Catalytic activity of copper modified bentonite supported ferrioxalate on the aqueous degradation and kinetics of mineralization of Direct Blue 71, Acid Green 25 and Reactive Blue 4 in photo-Fenton process

Abstract

In order to enhance depuration of pollutants in photo-Fenton process, copper modified bentonite supported ferrioxalate catalyst (CuMBFOx) was synthesized. The catalyst was characterized with TGA, XRF, XRD, FTIR, BET and SEM techniques. Its catalytic activity was evaluated on the degradation of Direct Blue 71 (DB71), Acid Green 25 (AG25) and Reactive Blue 4 (RB4) dye pollutants in batch photo-Fenton process without pH adjustment. The results showed complete depuration below the detection point of UV–vis spectrophotometer as monitored on their respective UV–vis degradation spectra. The extent of mineralization ability of the CuMBFOx was monitored with chemical oxygen demand (COD) analysis and was used to study the kinetics of mineralization of the dyes using a developed phenomenological mathematical model. The result showed that the efficiency reduced in the order DB71>AG25>RB4 owning to their chemical components and structural complexities. CuMBFOx demonstrated excellent qualities toward depuration of DB71, AG25 and RB4.