Monitoring of Amoxicillin and Cephalexin Antibiotics in Municipal WWTPs during Covid-19 Outbreak- A Case Study in Isfahan, Iran

Abstract Antibiotics are non-biodegradable drugs that used to inhibit the expansion and growth of microorganisms. The presence of antibiotics and their residues in the environments has resulted in an increased universal concern due to their contrary impacts on human healthiness and also the environment. Specially with the prevalence of Covid-19, the consumption of antibiotics to treat or prevent secondary infections have increased. Therefore, the presence of most prescribed antibiotics from ß-lactam class including amoxicillin and cephalexin were studied at two municipal WWTPs in Isfahan. Analytical method was extracted and then detected via HPLC/UV. Samples were collected from 2 wastewater treatment plants (WWTPs) on 13 sampling periods over 2 months on February and March 2020 during the outbreak of Covid-19. In WWTP A, the average concentration of amoxicillin in influent, effluent, and its removal efficiency was equal to 509.64 ± 161.97µg/l, 354.37 ± 201.41µg/l, 33.69 ± 30.22%, and the average concentration of cephalexin in influent, effluent, and its removal efficiency was 189.42 ± 176.06µg/l, 44.35 ± 43.72µg/l, 64.61 ± 26.52%, respectively. In WWTP B, the average concentration of amoxicillin in influent, effluent, and its removal efficiency was equal to 2134.82 ± 3031.53µg/l, 401.09 ± 205.86µg/l, 54.82 ± 33.29%, and the average concentration of cephalexin in influent, effluent, and its removal efficiency was183.69 ± 123.48µg/l, 40.64 ± 33.02µg/l, 72.89 ± 19.45, respectively. According to statistical points of view, the concentration of antibiotics in both WWTPs had significant differences and no critical correlation between removal efficiency of antibiotics with other principle wastewater parameters was observed.