Are iron chelates suitable to perform photo-Fenton at neutral pH for secondary effluent treatment?

Ferroin in dyes degradation by Fenton-like process: a chemical waste recycling perspective

“…It is possible to infer that all studied substances, including ferroin, were considerably degraded under experimental conditions. Degradation of the iron-chelates concomitantly to the target contaminants in photo-Fenton-like processes is related in the literature (Ahile et al 2021) Additionally, there is an inversely proportional increase of absorbance at λ ¼ 322 nm, evidencing the formation of Fe (III). Moreover, it is possible to infer that the stoichiometry of Fe(II) -Fe(III) conversion does not change during the reaction and no secondary processes occur due to the presence of a isosbestic point at λ ¼ 377 nm) (IUPAC 2019) (Figure 4).…”

“…Based on current literature (Gomes Júnior et al 2018;Ahile et al 2020Ahile et al , 2021O'Dowd & Pillai 2020), authors propose two main factors to consider regarding the apparent absence of Fe(III)-sludge: firstly, the proportion of Fe in comparison with the other components (H 2 O 2 , dyes) and the treatment conditions (pH, temperature) were very adequate in order to promote the degradation of target contaminants. The reaction time was not as short as initially desirable, but the absence of sludge mitigates this effect.…”

“…Despite the main Fenton reaction drawbacks are significantly mitigated, the efficiency in the degradation of pollutants is normally lower than the reached with classical Fenton treatments. For this reason, the search for better chelating agents and optimal conditions is matter of concern and a need for wastewater treatment researchers (Neyens & Baeyens 2003;Bokare & Choi 2014;De Luca et al 2014Pliego et al 2015;Wang et al 2016;Ahsan et al 2020;Chen et al 2020;Ahile et al 2021).…”

Advanced Oxidation Processes Based on Sulfate Radicals for Wastewater Treatment: Research Trends

“…In the last decades, the increase in population, industrial production and agricultural practices have caused a rise in the consumption and subsequent pollution of water [1][2][3][4][5][6][7]. The pollutants contained in wastewater (WW) are a group of heterogeneous substances [8].…”

“…On the other hand, it is important to note that the WW conventional treatments cannot fully degrade ECs [6,[24][25][26], since they were not initially designed to eliminate this group of pollutants [14]. Furthermore, for the particular case of biological processes, their operation can be affected by the toxicity of pollutants to be treated, leading to the inhibition of the microorganisms responsible for the treatment [11].…”