Effect of the Current Intensity in the Electrochemical Oxidation of Aqueous Phenol Wastes at an Activated Carbon and Steel Anode

Abstract

The effect of the current intensity in the electrochemical oxidation of aqueous phenol wastes at an activated carbon and steel anode was investigated. Results confirm that three reaction pathways were involved in the electrochemical process: direct degradation or electrochemical cold combustion, chemical oxidation, and polymerization. The chemical oxidation pathway was the most important for the range of current intensities studied. To interpret the experimental behavior, a simple mathematical model was proposed and tested, obtaining good agreements between experimental and simulated data.

A comparison of electrochemical degradation of phenol on boron doped diamond and lead dioxide anodes

“…Indeed, a sample of the electrolysed solution tested by HPLC showed a peak at 450 nm (characteristic of a coloured compound) at a retention time similar to that for HQ. The coloured intermediate is probably a phenol oligomer [6,11,24] having the same retention time of HQ; however, it was not possible to either identify it, or quantify it. Consequently, the concentrations of HQ presented in Fig.…”

“…Differences observed between curves a and d (for PbO 2 ) on the one hand, and b and c (for BDD) on the other hand, result probably from oxygen evolution, which increases with current density and improves mass transfer [24]. Figure 7 presents the variation of the TOC removal as a function of time for three current densities on BDD and PbO 2 anodes.…”

Degradation of Toxic Organic Contaminants by Graphene Cathode in an Electro‐Fenton System

“…Thus, there are two degradation pathways that may occur in the EF system. One is the anodic electrochemical oxidation process on the Pt anode [13] and the other is the cathodic ·OH oxidation process in which the CuO-graphene cathode catalyzes the two-electron reduction of O 2 to H 2 O 2 under certain potential, and the H 2 O 2 may be converted to ·OH [14]. The specific capacitance is the ratio of capacity and mass of the electrode, which could represent the reversibility and stability of the as-prepared electrode while charging/discharging.…”

Electrochemical Dechlorination of 2-Chlorophenol on Pd/Ti, Ni/Ti and Pd-Ni Alloy/Ti Electrodes

“…4,5 Another method explored for chlorinated organic compound degradation is electrochemical oxidation; however, the production of a polymer film at the electrode surface causes electrode deactivation. 6 In electrochemical oxidation, organic compounds can be oxidized up to carbon dioxide using a Boron Doped Diamond (BDD) electrode, but the electrode preparation is quite costly. 7 In order to avoid the problems caused by oxidation, electrochemical reductive dechlorination has been suggested as an alternative and promising method, because of several advantages, such as: rapid reaction, low-cost equipment, operating at room temperature and atmospheric pressure, and no production of secondary pollutants more toxic than the original.…”

“…10 In a ECH mechanism, the chemisorbed hydrogen atoms (H ads ) generated on the electrode surface by water electrolysis provide the driving force for chemical reduction causing the C-Cl bond cleavage from 2-CP. ECH involves several steps as described in reactions 1 through 6 11,12 : [5] (H ) ads M + (H ) ads M → H 2 + M Tafel step [6] where M represents the electrocatalytic metal or alloy. The key steps of the ECH process are proton reduction (H + ) and hydrogen adsorption (H ads ) (reaction 1).…”