Comparative electrochemical degradation of salicylic and aminosalicylic acids: Influence of functional groups on decay kinetics and mineralization

Rapid mineralization rate of acetylsalicylic acid in a tubular photochemical reactor: The role of the optimized excess of H2O2

“…On this concern, Fig. 1 gathers a few examples of AOPs, at their best conditions, employed to degrade and mineralize ASA surveyed on the literature up to date [13][14][15][16][17]. This figure highlights that the extension of both degradation and mineralization of ASA depend on several variables such as nature of AOP, initial concentration of ASA and the concentration of others inputs.…”

“…This figure highlights that the extension of both degradation and mineralization of ASA depend on several variables such as nature of AOP, initial concentration of ASA and the concentration of others inputs. More than 95% of mineralization is obtained for a few processes such as photo-catalysis [13] and photoeletro-Fento [14], but with a very long treatment time, over five hours. By optimizing the irradiation wavelength [15], a possible reduction on the treatment time is a viable alternative, as one hour of Solar-photo-Fenton stabilizes the degradation at 87%.…”

Electro-bioremediation of a mixture of structurally different contaminants of emerging concern: Uncovering electrokinetic contribution

“…It is known that the electro-chemical oxidation of organic contaminants comprises two mechanisms: (i) direct oxidation occurring at the anode surface by the chemisorbed •OH (E 0 = 2.8V), when an active electrode is used (similar to the one used here), and (ii) indirect oxidation through the generation of a mediator in the bulk solution (like active chlorine). The differences observed in the decay levels of the recalcitrant CECs might be explained by their structural differences [47], and/or distinct physicochemical properties (ESI 1). For example, in the 4-aminosalicylic acid the presence of a -NH 2 group in metaposition to -OH and para-position to -COOH slightly activated the electrophilic attack of •OH, compared to the salicylic acid without any -NH 2 group, in water samples using a boron doped diamond/air-diffusion cell [47].…”

“…The differences observed in the decay levels of the recalcitrant CECs might be explained by their structural differences [47], and/or distinct physicochemical properties (ESI 1). For example, in the 4-aminosalicylic acid the presence of a -NH 2 group in metaposition to -OH and para-position to -COOH slightly activated the electrophilic attack of •OH, compared to the salicylic acid without any -NH 2 group, in water samples using a boron doped diamond/air-diffusion cell [47]. In contrast, the electrophilic reaction of •OH was strongly deactivated when the -NH 2 group was placed in para-position in respect to -OH and meta-position in relation to -COOH in the 5-aminosalicylic acid molecule [47].…”