Ascorbic acid enhanced activation of oxygen by ferrous iron: A case of aerobic degradation of rhodamine B

Abstract

Molecular oxygen activation by ferrous ions (Fe(II)) in aqueous solution could generate reactive oxygen species (ROS) with high oxidation potential via reaction between Fe(II) and oxygen molecules (Fe(II)/air), however, ROS yielded in the Fe(II)/air process is insufficient for removal of organic pollutants due to the irreversible ferric ions (Fe(III)) accumulation. In this study, we demonstrate that ascorbic acid (AA) could enhance ROS generation via oxygen activation by ferrous irons (AA/Fe(II)/air) and thus improve the degradation of rhodamine (RhB) significantly. It was found that the first-order aerobic degradation rate of RhB in the AA/Fe(II)/air process in the presence of ascorbic acid is more than 4 times that of the Fe(II)/Air system without adding ascorbic acid. The presence of ascorbic acid could relieve the accumulation of Fe(III) by reductive accelerating the Fe(III)/Fe(II) cycles, as well as lower the redox potential of Fe(III)/Fe(II) through chelating effect, leading to enhanced ROS generation for promoting RhB degradation. This study not only sheds light on the effect of ascorbic acid on aerobic Fe(II) oxidation, but also provides a green method for effective remediation of organic pollutants.

Factors modifying the structural configuration of oxyanions and organic acids adsorbed on iron (hydr)oxides in soils. A review

“…A recent study by Huang et al (2017) confirmed the importance of the structural configuration of ascorbate on the hematite surface, and the monodentate mononuclear complex on the (012) surface led to a higher reductive dissolution rate than that of the bidentate monodentate complex on the (001) surface. The specific mechanism of ascorbate in the Fe 2+ /Fe 3+ cycle was suggested, and the reduced Fe 2+ caused molecular oxygen activation (Hou et al 2016). As a result, reactive oxygen species were generated, possibly causing the transformation of iron (hydr)oxides.…”

Synergistic Effect of Dielectric Barrier Discharge Plasma and TiO2-Pillared Montmorillonite on the Degradation of Rhodamine B in an Aqueous Solution

“…Purification of natural water resources from organic dyes due to their resistance to decomposition processes [1] is a problem of topical interest [2][3][4][5]. Conventional treatment technologies such as biological, physical and chemical methods [6][7][8][9][10] are neither cheap nor provide the required efficiency. Recently, special attention has been paid to advanced oxidative process (AOP) technologies, the use of which allows for the decomposition of pollutants into less toxic products with the processes of destruction occurring at high rates, which is a significant advantage [11][12][13].…”

Oxidative Treatment of Rhodamine B Solution on CoOx/sepiolite Catalysts

“…For example, a large amount of sludge disposal was created during the chemical and physical treatments [7,8-10-12] . Especially, adsorption, filtration processes did not destroy organic dyes which only incorporated them into the sludge waste [8,11,12] . On the contrary, advanced oxidation processes for the destruction of organic compounds have aroused much attractive in recent years [5,[12][13][14][15][16] .…”