Adsorption Behaviour of Low-Biodegradable Organics on Activated Carbon Surfaces

Adsorption isotherms of various low-biodegradable aromatic compounds on two different activated carbons were determined experimentally and described by FREUNDLICH-type isotherm equations. The equilibrium solid loadings derived from the measurements correlate reasonably well with the adsorbent surface areas and show decreasing values in the order 3-nitro-aniline ～ 4-chloroaniline > 3.5-dinitrobenzoic acid < phenylurea. Kinetic experiments in a differential column batch reactor were conducted in order to evaluate liquid-phase mass transfer and intraparticle diffusion parameters. The homogeneous surface diffusion model could be successfully applied for calculating surface diffusivities and predicting experimental concentration/time profiles.