Toward the Development of Efficient Electro-Fenton Reactors for Soil Washing Wastes through Microfluidic Cells

Abstract

This work focuses on the coupling of three different approaches into the same reactor at 11 the same time: microfluidic cells, anodic oxidation with diamond anodes and an electro-12 Fenton process. In order to supply oxygen a jet aerator was used and a CB/PTFE 13 Duocel ® Al foam cathode was installed to promote the formation of hydrogen peroxide. 14 This novel concept is applied for the direct treatment (without the addition of salts or 15 other reagents) of soil washing wastes obtained in the remediation of soil spiked with 16 clopyralid. Results obtained pointed out that this approach can increase the efficiency of 17 the process by folds as compared to traditional treatment technologies. The chemical 18 analysis of the intermediates showed different reaction mechanisms: anodic oxidation, 19 electro-Fenton and a negligible contribution of coagulation. The coupled system studied 20 in this work present several advantages such as high treatment efficiency and short 21 treatment time which indicates that the development of electrochemical reactors for 22 diluted liquid wastes is progressing in an adequate direction.

Towards a more realistic heterogeneous electro-Fenton

“…This same behavior was observed in the EF tests at lab scale. Also, one of the previous studies using the MF-FT coupled to the jet aerator available in the literature concluded, after testing current densities from 10 to 50 mA cm −2 (corresponding with 0.33 to 1.65 A, calculated with the wet cross section of the electrodes specified in the article), that increasing the current density reduced the efficiency of the EF treatment [13].…”

“…To the best of the authors' knowledge, there are only two previous studies that report the use of a MF-FT reactor combined with a jet aerator for an EF treatment at bench scale [10,13]. However, in both cases the EF assays were performed with homogeneous catalysts.…”

Testing the role of electrode materials on the electro-Fenton and photoelectro-Fenton degradation of clopyralid

“…Clopyralid is an organochlorinated herbicide from the class of the pyridine compounds (i.e., pesticides derived from picolinic acid) that have widespread use for control broadleaf weeds and woody plants [2]. Given its recalcitrance and toxicity, many research efforts have been devoted to study effective technologies capable of removing this type of contaminant from aqueous solution [3][4][5][6][7].…”

Environmental Applications of Boron‐Doped Diamond Electrodes: 2. Soil Remediation and Sensing Applications

“…The degradation and mineralization rate of the AO process using BDD anode can also be increased by combination with other processes such as electro-Fenton, [40][41][42] sonolysis [43][44][45][46] or photolysis. [43,[45][46][47][48][49] Such approach allows for providing an additional source of * OH and other oxidant species.…”