Peroxide activation by microbially synthesized sulfidated iron: Comparison against abiotic iron-based materials in terms of treatment efficiency and oxidative degradation pathway

Photosensitized Transformation of Hydrogen Peroxide in Dissolved Organic Matter Solutions under Simulated Solar Irradiation

“…Hydrogen peroxide (H 2 O 2 ) is an important reactive oxidant in aquatic redox processes and holds a unique position in aquatic environments, affecting the speciation and biogeochemistry of transition metals , as well as contributing to the degradation of natural and anthropogenic organic compounds. − H 2 O 2 is ubiquitously detected in various water environments, including freshwater, rainwater, estuarine, and marine environments, at concentrations varying from 0.01 to 30 μM. − Generally, the formation of H 2 O 2 in sunlit surface water is primarily from the dismutation of superoxide radicals (HO 2 · /O 2 · – ), which are produced by one-electron reduction of dioxygen. , Meanwhile, previous studies reported that the addition of external phenols would enhance the photoproduction of H 2 O 2 because the presence of external phenols as electron donors essentially promoted the photoproduction rate of O 2 · – . It is commonly accepted that the fate of H 2 O 2 is to generate a hydroxyl radical ( · OH), which is also critical in aquatic environments as a nonselective oxidant. − The formation of · OH from H 2 O 2 induced by transition metal catalysis (Fenton and Fenton-like reactions) or UV-irradiation is well known and has been extensively investigated. − However, the investigation of metal-independent and UV-light free production of · OH from H 2 O 2 to date is insufficient. Consequently, the detailed transformation mechanism of H 2 O 2 in aquatic environments is not fully understood.…”

Revealing the Generation of High-Valent Cobalt Species and Chlorine Dioxide in the Co3O4-Activated Chlorite Process: Insight into the Proton Enhancement Effect

“…High-valent metal species have attracted extensive attention in transition metal-activated peroxide/oxoacid processes using peroxymonosulfate (PMS), − hydrogen peroxide (H 2 O 2 ), , hypochlorous acid (HClO), and peracetic acid (PAA). − Compared with the oxygen/sulfur-containing radicals in traditional advanced oxidation processes (AOPs), high-valent metal species enable the selective oxidation of contaminants through diverse pathways, including hydrogen-/oxygen-atom transfer, electron transfer, and electrophilic addition. , To date, the significant contribution of high-valent metal species to organic contaminant oxidation has been confirmed in transition metal-activated peroxide/oxoacid processes. ,− …”