Continuous decolorization of dye solution by homogeneous Fenton process in a rotating packed bed reactor

Abstract

Continuous decolorization of Methyl Orange solution by homogeneous Fenton reaction was studied in a rotating packed bed reactor to intensify micromixing. In this equipment, the reactants flowed radially outward under centrifugal acceleration between a pair of rotating cylindrical disk packed with glass beads. The magnitude of the pseudo-first-order kinetic constant estimated from the experimental data was noted to increase with rotational speed and bed depth but did not significantly change with solution flow rate. It varied between 1.7 and 72 s−1 for the experimental conditions studied. The constant was over two orders of magnitude higher in rotating packed bed in comparison with conventional continuous stirred tank and packed bed reactors. Steady state was achieved in a much shorter time period in the former. The study also indicated that decolorization of a given volume of dye solution can be done at a faster rate by continuously recirculating the same volume of solution through rotating packed bed than in a mechanically agitated batch reactor.