| 1. |
- Hakobyan, Shoghik, 1981-
(författare)
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Antivirulent and antibiofilm salicylidene acylhydrazide complexes in solution and at interfaces
- 2015
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The growing bacterial resistance against antibiotics creates a limitation for using traditional antibiotics and requests development of new approaches for treatment of bacterial infections. Among the bacterial infections that are most difficult to treat, biofilm-associated infections are one of the most hazardous. Consequently, the prevention of biofilm formation is a very important issue. One of the techniques that are widely investigated nowadays for this purpose is surface modification by polymer brushes that allows generating antifouling antibacterial surfaces. Previously, it was reported that salicylidene acylhydrazides (hydrazones) are good candidates as antivirulence drugs targeting the type three secretion system (T3SS). This secretion system is used by several Gramnegative pathogens, including Pseudomonas aeruginosa, to deliver toxins into a host cell. Furthermore, the chemical structure of these substances allows formation of complexes with metal ions, such as Fe3+ and Ga3+. The antibacterial activity of Ga3+ is well known and attributed to its similarity to the Fe3+ ion. It has also been shown that Ga3+ ions are able to suppress biofilm formation and growth in bacteria. In this thesis the chemistry of antibacterial and antivirulence Ga3+-Hydrazone complexes in solution was studied. First, to get insights in the solution chemistry, the protonation and the stability constants as well as the speciation of the Ga3+-Hydrazone complexes were determined. Additionally, a procedure for anchoring one of the hydrazone substances to antifouling polymer brushes was optimized, and the resulting surfaces were characterized. Results showed that the complexation with Ga3+ ions stabilizes the ligand and increases its solubility. Ga3+ ion binds to the hydrazone molecule forming a strong chelate that should be stable at physiological conditions. The different biological assays, such as Ga3+ uptake, antivirulence and antibiofilm effects, indicated very complex interaction of these complexes with the bacterial cell. Negatively charged and zwitterionic surfaces strongly reduced protein adsorption as well as biofilm formation. Therefore, the antifouling zwitterionic poly-[2-(methacryloyloxy)ethyl]dimethyl-3- sulfopropyl)-ammonium hydroxide (pMEDSAH) brushes were post-modified and successfully functionalized with bioactive substances via a block-copolymerization strategy. However, in order to maintain the availability of the bioactive substance after functionalization, the hydrophobic polyglycidylmethacrylate (pGMA) top block is probably better to functionalize with a lipophilic molecules to reduce diblock copolymer brush rearrangement.
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| 2. |
- Weidemann, Eva, 1982-
(författare)
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Waste incineration residues : Persistent organic pollutants in flue gas and fly ash from waste incineration
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Modern societies produce large quantities of municipal solid waste (MSW), which is commonly disposed of by incineration. This has several advantages: it reduces the waste’s volume and sterilizes it while also enabling energy recovery. However, MSW incineration has some notable disadvantages, the most widely debated of which is probably the production and release of persistent organic pollutants (POP) such as polychlorinated dibenzofurans (PCDF), dibenzo-p-dioxins (PCDD), biphenyls (PCB) and naphthalenes (PCN). Of the 210 PCDF and PCDD congeners, 17 are toxic, with hormone-disrupting and carcinogenic properties. Twelve of the 209 PCB congeners and at least 2 of the 75 PCN also exhibit such properties. These POP form in the post-combustion zones of MSW incineration plants and are removed from the flue gas using filtering devices that trap them in the fly ashThis thesis concerns the formation and degradation of POP in processes related to MSW incineration. The first paper describes a case study in which PCDD were forming in filters designed to remove them from flue gases, causing emission-related issues in a full-scale MSW incineration plant. It was shown that the PCDD formation was probably due to chlorophenol condensation on the filters’ surfaces.The second paper describes the validation of a cooling probe designed to prevent POP formation during high temperature (>450 °C) flue gas sampling. The results obtained also confirmed that PCDF and PCDD formation takes place at temperatures below 600 °C.In the third paper, three different fly ashes were subjected to thermal treatment under an inert atmosphere in a rotary kiln and in sealed ampoules at 400 °C. The concentrations, degrees of chlorination and congener profiles of the POP in the treated ashes and emitted gases were compared to those for the untreated ashes. The trends observed for PCDF mirrored those for PCN, while the trends for PCDD closely resembled those for PCB. The PCDF congener profiles of the kiln ash were similar regardless of the initial ash composition, suggesting that the mechanisms of PCDF formation were similar in all cases.The fourth paper describes the surface characterization of the three fly ashes studied in paper three by SEM, EDX, XPS and XRD. In addition, the thermal desorption and subsequent degradation of POP from the ashes was studied at temperatures of 300-900 °C. The composition of the gases released as the temperature increased differed between the ashes and depended on their composition. Doping experiments using isotopically labelled PCDF and PCDD suggests that PCDD desorbed at lower temperatures than PCDF.This thesis examines several problems relating to POP formation during MSW incineration, from sampling to the ultimate fate of incineration residues. The results obtained illustrate the wide range of processes that contribute to thermal POP formation and degradation during and after MSW incineration.
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| 3. |
- Lindholm, Jerry, 1991-
(författare)
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Molecular-level controls on water and organics intercalation in layered minerals
- 2020
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Layered minerals are naturally abundant and often display a large surface area in relation to their weight. For swelling layered minerals, most of this area is contained between the layers in the interlayer space. Their large surface area makes them interesting in many different fields and applications, such as adsorbents, catalysts or as carriers for other particles that can be intercalated and exchanged. In order for the materials to be used effectively, it is hence necessary to have a fundamental understanding of how these processes occur, and ways to predict them.To address adsorption of water, an isotherm model was created to describe the hydration process on layered materials. The model decomposed the process of adsorptions into internal and external, adsorption and condensation, and could specifically handle hydration in the expanding interlayer nanopores. Adsorption and desorption isotherms of two different materials, Montmorillonite and Birnessite was successfully modelled, where the former was ion-exchanged with the counter-cations Li+, Na+, K+, Cs+, Mg2+, Ca2+, Sr2+, Cu2+, whereas the latter contained K+. This indicated that this isotherm model is applicable to also other layered materials. The adsorption process was also characterized experimentally with vibrational spectroscopy (FTIR) and multivariate statistical techniques (MCR), in order to generate spectral- and concentration profiles of the involved components.In order to also investigate adsorption of different organic molecules, the intercalation of alcohols and a cationic surfactant was investigated in separate studies. Clay-water-alcohol systems of eight alcohols were characterized experimentally by XRD as well as by molecular dynamics simulations, using different combinations of classical force fields for the clay (ClayFF, ClayFFMod, INTERFACE) and for the alcohols (CGenFF, GAFF, OPLS). It was found that the optimal force field combination varied with the fitting approach. A brute force sensitivity analysis indicated that the comparison with the experimental XRD data was more dependent on the relative interlayer loading than the positions of the atoms, an important result for future similar benchmarking studies.By intercalating and adsorbing a cationic surfactant (CTAB) to Montmorillonite at increasing concentrations, the effects of solvent polarity and the CTAB interlayer content on the Montmorillonite interlayer swelling was investigated. It was found that moderately polar solvents such as DMSO, in combination with CTAB in a planar bilayer configuration resulted in the greatest adsorption of the lipophilic solute alizarin.
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| 4. |
- Luong, N. Tan, 1995-
(författare)
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Water film-mediated mineralogical transformations and photocatalytic reactions
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Mineral particles capture water vapor in the atmosphere in the form of water films that are only few monolayers thick. Water films form nanoscale hydration environments that mediate a wide range of important reactions in nature and technology. This thesis explored two important phenomena that commonly occur within the confines of water films: mineralogical transformations (Topic 1) and photocatalytic decomposition of organics (Topic 2). These transformations were chiefly identified by vibrational spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy and (Transmission and Scanning) electron microscopy. Interpretations of reaction mechanisms were partially supported by chemometrics, kinetic and thermodynamic modeling, as well as molecular simulations.Mineralogical transformations (Topic 1) resolved in this thesis involved the hydroxylation (Papers I, II) and carbonation (Paper III) of periclase (MgO), and the oxidation of rhodochrosite (MnCO3) (Paper IV). Two types of MgO nanocubes with contrasting physical properties were used to resolve nucleation- and diffusion-limited hydroxylation reactions to brucite and carbonation reactions to amorphous magnesium carbonate (AMC). While nucleation-limited reactions completely transformed (8 nm) small and aggregated MgO nanocubes to brucite, the reactions became diffusion-limited in larger (32 nm) monodispersed MgO nanocubes because of brucite surface nanocoatings (Paper I). Additionally, brucite nanosheets grew under (GPa-level) crystallization pressures because of the important volumetric expansion of the reaction, which took place in a complex network of microporosity between the small and within the larger MgO nanocubes. Brucite stacking mechanisms, explored in Paper II, focused on the early stages of MgO-water interaction in water films of different thicknesses. These were suggested to involve the stacking and (epitaxial-like) growth of precursor Mg(OH)2 nanosheets in water films. Carbonation reactions explored in Paper III completely hampered hydroxylation reactions studied in Papers I and II, and produced AMC nanocoatings grown over an unreacted MgO core. Finally, oxidation-driven reactions involving rhodochrosite in Paper IV produced MnO2, Mn3O4, and MnOOH nanocoatings with growth rates being scaled with water loadings.Photocatalytic decomposition reactions of organics (Topic 2) were focused on the case of oxalate bound to TiO2 nanoparticles (Paper V). Photodecomposition rates scaled with humidity in oxygenated water films, and were explained by the combination of hole transfer (HT), ligand-to-metal charge transfer (LMCT), and the formation of hydroxyl radicals and reactive oxygen species. Decreasing rates in oxygen-free water films were, on the other hand, explained by water-driven charge localization, which eventually limited radical production and charge transfers via HT and LMCT. The reactions involved limited HT and LMCT processes which also competed with a charge recombination process across all humidity ranges.This thesis provides new insight into two key types of transformations mediated by water films on minerals. This knowledge can be used to understand the reactivity of mineral (nano)particles exposed to variations in atmospheric humidity and oxygen content, which are both highly relevant to a wide range of settings in nature and technology. It can also advance new ideas in the study of mineral growth, especially within the confines of nanometer-thick water films.
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| 5. |
- Pérez Morales, Carla, 1989-
(författare)
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Hydrothermal carbonization of digested sewage sludge and microalgae biomass : phosphorus and energy recovery
- 2024
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Sewage sludge and microalgae biomass are by-products of wastewater treatment, requiring careful management to avoid environmental and health risks. Both sewage sludge and microalgae have high moisture content, making thermochemical conversion challenging and energy intensive. Hydrothermal carbonization (HTC) presents a promising solution for converting these wet feedstocks into valuable resources. The thesis aimed to study HTC of sewage sludge and microalgae biomass, individually and combined (i.e., co-HTC). It focused on process parameters, mixing ratios, product characteristics, primary and secondary char formation, and resource recovery, with especial emphasis was on phosphorus and energy recovery as potential applications of the resulting hydrochars. Both the HTC and co-HTC experiments were conducted at 180, 215 and 250°C for 2 h (Papers I–IV).Paper I investigated co-HTC by combining microalgae and sewage sludge in various ratios, from 0 to 100% of sewage sludge. Results showed that higher sewage sludge proportions and carbonization temperatures led to lower degradation and carbonization rates. The addition of sewage sludge influenced secondary char formation and composition, reducing carboxylic acid and ketones while increasing higher molecular weight cholesterols. Moreover, sewage sludge hydrochars contained larger phosphorus quantities.In acid-leaching experiments (Papers II and III) using sewage sludge, phosphorus-extraction efficiencies surpassed 75%. Complete phosphorus recovery (100%) was achieved only with oxalate extraction at pH=1. Organic acids, utilized at a lower concentration (0.25 M) compared to mineral acids (2.5 M), acted as both acids and chelating agents, facilitating phosphorus recovery. Regardless of acid type, leaching from hydrochar transferred not only phosphorus but metals and heavy metals into the P-rich leachate, requiring post-treatment purification. Combustion studies of microalgae and sewage sludge co-hydrochar, and phosphorus extracted hydrochar from sewage sludge as solid fuels showed notable improvements in physicochemical and energy-related properties. Acid treatment improved carbon content, heating values, and fuel ratio, while significantly reducing ash content compared to untreated hydrochars (Paper IV). These properties decreased in the co-hydrochars with higher sewage sludge proportions due to differing carbon, volatile matter, and ash content between microalgae and sewage sludge. Thermodynamic equilibrium calculations predicted liquid slag and solid phase formation at combustion temperatures up to 1200°C. Experimental comparison with combustion ashes, analyzed through DRIFTS, SEM-EDS, and XRD, validated simulated compounds including Fe2O3, SiO2, feldspar, whitlockite, CaCO3, and CaSO4 in Paper IV. Notably, CaCO3 presence in ashes was confirmed by XRD but not reflected in calculation results. Microalgae hydrochar ashes were primarily composed of calcium phosphates and Fe2O3, visually confirmed by EDS mapping due to XRD limitations.The result of this thesis suggests that the HTC process offers a pre-treatment means of improving hydrophobicity and significantly reducing feedstock volumes. Additionally, the resource-recovery approach studied in this thesis, which uses sewage sludge and microalgae-derived hydrochars generated in wastewater treatment plants, is a step towards being an efficient management strategy for by-products generated by these plants.
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| 6. |
- Rambaran, Mark, 1994-
(författare)
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Tunable surfaces : using polyoxoniobates and -tantalates as molecular building blocks
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis describes and explains the use of aqueous polyoxometalates (POMs), as molecular building blocks in the fabrication of tunable solid-state materials, such as thin films. Microwave irradiation in the synthesis of Nb10, Nb6 and Ta6 is a rapid and efficient alternative to conventional hydrothermal methods, while offering equal – if not greater yields – of product. Through microwave irradiation, the concept of an activation pH of anhydrous Nb2O5, niobic and tantalic acids has been devised to explain what products are accessible from each oxide and under what conditions.The controlled deposition of metal oxide thin films is possible via an iterative spin coating and annealing process of POMs. This approach facilitates deposition of alkali-free, metal oxide thin films with varying crystallinity, thickness and roughness. The ability to deposit successive layers of these polyoxometalate films was a new approach to create thicker and layered metal oxide films. This approach offers an efficient and reproducible means of creating tunable metal oxide thin films or other solid-state structures, which exemplifies the use of POMs as molecular building blocks.Transition metal niobate thin films can be deposited onto silicon wafers via the aqueous deposition of transition metal-hexaniobate mixtures. This facilitates assessment of the electrochemical properties of these materials, without a need for coin cells or inert conditions. This allows for characterisation of the pseudocapacitive properties of these materials, which abodes well for developing electrochemical energy storage devices.The viability of using aqueous polyoxoniobate-alkali nitrate mixtures was leveraged as a means of depositing alkali niobate (LiNbO3, NaNbO3, KNbO3) thin films, plus Rb and Cs doped Nb2O5 films and powders. Synthesising solid-state niobates that can incorporate all the alkali cations, entirely from aqueous polyoxoniobate solutions, confers the ability to develop lead-free piezoelectric, ferroelectric and antiferroelectric materials without the use of expensive or energy intensive methods.
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| 7. |
- Yeşilbaş, Merve, 1987-
(författare)
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Thin water and ice films on minerals : a molecular level study
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Minerals in Earth’s crust and suspended in the atmosphere form water or ice films as thin as a few nanometers to as thick as a few micrometers, and beyond. Mineral-bound water and ice films in terrestrial systems (e.g. vadose zones, permafrosts) can impact the bio(geo)chemistry of nutrients and contaminants, water cycling, as well as possible land-air exchanges in terrestrial environments. In the atmosphere, films are tied to clouds and rain formation, and can influence the absorption and scattering of solar radiation of dust mineral aerosols. Water films are, at the same time, of interest to technology. They are even of interest in the study of asteroids, comets, and planet Mars. Still, their formation on the various types of minerals common to the environment is misunderstood.The aim of this thesis is to gain fundamental insight on the roles that minerals play on forming and stabilising thin water and ice films. This work is separated in two parts, with Part A associated with Papers I-II, and Part B with Papers III-V of the appendix of this thesis.In Part A of this work (Papers I-II), water loadings and vibrational signatures of thin water films were collected on 21 different minerals (metal oxides, silicates, carbonates) relevant to terrestrial environments, atmosphere and perhaps outer-space. Measurements were made on minerals of varied (i) composition, (ii) structure, (iii) morphology, (iv) particle size and (v) surface roughness. Loadings, measured by a microgravimetric Dynamic Vapour Sorption technique, were of a few monolayers in sub-micrometer-sized particles but of several hundreds to thousands of water layers in micrometer-sized particles (Paper I). This was seen in the Fourier Transform Infrared (FTIR) spectra of sub-micrometer-sized particles with different hydrogen bonding environments than liquid water. Micrometer-sized particles formed liquid-like films regardless of the mineral. Similar observations were made in the spectra of the thinnest water films remaining on these minerals after long periods of sublimation of ice overcoatings at sub-freezing temperatures (Paper II).In Part B of this work (Papers III-V), focus on the expandable clay mineral montmorillonite was made to study (i) intercalated water, (ii) ice and cryosalt formation inside microporous gels, and (iii) its interactions with intercalated CO2. FTIR extracted spectral components reflecting interlayer hydration states of ~0W, 1W and 2W monolayers of water (Paper III). Thermal dehydration/dehydroxylation experiments showed that the driest forms of montmorillonite strongly retained low levels of crystalline water in its structure. FTIR also showed that frozen wet gels of montmorillonite form ice and the cryosalt mineral hydrohalite. Ice was seen in rigid gels and aggregated compact particles, as well as low particle density with low salt content. In contrast, concentrated (>> 10 g/L) saline gels host hydrohalite, probably between and/or near aggregated clay particle walls. Field-Emission Cryogenic Scanning Electron Microscopy showed that ice microcrystals form in micropores of the gels (Paper IV). Finally, release rates of CO2 trapped in interlayers of montmorillonite, monitored by FTIR spectroscopy, were larger in the presence of 1-2W. The activation energy of CO2 release from~0W montmorillonite (34 kJ/mol) is comparable to other mineral surfaces. This study highlights that the most stabilised CO2 occur in of dry and cold conditions.This thesis will hopefully serve as a springboard for further work exploring the chemistry and physics of water and ice films at minerals surfaces. It should contribute to improve our understanding of the geochemistry of Earth’s soils, processes in the atmosphere, and even of space chemistry.
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| 8. |
- Chang, Ribooga
(författare)
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Design and Optimization of CO2 sorbents for Point Source Emissions and Direct Air Capture
- 2023
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis presents a comprehensive study on the design and optimization of CO2 sorbents, targeting two distinct applications: CO2 capture from point source emissions and Direct Air Capture (DAC). The research first introduces Na2HfO3 as a potential CO2 sorbent for point source emissions, using the molten salt effects of Na2CO3 and the thermal stability of HfO2. This combination results in a CO2 sorbent with impressive thermal and cyclic stability, through various optimization steps to enhance CO2 capture performance and efficiency. The study then shows into the structural disorder in Na2ZrO3, a chemically similar CO2 sorbent. This investigation fills a knowledge gap, offering new insights into the sorbent's behavior in CO2 capture. For DAC applications, the thesis explores the design of inorganic anion pillared metal-organic frameworks, focusing on the adjustment of M5+−F− bond lengths in inorganic anion pillars within M5+OFFIVE-1-Ni samples. These structural modifications impact the CO2 capture properties, particularly in terms of capacity and kinetics, demonstrating the potential of structural tuning in enhancing sorbent effectiveness. The synthesized samples exhibit good cyclic and water stability, suggesting their potential for practical DAC applications.
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| 9. |
- Jolsterå, Rickard
(författare)
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Surface reactions of magnetite and maghemite with dissolved and added ions in process water
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Reactions between mineral surfaces and dissolved species in process water, both inorganic and organic play an important role in mineral processing. Reverse flotation of finely comminuted iron ore is sometimes employed in order to remove the phosphorous mineral apatite. An anionic collector, designed to specifically adsorb at the calcium specific surface sites of apatite is added, rendering the apatite particles hydrophobic properties. However, some of the collector adsorbs also at the magnetite surfaces, thereby introducing undesired characteristics to the upgraded iron ore concentrate.Of this reason, magnetite and maghemite surfaces and their interactions with the most abundant and important ions in the process water during flotation, and their potential influence on collector adsorption at magnetite was studied. Maghemite was included in the experiments, since previous work had shown that oxidation of the magnetite surface into maghemite may occur during the processing of the iron ore concentrate. The complex system that the dissolved ions in the process water and the iron oxide particles constitute at flotation and agglomeration was divided into smaller subsystems.The protolytic characteristics for the magnetite-H+ and maghemite-H+ systems proved to be similar when their modelled intrinsic surface complexation constants were compared. However, the surface site density of magnetite was found to be 50 % greater than for maghemite. Both potentiometric titrations and ATR-FTIR spectroscopy were used to study and characterize the adsorption of silicate. The results from the surface complexation modelling suggested that the silicate adsorbed as monodentate surface complexes at the maghemite surfaces. The results showed a silicate adsorption maximum at pH 8.5 to 9.5 for both iron oxides. Within this range pH, the surface complex ΞFeOSiO(OH)2 - was proposed as the dominating surface specie in the maghemite-silicate system.The iron ore pellet additive olivine proved to release substantial amounts of Mg2+ when immersed in water, indicating that olivine probably is the main source of Mg2+ to the process water. Thus, the surface characteristic of olivine particles in water suspensions was studied. Since olivine proved to be a significant source of magnesium ions, adsorption of Mg2+ at maghemite and magnetite was studied and modelled. The results suggested that magnesium ions adsorbed as a mix of mono- and bidentate surface complexes when the number of surface sites was in excess. Increased amounts of Mg2+ i.e., ≥1 Mg2+ site-1, resulted in a model including only monodentate surface complexes.Experiments involving competitive adsorption of carbonate and silicate showed that added silicate replaced adsorbed carbonate. Other competitive experiments, with Mg2+ and Ca2+, showed that Mg2+ had a stronger affinity for the magnetite surface than Ca2+. The preferential adsorption of Mg2+ at the iron oxide surface may then have protective properties, by preventing adsorption of the calcium specific collector. Results from both in-situ ATR-FTIR spectroscopy and contact angle measurements indicated also that added Mg2+ reduced the adsorption of collector and thereby increased the wettability of the magnetite surfaces.
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| 10. |
- Niinipuu, Mirva, 1988-
(författare)
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Tailoring residue-derived carbon materials for the removal of wastewater contaminants : adsorption and surface properties
- 2019
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The availability of effective, low-cost wastewater treatment is necessary for increased water recycling and the prevention of environmental pollution on a global scale. Adsorption on activated carbons is commonly applied in wastewater treatment, but the high cost of conventional activated carbons limits the use of this technique. Several waste streams, such as the residues and by-products of food processing, agriculture and industrial processes, are currently inefficiently utilized and could be transformed into value-added carbon materials. Re-thinking how waste is utilized could reduce waste handling costs and increase resource efficiency, which would provide both economic and environmental benefits. Therefore, low-cost carbon materials prepared from renewable low-cost resources are an attractive alternative to decreasing the costs of wastewater treatment.The research underlying this thesis investigated the potential of carbonized residue materials to remove environmentally relevant concentrations of organic and inorganic contaminants from wastewater. The research covered in this thesis included the carbonization of tomato- and olive press wastes, rise husks, horse manure, municipal wastewater sludge and bio- and fiber sludges from pulp and paper mills. The effect of carbonization temperature and starting material was studied in terms of surface properties and contaminant removal to gain knowledge on which surface features are beneficial for the removal of different contaminants. The extent to which different chemical activations of carbonized materials improve the contaminant removal was also studied.The results demonstrate that carbonized materials are generally quite ineffective at removing organic compounds from water, which may be due to the low surface areas of these materials. Carbonization temperature was shown to alter the surface functionalities of the carbons, more specifically, high carbonization temperatures decreased oxygen-containing surface functionalities that benefitted the removal of most contaminants (which was most pronounced for Zn and trimethoprim). Further experiments investigated the role of the water matrix, and the results unexpectedly showed higher removal from a complex water matrix. Chemical activation improved removal efficiencies for all of the studied compounds, with the most pronounced effects observed for organic compounds. The activated carbons were able to completely remove fluconazole and trimethoprim from the landfill leachate water, and also showed high removal efficiensies (50-96%) of Cu and Zn. Furthermore, the results showed that adsorbate compounds may interact with the adsorbent surface in diverse ways, for example, via properties such as porosity and the presence of oxygen-containing functionalities or minerals. Also, adsorbate hydrophobicity (log Kow) affected the removal of organic compounds in some of the studied hydrochars. The research discussed in this thesis has highlighted that future studies should study the broad range of environmentally-relevant adsorbates through multi-component adsorption systems that include several complex water matrices.
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