A pilot-scale study was initiated to examine the behavior of viruses pulse injected into a distribution system. The influence of a free-chlorine residual and that of virus preadsorption to clay particles was evaluated by tracing the viruses both in the water flow and after elution from the biofilm. These experiments demonstrated, first, that virus preadsorption on 40 mg of Na-montmorillonite per liter increased the residence time of the viruses within the pilot plant by roughly three times and, second, that preadsorption to clay did not prevent viruses from being inactivated by chlorine. Moreover, with no clay added, a greater amount of viruses was recovered from the biofilm than from the water flow (by a factor of 2 or 10 in the absence or presence of chlorine, respectively), indicating a tendency for virus accumulation within biofilms.
If viruses are introduced into a drinking water distribution system they will be submitted to various phenomena, including inactivation, aggregation, adsorption but the actual inactivation rate is impossible to estimate. A pilot-scale study evaluated the behaviour of viruses sporadically introduced into a distribution system. In particular, phenomena such as virus adsorption onto clay particles or onto pilot surfaces covered by a biofilm, which could provide viruses with a protection against trace amounts of residual disinfectants were studied. Poliovirus 1, pre-adsorbed or not on particles of Na-montmorillonite, was pulse-injected into a pilot distribution system and traced both in the water flow and in the biofilm. The viral responses observed in the water flow at the pilot outlet can be described by a Gamma law or by an analytical model that includes both viral inactivation and adsorption to the biofilm. Pre-adsorption on 40mg/l Na-montmorillonite increases about 3-fold the residence time of the viruses within the pilot. In the presence of chlorine, pre-adsorption on clay does not prevent chlorine inactivation of viruses. In every case, a greater amount of viruses is recovered from the biofilm than from the water flow, by a 2-fold or by a 10-fold factor in the absence or presence of chlorine, respectively. Viral adsorption to biofilm is thus a leading phenomenon that, along with viral inactivation, directs the fate of the viruses introduced into a distribution system and, in particular, allows for their accumulation within the biofilm.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.