The Weber-Morris plots for pyridine uptake from aqueous solutions
on MN 200 and MN 500 at various initial pyridine concentrations
and temperatures are shown in Figs. 1 and 2, respectively. In
most cases, there is a time lag (hence a negative y-axis intercept)
in the initial stage of the adsorption, which indicates that pyridine
adsorption on both adsorbents experiences external film diffusion
resistance. In addition, two different regimes for pyridine adsorption
are observed, each of them showing linear behaviour, attributing to
the intraparticle adsorption of pyridine into the adsorbent pores