Heterogeneous photo Fenton-like oxidation of Procion Red MX-5B using walnut shell based green catalysts

Abstract

Abstract The walnut shell based photo Fenton-like catalysts were prepared and their performances in the removal of Procion Red MX-5B in aqueous solution were investigated. The influence of several operating parameters including the catalyst loading, the initial hydrogen peroxide concentration ([H2O2]o), pH and power of UV light on the degradation and the decolorization of Procion Red MX-5B were studied. The optimum reaction conditions obtained at room temperature were 2 mM of the initial hydrogen peroxide concentration, 0.25 g/l of catalyst loading and 3 of the initial pH for an initial dye concentration of 100 ppm. Under these conditions 50% degradation and 88.3% decolorization were achieved. Iron leaching in the treated dye solution was determined as 1.98 ppm which was below the European Union limits. The toxicity which was evaluated in terms of relative root growth inhibition rate of Lepidium sativum roots was 0.6%.