REGENERATION OF ADSORBENTS USING HETEROGENEOUS ADVANCED OXIDATION

Heterogeneous advanced oxidation involves the use of photoactive metal oxide catalysts illuminated with near-UV light to generate highly reactive species that can oxidize organic chemicals. This study examined the technical feasibility of using heterogeneous advanced oxidation for the regeneration of spent adsorbents. Adsorbability and regenerability of nonimpregnated and photocatalyst-impregnated adsorbents were evaluated. The nonimpregnated adsorbents were regenerated in titanium dioxide suspensions, whereas the photocatalyst impregnated adsorbents were regenerated in water in which no suspended photocatalyst particles were present. The results showed that the regeneration rates for the impregnated adsorbents were much faster than those for the nonimpregnated ones To obtain adsorption capacity recoveries of >90%, a regeneration time of about one-fifth of the adsorption time was required for the regeneration of an absorbent impregnated with platinized titanium dioxide whereas regeneration times longer than the adsorption times were required for the regeneration of the nonimpregnated adsorbents.