Assessing the Efficacy of A Mo2C/Peroxydisulfate System for Tertiary Wastewater Treatment: A Study of Losartan Degradation, E. coli Inactivation, and Synergistic Effects

This work examines the use of pristine Mo2C as an intriguing sodium persulfate (SPS) activator for the degradation of the drug losartan (LOS). Using 500 mg/L Mo2C and 250 mg/L SPS, 500 mu g/L LOS was degraded in less than 45 min. LOS decomposition was enhanced in acidic pH, while the apparent kinetic constant decreased with higher LOS concentrations. According to experiments conducted in the presence of scavengers of reactive species, sulfate radicals, hydroxyl radicals, and singlet oxygen participated in LOS oxidation, with the latter being the predominant reactive species. The presence of competitors such as bicarbonate and organic matter reduced the observed efficiency in actual matrices, while, interestingly, the addition of chloride accelerated the degradation rate. The catalyst showed remarkable stability, with complete LOS removal being retained after five sequential experiments. The system was examined for simultaneous LOS decomposition and elimination of Escherichia coli. The presence of E. coli retarded LOS destruction, resulting in only 30% removal after 3 h, while the system was capable of reducing E. coli concentration by 1.23 log. However, in the presence of simulated solar irradiation, E. coli was reduced by almost 4 log and LOS was completely degraded in 45 min, revealing a significant synergistic effect of the solar/Mo2C/SPS system.

Automated summary

This study examines the use of pristine Mo2C as a sodium persulfate (SPS) activator for the degradation of the drug losartan (LOS). The results show that acidic pH enhances LOS decomposition, and the apparent kinetic constant decreases with higher LOS concentrations. Sulfate radicals, hydroxyl radicals, and singlet oxygen are identified as the reactive species in LOS oxidation, with singlet oxygen being the predominant species. The addition of chloride accelerates the degradation rate, while bicarbonate and organic matter reduce the efficiency. The study also investigates the application of the Mo2C/SPS system for simultaneous LOS decomposition and elimination of Escherichia coli, with significant synergistic effects observed when simulated solar irradiation is present.