Decontamination of real textile industrial effluent by strong oxidant species electrogenerated on diamond electrode: Viability and disadvantages of this electrochemical technology

According to Solano et al. [32], electrolysis under BDD anode in aqueous media containing sulfate ions generates peroxodisulfate, a powerful oxidizing agent that can oxidize organic matter near the anode surface and in the bulk solution.

“According to these authors, electrolysis under BDD anode, in aqueous media containing sulfate ions, generates peroxodisulfate (Equation ( 2)), a powerful oxidizing agent that can oxidize organic matter near to the anode surface and in the bulk solution.”

The faster dye degradation compared to overall organic load removal can be explained because dye fragmentation requires only a primary oxidation stage, while COD and DOC reductions involve more complex multistage oxidative reactions, since dye oxidation usually results in different byproducts [31,32].

“This can be explained considering that, for the dye fragmentation (chromophore group breaking), only a primary oxidation stage is required, but, for COD and DOC reductions, more complex multistage oxidative reactions are involved, since the dye oxidation usually results in the formation of different byproducts [31,32].”

Similar results were observed by Solano et al. [32] when studying electrochemical treatment of a TDW sample using a BDD anode and in presence of sulfate ions.

“Similar results were observed by Solano et al. [32] when studying the electrochemical treatment of a TDW sample, using a BDD anode, and in the presence of sulfate ions.”

According to Solano et al. [32], the degradation process in the presence of sulfate occurs with significant formation of intermediates, but without formation of organochlorinated or other carcinogenic compounds, as in the case when oxidation is mediated by chloride species.

“It should be noted that, according to Solano et al. [32], the degradation process in the presence of sulfate occurs with significant formation of intermediates, but without formation of organochlorinated or other carcinogenic compounds, as in the case when oxidation is mediated by chloride species.”

The enhancement in EO performance was caused by production of peroxodisulfate that together with ROS oxidize organic matter from TDW.

“Even for small sulfate concentrations, as in the case of the TDW under study (672 mg L -1 ), we found an enhancement in the EO performance, caused, according to the authors, by the production of peroxodisulfate that, together with the reactive oxygen species (ROS) such as hydroxyl radicals, oxidize the organic matter from TDW.”