Use of Pt and Boron‐Doped Diamond Anodes in the Electrochemical Advanced Oxidation of Ponceau SS Diazo Dye in Acidic Sulfate Medium

Abstract

The electrochemical degradation of 2.5 L of Ponceau SS diazo dye solution in acidic sulfate medium has been studied in a prepilot flow plant with a boron-doped diamond (BDD)/airdiffusion or Pt/air-diffusion cell connected to an annular photoreactor. The decolorization and mineralization was enhanced in the order: electrochemical oxidation with electrogenerated H 2 O 2 < electro-Fenton < photoelectro-Fenton. The two former methods performed better with the BDD anode, whereas the latter yielded similar results for both anodes. From this, the use of less expensive active anodes such as Ti j Pt instead of nonactive BDD for photo-assisted Fenton-based electrochemical processes is recommended. In all methods, increasing current density led to a greater degradation rate, but with lower mineralization current efficiency and higher energy consumption. Five primary aromatic products and four final carboxylic acids were detected, along with recalcitrant products poorly removed by hydroxyl radicals and UVA radiation.

Electrochemical Technologies for Detecting and Degrading Benzoquinone Using Diamond Films

“…During the EO of BQ, the study of current density ( j ) was performed since it is an important electrochemical parameter that controls the quantity of . OH radicals generated . In this way, the tests were accomplished in a galvanostatic mode between 8.3 and 66.7 mA cm −2 .…”

“…Side parasitic reactions, such as the ones that consume . OH radicals, may be responsible for this fact, since they can be concomitantly enhanced . The oxygen evolution reaction (Eq.…”

Landfill Leachate Treatment by Combining Coagulation and Advanced Electrochemical Oxidation Techniques

“…[11] The main characteristic of this class of effluent (which differentiates it from the old ones, i. e., BOD/ COD < 0.1 [12] ) is its high organic load resulting from organic compounds with low molar mass, most of them highly biodegradable. [20][21][22][23] Coagulation-flocculation is a widely accepted pretreatment method employed to remove materials that are in colloidal suspension (organic and/or inorganic) or that remain dispersed in the solution and cannot be removed by conventional physical processes. [12] This characteristic hinders the application of biological processes, since numerous organic compounds in young leachate cannot be degraded by the microorganisms in these treatments.…”

“…[28] The use of AOPs has been considered the best solution to degrade refractory compounds in wastewater. [22,25,26,34,[40][41][42][43][44][45] Given the extraordinary properties of BDD electrodes, such as inert surface, low adsorption, high corrosion resistance in acidic media and high OER, [40] they are considered the most efficient inactive electrodes for the mineralization of several organic compounds. [32] Electrochemical methods (a typical AOP), in particular, have been extensively investigated for the treatment of organic and inorganic pollutants that are found in several types of effluents.…”

Catalytic Effect of Hydrogen Peroxide in the Electrochemical Treatment of Phenolic Pollutants using a BDD Anode

“…Attractive alternative technologies as Advanced Oxidation Processes (AOP‘s) to destroy toxic organic contaminants have emerged as promising methods for wastewater treatment, because they have been reported to be relatively simple, easy to control, and result in a high oxidation degree and compatibility with the environment ,,,. Among the latter, electrochemical oxidation is an effective method that entails the generation of highly oxidant species by electrolysis.…”