framework porous sorbents using sustainable precursors." Thesis, Uppsala universitet, Nanoteknologi och funktionella material, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-445896.
Di, Giuliano Andrea. "Synthesis, characterization and industrial applicability of combined sorbent-catalyst materials for sorption enhanced steam methane reforming." Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAF065/document.
Sorption enhanced steam methane reforming (SESMR), steam methane reforming (SMR) with in situ CO2 sorption by a solid sorbent, can lead to a sustainable exploitation of natural gas to produce H2. (CSCM). This thesis, as a part of ASCENT (Advanced Solid Cycles with Efficient Novel Technologies) project, deals with Ni-CaO-mayenite combined sorbent-catalyst material for SESMR, to study the effect of Ni fraction, its precursor salt (Ni nitrate or Ni acetate), and free CaO fraction. ICP AES, XRD, BET and BJH methods, SEM EDS, TEM EDS, TPR and TGA were used to characterize synthesized materials. Their reactivity was evaluated by tests in a packed bed microreactor, which served also as a screening tool to choose the most promising materials. Their industrial applicability was assessed by multicycle SESMR/regeneration tests in an automated packed bed bench scale rig
Jabbour, Rabih Elie. "Characterization of selected immobilized metal-ions using solid phase extraction sorbents." Diss., The University of Arizona, 1998. http://hdl.handle.net/10150/282773.
Bennett, J. "Absorption, storage and release characteristics of poly(1-methylpyrrol-2-ylsquaraine) particles." Thesis, Coventry University, 2008. http://curve.coventry.ac.uk/open/items/909fab9b-5abc-4467-93bb-cc8ad0d087a9/1.
Kassa, Meheret. "Phosphorous Desorbing Capacity of the Filter Materials Polonite® and Sorbulite®." Thesis, KTH, Mark- och vattenteknik (flyttat 20130630), 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-171844.
Ndunda, Elizabeth [Verfasser]. "Development of selective sorbent materials for the determination of polychlorinated biphenyls (PCBs) in the environment / Elizabeth Ndunda." Ulm : Universität Ulm, 2016. http://d-nb.info/1119894220/34.
Bhandari, Dhaval Ajit. "Hollow fiber sorbents for the desulfurization of pipeline natural gas." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/42838.
Bessho, Naoki. "Advanced pressure swing adsorption system with fiber sorbents for hydrogen recovery." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/42822.
DISTEFANO, GAETANO. "Nanoporous dipeptide crystals as selective gas sorbents and polymerization nanovessels." Doctoral thesis, Università degli Studi di Milano-Bicocca, 2012. http://hdl.handle.net/10281/29103.
Wongrod, Suchanya. "Biochars from solid digestates as sorbing materials for metal(loid)s removal from water." Thesis, Paris Est, 2019. http://www.theses.fr/2019PESC2023.
Sewage sludge digestate (SSD) and the organic fraction of municipal solid waste digestate (OFMSWD) are currently considered as alternative feedstocks for biochar production due to the high amount of the organic solid waste remaining at the end of the treatment. The pyrolysis of solid digestate is known as an alternative to promote the recycling of organic wastes and generate added-value bio-products (e.g. biochar). Generally, the digestate biochar has a much lower sorption capacity for metal(loid)s compared to activated carbons. Therefore, chemical treatment is considered as a potential option to improve the biochar surface properties and thus inducing a better sorption ability for metal(loid)s on the biochar surface. The biochars were treated with 2 M KOH or 10% H2O2 followed by batch washing or batch and subsequent column washings with ultrapure water. The physicochemical properties including the pH of point of zero charge, the surface area and cation exchange capacity were determined for all the biochars in order to link their improved surface properties to the enhanced sorption ability for metal(loid)s. All the biochars were then used to study the influence of chemical treatment and biochar washing procedure on the sorption behavior of Pb(II), Cd(II) and As(III, V) through the batch sorption kinetics and isotherms. Moreover, the As redox state distribution (i.e. As(III, V)) during the As(III) sorption onto the biochar surface and in liquid solution was determined by using solid-liquid extraction followed by liquid chromatographic analysis. Results showed increases of the sorption ability for Pb(II), Cd(II) and As(V) after chemical treatment. For instance, the maximum sorption capacity (Qm) of Cd(II) was increased from 15.4 µmol g−1 on the raw SSD biochar to 306.1 µmol g−1 after the KOH treatment (at initial pH 5.0). Similarly, the Qm of Pb(II) was also increased from 6.5 mg g⁻1 (raw SSD biochar) to 25 mg g⁻1 on the H2O2 modified SSD biochar. However, the sorption capacity for Pb(II) was not determined after KOH treatment due to the failing of the Langmuir isotherm model to fit the experimental data. This indicates that insufficient washing of the KOH-modified SSD biochar can hinder the Pb(II) sorption due to the release dissolved organic compounds from this biochar that may interact with Pb2+ and thereby forming Pb-ligand complexes in the solution. This highlights an important role of washing procedure for Pb(II) sorption by the biochar. The As redox distribution showed a large oxidation (70%) of As(III) to As(V) in KOH-modified SSD biochar with batch washing, while As(III) was partially oxidized (7%) in the KOH-modified SSD biochar with batch and subsequent column washings. The As extraction followed by liquid chromatographic analysis was successfully established to quantitatively recover arsenic (i.e. As(III, V)). The oxidation of As(III) was strongly induced by the biochar and to a lesser extent by the release of dissolved compounds from the biochar. In summary, digestate biochars with the chemical treatment followed by a proper biochar washing procedure can be successfully used as potential sorbents to enhance the Pb(II), Cd(II) and As(III, V) sorption capacity. Moreover, the determination of As redox distribution on the biochars and in liquid phase during the sorption process can be achieved through the As extraction and chromatographic analysis, providing a better understanding of the transformation between As(III) and As(V) in the biochar-liquid sorption system
Whitten, Lisa Jane. "The production and characterisation of sorbents from lignocellulosic materials and their application in NOâ†x/SOâ†x removal." Thesis, Queen's University Belfast, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.394526.
Maciel, Edvaldo Vasconcelos Soares. "Síntese de novos materiais à base de grafeno para aplicação em microextração por sorvente empacotado MEPS na extração de tetraciclinas presentes no leite com posterior análise por cromatografia líquida acoplada a espectrometria de massas sequencial ." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/75/75135/tde-07022018-103749/.
Nowadays, the rise of world population and industrial expansion are leading to an increase in consumption and consequently waste generation. Large quantities of chemical residues are released into the environment affecting humans and wildlife. Among these residues, antibiotics used in medicine and veterinary are classified as an emerging contaminant due to their low degradation rate, ineffectiveness of wastewater treatment and consequently water and food contamination. An effort has been made to develop microextraction techniques to remove these drugs using reduce volume of solvent and chemical consumable and researches of new sorbent phases are increasing due the high potential to improve these microextraction techniques. Recent studies pinpoint graphene (G) as an effectively sorbent phase to act in sample preparation. G has a structure composed by carbon nanosheets arranged in a honeycomb pattern with large surface area (3600 m2 /g) and delocalized π-electrons system that suggests good interaction between them and contaminants compounds such as veterinary drugs, pesticides, personal care products etc. This study focuses to evaluate sorbent phases based upon graphene particle supported on silica to analyze Tetracycline residues present in milk. For this purpose, was used microextraction by packed sorbent - MEPS as sample preparation method with analysis by liquid chromatography and mass spectrometry. The characterization of synthesized materials was performed by scanning electron microscopy - SEM and vibrational spectroscopy in infrared region - FTIR. The results suggest that synthesis of graphene\'s particles as well as the coating of silica surface with these materials were both performed. To evaluate extraction efficiency each sorbent material: GO-Sil, G-Sil, G, C18-GO-Sil were tested in MEPS and confronted to commercial phases: C8 and C18. By the results, G-Sil was choose to application as sorbent phase. MEPS extractions were optimized and the effect of some factors was investigated by application of experimental design. Firstly, a factorial experimental design 2(4-1) was executed to evaluate chemistry variables such as elution solvent, washing solution, media ionic strength and inclusion of EDTA salt in Mcllvaine solution. After, an experimental design 23 was made in order to estimate the cycles of MEPS extraction like sampling, washing and elution steps. By the results, an optimized extraction conditional was achieved and evaluation of validation parameters was carried out on sequence based on the ICH - Q2 (R1) guide. The method showed linearity ranging from 15 - 110 µg/L, LOQ values from 0,05 to 0,9 µg/L and good selectivity. Precision showed relative standard deviation RSD less than 18% to intra and inter-day analysis. The developed method was applied in analysis of eleven milk samples including bovine, caprine and ovine milk and milk powder. Application in samples from different species enhances the versatility of this analytical method and show the great potential for graphene\'s particles to act as sorbent phase in sample preparation.
Erans, Moreno Mari´a. "Enhanced sorbents for the calcium looping cycle and effects of high oxygen concentrations in the calciner." Thesis, Cranfield University, 2017. http://dspace.lib.cranfield.ac.uk/handle/1826/12914.
Norman, Per-Albin. "Filter Materials for Sorption of Cu and Zn in Stormwater Treatment: A Batch Equilibrium and Kinetic study." Thesis, Luleå tekniska universitet, Arkitektur och vatten, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-68059.
I denna studie undersöktes potentialen för fem material att avskilja löst koppar (Cu) och zink (Zn) från dagvatten. Studien inleddes med skaktest för att testa sorptionsförmågan hos materialen vid olika metallkoncentrationer relevant för dagvatten. Detta gjordes i både singel och binära test för att undersöka om någon konkurrerande sorption skedde mellan metallerna. Langmuirs, Freundlichs och Sips isotermmodeller anpassades även till resultatet. Genom geokemisk modellering var det även möjlig att undersöka om utfällning av metaller var sannolik. Till sist gjordes kinetiska studier för att undersöka om reaktionshastigheten för sorption av Cu och Zn till filtermaterialen var relevanta i ett brunnsfiltersammanhang. Resultaten visar att biokol hade den största sorptionsförmågan följt av torv, bark, sidenört och polypropylen. Det kunde även konstateras att koppar konkurrerade om sorptionsplatser för zink vid högre koncentrationer och att sorptionskapaciteten för biokol, torv och bark, vid koncentrationer mellan 50-100 µg/l Cu och 50-500 µg/l Zn, är tillräckligt hög för att uppfylla gränsvärdena för utsläpp av dagvatten. För dessa sorbenter var reaktionshastigheten betydande. Kinetiktesten visade att vid en initial koncentration på 1,000 µg/L var 83% av metallerna sorberade efter 5 minuter och efter 10 minuter var denna siffra uppe i 93%. Bark and torv uppvisade även ett lågt uppmätt pH och lakade löst organisk kol (DOC). Langmuir och pseudo-andra ordningens ekvation kunde anpassas väl till datat samtidigt som den geokemiska modelleringen visade att utfällning av metaller var osannolikt. Detta antyder att kemisk adsorption kan vara den mekanism som till störst del stod för avskiljningen av Cu och Zn. Studien kan inte fastställa något om filtermaterialens fältprestanda, men kan användas som underlag för att jämföra och att välja sorbenter för efterföljande kolumntester.
Formas project 2016-75
Петрушка, І. М. "Науково-методологічні основи екологічно безпечних технологій очищенння стічних вод сорбентами мінерально-сировинної бази України". Thesis, Івано-Франківський національний технічний університет нафти і газу, 2013. http://elar.nung.edu.ua/handle/123456789/4636.
Диссертация посвящена разработке научно-методологических основ экологически безопасных технологий очистки сточных вод от органических красителей, растворителей и радионуклидов сорбентами минерально-сырьевой базы Украины. В работе приведены теоретические и экспериментальные исследования процессов адсорбционной очистки жидкостных сред природными дисперсными сорбентами, методы модифицирования этих сорбентов в зависимости от необходимой степени их активации, а также рассмотрена перспективность использования жидкостной хроматографии для разделения многокомпонентной системы органических растворителей методом селективной адсорбции (промышленной хроматографии). Решенная научно-техническая проблема дала возможность разработать и внедрить высокоэффективные технологии очистки стоков, загрязненных красителями, органическими растворителями и радионуклидами. На основании теоретических и экспериментальных исследований процессов кислотного модифицирования бентонитов разработана классификация методов модифицирования природных сорбентов в зависимости от вида загрязнителя, а также рассчитаны адекватные математические модели, вычислены значения кинетических коэффициентов и предложены принципиальные технологические схемы реализации процессов. Разработанные теоретические основы моделирования процессов очистки сточных вод адсорбцией природными и модифицированными сорбентами. Предложены математические модели для прогнозирования лимитирующей стадии процесса сорбции на основании теории локальной изотропной турбулентности для аппаратов с механическими устройствами - при расчете внешнедиффузионных параметров, а также внутридиффузионных параметров с использованием теоретических расчетов эффективных коэффициентов внутренней диффузии. Исследована сорбция Сs и Sг с жидких радиоактивных отходов на модифицированных глинистых минералах и установлены оптимальные условия процесса. Доказано, что в случае применения модифицированных глинистых сорбентов не наблюдается вторичное загрязнение воды металлами-модификаторами. Проведена идентификация экспериментальных данных адсорбции радионуклидов существующим теоретическим изотермам сорбции. Исследованны аспекты использования жидкостной хроматографии в промышленных условиях для разделения смеси органических растворителей. Решения адсорбционной модели использованы для прогнозирования конкурентного равновесия адсорбции раствора и активного компонента подвижной фазы на основе изотерм адсорбции, а стандартные изотермы адсорбции определенные на основании дополнительных данных адсорбции, измеренных в инертной системе. Предложена принципиальная технологическая схема хроматографического разделения смеси органических растворителей. Основные результаты переданы для внедрения в производство и используются в учебном процессе.
On the basis of theoretical and experimental investigations of the acid modification bentonite developed adequate mathematical model, calculated values of the kinetic coefficients and the proposed process flow diagram the process. The theoretical basis of modeling processes of cleaning liquid media by adsorption of natural sorbents. The proposed mathematical model of the process to establish the rate-limiting step by calculating external diffusion parameters (based on the theory of locally isotropic turbulence for vehicles with mechanical devices) and internal diffusion parameters (using theoretical calculations of effective internal diffusion coefficient). Investigated the adsorption of Cs and Sr on the modified clay minerals and optimum process conditions. Proved that in the case of the modified clay adsorbents is observed secondary pollution of water modifier metal. Identified on the experimental data of adsorption of radionuclides existing theoretical sorption isotherms. Studied aspects of liquid chromatography in industrial conditions for separating a mixture of organic solvents. Solutions of the adsorption model used to predict the competitive equilibrium adsorption solution and the active component of the mobile phase on the basis of the adsorption isotherms, and the standard adsorption isotherms determined on the basis of additional data of adsorption measured in an inert system. A basic flow diagram of chromatographic separation of a mixture of organic solvents. Main results released for implementation in production and use in the classroom.
Mothibedi, Kediemetse (Kedimetse). "A study of electrospun nanofibers and diatomaceous earth materials for the extraction of alkaloids, flavonoids and aromatic amines in various matrices." Thesis, Rhodes University, 2013. http://hdl.handle.net/10962/d1003052.
Bratkowska, Dominika. "Development and application of new polymeric materials for sorptive extraction techniques." Doctoral thesis, Universitat Rovira i Virgili, 2011. http://hdl.handle.net/10803/63173.
The development of different materials for sorptive extraction techniques is a continuously evolving field of research. Although there have been significant developments in this area, the extraction of polar analytes is still considered the bottleneck of the extraction process. The efforts have been undertaken to improve capacity and selectivity. For this reason, one of the main objectives of this Thesis is to develop new materials to extract polar organic contaminants from water samples. The first part reports on the development of new polymeric materials for solid-phase extraction including hypercrosslinked polymers with hydrophilic character, mixed-mode ion-exchange hypercrosslinked sorbents and supported ionic liquid polymeric phases and their evaluation as SPE sorbents for the extraction of polar contaminants, followed by LC analysis. The second part is focused on the preparation of new stir bars with polar monolithic coatings and their application to stir bar sorptive extract polar analytes from environmental water samples.
ALVARADO, DIAZ MARIA ELENA 396268, and DIAZ MARIA ELENA ALVARADO. "Efecto de la temperatura sobre las propiedades de los materiales carbonosos provenientes de la pirólisis de lodos residuales y su aplicación como sorbentes de iones en soluciones bimetalicas de cadmio y cromo." Tesis de maestría, Universidad Autónoma del Estado de México, 2015. http://hdl.handle.net/20.500.11799/65634.
En este trabajo de investigación se obtuvieron 5 materiales carbonosos provenientes de la pirólisis de lodos residuales a diferentes temperaturas 400, 500, 600, 700 y 750 ºC basados en el análisis termogravimétrico (TGA) y térmico diferencial (DTA) del lodo residual seco, el incremento en la temperatura de pirólisis le confirió al material carbonoso diversas propiedades estructurales, morfológicas y texturales. Estas variaciones en las propiedades se determinaron a partir de las siguientes técnicas: Micronanalisis elemental por Dispersión de Energía de Rayos-X (EDS), Espectroscopia Infrarroja (IR), Microscopia Electrónica de Barrido (MEB) y Fisisorción de Nitrógeno.
UAEM
Yang, Xiangxin. "Sol-gel synthesized nanomaterials for environmental applications." Diss., Manhattan, Kan. : Kansas State University, 2008. http://hdl.handle.net/2097/884.
Douzet, Jérôme. "Conception, construction, experimentation et modelisation d’un banc d’essais grandeur nature de climatisation utilisant un fluide frigoporteur diphasique a base d’hydrates de tbab." Thesis, Saint-Etienne, EMSE, 2011. http://www.theses.fr/2011EMSE0616/document.
For some years, new industrial processes have been developed and marketed in the refrigeration and air conditioning fields. Among systems which begin to have good business opportunities some are using two-phase secondary refrigerants solid / liquid. This kind of technology offers the advantages of reducing the use of classical refrigerants which are regulated and can smooth the production of cold over 24 hours with its ability to store the slurry. At the European level, thanks to the efforts of several manufacturers, the refrigeration field is developing fast with respect to the use of ice slurries. Moreover the industrial or district air conditioning field is a major energetic issue in terms of the immediate energy it requires as well as in terms of "peaks" generated during certain periods of the day.In this field, especially in Japan, the use of “PCM” (Phase Change Material) is additionally developing. In this technological segment, the PCM used are hydrate slurries. This solution has the advantage of crystallizing at positive temperatures which is more suited for the air conditioning than ice slurries.This research work deals with the adaption of a refrigeration technology available on the European market to the field of air conditioning. The fluid used is an aqueous solution of TBAB (Tetra-Butylammonium Bromide) with a crystallization temperature at atmospheric pressure which can be adjusted to a temperature between 6 and 12°C. The experimental device designed and installed is a real size prototype able to cool 4 rooms. Both the industrial demonstrator as well as instrumented test bench allowed us to carry out practice sessions which demonstrated the feasibility of the process. It also allowed us to design improvements and new developments. In parallel to the construction and the experiments, additional measurements concerning some thermo-physical characteristics of TBAB hydrate slurries were conducted in specialised laboratory. Finally, a modelling tool was also developed in order to relate our experiments with theoretical thermo-physical phenomena. This numerical model is intended to be a predicative tool for the design of new installations and for the development of the prototype
Silva, Mojica Ernesto. "Polymer-silica Hybrids for Separation of CO2 and Catalysis of Organic Reactions." University of Akron / OhioLINK, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=akron1398439043.
Lin, Chieh-Yen, and 林杰燕. "Synthesis and Characterization of Novel Ca-Mg-Mixed Metal Organic Framework as Sorbent Precursor Material for Efficient High Temperature CO2 Capture." Thesis, 2015. http://ndltd.ncl.edu.tw/handle/qtyppr.
Lin, Yung-Hua, and 林詠樺. "New Graphene/Acrylic resin based Composite Sponge Material as Solid Phase Extraction Sorbent for the Determination of Triazine Herbicides in Aqueous sample by HPLC-UV." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/67091200849791713102.
國立中興大學
化學系所
104
In this study, we have developed a new material ‘Graphene based acrylic resin composite sponge material’ as sold phase extraction sorbent material for the extraction of triazine herbicides in aqueous solution and determination by HPLC-UV. The adsorption capacity of acrylic resin material was enhanced by adding graphene nanosheets as fillers. This composite sponge material was prepared by mixing of graphene oxide, acrylic resin, cross-linking agents and foaming agents and then inflated with air to foam by Frother. And the foam material was heated at two stages to obtain Graphene/Acrylic resin based Composite Sponge Material. In the extraction procedure, the sponge material was placed into the syringe and sample solution was aspirated into the syringe barrel for rapid adsorption/extraction. Then the adsorbed analytes were desorbed using organic solvent, and dried by nitrogen, then re-dissolved with 100 μL acetonitrile for HPLC-UV analysis. In order to obtain the best extraction efficiency, the parameters affecting the conditions including graphene content, the pH of sample solution, the salt addition and desorption solution were investigated thoroughly. Under the selected conditions, composite sponge materials were synthesized with 15 mg of graphene and 1 mL acrylic resin solution. 10 mL of aqueous solution (pH 7) was used for sample loading and followed with elution using 3 mL acetone. Under the optimal conditions, the limit of determination (LOD) and limit of quantitation (LOQ) for five triazine herbicides were between 0.3 ng/mL and 0.9 ng/mL. The relative standard deviations (RSD) were less than 3%. Recoveries were ranged between 82.8 % - 107 %. The total sample preparation steps were taken only 10 minutes. These results indicated that the Graphene/Acrylic resin Composite Sponge Material based solid phase extraction method is a rapid, sensitive, easy to handle and eco-friendly sample preparation method.
Yeh, Chih-Kuei, and 葉芷溎. "Rapid preparation of In-pipette tip graphene sol-gel based monolithic sorbent material for the extraction of UV filter in aqueous samples for HPLC-UV analysis." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/30212939899811915383.
國立中興大學
化學系所
104
This study demonstrates a simple and rapid method for the preparation of graphene based in-pipette tip monolithic micro solid phase extraction (μSPE) sorbent via an improved sol-gel technique using polyethylene glycol (PEG) as porogenic material. For the first time, the prepared graphene sol-gel based in-pipette tip monolithic μSPE sorbent was applied for the analysis of UV filters in environmental water samples and in cosmetics (as target compounds) using HPLC-UV. The graphene sol-gel in-pipette tip monolith was prepared by mixing appropriate amounts of graphene oxide (GO, a stationary phase sorbent) and tetramethyl-orthosilicate (TMOS, a sol-gel precursor), tetraethyl orthosilicate (TEOS, as a co-precursor), polyethylene glycol (PEG-6000, a sol-gel active organic polymer), and pyridine (as sol-gel catalyst) in the 20 mL glass vial. Then, the mixture solution transferred into plastic pipette tip and kept at hot air-oven (50°C) for polymerization. After the polymerization, the sorbent materials were washed with methanol, 0.01% HCl solution and pure water to remove un-reactants. After that, the prepared in-pipette tip sorbent material was immersed in 0.5% hydrazine solution for the reduction of graphene oxide to graphene. And then, the material was immersed in 10% dichlorodimethylsilane solution for the silicon alkylation. PEG was used to lengthen the sol-gel network and to improve the structure rigidity and permeability (porosity) of the prepared monolithic sorbent material. For the extraction of UV filters, important parameters that influence the extraction efficiencies were thoroughly investigated and optimized. Under the optimal conditions, the limit of determination (LOD) and limit of quantitation (LOQ) for four UV filters were below 0.05 ng/mL and 0.2 ng/mL, respectively. The relative standard deviations (RSD) were all less than 6.0 %. It only took less than 12 min for the total μSPE procedure. Recovery were ranged from 88.0-103.6 % and the RSDs were all lower than 6.2 %. Compared with traditional sol-gel preparation methods, this graphene sol-gel in-pipette tip monolithic method required less polymerization time (due to the usage of pyridine as base catalyst) and the synthesized material showed good permeability. Results showed that the proposed method is a simple, fast, sensitive and eco-friendly sample preparation method.
Chiang, Yi-Chieh, and 江怡潔. "Graphene Modified Silica as On-line Solid Phase Extraction Sorbent Material for the Rapid Analysis of Alkylphenol and Bisphenol A in Environmental Water Samples by HPLC-PDA." Thesis, 2014. http://ndltd.ncl.edu.tw/handle/05121041810637550057.
國立中興大學
化學系所
102
In this study, graphene modified silica microspheres was applied as a new sorbent material for on-line solid phase extraction (SPE) coupled to high-performance liquid chromatography with photodiode array detection (HPLC-PDA) for the determination of Alkylphenol (APs) and Bisphenol A (BPA) in environmental water samples. In this research, the carboxylic acid groups present on grapheme oxide (GO) were activated with EDC/NHS catalyst for amide bond formation with the silica microspheres. Then, the graphene functionalized silica composite (G@SiO2) was prepared through hydrazine reduction of GO bonded silica (GO@SiO2) composite under microwave irradiation. Surface morphology of the synthesized material was characterized using FT-IR and FE-SEM. In order to achieve the maximum extraction efficiency, various synthesis conditions were optimized including the concentration of EDC/NHS catalyst and the synthesis time; Furthermore, different parameters that affecting the extraction condition such as pH of the sample solution, volume of desorption solvent, loading rate of sample solution and salt effect. Experimental results indicate that 50mM EDC/NHS catalyst in GO solution (0.5 mg/mL), and the addition of 0.5 g of amine-modified silica microspheres under stirring for 12 hours shows the best synthesis results. Under the selected conditions, including 0.6 mL min-1 of loading rate of sample solution at pH 6 with no added of salt, 80μL of Acetonitrile as desorption solvent showed the maximum extraction efficiency for AP and BPA. Under the optimal conditions, the linear ranges were ranged between 0.5-50 ng/mL for AP and BPA in river water. The correlation coefficients were greater than 0.9962. Quantitation limits were lower than 0.26 ng/mL and the detection limits were lower than 0.08 ng/mL. The presented on-line SPE method was applied to the real water analysis and the relative recoveries were ranged from 81.6-101.6% for spiked analytes in river water samples. The experimental results exhibited that the presented method is a simple, rapid, convenient, efficient and eco-friendly sample preparation method for the determination of APs and BPA in environmental samples.
"Enhanced Desorption in Novel Sorbent Materials Using Ultrasound." Master's thesis, 2018. http://hdl.handle.net/2286/R.I.49098.
Dissertation/Thesis
Masters Thesis Mechanical Engineering 2018
Wang, Dongmei. "Use of lignocellulosic materials as sorbents for phosphorus removal." 2002. http://catalog.hathitrust.org/api/volumes/oclc/50318006.html.
Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 71-82).
"Synthesis and Characterization of Chitosan-Glutaraldehyde Sorbent Materials For the Removal of Arsenate." Thesis, 2014. http://hdl.handle.net/10388/ETD-2014-08-1612.
Morris, Eric Adde. "Modification of Carbonaceous Materials with Sulfur and Its Impact on Mercury Capture and Sorbent Regenertion." Thesis, 2012. http://hdl.handle.net/1807/36293.
Erto, Alessandro. "Adsorbimento di composti organici volatili (VOCs) in soluzione acquosa su materiali sorbenti granulari." Tesi di dottorato, 2008. http://www.fedoa.unina.it/1849/1/Erto_Ingegneria_Chimica.pdf.
Ogenga, Daniel Onyango. "Performance of South African calcium/siliceous-based materials as sorbents for SO2 removal from Flue gas." Thesis, 2009. http://encore.tut.ac.za/iii/cpro/DigitalItemViewPage.external?sp=1000417.
South Africa produces 41.3 GWe per year of which 90% is coal-derived. During combustion of coal, sulfur contained in the fuel is converted to SO2. The gas poses a serious danger for the human and environmental health. The health hazards associated with SO2 include hair loss, throat inflammation, impaired vision and respiratory illnesses. Sulfur dioxide is also forms acid rain, which leads to acidification of soils, waterways and forests. The main objective of this investigation is to explore methods of increasing lime utilization using South Africa calcium/siliceous-based sorbents for the purposes of removal of SO2 in the Flue Gas Desulfurization (FGD) system. Consequently, this study presents experimental findings on the preparation, characterization and sulfation of locally available fly ash, calcium oxide (CaO) and bottom ash. CaO was obtained from calcination of limestone in a laboratory kiln at a temperature of 900 °C and CaO/fly ash sorbent prepared using an atmospheric hydration process.
Νικολακοπούλου, Μυρτώ Γεωργία. "Η ρόφηση ρύπων σε ανόργανα υλικά μεγάλης ειδικής επιφάνειας και διαφορετικού επιφανειακού φορτίου". Thesis, 2013. http://hdl.handle.net/10889/7475.
Water treatment is a necessary and standard practice since decades. Adsorption technology in water treatment is one of many techniques being used. Activated carbon is the most widely applied adsorbent in water treatment, however its high production cost has led scientific research to investigate alternative low cost sorbent materials. This need has developed scientific interest towards novel materials most of them derived from biomass, but also inorganic oxides that are abundant in nature. The present study focuses on the investigation of the capacity of natural oxides to adsorb aromatic organic compounds and heavy metals. Specifically, sorption of phenanthrene, 2-naphthol and mercury onto aluminum, titanium, silicon and ferric oxides was examined, for the evaluation of these materials as sorbents, compared to pyrolized biomaterials. For the study of sorption of phenanthrene and 2-naphthol, batch experiments were conducted at room temperature, using artificial seawater and fresh water, different mass of sorbent material at different contact time. Sorption kinetics and the pollutant removal percentages were determined. The proportion of phenanthrene removal increased with the increase of the mass of the sorbent material. Sorption distribution coefficient Kd ranged between 1 and 10 L/Kg. These values are 2 to 4 orders of magnitude lower than the respective values shown for biomaterials and for pyrolysis products, respectively. Maximum sorption capacity of phenanthrene (55 % proportion removal) was shown by γ-alumina, with a specific surface area equal to 270 m2/g, after 8 days. Minimum sorption capacity (14 % proportion removal) was shown by γ-alumina, with a specific surface area equal to 120 m2/g, after 10 days. Titania, with a specific surface area equal to 120 m2/g, adsorbed a proportion of 52 % of the initial concentration of phenanthrene, after 8 days. Sorption experiments of 2-naphthol from γ-alumina, did not show a measurable sorption. Sorption of mercury from γ-alumina and ferric oxides was studied, conducting batch experiments at 25 °C, pH 5, 24 h contact time. The experiments resulted to an isotherm curve that was evaluated using different sorption isotherm models. An increase of the proportion of mercury removal, with the increase of the mass of γ-alumina was observed. Maximum proportion of mercury removal (93% of the initial concentration) was observed with the addition of γ-alumina of 1 g or more. At Ce=15 mg/L, qe=0,91 mg/g was measured. This value is 1 to 2 orders of magnitude lower, than the respective values shown for biomaterials and for pyrolysis products, respectively. Even though ferric oxides’ specific surface area was estimated at 55 m²/g, they did not show a measurable sorption capacity for any of the pollutants tested in the present study. Even though the materials examined in the present study, were of large specific surface area, their sorptive properties shown, are not competitive with the respective properties of biomaterials. Thus, they cannot be considered as promising sorbents for the removal of phenanthrene, 2-naphthol, or mercury from water.
Langwenya, Siphiwe P. "Utilization of coal-based sorbents and their fabrication into carbon nanomaterials for the removal of organics from wastewater." Thesis, 2011. http://hdl.handle.net/10210/3630.
With increasing industrial activities in South Africa, many of its waters are contaminated with both organic and inorganic pollutants. This is also a worldwide challenge which has resulted in an escalation in research efforts to combat it. Organic pollutants, for example, can be harmful to human health and the environment. Even when present at low concentrations, they tend to bio-accumulate and interact with endocrine systems. Therefore it is necessary that these pollutants are removed from effluents before they are integrated with water systems such as rivers and lakes. In an effort to utilize economic and efficient removal techniques, low cost and locally available materials have been used as potential adsorbents for the removal of these organic pollutants from synthetic wastewater. These coal-based materials were further fabricated into nanoporous sorbents through activation processes to improve their adsorption properties. The project reported in this dissertation was thus undertaken to explore, specifically, the efficacy of coal and coal-based sorbents (acid treated coal, activated carbon and activated fly ash) in their ability to remove phenolic compounds from wastewater.
de, Falco Giacomo. "Adsorption of H2S and HCHO on new generation materials based on composite Zn-Cu sorbents and surface active carbon materials: effect of physico-chemical properties on the process performance." Tesi di dottorato, 2018. http://www.fedoa.unina.it/12706/1/PhD_thesis_de_Falco_Giacomo.pdf.
Kargol, Marta. "Preparation and characterization of new mesoporous inorganic molecular sieves and their application for light hydrocarbons separation." Rozprawa doktorska, 2005. https://repolis.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=5100.
Kargol, Marta. "Preparation and characterization of new mesoporous inorganic molecular sieves and their application for light hydrocarbons separation." Rozprawa doktorska, 2005. https://delibra.bg.polsl.pl/dlibra/docmetadata?showContent=true&id=5100.
Brandès, Ricardo. "Développement de matériaux absorbants utilisant le chitosane et la cellulose phosphorylée pour l'élimination des contaminants toxiques des eaux usées = Development of sorbent materials using chitosan and phosphorylated cellulose for the removal of toxic contaminants from wastewater." Thèse, 2020. http://depot-e.uqtr.ca/id/eprint/9535/1/eprint9535.pdf.