Regeneration of Spent Adsorbents Using Advanced Oxidation (Preprint).

摘要

The removal of organic contaminants from water by adsorption processes results in spent adsorbents; and, in this research, the use of advanced oxidation processes for regeneration of adsorbents and destruction of adsorbed contaminants is investigated. These two advanced oxidation processes are examined: (1) hydrogen peroxide/ozone and (2) UV light/hydrogen peroxide. The impacts of size and type of adsorbent, adsorbate and temperature on the destruction efficiency of adsorbed contaminants, the rate and the required quantity of oxidants are investigated. This study demonstrated that the regeneration of adsorbents by advanced oxidation is not practical. The regeneration rate was found to be much faster for smaller particle size adsorbents and weakly adsorbed compounds; and, in some cases, nearly 100% of the virgin capacity was recovered after regeneration. However, in all cases, the regeneration process consumes more oxidants than would be required by simply using a conventional advanced oxidation process for destroying organic contaminants. The high consumption of oxidants may be due to the slow rate of organic desorption and redox reactions with the adsorbent surface. Accordingly, regeneration processes using advanced oxidation is not practical unless an adsorbent is developed that exhibits fast desorption kinetics, and the surface does not react with the oxidants.