Heterogeneous Fenton process coupled with microfiltration for the treatment of water with higher arsenic content

Pramod, L.; Gandhimathi, R.; Lavanya, Addagada; Ramesh, S.; Nidheesh, P.V.

doi:10.1080/00986445.2019.1674814

Cited by 13 publications

(2 citation statements)

References 36 publications

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“…•− because of the lower one-electron reduction potential [44,53]. Because of reactions (18) and (19), one might expect that carbonate and bicarbonate inhibit the degradation of pollutants in the presence of ZVI/PS. This is often observed, but in several circumstances the scenario is more complex because the effects of carbonate and bicarbonate on degradation also depend on their concentration, the pH, and the nature of target pollutant(s).…”

Section: Effect Of Inorganic Anions 321 Chloridementioning

confidence: 99%

“…Other alternatives to increase the efficiency of the Fenton reaction are to use supports for iron oxides or include Fe oxides into composite porous materials (clay, zeolites, activated carbon, polymers and multiwalled carbon nanotubes, Nafion films, pumice particles, ashes, and aluminates) [ 4 , 5 , 14 , 15 , 16 , 17 ]. The overall performance of the Fenton reaction may even be increased in such conditions because the support adsorbs the pollutant molecule and, in some cases, can also facilitate different pathways that generate radicals for pollutants degradation [ 5 , 18 , 19 , 20 ].…”

Section: Introductionmentioning

confidence: 99%

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A Review on the Degradation of Pollutants by Fenton-Like Systems Based on Zero-Valent Iron and Persulfate: Effects of Reduction Potentials, pH, and Anions Occurring in Waste Waters

et al. 2021

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Among the advanced oxidation processes (AOPs), the Fenton reaction has attracted much attention in recent years for the treatment of water and wastewater. This review provides insight into a particular variant of the process, where soluble Fe(II) salts are replaced by zero-valent iron (ZVI), and hydrogen peroxide (H2O2) is replaced by persulfate (S2O82−). Heterogeneous Fenton with ZVI has the advantage of minimizing a major problem found with homogeneous Fenton. Indeed, the precipitation of Fe(III) at pH > 4 interferes with the recycling of Fe species and inhibits oxidation in homogeneous Fenton; in contrast, suspended ZVI as iron source is less sensitive to the increase of pH. Moreover, persulfate favors the production of sulfate radicals (SO4•−) that are more selective towards pollutant degradation, compared to the hydroxyl radicals (•OH) produced in classic, H2O2-based Fenton. Higher selectivity means that degradation of SO4•−-reactive contaminants is less affected by interfering agents typically found in wastewater; however, the ability of SO4•− to oxidize H2O/OH− to •OH makes it difficult to obtain conditions where SO4•− is the only reactive species. Research results have shown that ZVI-Fenton with persulfate works best at acidic pH, but it is often possible to get reasonable degradation at pH values that are not too far from neutrality. Moreover, inorganic ions that are very common in water and wastewater (Cl−, HCO3−, CO32−, NO3−, NO2−) can sometimes inhibit degradation by scavenging SO4•− and/or •OH, but in other cases they even enhance the process. Therefore, ZVI-Fenton with persulfate might perform unexpectedly well in some saline waters, although the possible formation of harmful by-products upon oxidation of the anions cannot be ruled out.

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