Comparison between Fenton oxidation process and electrochemical oxidation for PAH removal from an amphoteric surfactant solution

Abstract

The decomposition of polycyclic aromatic hydrocarbons in a creosote oily solution and in synthetic solutions containing naphthalene and pyrene was investigated in the presence of an amphoteric surfactant using electrooxidation by comparison to Fenton oxidation process. Electrolysis was carried out using a parallelepipedic electrolytic 1.5-L cell containing five anodes (expanded titanium covered with ruthenium) and five cathodes (stainless steel) alternated in the electrode pack, whereas Fenton oxidation process was carried out in 500 mL Erlenmeyer glass-flasks in which H 2 O 2 and Fe 2? were added. Using electrochemical oxidation, the sum concentration of 16 polycyclic aromatic hydrocarbons investigated could be optimally diminished by up to 80-82% by applying a current density of 9.23 mA cm -2 and a pH of 4.0 or 7.0 for 90-min reaction period. By comparison, the best yield (46%) of Fenton oxidation process for polycyclic aromatic hydrocarbons degradation was recorded by using H 2 O 2 /Fe 2? molar ratio of 11.0 and a pH of 4.0.

Experimental design methodology applied to electrochemical oxidation of the herbicide atrazine using Ti/IrO2 and Ti/SnO2 circular anode electrodes

“…Likewise, the herbicide atrazine and their intermediates can be transformed via attacks of hydroxyl radical into further intermediates, including ring-opened structures. The above mentioned hypothesis of intermediates and CO 2 formation was based on the results described elsewhere [38]. The same effect was observed, when naphthalene and pyrene synthetic solutions were individually subjected to electrolysis using the same type of anode material (Ti/IrO 2 ) in the presence of chloride ions [38].…”

“…The above mentioned hypothesis of intermediates and CO 2 formation was based on the results described elsewhere [38]. The same effect was observed, when naphthalene and pyrene synthetic solutions were individually subjected to electrolysis using the same type of anode material (Ti/IrO 2 ) in the presence of chloride ions [38]. However, additional experiments should be carried out to rigorously put into evidence the formation of by products during electrooxidation of the herbicide atrazine.…”

Remediation of soils contaminated by hydrophobic organic compounds: How to recover extracting agents from soil washing solutions?

“…This high oxidant demand is the main issue for the treatment of SW solution by AOPs. For example, 49 g L -1 (using sequential addition) and 30 g L -1 of H2O2 was necessary to achieve 95% and 96% COD removal from a SW solution [25,146]. As regards to the EF process, the treatment of a SW solution containing PAH and TW80 as EA, required 0.69 kWh per gram of TOC removed [145].…”

Electrochemical Conversion of Unreactive Pyrene to Highly Redox-Active 1,2-Quinone Derivatives on a Carbon Nanotube-Modified Gold Electrode Surface and Its Selective Hydrogen Peroxide Sensing

“…Pyrene (PYR), one of the carcinogenic polyaromatic hydrocarbons (PAHs), has been considered to be a priority pollutant by the United States Environmental Protection Agency (U.S. EPA). , It is highly unreactive and rigid in structure. Several stringent biological and chemical oxidation methods were reported for the decarcinogenation of PYR (e.g., bacteria and fungi extracellular peroxidase, , the Fenton reagent (Fe 2+ + H 2 O 2 ), photocatalysis, electroenzymatic reaction, ozone reaction, and permanganate treatment). The violent chemical oxidation reactions often resulted in the formation of various products such as CO 2 , monohydroxypyrene, and 1,2-, 1,6-, or 1,8-pyrenedione. , Meanwhile, the electrooxidation of various pyrene derivative self-assembled monolayers (SAMs) on gold surfaces, which have been prepared via 11-mercaptoundecanoic acid and adipoyl chloride linkers to 1,6- or 1,8-pyrenedione derivatives in a strong-acid medium, was also reported. − Note that it is highly intricate to oxidize the rigid π-bonded PAH structure without any enzymes or a derivatization approach.…”