Degradation of reactive dye using heterogeneous photo-Fenton catalysts: ZnFe₂O₄ and GO-ZnFe₂O₄ composite

Abstract

Dyes, being potential pollutants, need alarming attention for their degradation from wastewater. Advanced oxidation processes (AOPs) are among the most effective methodology for the degradation of pollutants. In the present study, the heterogeneous photo-Fenton catalysts (ZnFe 2 O 4 and graphene oxide based ZnFe 2 O 4 composite) were prepared and used to study the degradation of synzol red reactive dye. The prepared catalysts were well characterized by using SEM, FTIR and XRD analysis. The effect of various parameters like pH, catalysts dosage, H 2 O 2 dosage, effect of dye concentration and irradiation time during heterogeneous photo-Fenton processes was studied. The results showed 57% and 94% degradation of dye under optimized conditions (e.g. pH=3, Catalysts dose=75 mg l −1 for ZnFe 2 O 4 and 50 mg l −1 for GO-ZnFe 2 O 4 , H 2 O 2 dose=27 mM and irradiation time of 60 min) was observed for ZnFe 2 O 4 and GO-ZnFe 2 O 4 , respectively. A comparison of degradation potential of catalysts using various light sources like UV-254 nm, ambient solar light and white LED, was studied. The current findings support the application of solar and LED light for the degradation of organic pollutants in wastewater. The stability and reusability of these catalysts for the degradation of the dye were also studied. The GO-ZnFe 2 O 4 composite showed negligible iron leaching and no considerable reduction in degradation efficiency upto six consecutive cycles of reusability. It has been found that the composite (GO-ZnFe 2 O 4 ) showed enhanced degradation of dye as compared to ZnFe 2 O 4 .

Investigation of Fe-Doped Graphitic Carbon Nitride-Silver Tungstate as a Ternary Visible Light Active Photocatalyst

“…All the characteristic peaks of g-C 3 N 4 and Ag 2 WO 4 are present in the Fe-doped ternary composite but with lesser intensities than the undoped CN-AW and Fe-CN composites. However, the strong intensity of diffraction peaks in both the composites suggests the successful synthesis and crystalline nature of composites [25]. ere is also a very slight shift of the peak at a diffraction angle of 2θ � 45.3 °, corresponding to a plane (402) towards higher diffraction angles, indicating the insertion of Fe into the host composite lattice.…”

UV-Accelerated Photocatalytic Degradation of Pesticide over Magnetite and Cobalt Ferrite Decorated Graphene Oxide Composite

“…The iron leaching of all catalysts, after each reusability run, was checked using atomic absorption spectroscopy, and the results obtained are presented in Table 1. The low iron leaching values (far below the European Union Standard i.e., 2.0 mg/L [12]) suggest that the heterogeneous catalysts are stable towards metal leaching from solid to liquid state. • As per EU directives, Fe leaching should not be higher than 2.0 ppm.…”

“…Earlier, studies revealed that persistent organic pollutants have been treated with many conventional processes such as chemical, physical, and biophysical processes but proved inefficient. In recent years, effective and viable treatment technologies widely used were Advanced Oxidation Processes (AOPs) [11,12]. These Processes involve the in situ production of oxidizing species such as hydroxyl radicals ( • OH).…”

Combined Action of Adsorption and Catalytic Oxidation in Aluminum Dye Removal by Groundwater Treatment Waste

“…The efficiency of the heterogeneous Fenton process was improved by using the nanomaterial composed of ferric oxide, silica, and alumina (Nguyen et al, 2021). Degradation of Synozol Red reactive dye was achieved using ZnFe 2 O 4 catalyst and the composite prepared from ZnFe 2 O 4 and graphene oxide (Nadeem et al, 2020). Nanocomposites of goethite and akaganeite demonstrated photocatalytic activity by removing the color of Methyl Orange (Pal et al, 2020).…”