Inactivation of Coxsackievirus by Chlorine, Silver, and Solar Disinfection for Safe Global Water

In the field of drinking water treatment, viruses have emerged as pathogens of concern, both in the developed and developing world. Due to the formation of regulated disinfection byproducts (DBPs), the use of free chlorine and ozone, two disinfectants commonly used for virus control, is decreasing, and alternative disinfectants that are less effective against viruses are being adopted. Combined chlorine, or monochloramine, and ultraviolet (UV) light are being used by some utilities to reduce formation of the regulated DBPs, and do not perform as effectively against viruses. Adding to these concerns, the inactivation of many viruses has not been characterized completely, even with common disinfectants. Disinfection technologies currently recommended or implemented for safe drinking water in developing regions are not always completely effective in the challenging surface waters typical of these areas. For example, surface waters are commonly contaminated with inorganic and organic nitrogen from human and animal waste and upon addition of free chlorine, chloramines are formed. Therefore, it is necessary to understand the inactivation of viruses with both forms of chlorine. Disinfection by silver ion has the potential for a point-of use treatment system within communities and at the household level. Although, solar disinfection has not shown to be extremely effective against viral inactivation, it is used in many parts of the world and also has the potential to be combined with other treatment technologies for a greater disinfection efficacy.In this study, the inactivation of coxsackievirus, a single-stranded RNA virus in the family of Picornavirus and of the genus Enterovirus, with free and combined chlorine, silver, and solar light was characterized. Coxsackievirus is highly virulent, with health effects including respiratory illnesses, diarrhea, fever, myocarditis, aseptic meningitis, miscarriages, and other adverse effects. As a result it has been identified as a virus of concern in drinking water. Data indicate that coxsackievirus is relatively resistant to both free and combined chlorine, making the full characterization of its inactivation kinetics an important venture. Results from chlorine, monochloramine silver ion, and solar light disinfection will be presented. These results will likely impact decision making for the overall optimization of pathogen control in global drinking water treatment.