Orientated construction of visible-light-assisted peroxymonosulfate activation system for antibiotic removal: Significant enhancing effect of Cl

Antibiotic contaminants can migrate over long distances in the water, thus possibly causing severe detriment to the environment and even potential harm to human health. Heterogeneous activation of peroxymonosulfate (PMS) assisted by visible light is an emerging and promising technology for the purification of such wastewater. This study designed an ultra-efficient and stable PMS activator (FeCN) to restore the typical antibiotic-polluted water under harsh conditions. About 90.94% of sulfamethoxazole (SMX) was degraded in 35 min in the con-structed FeCN+PMS/vis system, and the reaction rate constant was nearly 50-fold higher than direct photo -catalysis. Electron spin resonance, quenching experiments, LC/MS technique, eco-toxicity assessment, and density functional theory validated that the SMX removal was dominated by the attack of h+, center dot O2- and 1O2 on the active atoms of SMX molecules with high Fukui index, presenting as a simultaneous degradation and detoxifi-cation process. Such a visible-light-assisted PMS activation system also had good resistance to the environmental water bodies and a broad spectrum in the degradation of various pollutants. In particular, Cl- (50 mM) could significantly accelerate the removal of SMX with a 32.6-fold increase in catalytic activity, and the mineralization efficiency could reach 56.6% under identical conditions. Moreover, this Cl- containing system excluded the degradation products of disinfection by-products, and such a system was also versatile for different contaminants. This work demonstrates the feasibility of the FeCN+PMS/vis system for the remediation of antibiotic-contaminated wastewater in the presence and absence of Cl-, and also highlights their great potential in WWTPs.

Automated summary

Antibiotic contaminants in water can cause environmental damage and potential harm to human health. This study developed an efficient peroxymonosulfate (PMS) activation system (FeCN) to purify antibiotic-polluted water. The system showed high degradation efficiency of sulfamethoxazole (SMX) through the attack of active atoms by h+, center dot O2-, and 1O2, resulting in simultaneous degradation and detoxification. The FeCN+PMS/vis system also demonstrated resistance to environmental water bodies and wide applicability in degrading various pollutants, with chlorine significantly enhancing SMX removal and mineralization efficiency. This research showcases the potential of FeCN+PMS/vis system in treating antibiotic-contaminated wastewater.