Water contamination with various microorganisms is life de facto. TiO₂ semiconductor nanoparticles were widely described in bacterial inactivation. However, such a process may yield hazardous organic stuff in water. Complete bacterial mineralization is thus imperative. This study describes how anatase TiO₂ nano-powders, suspended in water, photo-catalyzes inactivation and complete mineralization of Staphylococcus aureus, using UV radiations of simulated solar radiations. Total organic carbon (TOC) analysis confirms bacterial photo-mineralization. Bacterial mineralization is further evidenced by appearance of ammonium ion in the treated water.   In the dark, and under visible light using a cut-off filter, only a small fraction of bacteria is inactivated with no mineralization. Nano-film catalysts are also examined in batch reaction systems. The film catalyst exhibits higher photocatalytic efficiency, with turnover frequency of up to ~4.9x10⁸ CFU/g.min, compared to ~5.8x10⁶ CFU/g.min for the nano-powder film counterparts. Powder catalyst lost up to 65% of its efficiency on reuse, due to technical mass loss during recovery. The film catalyst retains about 96% of its efficiency upon second reuse, showing its feasibility in application. Moreover, the film catalyst is useful in continuous flow reaction system, with efficiency 5.4x10⁸ CFU/g.min higher than in the batch system, and no measurable efficiency loss in reuse. The results open the way to use the present photodegradation process at large-scale water purification processes.

Title

Reaction Chemistry and Engineering

Publisher

Royal Society

Publisher Country

United Kingdom

Indexing

Thomson Reuters

Impact Factor

3.9

Publication Type

Both (Printed and Online)

Volume

--

Year

2024

Pages

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