Transport and removal of viruses in soil: Evaluating low-cost filtering materials for groundwater protection

The transport of pathogenic viruses through soil poses significant risks to groundwater contamination and public health. This study investigates the removal efficiency of viruses in soil systems amended with low-cost filtering materials, including magnesite, calcined magnesite, iron filings, biochar, zeolite, limestone, and bauxite. Laboratory-scale column experiments and field studies were conducted using bacteriophages MS2 and ΦX174 as viral surrogates to evaluate adsorption, transport, and inactivation mechanisms. The results indicated that calcined magnesite exhibited the highest virus removal efficiency (∼100 %), followed by iron filings (65 %) and magnesite (32 %), while biochar, zeolite, limestone, and bauxite demonstrated minimal removal (<18 %). The superior performance of calcined magnesite is attributed to its high surface reactivity, electrostatic interactions, and pH-modulating effects. Additionally, soil amendments with these materials influenced microbial community composition, with iron filings and calcined magnesite reducing bacterial diversity and promoting Actinobacteria growth while inhibiting Acidobacteria and Bacteroidetes. These findings suggest that industrial and agricultural waste materials can serve as cost-effective solutions for virus removal in soil and water systems, with potential applications in groundwater protection and wastewater irrigation management.