Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
Browse
4 results
Search Results
Master Thesis Ceramic Microfiltration Membrane Design Towards Oil Removal in Metal Industry Wastewater Streams(01. Izmir Institute of Technology, 2020) Eren, Muhammet Şakir Abdullah; Çiftçioğlu, MuhsinIncreasing water scarcity is an important threat to the whole world. The use of too much water during the production processes and the insufficient level of reuse of this water and the increasing quantities of oil containing waste generated in many industrial activities cause dangerous consequences for the environment. Highly concentrated oil-inwater emulsions are very harmful for aquatic life, soil, atmosphere and human health. Traditional treatment methods are not effective in the removal of emulsified oil droplets which have less than 20 µm of droplet size. Ceramic micro/ultrafiltration membranes have been explored and developed in recent years due to their superior advantages in oil containing water treatment/purification. The aim of this MSc study was to produce tubular ceramic supports and microfiltration membranes for the removal of oil from stable oil in water emulsions used as metal cutting fluids. The prepared metal cutting fluids were fed to the crossflow filtration system and the effects of experimental parameters such as transmembrane pressure (TMP), crossflow velocity (CFV) and oil content on membrane performance/permeate flux were investigated. The single/double layered coatings on the support surfaces were formed in the preparation of the microfiltration membranes by using stable 0.4 µm α-alumina suspensions. The 1 layer and 2 layers containing microfiltration membranes were heavily fouled and very low permeate fluxes were obtained in an hour of treatment. This was attributed to the formation of a thin oil layer on the microfiltration membrane surfaces. The reduction of the total suspended solids (TSS) and turbidity were determined as ~100 %. A stable permeate flux with a lower extent of membrane fouling and concentration polarization was obtained with 1% oil content and the support membrane and TMP=2 bars.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, MuhsinThe 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 Preparation of Asymmetric Ti̇o2 Based Nano/Ultrafiltration Membranes for Wastewater Treatment(Izmir Institute of Technology, 2017) Odabaşı, İklima; Çiftçioğlu, MuhsinFresh water scarcity have been the most fundamental problem in the world and is already affecting mankind and human activities. This problem forced an increasing effort in the reuse of wastewater originating from municipal, agricultural, and industrial activities. The textile industry demands large amounts of water and produces large quantities of wastewater. Adsorption, filtration, ozonation and photocatalysis techniques are currently used for wastewater treatment and safe discharge to the environment. Although membrane filtration necessitates a high initial setup cost, it has a high potential and may cause significant cost savings through the reuse of water and salts. The membrane based technologies are widely accepted to be the best method when compared with the currently available technologies for wastewater treatment. Extruded tubular alumina supports were coated by stable colloidal sols and polymeric sols prepared by using sol-gel based techniques for the formation of selective micro/ultra/nanofiltration layers in this work. Textile wastewater treatment (with and without pre-treatment) and membrane fouling analysis was conducted. The performances of the membranes were determined through the characterization of permeates by spectrophotometer. The reduction of colors (Pt-Co, m-1), turbidity and suspended solids content were about 99%, 100% and 100%, respectively. The incorporation of a coagulation stage by using Al2(SO4)3 followed by a successive filtration reduced the membrane/irreversible fouling levels in the MF/UF membranes significantly. The Pt-Co 455 values of permeates were determined to be in the 15-260 range which are below the discharge criteria bringing the possibility of the reuse of some of these permeates.Master Thesis Application of Tubular Ceramic Nanofiltration Membranes for Textile Waste Water Desalination(Izmir Institute of Technology, 2017) Yaldız, Safiye; Çiftçioğlu, MuhsinTextile 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.