학술논문

Role of biofilm on virus inactivation in limestone aquifers: implications for managed aquifer recharge.
Document Type
Article
Source
Journal of Environmental Health Science & Engineering. 1/15/2020, Vol. 18 Issue 1, p21-34. 14p.
Subject
*GROUNDWATER recharge
*VIRUS inactivation
*MICROBIAL inactivation
*LIMESTONE
*AQUIFERS
*CARBONACEOUS aerosols
*MONOVALENT cations
*PARTICLE size distribution
Language
ISSN
2052-336X
Abstract
Background: Virus, as nano-sized microorganisms are prevalent in aquifers, which threaten groundwater quality and human health wellbeing. Virus inactivation by attachment onto the limestone surfaces is a determining factor in the transport and retention behavior of virus in carbonaceous aquifers. Methods: In the present study, the inactivation of MS2 -as a model virus- by attachment onto the surfaces of limestone grains was investigated in a series of batch experiments under different conditions such as limestone particle size distribution (0.25–0.50, 0.5–1 and 1–2 mm), treated wastewater and RO water, temperature (4 and 22 °C), initial MS2 concentrations (103–107 PFU/mL) and static and dynamic conditions. The experimental data of MS2 inactivation was also fitted to a non-linear kinetic model with shoulder and tailing. The characteristics of biofilm on the surfaces of limestone aquifer materials were assessed using scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM). Results: The inactivation rate of virus decreased with increasing the adsorbent diameter. Furthermore, virus inactivation was greater at room temperature (22 °C) than 4 °C, in both static and dynamic conditions. The inactivation of virus via attachment onto the limestone aquifer materials in dynamic conditions was higher than under static conditions. In addition, fitting the experimental data with a kinetic model showed that virus inactivation was high at higher temperature, smaller limestone grains and dynamic conditions. Moreover, the experiments with treated wastewater showed that in authentic aqueous media, the virus inactivation was considerably higher than in RO water, due to the presence of either monovalent or divalent cations and surface roughness created by biofilms. Conclusion: Finally, in terms of managed aquifer recharge systems, the presence of biofilm increases bacteria and virus retention onto the aquifer surfaces. [ABSTRACT FROM AUTHOR]