Removal efficiency and mechanisms of natural mineral materials for bacteriophages MS2 and ΦX174 in aqueous environments.

Effective virus retention by natural minerals depends on surface physicochemical properties, but systematic side-by-side comparisons under realistic flow conditions and mechanistic explanations for material differences remain scarce. To address this gap, we initially screened nine natural minerals and evaluated four candidates (anthracite, lignite, coal gangue, and volcanic rock) for the removal of bacteriophages MS2 and ΦX174, using both batch equilibrium assays and saturated column transport experiments. In batch tests, the removal efficiency followed the order: anthracite > lignite > coal gangue > volcanic rock. Adsorption approached equilibrium within 3 h and was thermodynamically spontaneous, endothermic, and entropy-driven. Under dynamic flow-through conditions, anthracite exhibited consistently superior performance among the tested materials, achieving removal efficiencies of 99.75% for MS2 and 98.24% for ΦX174, and cumulative adsorption reaching up to 1.24×1011 PFU/g for the two phages combined in the long-term column experiments. Integration of transport modeling, XDLVO theory, and surface characterization indicates that electrostatic attraction is the primary mechanism governing virus retention on anthracite, with hydrophobic interactions and surface functional groups serving as complementary contributions. These results provide a quantitative basis for understanding virus-mineral interactions and identify anthracite as a material with strong retention capacity warranting further investigation under environmentally relevant conditions.