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

Abstract

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 μg/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.

Persulfate Activation Using Biochar from Pomegranate Peel for the Degradation of Antihypertensive Losartan in Water: The Effects of Pyrolysis Temperature, Operational Parameters, and a Continuous Flow Reactor

“…Sodium nitrate (NaNO 3 ≥ 99.0%, CAS: 7631-99-4), sodium persulfate (SPS ≥ 99.5%), losartan potassium (LOS), humic acid (HA, technical grade), tert-butyl alcohol (t-BuOH), sodium azide (NaN 3 ), sodium bicarbonate (NaHCO 3 ), ortho-phosphoric acid (H 3 PO 4 ≥ 85%), and sulfuric acid (H 2 SO 4 ) were obtained from Sigma-Aldrich (St. Louis, MO, USA). Further details for the above reagents and LOS can be found in the work of Ioannidi et al [65]. Sodium hydroxide (NaOH, CAS: 1310-73-2) and sodium chloride (NaCl ≥ 99.5%, CAS: 16610-31000) were purchased from Penta (Radiová, Prague, Czechia).…”

“…Moreover, the adsorption of SPS on the biochar can influence the total surface charge and, thus, the adsorption of LOS. Therefore, the high oxidation yield in acidic conditions is likely due to the increased adsorption of SPS on the surface of BC850, resulting in the production of more reactive species such as sulfate and hydroxyl radicals [65,66].…”