Comparative Adsorption of Nitrophenols on Macroporous Resin and Newly-Synthesized Hypercrosslinked Resin

The comparative adsorption of o-nitrophenol, m-nitrophenol and p-nitrophenol onto a macroporous polymeric adsorbent (Amberlite XAD-4) and a hypercrosslinked polymeric adsorbent (NJ-8) was investigated. Adsorption equilibrium isotherms were measured by batch equilibration over the temperature range 283–323 K, and two kinds of isotherm model (Langmuir and Freundlich) provided the best fit of the experimental data. The adsorption capacity for each adsorbate on NJ-8 was ca. twice that on Amberlite XAD-4, which is explained by the micropore structure and stronger donor–acceptor interaction of NJ-8 resin. Mini-column experiments showed that NJ-8 resin exhibited the longest breakthrough time. The enthalpy of adsorption was estimated from the temperature dependence of adsorption.