Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Functionalized Cellulose-Based Adsorbent for Lithium Recoveryfrom Aqueous Solutions(01. Izmir Institute of Technology, 2021) Nampeera, Jackline; Yüksel Özşen, Aslı; Yüksel Özşen, Aslı; 01. Izmir Institute of Technology; 03.02. Department of Chemical Engineering; 03. Faculty of EngineeringThis study focused on generation of low-cost yet highly effective lithium selective bio-sorbent from olive pruning waste mainly olive branches. Olive branches were treated with NaOH that eliminated non-cellulosic materials and activated hydroxyl groups that inhibit the formation of active sites. Olive branches were then functionalized through homogeneous phosphorylation at 150 ⁰C. POB, NOB, and FOB samples were subjected to SEM, XRD, FTIR, BET, XPS, and TGA to observe the changes in their structure and properties. Factors affecting lithium adsorption were investigated on the synthesized FOB in a batch system and analyzed by ICP-OES. Adsorption isotherms are well fitted to the Freundlich isotherm model than the Langmuir isotherm model which exhibited a maximum adsorption capacity of 6.7 mg/g at 30 ⁰C. Kinetic studies exhibited fast kinetics and equilibrium was attained in 6 minutes while thermodynamic studies showed an exothermic, spontaneous reaction and increased randomness at the interaction interface. Regeneration studies proved the sustainability of FOB with Li+ desorption efficiency of 99.6% in 1.0 M HCl. The synthesized FOB displayed a better degree of column utilization and elution efficiency; 56.8% and 95.8% than Lewatit TP 260; 16.0% and 50.4% respectively in the adsorption column studies performed at room temperature. However, it exhibited a poor breakthrough capacity of 2.1 mg Li/ml sorbent than Lewatit TP 260 with 1.33 mg Li/ml sorbent. Based on all experimental results, the novel functionalized olive branches (FOB) proved a potential lithium selective bio-sorbent and can be applied in the recovery of lithium from its aqueous sources.Master Thesis Physiological and Biochemical Characterization of Drought Tolerance in Chickpea(Izmir Institute of Technology, 2012) Keskin, Hilal; Frary, Anne; Frary, Anne; 04.03. Department of Molecular Biology and Genetics; 04. Faculty of Science; 01. Izmir Institute of TechnologyChickpea (Cicer arietinum cv. Gokce.) is an agronomically and economically significant plant for Turkey. It is successfully grown under severe drought conditions which limit the growth of other plants. It is generally affected by terminal drought which causes retardation of flowering and decreases yield in Mediterranean and subtropical climates. The aim of this study was to determine significant factors which can be used to identify chickpea plant tolerance to drought stress. With this objective we assessed physiological (fresh and dry weight, relative and real water content) and biochemical (enzymatic and non-enzymatic antioxidants, malondialdehyde, total protein and phytohormone contents) parameters which were used to measure the impact of drought on chickpea. To determine drought's effects, we collected stressed (drought treated) and control (non drought treated) samples from the chickpea cultivar Gokce. Results showed that both fresh and dry weights of plants increased while real and relative water contents of plants decreased under drought stress. There was an increase in both malondialdehyde (MDA) and total protein contents under drought stress. Furthermore, glutathione reductase (GR) and catalese (CAT) enzyme activity increased in drought treated plants whereas guaiacol peroxidase (POD) and superoxide dismutase (SOD) enzyme activity decreased. Moreover, contents of indole acetic acid (IAA) and abscisic acid (ABA) increased in all tissue parts while contents of salicylic acid (SA), gibberellic acid (GA) and jasmonic acid (JA) increased in specific plant tissue parts during drought treatment. In conclusion it is obvious that all of these characters play essential roles in the drought tolerance of plants.Master Thesis Laser Induced Breakdown Spectroscopic Analysis of Metal Aerosols Generated by Pneumatic Nebuliztion of Aqueous Solutions(Izmir Institute of Technology, 2010) Ateş Arıca, Dilek; Yalçın, Şerife; Yalçın, Şerife; 04.01. Department of Chemistry; 04. Faculty of Science; 01. Izmir Institute of TechnologyLaser Induced Breakdown Spectroscopy, LIBS, is an analytical technique used to determine the elemental composition of samples in all forms. In this study, an experimental LIBS system has been designed and constructed for the analysis of metal aerosol particles that are generated by a pneumatic nebulizer. This research provides a basis and preliminary data for the construction of a portable LIBS system to analyze metals in aqueous environments.The aerosol particles generated from the pneumatic nebulizer travel through a sample introduction unit to reach the sample cell in which they interact with the laser beam. The source of light is a Nd:YAG laser at 532 nm, 10 Hz. When the laser beam is focused inside the sample cell, plasma is generated, and the emission containing the spectral information about the sample being analyzed is focused onto the spectrograph and detected by a gated detector. The optimum optical and experimental parameters were systematically investigated.The aqueous analyte solutions were prepared from their salts before introduced into the system. In this work, laser-induced breakdown spectroscopic emissions of Na, Ca, Mg and K aerosols were studied. In single shot mode, the minimum detectable aqueous concentrations were found as 250 ppb, 500 ppb, 400 ppb and 10 mg/L respectively. For 10 shot accumulated analyses in repetitive mode, based on 3. criterion, the detection limit (LOD) was determined as 1 mg/L, 0.6 mg/L, 1.5 mg/L and 16.3 mg/L respectively. The efficiency of the drying unit has been evaluated by particle size measurements. It has been shown that the Na aerosols with particle size of 4.3 .m decreases to 0.5 .m after passing through the membrane dryer unit.