Electro‐Fenton decolourization of dyes in batch mode by the use of catalytic activity of iron loaded hydrogels

Abstract

BACKGROUND: Electro-Fenton technology has demonstrated great potential for the degradation of recalcitrant organic contaminants in polluted wastewaters. In this technology, the decomposition of hydrogen peroxide is catalysed by the presence of iron, and powerful oxidants, hydroxyl radicals, are generated. However, there is concern over the reduction of iron released in the treated effluent. Therefore, retention of catalyst is required, and advances in electro-Fenton heterogeneous catalysis are necessary. In this study, the use of polyacrylamide hydrogel was evaluated as a support for the iron, and the performance of the catalyst (Fe-PH) developed was assayed in the electro-Fenton degradation of two dyes, Reactive Black 5 and Blue Sella Solid. RESULTS: First, the synthesis of Fe-PH catalyst was studied. The results showed that the loaded hydrogel with a mixture of Fe(II) and Fe(III) in 1:2 molar ratio reached the highest decolourization efficiency. The performance of the optimized Fe-PH catalyst was evaluated in the decolourization of the selected dyes. These studies demonstrated the satisfactory performance of electro-Fenton using Fe-PH catalyst as well as its reusability. CONCLUSION: In summary, the Fe-PH catalyst developed gives the promise of wastewater treatment by means of an electro-Fenton process.

Coated nickel foam electrode for the implementation of continuous electro‐Fenton treatment

“…Several researchers have focused their efforts on improvement of the key variables involved in this technology such as electrode material, initial pH and Fenton's reagents . In relation to the last one, a huge amount of research has been carried out on the development of a heterogeneous catalyst able to provide the iron necessary in the release after the treatment, avoiding the iron sludge generated at the end of the treatment and its release after treatment.…”

Effective monitoring of the electro-Fenton degradation of phenolic derivatives by differential pulse voltammetry on multi-walled-carbon nanotubes modified screen-printed carbon electrodes

“…In order to improve the efficiency of this treatment the use of heterogeneous electro-Fenton process has been postulated. Nowadays, different catalysts have been used in heterogeneous electro-Fenton reactions such as iron-alginate gel, iron-carbon, iron-zeolite, magnetite, iron-hydrogels… [15][16][17][18][19]. By use of heterogeneous catalysis the reuse of iron and the operation in continuous mode are possible [15,20].…”

“…A number of methods have been developed to monitor electro-Fenton degradation, where GC-MS [21,22], UV-Vis spectroscopy [19], HPLC and IC [23,24] are the most common techniques to follow the evolution of electrolysis; however, little attention has been paid to the use of electroanalytical techniques [25,26] and under our knowledge no references were found to monitor degradation of cresols.…”

Electrochemical degradation of RB-5 dye by anodic oxidation, electro-Fenton and by combining anodic oxidation–electro-Fenton in a filter-press flow cell

“…Glassy carbon electrodes also have been used [29] as well as graphite (area 15 cm 2 ) and Fe alginate gel beads and iron-loaded sepiolite [30,31]. Bocos et al used two graphite sheets electrodes of 15 cm 2 area and an iron supported in polyacrylamide hydrogel [32].…”