Abstract

Kinetics of the Photocatalytic degradation of chlorendic acid [1, 4, 5, 6, 7, 7-hexachlorobicyclo-(2, 2, 1)- hept-5-ene-2, 3-dicarboxylic acid], a flame retardant found in the environment, has been investigated in aqueous heterogeneous solutions using TiO2 (Degussa P-25) powder in the presence of artificial ultraviolet radiation and oxygen. High-performance liquid chromatography (HPLC) with detector set at 221 nm was used to monitor the concentration of chlorendic acid during the degradation. The degradation kinetics followed a Langmiur-Hinshelwood type equation. The apparent photocatalytic rate constant k, was calculated as 12.0 ± 1.38 mg L-1min-1. The influence temperature and catalyst loading were studied. Results showed that initial degradation rates increased with reaction temperature. The optimal TiO2 concentration for the photocatalytic process was determined as of 2 g/L. Kinetic data on the degradation of persistent organic pollutants will assist in the design of efficient protocols for their removal from the environment.

Key words: Chlorendic acid, TiO2, High-performance liquid chromatography (HPLC) and degradation.