title: Transport and removal of viruses in saturated sand columns under oxic and anoxic conditions--Potential implications for groundwater protection.
abstract: To protect groundwater as a drinking water resource from microbiological contamination, protection zones are installed. While travelling through these zones, concentrations of potential pathogens should decline to levels that pose no risks to human health. Removal of viruses during subsurface passage is influenced by physicochemical conditions, such as oxygen concentration, which also affects virus survival. The aim of our study was to evaluate the effect of redox conditions on the removal of viruses during sand filtration. Experiments in glass columns filled with medium-grained sand were conducted to investigate virus removal in the presence and absence of dissolved oxygen. Bacteriophages MS2 and PhiX174, as surrogates for human enteric viruses were spiked in pulsed or in continuous mode and pumped through the columns at a filter velocity of about 1m/d. Virus breakthrough curves were analyzed by calculating total viral elimination and fitted using one-dimensional transport models (CXTFIT and HYDRUS-1D). While short-term experiments with pulsed virus application showed only small differences with regard to virus removal under oxic and anoxic conditions, a long-term experiment with continuous dosing revealed a clearly lower elimination of viruses under anoxic conditions. These findings suggest that less inactivation and less adsorption of viruses in anoxic environments affect their removal. Therefore, in risk assessment studies aimed to secure drinking water resources from viral contamination and optimization of protection zones, the oxic and anoxic conditions in the subsurface should also be considered.
authors.affiliation: Federal Environment Agency, Section Microbiological Risks, Corrensplatz 1, 14195 Berlin, Germany.
authors.forename: Anne
authors.initials: A
authors.lastname: Frohnert
authors.affiliation: Federal Environment Agency, Section Drinking Water Resources and Treatment, Schichauweg 58, 12307 Berlin, Germany.
authors.forename: Susann
authors.initials: S
authors.lastname: Apelt
authors.affiliation: Federal Environment Agency, Section Drinking Water Resources and Treatment, Schichauweg 58, 12307 Berlin, Germany.
authors.forename: Sondra
authors.initials: S
authors.lastname: Klitzke
authors.affiliation: Federal Environment Agency, Department of Drinking Water and Swimming Pool Hygiene, Schichauweg 58, 12307 Berlin, Germany.
authors.forename: Ingrid
authors.initials: I
authors.lastname: Chorus
authors.affiliation: Federal Environment Agency, Section Microbiological Risks, Corrensplatz 1, 14195 Berlin, Germany.
authors.forename: Regine
authors.initials: R
authors.lastname: Szewzyk
authors.affiliation: Federal Environment Agency, Section Microbiological Risks, Corrensplatz 1, 14195 Berlin, Germany. Electronic address: hans-christoph.selinka@uba.de.
authors.forename: Hans-Christoph
authors.initials: HC
authors.lastname: Selinka
mesh_terms: D000327:Adsorption; D060766:Drinking Water / Q000821:virology*; D005374:Filtration; D060587:Groundwater / Q000821:virology*; D006801:Humans; D017909:Levivirus; D008962:Models, Theoretical; D010084:Oxidation-Reduction; D010100:Oxygen; D012822:Silicon Dioxide; D014780:Viruses; D014871:Water Microbiology; D018508:Water Purification / Q000379:methods*
chemical_list: D060766:Drinking Water; D012822:Silicon Dioxide; D010100:Oxygen
keywords: Bacteriophages; Groundwater; Health risk; Transport; Viruses