Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

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Access Right: Open AccessSubject: search.filters.subject.Nanofiltration

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  • Master Thesis
    Development of Polyamideimide Based Nanofiltration Membranes for Separation of Dyes and Salts in Textile Wastewater Treatment
    (Izmir Institute of Technology, 2019) Metecan, Ayşe; Alsoy Altınkaya, Sacide
    The textile wastewater contains a significant level of organic dyes and inorganic salts. Separation of a vast amount of organic dyes and inorganic salts is important not only to comply with strict regulations but also to recover dyes for reuse during the process. Nanofiltration is proposed as a cost-effective alternative solution for dye and salt separation compared to traditional techniques. The main objective of this thesis is to develop a polyamideimide based positively charged nanofiltration membranes with high permeability, and high selectivity for separation of dyes and salts in textile wastewater treatment. Polyamide-imide (PAI) is an excellent choice for membrane production because of its superior processability, good mechanical features, and high chemical and thermal resistance. Its imide groups are crosslinked with polyethyleneimine (PEI), which is a suitable material to obtain a positively charged surface. In this study, support membranes of various pore sizes were produced by changing the composition of the coagulation bath and casting solution during the phase inversion method. Then, the optimum support membrane was in-situ modified with the alginate and coordinated with the metal ions for high permeability and high selectivity. The influences of the metal concentration and reaction time on the membrane performances were examined. It has been demonstrated that resulted nanofiltration membrane has high solute permeability (>22 L / m2 h bar), high dye rejection (~ 95 %) and low salt rejection (~ 11 %). Moreover, this membrane was tested in the treatment of real textile wastewater samples. Salts in wastewater permeated, while high amounts of dye were rejected.
  • Master Thesis
    Preparation and Application of Subnano Ceramic Filtration Membranes for Organic Species Removal From Aqueous Streams
    (Izmir Institute of Technology, 2017) Yaltrık, Kaan; Çiftçioğlu, Muhsin; Çiftçioğlu, Muhsin
    The purpose of this MSc work was to investigate the effects of neodymium/zirconium doping on the phase structure evolution of the selective titania nanofiltration (NF) membrane layers for the rejection of subnano sized organic compounds. A dilatometric study was carried out on unsupported membranes prepared from polymeric sols with different neodymium and zirconium levels. The development of functional abilities towards the design of the pore structure in the subnano range by controlling the nanostructural evolution of the selective NF layers was the fundamental purpose of this work. The neodymium doping level was varied in the 0.3-5.0% range and the zirconium mixing level was varied in the 0-100% range based on stable metal oxide molar compositions. Dilatometric characterization results have shown that dopant level effects the nanophase evolution and the densification behavior considerably. The dynamic light scattering results have shown that the polymeric species in the sol were predominantly 2-4 nm in size and had a very narrow size distribution. XRD analysis results indicated titania anatase crystallite sizes were reduced significantly with neodymium doping or zirconia mixing and the phase transformations were retarded by about 200°C. HR-TEM images of selected zirconia mixed or neodymium doped unsupported membrane powders also added new information to the XRD/dilatometry derived nanophase evolution results. The determination of the molecular weight cut-off values and pure water fluxes of the NF membranes which would be prepared by using these polymeric sols in the near future may generate valuable knowledge on the subnano separation abilities of these NF membranes.
  • Master Thesis
    Development of Thin Film Composite Nanofiltration Membranes With Layer by Layer Polyelectrolyte Deposition
    (Izmir Institute of Technology, 2017) Tekinalp, Önder; Alsoy Altınkaya, Sacide
    Nanofiltration (NF) membranes are usually prepared in thin film composite (TFC) structure through polymerization of various monomers or coating of previously synthesized polymer on porous support membranes. Layer by layer (LbL) deposition of polyelectrolytes on a porous support is a facile and convenient method for the sake of producing NF membranes. This study intends to manufacture TFC NF membrane via alternating polyelectrolyte deposition with limited number of layers on polysulfone/sulfonated polyethersulfone (PSF/SPES) porous support membrane. Polyethyleneimine (PEI) and alginate (ALG) were chosen as polyelectrolyte pairs. The support membranes with different pore sizes were prepared via nonsolvent induced phase inversion method by changing compositions and thickness of casting solution as well as composition of coagulation bath. The polyelectrolytes were deposited dynamically in a dead end filtration module at 1 bar. The influences of supporting electrolyte, polyelectrolyte pH and concentration as well as type of coating method on the membrane performances were investigated. The membranes were characterized by SEM, AFM, staining, and contact angle measurements. Stability and fouling tendency of produced membranes were determined. It was demonstrated that NF membrane (83% PEG1000 rejection) with a high flux (14 L/m2.h.bar) can be manufactured by depositing only a single layer of PEI. Further deposition of ALG on PEI-coated membrane resulted in water permeability of 15.5±0.3 L/m2.h.bar with 89.1±0.6% PEG1000 rejection by adjusting PSF:SPES ratio to 4:1.
  • Master Thesis
    Application of Tubular Ceramic Nanofiltration Membranes for Textile Waste Water Desalination
    (Izmir Institute of Technology, 2017) Yaldız, Safiye; Çiftçioğlu, Muhsin
    Textile industry generates coloured wastewater containing a significant level of dye/inorganic salts. Environmental concerns and efficient energy use make the recovery of reusable water and salts from textile wastewater vital globally. Ceramic nanofiltration (NF) membranes are becoming increasingly important for the recovery and purification of dyes and salts (e.g., NaCl) in high salinity waste streams. They have superior chemical/mechanical/thermal properties compared to their polymeric counterparts. Desalination performances of the ceramic NF membranes depend on the concentration and chemical structure of the target ions, pH of feed and the wastewater stream along with the chemical/surface/nanostructural properties of the selective NF layer. Metal oxides are generally used as NF layer materials due to their amphoteric behaviour. Repulsive/attractive forces between the ionic species in the solution and the NF layer may make the separation of ionic species possible. In this work, zirconia doped titania based NF layers were designed. Desalination experiments were conducted with 10-3 M Na2SO4 and MgSO4 salts at different pH values. Salt retention capacities of 5 different membranes were determined. Percent retention was calculated using ion concentrations in permeate and retentate streams. The Mg2+ and SO4 -2 ion concentrations were determined by titration with 0.01 M EDTA and by spectrophotometer at 420 nm, respectively. A clear pH dependency of the salt retention was found in filtration tests. The highest SO4 -2 and Mg+2 ion retentions were obtained with using MF+disperel (boehmite)+P2 (600 0C)+TTIP hydrosol+Ti/Zr polymeric (double layer) membrane as 95% and 91%, respectively.
  • Master Thesis
    Preparation and Characterzation of Ceramic Micro/Ultra Membranes for Separation Processes and Wastewater Treatment
    (Izmir Institute of Technology, 2016) Kırkbaş, Öncel; Çiftçioğlu, Muhsin
    The availability of fresh water is vital for life, sustainable growth and healthy ecosystems on earth. Increasing world population, a changing climate, intensive agricultural practices, economic growth and urbanization will undoubtedly continue to make the issue of water scarcity a global priority for years to come. The gap between the need and the supply of water globally is increasing steadily which necessitates significant measures to be taken towards conservation, and reuse of industrially, domestically and agriculturally used water. Textile industry is one of the leading industries in the use of fresh water and the generation of wastewaters. Technologies currently in use towards industrial and domestic water treatment like sedimentation, chemical coagulation, biological treatment etc. cannot produce reusable water but also generate significant amounts of solid waste. Membranes are now widely accepted to have the potential of supplying cost-effective solutions for water treatment and a growing range of purification and separation problems. The number and the pore structure design of the multiple selective layers on the inner surfaces of tubular α-alumina supports vary with the nature of the intended separation application. Although the nature of MF membranes is relatively well developed, current research is concentrated on the design of nanoporous phase structure in NF and UF selective layers. Selective micro/ultra/nanofiltration layers were formed on extruded tubular alumina supports by colloidal/sol-gel techniques. The performance of these selective layers were investigated by the experiments performed with textile wastewater. Permeates from ceramic tubular membranes were characterized by spectrophotometer. The suspended solids and color (Pt-Co) were reduced by 90% and 80%. respectively.