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 inhibit the expansion and growth of microorganisms. Especially with the prevalence of Covid-19. the consumption of antibiotics has increased. Therefore. the presence of most prescribed antibiotics from beta-lactams including amoxicillin and cephalexin were studied at two municipal WWTPs in Isfahan. The analytical method was to extract antibiotics from the aqueous phase and then detected them via HPLC/UV. Samples were collected from 2 WWTPs for 13 sampling periods over 2 months between 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 509.64 +/- 161.97 mu g/L, 352.96 +/- 203.88 mu g/L, 34.35 +/- 31.38, and the average concentration of cephalexin in influent. effluent, and its removal efficiency was 189.42 +/- 176.06 mu g/L, 32.6 +/- 49.59 mu g/L, 78.75 +/- 23.81, respectively. In WWTP B. the average concentration of amoxicillin in influent, effluent, and its removal efficiency was 2134.82 +/- 3031.53 mu g/L, 401.09 +/- 205.86 mu g/L, and 54.82 +/- 33.29. respectively. Also, the average concentration of cephalexin in influent. effluent. and its removal efficiency was 183.69 +/- 123.48 mu g/L, 23.01 +/- 40.71 mu g/L, and 87.65 +/- 21.76, respectively. According to Mann-Whitney test results, the concentration of antibiotics in both WWTPs had significant differences (p-value < .05), and according to results from the Spearman test no correlation between removal efficiency of antibiotics with other principles wastewater parameters was observed.