Application of green nanoemulsion to treat contaminated water (bulk aqueous solution) with azithromycin

The present work aimed to remove azithromycin (AZM) from the contaminated aqueous system using a water/ethanol/transcutol/Capryol-90 green nanoemulsion. The drug is identified as a potential pharmaceutical contaminant detrimental for flora and fauna of aquatic lives as well as human health. Green nanoemulsions were tailored and characterized for thermodynamic stability, size, polydispersity index (PDI), zeta potential, viscosity, refractive index (RI), and morphological assessment using a transmission electron microscopy (TEM). Moreover, nanoemulsions were investigated for percent removal efficiency (%RE) and factors affecting percent removal efficiency (%RE). The results suggested that the developed green nanoemulsions (ANE1-ANE5) were transparent (˂ 200 nm) and stable. ANE5 exhibited the lowest value of globular size (49 nm), PDI (0.17), viscosity (~ 93 cP), and optimum zeta potential (-27.8 mV). The value of %RE depended upon the content of water and Capryol-90 of the nanoemulsion. Furthermore, the value of %RE was found to be increased with increased content of water, whereas this was decreased on increasing the Capryol-90 content in the nanoemulsions. Similarly, on decreasing the values of size and viscosity, the %RE values were observed to be increased. There was insignificant impact of the duration of exposure time on %RE. Thus, the maximum %RE value (96.8%) was obtained by ANE5 from the aqueous solution after 20 min of contact time with ANE5. Thus, this method could be a promising approach to remove AZM from the contaminated water and serve as an alternative to conventional methods.