Master Degree / Yüksek Lisans Tezleri
Permanent URI for this collectionhttps://hdl.handle.net/11147/3008
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Master Thesis Effects of Biosurfactants on Remediation of Soils Contaminated With Pesticides(Izmir Institute of Technology, 2002) Zenginyürek, Özlem; Ertürk, Handan; Ertürk, Handan; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyPesticides have played a significant role in increasing food production, and in view of growing worldwide food demand. Nevertheless; some of them have been classified as persistent toxic chemicals. This has resulted in serious concern about environmental contamination. Once a pesticide or toxic chemical find its way in the environment, a major part of it comes in contact with soil. There are several possible sources of pesticide contamination; at manufacturing, storage, or user sites. The most serious examples of pesticide contamination are typically the result of poor production and waste management practices of pesticide manufacturing, formulation, and application facilities. Improper storage, handling, and also have resulted in pesticide contamination at these sites and at landfills. Today, many remediation technologies are used to remove the pesticides from the soil. One of the soil treatment methods is enhanced biodegradation. Bioremediation of the soil has often proven to be a cheap solution for contaminated soil problem. This research was conducted to investigate the effectiveness of biologically produced surfactants (biosurfactants) on the biodegradation of pesticide-contaminated soil and evaluate the potential for biosurfactant-enhanced bioavailability of pesticide in soil. In order to determine the effectiveness of biosurfactants on pesticides, sophorolipid and rhamnolipid type biosurfactants were used. These biosurfactants were chosen since they are well characterized and their stimulating effect on the biodegradation of hydrophobic substrates was described in the literature. In this study, endosulfan and trifluralin were selected as pesticides. The study was performed in two stages in laboratory conditions. In the first part of the experiment, degradation of endosulfan-contaminated soil was studied by the presence of sophorolipid and in the second part of the experiment; rhamnolipid (JBR 425) was used on the removal of trifluralin-contaminated soil. Throughout the experiment, three different concentrations of sophorolipid and rhamnolipid were applied to soil which, are 0.98, 9.75 and 195 ppm for sophorolipid and 1.6, 100 and 1000 ppm for rhamnolipid. The effectiveness of synthetic or microbial surfactants on biodegradation of chemicals has been investigated by many researchers. However, studies about the biosurfactant enhanced soil remediation for the pesticide contaminants are limited. Besides that, the outcome of surfactant applications has been highly system-specific, conflicting results reported in the literature. Therefore, despite the general trends outlined in literature, the effect of biosurfactants on the biodegradation of organic compounds is poorly understood. Opposed effects are frequently observed. This study is the first M.Sc. thesis study about the use of biosurfactant enhanced bioremediation of pesticides in Turkey. The results from first part of our study obtained from sophorolipid, were not satisfactory since the degradation patterns for endosulfan were not affected by the presence of sophorolipid. According to the second experiment results, removal of trifluralin ranged from 24-35 %, with the increase in rhamnolipid concentrations. Addition of rhamnolipid (JBR 425) into the soil was found to increase the degradation rate of trifluralin by 13 % as compared to the control soil column. Additional time would probably increase the rate of degradation and bioavailability, as a result of providing the adaptation of microorganisms in contaminated soil media and formation of more bioavailable metabolites.Master Thesis Use of Domestic Minerals for Vegetable Oil Bleaching(Izmir Institute of Technology, 2004) Erten, Yasemin; Ertürk, Handan; Ertürk, Handan; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyIn this thesis, acid activation and characterization studies were conducted for different clay samples and bleaching capacity of the selected acid activated clay samples for sunflower oil were determined. The samples selected for this study were naturally occuring clays from Ankara and Eskiehir regions. The acid activated zeolite was also used for the purpose to compare its bleaching performance with commercial bleaching clay, Tonsil and the acid activated clays.The clay minerals were activated with hydrochloric acid (HCl) at three acid concentrations (1 N, 3 N, 5 N), activation times (1h, 2h, 3h) and different dry clay/acid ratios. The clay samples from the Ankara and Eskiehir regions were defined as montmorillonite according to X- ray diffraction (XRD). XRD results proved that acid activation caused structural changes in the treated montmorillonites, montmorillonite peaks gradually disappearing and yielding to an amorphous montmorillonite structure.The TGA results showed a significant weight loss between 30 C - 200 C ( 15%) for the Ankara clay and between 20 - 200 (12%) for the Eskiehir clay. This was most probably due to the removal of free and hydrogen-bonded water molecules. Maximum surface area was obtained for the acid activated Ankara clay treated with 1 N HCl for 3 hours. It was determined to be 849.1 m2/g. Also, maximum surface area was 269.7 m2/g for the acid activated Eskiehir clay treated with 5 N HCl for 1hour. Then the surface area of the acid activated clays decreased sharply with the acid activation. The chemical compositions of the solutions and clays after acid activation were determined using ICP and EDX analysis, respectively. According to the results, the dissolution amount of CaO, Na2O, MgO, K2O, Fe2O3 and Al2O3 increased along with increasing acid concentration and treatment time. The SiO2 content and the Si02/Al2O3 ratio increased as a result of dissolving of aluminium ions. This ratio increased from 6.0 to 7.5 for the acid activated Eskiehir clay and from 2.7 to 3.9 for acid activated Ankara clay.Acid activated clays were tested for the assessment of their bleaching efficiency for sunflower oil in the laboratory. Bleaching tests were carried out with earths prepared at different acid activation conditions such as acid concentration and activation times. The absorbance value was measured at 455 nm and found to be 0.429 for the neutralized sunflower oil. Peroxide value and free-fatty acid content of the neutralized oil were found to be 16.8 meq/kg and 0.07 %, respectively. The oil bleached with the acid activated Ankara clay had a peroxide value of 46.2 meq/kg first, which decreased to 22.4 meq/kg and the free-fatty acid content was observed to be around 0.08 %. For acid activated Eskiehir clay, peroxide value of the bleached oil initially increased up to 31.2 meq/kg, then decreased under the peroxide value of neutralized oil (16.8 meq/kg) and free-fatty acid content of bleached oil approximately was around 0.09 %.The bleaching parameters which were used for testing were 1 % earth concentration and 30 minutes contact time at 100°C bleaching temperature. At these selected parameters, acid activated Eskiehir clay (5 N 1h HCl treatment), Ankara clay (1 N 3h HCl treatment) and zeolite (2 N 6h HNO3 treatment) were compared with the commercial bleaching clay, Tonsil. The smallest value of absorbance and bleaching efficiency were found to be 0.084 and 80 %, respectively with the Eskiehir clay and these values were determined to be 0.083 and 81 % with the Tonsil under the same conditions. The absorbance value and bleaching efficiency of the bleached oil with acid activated Ankara clay were determined to be 0.114 and 73 %, respectively using the selected bleaching parameters. Bleaching performance of Ankara clay was found to be lower when compared with the result of Eskiehir clay.At the selected bleaching point, results of lovibond red and yellow color of bleached oil indicated that the Eskiehir clay and Tonsil were close to each other in bleaching efficiency (Red color: 0.8 and 1.1; yellow color: 20 and 20 for Tonsil and Eskiehir clay, respectively). Zeolite did not reach the required bleaching performance.The bleaching efficiency was 25 % with raw zeolite and it hardly increased to 46 % with the acid activated zeolite. In addition, red and yellow color values were higher than the other clays (red color:2.6; yellow color: 30).As a result, Eskiehir clay gave a better bleaching performance compared to Ankara clay and Zeolite. Maximum bleaching efficiency was achieved after 30 minutes of contact time with 1 % earth concentration at 100 °C bleaching temperature following 5 N 1h HCl treatment for Eskiehir clay.Master Thesis Spectroscopic Determination of Major Nutrients (n, P, K) of Soil(Izmir Institute of Technology, 2003) Şen, İlknur; Şen, İlknur; Ertürk, Handan; Ertürk, Handan; 03.08. Department of Food Engineering; 03. Faculty of Engineering; 01. Izmir Institute of TechnologyThe aim of this study was to determine the major soil nutrients (nitrogen, phosphorus and potassium) which mainly affect the raw material quality of food, using near infrared reflectance spectroscopy (1000-2500 nm). Genetic inverse least squares and partial least squares were used to predict the concentrations of major soil nutrients.The soil samples, collected from Menemen Application and Research Farms, were prepared for the near infrared analysis by using two different methods. According to the first method, two experiments were performed. The soil samples of which were oven dried and screened through a 2 mm sieve, were mixed with NPK fertilizer in the concentration range of 1-15% (wt/wt) (first experiment), and with NH4NO3 and TSP fertilizers in the concentration range of 0.075-0.3% (wt/wt) (second experiment). Using genetic inverse least squares method, regression coefficients of 0.9820, 0.9779 and 0.9906 were obtained for the prediction of nitrogen, phosphorus and potassium concentrations in samples containing NPK fertilizer, respectively. In the second experiment, prediction of nitrogen concentration in samples containing NH4NO3 fertilizer was done reliable with a regression coefficient of 0.8409 using genetic inverse least squares method. On the other hand, regression coefficient of 0.6005 was obtained for the prediction of phosphorus concentration in samples containing TSP fertilizer with the same statistical method.The second method differed from the first one by eliminating the drying of soil samples and moisturizing step following the addition of fertilizers into soil samples. The aim was to prevent baseline shifts in the spectra arising from the moisture changes in the samples. Five types of fertilizer [KNO3, CaNO3, TSP, (NH4)2SO4, NPK] were used in the preparation of samples in the concentration range of 0.02-0.5% (wt/wt). Using genetic inverse least squares method, calibration models produced between the reflectance spectra and the nutrient concentrations had regression coefficients greater than 0.80, however the prediction ability of the models was poor (R2<0.50) except for the samples containing (NH4)2SO4 and NPK fertilizers. The regression coefficients for the prediction of nitrogen and sulfur concentrations in (NH4)2SO4 containing samples were found as 0.8620 and 0.8555, respectively. For the prediction of nitrogen, phosphorus and potassium concentrations in NPK containing samples, the regression coefficients were found as 0.6737, 0.7633 and 0.8724, respectively. The partial least squares method was also used for the prediction of nutrient concentrations in the samples prepared according to the second method. Except samples containing (NH4)2SO4 fertilizer, nitrogen, phosphorus and potassium amounts could not be predicted in the other samples using partial least squares method (R2<0.20). The regression coefficients obtained for the prediction of nitrogen and sulfur amounts in (NH4)2SO4 containing samples were 0.9301.An additional work was carried out with laboratory analyzed soil samples collected from several points of two agricultural fields in Menemen Application and Research Farms. Total nitrogen, extractable phosphorus and exchangeable potassium amounts were determined by Agricultural Engineering Department of Ege University according to the Kjeldahl method, Bingham method and ammonium acetate method, respectively.Predictions of these nutrient concentrations by genetic inverse least squares method were poor (R2< 0.20). Using partial least squares method, the nutrient concentrations could not be predicted (factor number . 0).The results of this study indicate that, near infrared reflectance technique provided rapid, non-destructive and simultaneous determination of nitrogen, phosphorus and potassium concentrations in soil- fertilizer mixtures depending on the sample preparation steps, fertilizer types and concentrations and multivariate calibration methods (genetic inverse least squares and partial least squares methods).