|SASIDHARAN, SALINI - Flinders University|
|SIMUNEK, JIRKA - University Of California|
|TORKZABAN, SAEED - Flinders University|
|VANDERZALM, JOANNE - Commonwealth Scientific And Industrial Research Organisation (CSIRO)|
Submitted to: Journal of Hydrology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/25/2017
Publication Date: 10/27/2017
Citation: Sasidharan, S., Bradford, S.A., Simunek, J., Torkzaban, S., Vanderzalm, J. 2017. Transport and fate of viruses in sediment and stormwater from a managed aquifer recharge site. Journal of Hydrology. 555:724-735. https://doi.org/10.1016/j.jhydrol.2017.10.062.
Interpretive Summary: Managed aquifer recharge with treated wastewater and stormwater runoff that contains disease causing viruses has been proposed as a means to increase scarce water supplies. This paper examines the transport and fate of three viruses during managed aquifer recharge (MAR) conditions. These viruses were always very effectively removed by the soil. Current MAR guidelines only give credit for virus removal by death or inactivation in the water. However, our results demonstrated that virus removal in the soil occurred at a much higher rate, and this suggests that current guidelines may be overly Conservative. These results will be of interest to scientists, engineers, health officials, and regulators that are concerned with the reuse of water from MAR sites.
Technical Abstract: Enteric viruses are one of the major concerns in water reclamation and reuse at managed aquifer recharge (MAR) sites. In this study, the transport and fate of bacteriophages MS2, PRD1, and FX174 were studied in sediment and stormwater (SW) collected from a MAR site in Parafield, Australia. Column experiments were conducted using SW, stormwater equilibrium with the aquifer sediment (EQ-SW), and two pore-water velocities (1 and 5 m day-1) to encompass expected behavior at the MAR site. The aquifer sediment effectively removed these viruses under all of the considered MAR conditions (>92.3%). However, much greater virus removal (4.6 log) occurred at the lower pore-water velocity and in EQ-SW (with higher ionic strength and Ca2+ concentration), which are found farther from the injection well. Virus removal was greatest for MS2, followed by PRD1, and then FX174 for a given physicochemical condition. The vast majority of the attached viruses were irreversibly attached or inactivated on the solid phase, and injection of Milli-Q water or beef extract at pH=10 only mobilized a small fraction of attached viruses (<0.64%). Virus breakthrough curves (BTCs) were successfully simulated using an advective dispersive model that accounted for rates of attachment (katt), detachment (kdet), irreversible attachment or solid phase inactivation (µs), and blocking. Existing MAR guidelines only consider the removal of viruses via liquid phase inactivation (µl). However, our results indicated that katt >µs >kdet >µl , and katt was several orders of magnitude greater than µl, suggesting that existing MAR guidelines may be overly conservative. Interestingly, virus BTCs exhibited blocking behavior and the calculated solid surface area that contributed to the attachment was very small. Additional research is therefore warranted to study the potential influence of blocking on viruses transport and potential implications for MAR guidelines.