Advanced nanostructured materials in solar interfacial steam generation and desalination against pathogens: combatting microbial-contaminants in water - a critical review

The consumption of biologically-contaminated water annually leads to hundreds of thousands of deaths, most of which occur among children in developing countries. Solar-based water desalination systems are emerging as a promising, low-cost, and environmentally friendly solution to provide safe drinking water. The use of nanostructured materials in solar stills and solar interfacial evaporation systems is considered a highly effective method for performance improvement. These nanomaterial-assisted solar desalination systems can eliminate biological contaminants in water through various mechanisms. This paper presents, for the first time, an extensive review of the effectiveness of solar stills and solar interfacial evaporators aided by various forms of nanomaterials in combating biological contamination, including viruses, bacteria, protozoa, fungi, and antimicrobial resistance (AMR) pathogens. We specifically focus on pathogens with global catastrophic biological risk (GCBR) characteristics, particularly viruses and AMR pathogens. Special attention is given to the role of AMR pathogens and their potential transmission routes in the environment and water bodies, as they pose significant potential for future pandemics. The effectiveness of solar stills and solar interfacial steam generation methods is examined in light of their inactivation mechanisms, operational principles, crucial environmental parameters, and pathogen characteristics. Challenges and potential directions for future research are also discussed and proposed.