Sources, enumerations and inactivation mechanisms of four emerging viruses in aqueous phase.

Emergence and re-emergence of four types of severely infectious viruses have claimed significant numbers of lives when anthropogenic activities contribute to the mutagenesis of these pathogens and infectivity of these pathogens has been noticeably altered. However, both point and non-point sources can transport these viruses in water treatment and resource recovery facilities (RRF) where the presence of these pathogens in aerosolized form or in suspension can cause astronomical public health concerns. Hence, numerous scientific studies have been reviewed to comprehend the possible inactivation mechanisms of those viruses in aqueous phase where thermal-, photo-, and chemical-inactivation have confirmed their effectiveness in restraining those viruses and inactivation mechanisms are the major focuses to apprehend the quick and cost-effective virus removal process from water and RRF. Although practical applications of nano-sized disinfectants have challenged researchers, those disinfectants can completely kill the viruses and hamper RNA/DNA replication without any sign of reactivation or repair. Moreover, limitations and future research potential are discussed so that efficacious strategic management for a treatment facility can be developed at the forefront of fighting tactics against an epidemic or a pandemic. Enumerations, besides state-of-the-art detection techniques with gene sequences, are mentioned for these viruses.

Natural and anthropogenic radionuclides in water and wastewater: Sources, treatments and recoveries.

Water-energy nexus in the context of changing climate amplifies the importance of comprehending the transport, fate and recovery of radioisotope. While countries have been more interested for zero/low greenhouse gas emission technologies, energy production from nuclear power plant (NPP) can be a prominent solution. Moreover, radioisotopes are also used for other benefits such as in medical science, industrial activities and many more. These radionuclides are blended accidently or intentionally with water or wastewater because of inefficacious management of the nuclear waste; and therefore, it is an imperative task to manage nuclear waste so that the harmful consequences of the waste on environment, ecology and human health can be dispelled. Due to generation of significant amount of waste throughout its utilization, a noticeable number of physical, chemical and biological processes has been introduced as remediation processes although mechanisms of optimum removal process are still under investigation. Removal mechanisms and influencing factors for radionuclide removal are elucidated in this review so that, further, operation and process development can be promoted. Again, resource recovery, opportunities and challenges are also discussed for elevating the removal rates and minimizing the knowledge gaps existing in development and applications of novel decontamination processes.

Contaminated aquatic sediments.

Aquatic sediments are contaminated by different anthropogenic activities and natural deposition. This review manuscript has discussed on published manuscript in 2019 based on monitoring and identification of contaminants, GIS application and isotopic evaluation for monitoring of pollutants, physicochemical and biochemical fate and transport of the pollutants as well as remediation and toxicity analysis so that environmental and ecological impacts due to pollution can be minimized.

Antimicrobial nanomaterials as water disinfectant: applications, limitations and future perspectives.

Nanotechnology and its application is one of the rapidly developing sciences. As demand of fresh drinking water is increasing, nanotechnology can contribute noticeable development and improvement to water treatment process. Disinfection process is the last and most important step in water and wastewater treatment process. Some nanomaterials can be used as disinfectants due to their antimicrobial properties and reduce the possibility of harmful disinfection by-products (DBPs) formation during traditional disinfection process. A significant number of research efforts is done or going on to understand the mechanisms and enhance the efficiency of nanomaterials as antimicrobial agents, although it will take more time to understand the full potential of nanomaterials in this field. This review paper focuses on inactivation pathways of benign nanomaterials, their possible and probable application and limitations as disinfectants and future opportunities for their application in water cleaning processes.