Removal of Food Additives from Water in the Presence of Layered Double Hydroxide Catalysts by Peroxymonosulfate Activation and H2O2
Project no. 22402 · Status: Kapanmış · 2021
Summary
<p>In the present study, peroxymonosulfate and hydrogen peroxide activation performances of various layered double hydroxide (LDH) catalysts were tested for the removal of the model food dye, tartrazine, from aqueous solutions. Catalytic activities of Cu-Fe-LDH, Co-Fe-LDH and Ni-Fe-LDH were compared in the presence of peroxymonosulfate and hydrogen peroxide. In the catalyst screening experiments performed by using different oxidants, Co-Fe-LDH and peroxymonosulfate were determined as the most suitable catalyst and the oxidant, respectively. The interactive effects of the catalyst loading, pH and the molar ratio of the oxidant to dye were investigated and the reaction conditions were optimized by using Box-Behnken Design and response surface methodology. Under the optimum reaction conditions which were determined as 2 g/L catalyst loading, pH 3, and 11.36 oxidant/dye molar ratio, 87.35% organic matter removal and 97.47% decolorization efficiencies were calculated. According to the results of the radical trapping experiments, it was concluded that hydroxyl radicals were effective in dye removal. Toxicity tests showed that <em>L.sativum</em> root growth inhibition was 21.6% in treated dye solutions. In the kinetic study, it was found that dye removal by peroxymonosulfate activation in the presence of Co-Fe-TÇH complied with the second-order reaction rate model. Activation energy and the pre-exponential factor were calculated as 33.7 kJ/mol and 720,1 L.mg-1.min-1, respectively.</p>