Abstract

Pollutant adsorption from aqueous solutions is usually controlled by diffusion or mass transfer which can be external film diffusion or intraparticle diffusion or both, depending on the relative magnitude of the film and intraparticle mass transfer resistances. Traditionally the Biot number is used to characterize mass transfer controlling mechanism in adsorption. In this work a new quantitative characterization method is proposed. Specifically the average fractional film mass transfer resistance is defined and used as an indicator of the relative importance of film and intraparticle mass transfer resistances. The average fractional film mass transfer resistance varies from 0 to 1, corresponding respectively to complete intraparticle diffusion control and complete film diffusion control. Numerical simulations of batch adsorption processes are performed and the corresponding average fractional film mass transfer resistance calculated for a wide range of process parameters. Based on the simulation results a correlation is obtained between the average fractional film mass transfer resistance and the Biot number, the adsorbate partition ratio and the separation factor. It is shown that the Biot number alone is not sufficient to characterize mass transfer controlling mechanism in adsorption.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.