Production of Reactive Oxygen Species by the Reaction of Periodate and Hydroxylamine for Rapid Removal of Organic Pollutants and Waterborne Bacteria

Abstract

Periodate (PI, IO 4 − ) can be activated by hydroxylamine (HA), resulting in the rapid removal of organic pollutants within seconds. While the previous studies on PI-based advanced oxidation processes (AOPs) have proposed iodate radical ( • IO 3 ) as the major reactive species, no evidence of • IO 3 production was found in the present PI/HA system. Reactive oxygen species (ROS) including • OH, HO 2• , and 1 O 2 are proposed to be the main oxidants of the PI/HA system, which is supported by various tests employing the scavengers, chemical probes, and spin-trapping electron paramagnetic resonance (EPR) technique. To minimize the risk of toxic iodinated byproduct formation caused by reactive iodine species such as HOI and I 2 , the molar ratio of HA/PI was optimized at 0.6 to achieve the stoichiometric conversion of IO 4 − to iodate (IO 3 − ), a preferred nontoxic sink of iodine species. The PI/HA system also efficiently inactivated both Gram-positive and -negative bacteria with producing 1 O 2 as the dominant disinfectant. The mechanism of ROS production was also investigated and is discussed in detail. This work offers a simple and highly efficient option for PI activation and ROS production which might find useful applications where urgent and rapid removal of toxic pollutants is needed.

Defects on CoS2−x: Tuning Redox Reactions for Sustainable Degradation of Organic Pollutants

“…OH or . O 2 − , and 1 O 2 , respectively [12] . As shown in Figures 2 b–d, in the CoS 2 ‐1.5 h system, strong 1 O 2 signal and extremely weak .…”

“…Besides, EPR technology was employed to further investigate the existence of three ROSs, coupled with 5, 5-dimethyl-1-pyrroline (DMPO) and TEMP as spin-trapping reagents for the capture of COH or CO 2 À , and 1 O 2 , respectively. [12] As shown in Figures 2 b-d, in the CoS 2 -1.5 h system, strong 1 O 2 signal and extremely weak CO 2 À signal were detected, but no COH signal was detected, which proved that 1 O 2 was the main ROS in the CoS 2 -1.5 h system. After Fe 2+ was added, the 1 O 2 signal became even stronger, and the concentration of CO 2 À also increased significantly, but the COH signal was still not detected, which meant that the addition of Fe 2+ promoted the production of 1 O 2 and O 2 À , and there may (Figures 2 b,d), which demonstrated that 1 O 2 was converted from C O 2 À , and the addition of Fe 2+ promoted the generation of CO 2 À directly and 1 O 2 indirectly.…”

Defects on CoS2−x: Tuning Redox Reactions for Sustainable Degradation of Organic Pollutants

“…Besides, EPR technology was employed to further investigate the existence of three ROSs, coupled with 5, 5-dimethyl-1-pyrroline (DMPO) and TEMP as spin-trapping reagents for the capture of COH or CO 2 À , and 1 O 2 , respectively. [12] As shown in Figures 2 b-d, in the CoS 2 -1.5 h system, strong 1 O 2 signal and extremely weak CO 2 À signal were detected, but no COH signal was detected, which proved that 1 O 2 was the main ROS in the CoS 2 -1.5 h system. After Fe 2+ was added, the 1 O 2 signal became even stronger, and the concentration of CO 2 À also increased significantly, but the COH signal was still not detected, which meant that the addition of Fe 2+ promoted the production of 1 O 2 and O 2 À , and there may Angewandte be complex radical conversion processes during the reaction processes.…”

COVID-19 drugs in aquatic systems: a review

“…The results demonstrated that electrochemical oxidation supported by solar power could be used for treating wastewater on-site in regions that have poor wastewater and energy infrastructure. Additionally, reactive species can be produced by chemicals such as ozone (Leresche et al 2019 ), periodate, and hydroxylamine (Sun et al 2020 ). However, using periodate and hydroxylamine poses serious ecological challenges since it requires potentially toxic reagents, elicits water acidification, rarely mineralizes the pollutants, and often produces potentially toxic transformation products (Sun et al 2020 ).…”