Catalytic wet oxidation of phenolic wastes

Abstract

The effective removal of toxic chemicals from water is a problem of increasing importance. Aqueous phase oxidation of dilute organic contaminants is an attractive alternative to separation and/or incineration for the treatment of waste water. Although wet oxidation can be carried out under a variety of reaction conditions, the present study is concerned with subcritical heterogeneous catalytic oxidation of organics with air. This method has the advantages of speed and mild temperature and pressure conditions which translate into a safe and cost effective process that does not create a new waste stream. The objective of this study was to evaluate catalyst activity and kinetic parameters for the oxidation of phenol to C02 and water with a platinum on titania catalyst in a batch autoclave reactor. Results indicate that a 5% by weight platinum on titania catalyst is effective for the wet oxidation of phenol at 175'C with 5 g/L catalyst loading. Catalytic oxidation of phenol at four temperatures and various initial concentrations allowed calculation of simplified kinetics. Attempts to identify intermediate oxidation product met with only limited success.