Investigation of Catalytic Performances of Layered Double Hydroxides in the Removal of Oxytetracycline Hydrochloride from Aqueous Solutions
Project no. 22394 · Status: Kapanmış · 2020
Summary
<p>In this thesis, the performance of photo fenton-like oxidation and catalytic wet air oxidation of oxytetracycline HCl (OTC-HCl) using double-layer hydroxide catalysts was investigated. The performances of methods were compared with three different double-layer catalysts (Cu-Fe LDH, Co-Fe LDH and Ni-Fe LDH). The most selective catalyst was determined for each method. Box Behnken statistical experiment design and the response surface methodology was used to investigate the effects of the independent variables on the response function and to determine the optimum conditions maximizing the percent removal of oxytetracycline.</p><p>For the photo Fenton-like oxidation of OTC-HCl, the optimum reaction conditions were determined as catalyst loading =1.5g/L, H2O2 concentration = 1.5mM, pH=5 in the presence Ni-Fe LDH catalyst in the presence of visible light source The degradation efficiency was evaluated as around 68% at these optimum conditions. Kinetic studies were performed at these optimum conditions and it is found that the system fits first order one step kinetic model.</p><p>For the Catalytic Wet Air oxidation of oxytetracycline wastewater the most selective catalyst was determined as Cu-Fe LDH catalyst. The optimum conditions were determined as 0.5 g/L Cu-Fe LDH catalyst loading, at pH 7 and at temperature of 70℃ At these conditions the removal percentage was around 92%. According to the kinetic studies it was observed that the removal of oxytetracycline by CWAO process follows two steps second order order reaction.</p><p>According to the toxicity tests, it was concluded that the photofenton-like oxidation method (Relative Root Growth 52%) was less effective in reducing the toxicity in wastewater, while the wet air oxidation was more effective (Relative Root Growth 64%).</p>