Azo boyar maddelerin organik atık üzerinde metal emdirilmiş bir katalizör kullanılarak ileri oksidasyon yöntemleriyle ve karşılaştırmalı olarak biyolojik oksidasyon ile giderimi

In this study, the removal of Procion Red MX-5B azo dye was investigated using several advanced oxidation methods in the presence of walnut shell based catalysts and comparatively biological oxidation in which the walnut shells were used as immobilizing agent for the microorganisms. The advanced oxidation methods comprising Fenton like oxidation, photocatalytic oxidation, photo-Fenton like oxidation and catalytic wet air oxidation (CWAO) were applied in the presence of iron on activated carbon catalysts (Fe/AC) containing 10% iron by weight. In addition to Fe/AC, Fe-TiO2 loaded on activated carbon catalysts (Fe-TiO2/AC) were used in photocatalytic oxidation. (Fe-TiO2)/Catalyst:1/10 by wt. and Fe/TiO2:1/100 by wt. in the photocatalyst. In the biological oxidation, due to the oxidizing enzymes they secreted, the white rot fungi Phanerochaete chrysosporium and Trametes versicolor were selected to remove Procion Red MX-5B. The activated carbon, which was used as catalyst support, were prepared using physical activation and three chemical activation methods, using HNO3, ZnCl2 and KOH agents. The catalysts were characterized by Scanning electron Microscopy, X-Ray Diffractometry and Brauner Emmett Teller analyses. The performances of the catalysts were compared in the catalyst screening experiments. The highest removal efficiencies in the Fenton like, photo-Fenton like processes were obtained in presence of KOH activated catalyst whereas ZnCl2 activated catalyst was the most efficient one in the CWAO. Parametric studies were carried to determine of the optimum conditions for each of the advanced oxidation method in the presence of the most suitable catalyst. Under the optimum reaction conditions, the degradation efficiencies are calculated as 51.6%, 50%, 27.1% and the decolorization efficiencies were evaluated as 91.6%, 88% and 13.9% in the Fenton like, photo-Fenton like, and CWAO processes, respectively. Toxicity tests and kinetic study were performed for Fenton like oxidation which was determined to be the most efficient one among the advanced oxidation methods tested in this study. The toxicity tests with Lepidium sativum showed that the growth inhibition was 1.1% after the treatment. It was found that the decolorization kinetics of Procion Red MX-5B followed pseudo-first order reaction kinetics in the temperature range of 30-60℃ and pseudo-second order reaction kinetics at 70℃. The activation energy was determined by 47.36 kJ/mol. In the biological oxidation Phanerochaete chrysosporium and Trametes versicolor were immobilized on walnut shells to treat solutions of Procion Red MX-5B. Trametes versicolor was determined to be more effective in decolorization in comparison with Phanerochaete chrysosporium and 52.7% decolorization and 5.1% degradation were observed under optimum reaction conditions in the presence of this fungus. When the efficiencies of the biological and advanced oxidation methods are compared Fenton like and photo-Fenton like oxidation methods were determined to be much more effective than the biological oxidation method.