Using a number of carbon black samples, which in some instances showed
very different textural properties and adsorption capacity, the effec
t of temperature on the adsorption of p-nitrophenol (PNP) from aqueous
solution was investigated. From the adsorption isotherms determined a
t 20, 30 and 40-degrees-C, the plot of b (the slope of ln X = a + bT,
where X was the amount of PNP adsorbed) against the relative concentra
tion (C/C0) enabled us to compare the thermal stability of the adsorbe
d state for all adsorbents and to follow its variation with C/C0. The
stability was strongly dependent on textural properties of the adsorbe
nts. It was lower when the adsorption occurred on the external surface
or in large pores than when the process took place in micropores. The
influence of the lateral interactions on the stability appeared to be
marked. The stability of the adsorbed state at high surface coverages
and above the first adsorption layer as well as the activated diffusi
on process could also be studied.