Kinetics of acrylonitrile adsorption from an aqueous solution using Dowex Optipore L-493

Adsorption is widely applied in water treatment and activated carbon is the most common adsorbent. Slow intraparticle mass transfer and incomplete regeneration of the activated carbon form drawbacks in adsorption processes. Recently the use of polymeric sorbents as an alternative for activated carbon has been increasing. In this study the kinetics of the adsorption of acrylonitrile from an aqueous solution onto Dowex Optipore L-493, a polymeric sorbent, is examined using zero-length columns. The adsorption equilibrium was found by use of batch experiments and it could be described by a Langmuir isotherm. The external mass transfer was estimated by use of correlations. The intraparticle surface diffusion coefficient was found to be 2.0 × 10−10 m2/s. The fast intraparticle mass transfer allows running adsorption columns with a high superficial velocity which is desirable for industrial processes.

Figure optionsDownload as PowerPoint slideHighlights
► Adsorption of acrylonitrile onto the polymeric adsorbent Dowex Optipore was studied.
► Acrylonitrile was adsorbed from an aqueous solution.
► Acrylonitrile diffusion inside the particles is fast.
► Possibly acrylonitrile forms a second liquid phase inside the pores.
► Acrylonitrile can then be transported by capillary pressure gradients.