多孔性粉体による液相吸着

抄録

The effect of synthetic aluminium silicate of different sizes, pore and mesh, on the adsorption of methylene blue (MB) from aqueous solution has been investigated. Two gels have been employed as the adsorbent, one containing 20.3% alumina (SA-I), and the other 5.2% alumina (SA-III). Between these two gels there is a marked difference in the distribution of pore volume. SA-I has many macropores and SA-III abounds in micropores.
Adsorption of MB cations by SA-I reaches its equilibrium in relatively a short time. On the other hand, the adsorption by SA-III is at very low rate and takes many hours to attain its equilibrium. It is supposed that the low adsorption rate is due to the hindrance to the MB's penetration into the micropores of the gel.
If the mesh size of adsorbent is reduced the rate of adsorption increases accordingly. Plots of x/x_∞ against t^1/2 for SA-III of various mech sizes are linear, and the rate constant is inversely proportional to the particle's diameter. (x and x_∞ are the quantities of MB adsorbed after time t and at equilibrium.) The intercept on the axis of x/x_∞ (m) is also inversely proportional to the particle's diameter. This supports the view that m is related to the external surface area of the adsorbent.