Novel Electro-Fenton Approach for Regeneration of Activated Carbon

Abstract

An electro-Fenton-based method was used to promote the regeneration of granular activated carbon (GAC) previously adsorbed with toluene. Electrochemical regeneration experiments were carried out using a standard laboratory electrochemical cell with carbon paste electrodes and a batch electrochemical reactor. For each system, a comparison was made using FeSO4 as a precursor salt in solution (homogeneous system) and an Fe-loaded ion-exchange resin (Purolite C-100, heterogeneous system), both in combination with electrogenerated H2O2 at the GAC cathode. In the two cases, high regeneration efficiencies were obtained in the presence of iron using appropriate conditions of applied potential and adsorption-polarization time. Consecutive loading and regeneration cycles of GAC were performed in the reactor without great loss of the adsorption properties, only reducing the regeneration efficiency by 1% per cycle during 10 cycles of treatment. Considering that, in the proposed resin-containing process, the use of Fe salts is avoided and that GAC cathodic polarization results in efficient cleaning and regeneration of the adsorbent material, this novel electro-Fenton approach could constitute an excellent alternative for regenerating activated carbon when compared to conventional methods.

On the ability to electrogenerate hydrogen peroxide and to regenerate ferrous ions of three selected carbon-based cathodes for electro-Fenton processes

“…The development of an electrochemical process capable of producing the Fenton reagent at selected cathodes has overcome the main drawbacks represented by the need of notable amounts of reagents and the overproduction of iron-containing sludge. Due to the results obtained, this technology has experienced a fast development and its applications over the years have ranged from treatment of dyes [4][5][6], pesticides [7,8] herbicides [9], explosives [10], surfactants [11], drugs [12,13], real effluents [14][15][16] and spent adsorbent regeneration [17].…”

A study on heterogeneous Fenton regeneration of powdered activated carbon impregnated with iron oxide nanoparticles

“…A common feature of all AOP studied so far for spent AC regeneration is the external addition of H2O2 as a source of • OH (Bach and Semiat, 2011;Anfruns et al, 2013). Other techniques involve the combination of H2O2 with other radical promoters, such as O3, UV and iron salts (Fenton reaction) (Horng and Tseng, 2008;Banũelos et al, 2013). However, their commercial use in full-scale treatment plants is limited due to specific drawbacks, including high energy consumption, separation problems of applied suspended catalysts and difficulties of scaling-up (Zanella et al, 2014;Salvador et al, 2015).…”

Prussian blue/TiO2 nanocomposites as a heterogeneous photo-Fenton catalyst for degradation of organic pollutants in water

“…[11][12][13] This paper focuses on the development of a novel heterogeneous photoFenton reaction system consisting of nanocomposites in combination with H 2 O 2 and UV. The scheme given in Fig.…”