Using Hybrid Coupling Processes for the Treatment of Waste Containing Halosulfuron‐Methyl Herbicide

Abstract

This work aims to demonstrate the importance of coupling different degradation processes for the removal of the commercial herbicide Halosulfuron‐Methyl (HSM). Using anode oxidation (AO) on boron‐doped diamond as the base process; cathodically produced H2O2 (AO/H2O2), UV light (AO/UV), AO/UV/H2O2, electro‐Fenton and photoelectron Fenton (PEF) are employed as hybrid processes for HSM degradation. All hybrid processes employed in the study exhibited synergism with AO, and the UV‐irradiated processes presented an outstanding performance. In particular, the AO/UV/H2O2 process exhibited 90 % mineralization after 3 h of treatment, whereas the PEF process exhibited a complete removal of HSM after 45 min of treatment. In addition to the noticeable advantages of hybridization, the application of higher current densities is found to accelerate the degradation/mineralization of the compound of interest, although the process tends to be more energy demanding. In such a case, the use of a hybrid treatment process coupled to UV‐irradiation allows one to mitigate this constraint while contributing toward obtaining higher mineralization degrees. The degradation/mineralization of more concentrated solutions is, however, found to occur more sluggishly under the treatment mechanisms investigated here, requiring longer times, although the process is noticeably more efficient in photo‐irradiated processes, which recorded current efficiencies of above 100 %.

Phosphorus‐Doped Porous Carbon Coated Graphite Felt as An Efficient and Reusable Cathode for Electro‐Fenton Degradation of Parabens

“…Nevertheless, pyrocatechol (6) and resorcinol (7) would be converted to pyrogallol (15) after being attacked by •OH. There was a mutual conversion between maleic acid (9) and fumaric acid (10). And (Z)-4-oxobut-2-enoic acid (11) and succinic acid (12) were derived from (2Z,4Z)-hexa-2,4-dienedioic acid (8), maleic acid (9) and fumaric acid (10).…”

“…There was a mutual conversion between maleic acid (9) and fumaric acid (10). And (Z)-4-oxobut-2-enoic acid (11) and succinic acid (12) were derived from (2Z,4Z)-hexa-2,4-dienedioic acid (8), maleic acid (9) and fumaric acid (10). The (Z)-4-oxobut-2-enoic acid (11) was oxidized to glyoxylic acid (25).…”

“…In comparison to physical adsorption and biodegradation, advanced oxidation processes (AOPs) are swift, efficient, thorough, and non-polluting techniques for removing organic pollutants in water such as pesticides, dyes, and pharmaceuticals. [9][10][11][12][13][14][15] AOPs might convert refractory organic toxins into low molecular substances or even carbon dioxide and water, attributed to the high oxidation potential of hydroxyl radical (•OH) (E = 2.8 V), which is higher than that of hydrogen peroxide (H 2 O 2 ) and chlorine. [16,17] O…”