Minimizing Virus Transport in Porous Media by Optimizing Solid Phase Inactivation.

Area of Science:

• Environmental microbiology
• Water quality engineering
• Geomicrobiology

Background:

• Virus transport in porous media is a significant concern for water safety, especially in managed aquifer recharge.
• Understanding virus fate, including inactivation and retention, is crucial for predicting contamination risks.

Purpose of the Study:

• To investigate the influence of virus type, temperature, storage duration, and temperature cycling on virus transport and fate in saturated sand columns.
• To evaluate the effectiveness of solid phase inactivation and its dependency on environmental factors.

Main Methods:

• Experiments using saturated sand-packed columns with two virus types (PRD1 and ΦX174).
• Varied conditions including temperature (4°C and 20°C), no-flow storage duration (0-70 days), and temperature cycling.
• Utilized a transport model incorporating advection-dispersion, attachment, detachment, inactivation (solid and liquid phase), and a Langmuirian blocking function.

Main Results:

• The vast majority of viruses (84-99.5%) were irreversibly retained on sand.
• A small fraction of reversibly retained viruses posed a long-term contamination risk.
• Higher temperatures and longer storage periods significantly reduced virus transport and risk due to enhanced solid phase inactivation.
• Solid phase inactivation (μ) was the dominant removal mechanism, significantly exceeding liquid phase inactivation (μ).

Conclusions:

• Solid phase inactivation, temperature, and storage duration are critical factors in eliminating virus transport in porous media.
• Findings have implications for managed aquifer recharge, suggesting control of temperature and residence time to enhance virus removal.
• Variations in sand and virus surface properties influence adhesion strength, affecting release and inactivation rates.