Catalyst-Free Periodate Activation by Solar Irradiation for Bacterial Disinfection: Performance and Mechanisms

Abstract

Periodate (PI)-based advanced oxidation process has recently attracted great attention in the water treatment processes. In this study, solar irradiation was used for PI activation to disinfect waterborne bacteria. The PI/solar irradiation system could inactivate Escherichia coli below the limit of detection (LOD, 10 CFU mL–1) with initial concentrations of 1 × 106, 1 × 107, and 1 × 108 CFU mL–1 within 20, 40, and 100 min, respectively. •O2 – and •OH radicals contributed to the bacterial disinfection. These reactive radicals could attack and penetrate the cell membrane, thereby increasing the amount of intracellular reactive oxygen species and destroying the intracellular defense system. The damage of the cell membrane caused the leakage of intracellular K+ and DNA (that could be eventually degraded). Excellent bacterial disinfection performance in PI/solar irradiation systems was achieved in a wide range of solution pH (3–9), with coexisting humic acid (0.1–10 mg L–1) and broad solution ionic strengths (15–600 mM). The PI/solar irradiation system could also efficiently inactivate Gram-positive Bacillus subtilis. Moreover, PI activated by natural sunlight irradiation could inactivate 1 × 107 CFU mL–1 viable E. coli below the LOD in the river and sea waters with a working volume of 1 L in 40 and 50 min, respectively. Clearly, the PI/solar system could be potentially applied to disinfect bacteria in water.

Visible-Light-Driven Zinc Oxide Quantum Dots for the Management of Bacterial Fruit Blotch Disease and the Improvement of Melon Seedlings Growth

“…Excessive ROS-induced cell membrane damage can cause the release of intracellular constituents (such as proteins and DNA) into the reaction suspension. It was reported that the DNA concentration was used as an indicator for the DNA damage of bacterial cells . According to the reported literature, the concentration of DNA in the ZnO QDs-treated cells was measured .…”

Enhanced anaerobic digestion of waste activated sludge with periodate-based pretreatment

“…Homogeneous Fe 2+ contained in WAS participated in the activation process of PI through an electron transfer mechanism [ 11 ], forming •O 2 − (equation (1) ). The precursor •O − was produced by the I–O bond cleavage in PI after activation [ 26 ]. The •OH might be generated through the protonation of •O − , followed by the reaction of IO 4 − and OH − to form •O 2 − .…”

“…It was reported that TBA, p-BQ, and FFA were used as •OH (k •OH = 3.8–7.6 × 10 8 M s −1 ), •O 2 − ( = 9.8 × 10 8 M s −1 ), and 1 O 2 (k 1 O 2 = 1.2 × 10 8 M s −1 ) scavenger [ 25 ], respectively. Besides, phenol has been documented as a scavenger for both iodine radicals (e.g., •IO 3 and •IO 4 ) and •OH [ 26 ]. More information was presented in Supplementary Material.…”

Recent advances in metal-free catalysts for the remediation of antibiotics, antibiotic resistant bacteria (ARB), and antibiotic resistant genes (ARGs)

“…Except PS, PI was also combined with photocatalysis for ARB inactivation. Liu et al 304 demonstrated that E. coli (1 Â 10 8 CFU mL À1 ) was effectively inactivated below the limit of detection (10 CFU mL À1 ) within 100 min by PI/solar-induced AOPs. ROS such as O 2 c À and cOH were responsible for bacterial disinfection, which would attack and penetrate the cell membrane.…”