LEE- Çevre Bilimleri Mühendisliği ve Yönetimi- Yüksek Lisans

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http://hdl.handle.net/11527/19237

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Yazar "Bakar, Hamza" ile LEE- Çevre Bilimleri Mühendisliği ve Yönetimi- Yüksek Lisans'a göz atma
  • Öge
    Fabrication of thin film nanocomposite membranes using metal organic frameworks, experimental performances and economical analysis on desalination and dye removal
    (Graduate School, 2024-06-28) Bakar, Hamza ; Paşaoğlu, Mehmet Emin ; 501211750 ; Environmental Sciences Engineering and Management
    ürkiye is included in the category of countries that will experience high water stress according to projections for the year 2030. The degradation of surface waters due to anthropogenic impact, such as discharge of untreated and/or dyed wastewater, throwing solid and hazardous wastes into, along with their reduction due to climate change, and the overexploitation of groundwater are gradually diminishing our drinking water resources. Desalination of seawater, which holds 97.5% of the Earth's water, to make it suitable for drinking water is emerging as a hot topic. One of the most used methods for desalination of salty water is membrane technologies nevertheless the desalination technique with membranes has low efficiency when looking at the benefit-cost analysis. Therefore, studies on membrane modifications, which are economically feasible and highly efficient in terms of high-quality effluent standards, are gaining momentum. Innovations in material science are making membranes economically more feasible for use in desalination and dye removal. Within the scope of this study, metal organic frameworks (MOFs) thin film nanocomposite coated membranes classified as nanofiltration membrane were tested with seawater and dyed water to remove salt, dye, and change the flux in the treatment of salty and dyed water. Both synthetic dye solutions and synthetic seawater were used in these trials. In this study, metal organic framework and MOF-doped thin film composite-coated flat sheet membranes were produced at laboratory scale, and their characterization studies and economic analyses were completed. Additionally, the production of electrospun membranes were carried out, and the durability changes of the electrospun membranes depending on the environmental conditions were observed. First of all, ZIF-8 (Zeolitic imidazolate framework-8) and UiO-66 (University of Oslo-66) metal-organic framework (MOF) were produced in accordance with the methods in the literature. Characterization of these produced nanoparticles was made by XRD (X-ray diffraction), FTIR (Fourier Transform Infrared), Raman Spectroscopy, Zeta Potential, BET (Brunauer–Emmett–Teller), SEM (Scanning Electron Microscopy) and compared with the results in the literature. Polysulfone (PSU) was used as the polymer, N-Methyl-2-pyolidene (NMP) was used as the solvent, and polyvinylpyrrolidone (PVP K30) was used as the identity generator with the phase method that produced ultrafiltration membranes designed to be used in both pre-treatment and bed. Then, thin film-coated nanofiltration membranes were obtained by adding 0.01% of MOF types ZIF-8 and UiO-66. One of the most preferred processes in the operation of nanofiltration membranes is the thin film polyamide coating. The interfacial polymerization technique is used to form the polyamide layer. In this method, interfacial polymerization occurs simply by reacting the amine group with a monomer and organic acid. The thin-film composite (TFC) approach is an alternative term for this procedure. In the literature, the term "thin film nanocomposite" (TFN) refers to the use of nanoparticles in the active layer of the TFC technique. The aim of TFN is to reduce the durability of the polyamide layer while increasing the dye and salt removal efficiency and flux by adding nanomaterials. In the characterization of UF membranes, some of the expanded polymer solutions were separated, and the viscosity of the solution was examined. Pure water fluxes were examined under 1-2-3-4 bar pressures, and permeability was calculated. Experiments on the durability characterisation of NF membranes made in a lab include pure water fluxes (PWF) at 8 bar pressure, dye removal efficiency and fluxes under 7 bar, NaCl salt adhesion efficiencies and fluxes under pressure between 5-35 bar, zeta potential analysis, FTIR analysis, contact angle analysis, SEM analysis, surface roughness analysis with an optical profilometer, and thermogravimetric analysis. The electrospinning membrane was produced at different flow rates with solutions in the percentage distribution of 16-17-18-19% and 20% of PSU. While NMP was first used as the dissolution during production, as a result of the evaporation problem, DMF solvent was chosen to prepare the solution. A better structural formation was observed by controlling the environmental conditions of electrospinning. Electrospinning membrane formation, solvent evaporation controlled ambient temperature and humidity conditions led to more uniform membrane formation as the temperature increased. Faster evaporation of dimethylformamide (DMF) solvent at elevated temperatures resulted in reduced wetness of the fibers. Conversely, under less favourable room conditions, residual DMF solvent in the fibers led to thinner membrane walls and poorer shaping. Regarding salt rejection and permeability, the bare, ZIF-8, and UiO-66 thin-film composite (TFC) membranes exhibited similar salt rejection rates. However, the UiO-66 TFC membrane demonstrated significantly higher flux compared to the others, achieving a flux of 190 LMH (litres per square meter per hour) while ZIF-8 and bare TFC membranes had a flux of 130 LMH. In dye fouling experiments, the dye removal performance of bare TFC membrane, ZIF-8, and UiO-66 TFC membranes was comparable. However, irreversible fouling was lower in ZIF-8 (20%) and UiO-66 (10%) TFC membranes compared to bare TFC membrane (30%). This enhancement can be attributed to the high adsorption capacity of metal-organic frameworks (MOFs), which effectively mitigate long-term fouling. Economically, both ZIF-8 and UiO-66 TFC membranes are more feasible than the bare TFC membrane. The expected return on investment (ROI) for the bare TFC membrane facility is 8 years and 5 months, while the ZIF-8 TFC membrane facility is expected to achieve ROI after 7 years and 6 months. The UiO-66 TFC membrane facility is projected to achieve ROI in 5 years and 6 months. Among the three production methods, the UiO-66 TFC membrane has the highest initial investment cost but the shortest payback period. Considering economic feasibility and irreversible fouling regimes, UiO-66 is identified as the most suitable MOF for TFC membranes, while ZIF-8 is economically viable and suitable in terms of irreversible fouling and production feasibility.