Reuse of TiO2-based catalyst for solar driven water treatment; thermal and chemical reactivation

- We study the solar driven degradation of diclofenac by reused photocatalyst.
- Novel TiO2-zeolite based photocatalysts were used.
- Thermal and chemical reactivation strategies were used using response surface modeling.
- Thermal reactivation yielded higher diclofenac and overall organic carbon removal.
- Chemical reactivation slightly improved photocatalyst stability and biodegradability in reuse cycles.

Reuse of photocatalyst and activity-loss in consecutive cycles presents a major hurdle in the environmental application. In this study, thermal and chemical treatments have been investigated as potentially viable methods for photocatalyst reactivation. A composite prepared from titania and iron-exchanged zeolite was used as photocatalyst for diclofenac (DCF) removal under simulated solar irradiation. DCF and total organic carbon (TOC) removal extents, biochemical and chemical oxygen demand were monitored in reuse cycles, for air-dried, and thermally and chemically reactivated photocatalyst. Thermal reactivation yielded higher DCF and TOC removal extents, while chemical reactivation slightly improved photocatalyst stability and biodegradability in reuse cycles.

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