Poliovirus-1 adsorption to Na-montmorillonite was studied in a complex, although known aqueous environment. Influences of salt concentration and valence, as well as virus load, clay concentration, and organic matter concentration were determined by the viral adsorption and/or loss. Use of experimentally designed experiments according to Doehlert’s matrices allowed for the detection and quantitation of the main effects on the viral response, as well as interaction effects between tested parameters. Thus, during the reassessment of the higher efficiency of multivalent cations on virus adsorption than monovalent ones, and that 10 mg/l of clay material did not provide a protective effect towards inactivation by tannic acid, we were able, first, to observe an apparent correlation between viral inactivation and ionic strength, which we explain by a potentiating action of salts, and second, to detect a tannic acid/aluminium specific interaction that seemed to be responsible for the unavailability of these elements for their respective interaction with viruses. Tannic acid thus appeared to be a realistic model for organic matter, pointing out its possible involvement in both virus adsorption and virus inactivation phenomena.