Investigation of the photo-Fenton-plasma jet-TiO 2 catalyst synergistic triple action for degradation of synthetic dyes

Synthetic dyes are widely used in cosmetic, textile, food, paper, and pharmaceutical industries. During dying, large volumes of synthetic dyes are directly discharged into open drains, leading to serious environmental and health hazards. This study investigates the photo-Fenton-plasma-photocatalyst synergistic triple action for degradation of synthetic dyes. The aim of this study is to remove methylene blue dye using a combined Photo-Fenton/TiO 2 /UV method, with an argon plasma jet serving as source of UV radiations. OES was employed to detect reactive radicals in the argon plasma jet, which drive the Photo-Fenton reaction in combination with TiO 2 photocatalyst. Prior to the dye degradation experiments, the photocatalyst was characterized for its structural and morphological properties. Experimental design and optimization were conducted using the Design of Experiments, specifically the Box-Behnken design. Optimal conditions for dye degradation were determined: Fe² + concentration of 0.50 g/L, H 2 O 2 concentration of 2.25 g/L, and TiO 2 concentration of 0.50 g/L. Under these conditions, a maximum methylene blue removal efficiency of 98.5% was achieved after 45 min of plasma exposure. According to the optimization analysis, the highest degradation was observed at Fe² + , H 2 O 2 , and TiO 2 concentrations of 0.50 g/L, 1.1717 g/L, and 1.50 g/L, respectively.