Water contamination with various microorganisms is life threatening. TiO2 semiconductor nanoparticles
have been widely described for bacterial inactivation. However, such a process may yield hazardous
organic matter in water; complete bacterial mineralization is thus imperative. This study describes how
anatase TiO2 nanopowder, suspended in water, photocatalyzes the inactivation and complete
mineralization of Staphylococcus aureus using UV radiation from simulated solar radiation. Total organic
carbon (TOC) analysis confirms bacterial photo-mineralization. Bacterial mineralization is further evidenced
by the appearance of ammonium ions in the treated water. In the dark, and under visible light using a cutoff
filter, only a small fraction of bacteria is inactivated with no mineralization. Nanofilm catalysts are also
examined in batch reaction systems. The film catalyst exhibits a higher photocatalytic efficiency with a
turnover frequency of up to ∼4.9 × 108 CFU g−1 min−1 compared to ∼5.8 × 106 CFU g−1 min−1 of the
nanopowder film counterparts. The powder catalyst lost up to 65% of its efficiency on reuse. This is due to
catalyst lost mass during recovery by filtration. The film catalyst retains about 96% of its efficiency upon
second reuse, showing its feasibility in application. Moreover, the film catalyst is useful in a continuous flow
reaction system with an efficiency of 5.4 × 108 CFU g−1 min−1, which is higher than that in the batch system,
and no measurable efficiency loss in reuse. These results open the door to use the present
photodegradation process in large-scale water purification processes.

العنوان

Reaction Chemistry & Engineering

الناشر

RSC

بلد الناشر

المملكة المتحدة

Indexing

Thomson Reuters

معامل التأثير

3,9

نوع المنشور

Both (Printed and Online)

المجلد

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السنة

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الصفحات

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