Time-dependent sorption of Cd2+ on CaX zeolite: Experimental observations and model predictions

Details Time-dependent sorption of Cd2+ on CaX zeolite: Experimental observations and model predictions Time-dependent sorption of Cd2+ on CaX zeolite: Experimental observations and model predictions

Oct 2006

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2006gecoa..70.4850a&link_type=abstract

Geochimica et Cosmochimica Acta, Volume 70, Issue 19, p. 4850-4861.

Computer Science

Scientific paper

Sorption, fixation and desorption kinetics of Cd2+ on calcium-exchanged zeolite-X were studied using an isotopic dilution technique utilizing 109Cd. The technique provided reliable measurements of time-dependent fixation of Cd and was validated using chabazite, which demonstrated wholly reversible Cd2+ ion exchange. A first-order kinetic model was developed to describe the progressive transfer of Cd2+ to a less reactive form in X-zeolite, following initial sorption, and subsequent desorption of Cd subject to different initial contact times. The kinetic model differentiates between two ‘pools’ of sorbed Cd2+ on zeolite-X, designated labile and non-labile sorbed Cd in which the labile sorbed Cd is in immediate equilibrium with the free Cd2+ ion activity in solution. Additionally, an intra-particle diffusion model was developed and compared with the kinetic model to determine whether time-dependent Cd sorption is controlled by reaction kinetics or diffusion within zeolite particles. The kinetic model provided a much better fit to the experimental data (R2 = 0.987) than the diffusion model. The rate constants describing Cd dynamics in CaX zeolite gave a half-time for Cd desorption of ˜77 d, for release to a ‘zero-sink’.

Affiliated with

Also associated with

No associations

Rating

Time-dependent sorption of Cd2+ on CaX zeolite: Experimental observations and model predictions does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Time-dependent sorption of Cd2+ on CaX zeolite: Experimental observations and model predictions, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Time-dependent sorption of Cd2+ on CaX zeolite: Experimental observations and model predictions will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-905568