Removal of chemical and microbial water pollutants by cold plasma combined with Ag/TiO2-rGO nanoparticles

This study aimed to investigate the synergistic effect of the cold atmospheric plasma (CAP) and heterogeneous photocatalytic processes in an aqueous solution to enhance water purification efficacy and reduce the energy cost required by CAP. 0.1% Ag/TiO2-reduced graphene oxide (rGO) nanoparticles (NPs) photo-composite were prepared and fully characterized. Data showed that Ag nanoparticles and the rGO play an important role in increasing the efficiency of the whole treatment process and the photo-composite (0.1% Ag/TiO2-1% rGO at 400 degrees C) revealed the highest phenol removal rate with excellent reusability. Also, complete inactivation (similar to-5log(10) reduction) of both E. coli and S. aureus by NPs was observed without CAP exposure, whereas a minimal effect (0.1-0.5 log(10)) on viruses (Adenovirus (AdV), rotavirus, and phi X174) was observed after 10 min incubation. Interestingly, the photocatalytic virus inactivation test was promising, as it resulted in > 4.7log(10) reduction of AdV at 2 min treatment, whereas <1log(10) could be reduced using only CAP at the same treatment time. Accordingly, we believe that this work could provide new insights into how the synergy between CAP and 0.1% Ag/TiO2-1% rGO photo-composite in aqueous media imposes a great potential for environmental applications, such as water purification and microbial inactivation.