Engineered multi-walled carbon nanotubes for disinfecting wastewater

Abstract

Discharging a considerable amount of untreated effluent directly into a water body significantly impacts water quality. Contaminated water can spread waterborne infections, resulting in exponentially high death rates worldwide. Although carbon nanotubes are frequently employed in industry, little is understood about how they may affect aquatic microbial ecosystems. Therefore, the present investigation aimed to exploit multi-walled carbon nanotubes (MWCNTs) as a potential disinfectant to eliminate waterborne bacteria during wastewater treatment. The current study utilized six different microbial strains, including Escherichia coli O157, Salmonella enterica, Staphylococcus aureus, Enterococcus faecalis, Risopus oryzae, and Rhizomucor miehei, to examine the antimicrobial properties of MWCNTs. The physical and morphological properties of MWCNTs were characterized using transmission electron microscope (TEM), scanning electron microscope (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), Dynamic light scattering (DLS), and zeta potential. The FTIR spectra of MWCNTs have appeared at 11,029 cm−1, and the zeta potential and particle size recorded at −28.89 mV and 425 nm, respectively. On the other hand, the results indicated that the width of the inhibition zone varied between 11 and 29 mm for E. coli O157, 11–31 mm for S. enterica, 16–37 mm for S. aureus, 14–34 mm for E.faecalis, 10–26 mm for R. oryzae, and 10–24 mm for Rh. miehei. The reduction rate of disinfection was estimated. The effective dose of MWCNTs (4xMIC) in a disinfection experiment could all selectedpathogens after 125 min exposure time. This study provided an overview of the antimicrobial properties of MWCNTs, their multiple modes of action against pathogens, and their usefulness in wastewater disinfection and microbial control. Thus, this current research work can also recommend MWCNTs as a good solution and beneficial disinfecting agent for inactivating waterborne pathogens within wastewater handling.