Modified Natural Diatomite with Sorptive and Antibacterial Properties for Respiratory Protection Applications

Diatomite combines a highly porous structure with strong sorption capacity, making it an attractive material for use in medical face masks. In this study, natural diatomite from the Zhalpak deposit (Mugojar Mountains, Kazakhstan) was subjected to sequential physicochemical modification to develop a sorbent for this application. This treatment sequence substantially altered the chemical composition, pore structure, and crystalline phases of the material, resulting in the modified sorbent DE-H2SO4-600f. Its interaction with Enterococcus faecium differed markedly from that of untreated diatomite: after 7 h of contact, recoverable viable bacterial counts were reduced approximately 1200-fold relative to the initial level. In a separate experiment at a high sorbent-to-liquid ratio, no bacterial growth was detected after 24 h under the tested conditions. These findings demonstrate a pronounced reduction in recoverable viable bacteria following contact with the modified diatomite and support its potential future incorporation as a functional component in medical face masks and related respiratory-protection systems.