Removal of aqueous Fe2+ using MnO2–clinoptilolite in a batch slurry reactor: Catalyst synthesis, characterization and modeling of catalytic behavior

An Iranian clinoptilolite has been modified with MnO2 for the catalytic removal of Fe2+ cations from water in a batch slurry reactor. The modified zeolite was subjected to FESEM, XRD, WDX, XRF and specific surface area analysis. A correlation for the intrinsic catalytic reaction rate incorporating both Fe2+ and dissolved oxygen concentration as a function of reaction temperature has been presented. The effect of the modified zeolite aggregate particle size on the iron removal kinetics has been investigated. It was shown that for particles larger than 150 μm, diffusion through the mesopores of the zeolite aggregate is rate controlling. The effective diffusion coefficient through the particles at RT has been calculated as 2.3 × 10−6 cm2 s−1. It is shown that liquid phase molecular diffusion within the mesopores is the dominating mass transfer mechanism.