Table 2
Compositions of surface elements on the polymeric adsorbents derived from XPS analysis
the postcrosslinked polymer has the highest adsorption capac- ity towards aqueous MTBE. Note that Huajing GAC used in this study had a BET surface area of 661.3m2 g−1, whereas commer- cial activated carbons with surface area more than 800 or even 1000 m2 g−1 demonstrated much higher adsorption capacity for MTBE [11,12]. Taking the manufacturing costs into consideration, the postcrosslinked polymer is not yet cost competitive relative to activated carbon. Further work is in progress to improve the adsorp- tion capacity of postcrosslinked polymer at reduced cost, and the results of investigation will be reported in the future.
For MTBE adsorption onto the chloromethylated polymer and the nonpolar porous polymer, typical L-type isotherms were observed. In contrast, a linear adsorption isotherm was observed for MTBE adsorption over the postcrosslinked polymer.
To elucidate the mechanism of MTBE adsorption onto the poly- meric adsorbents, simulation of the adsorption isotherms was con- ducted. Simulation results showed that the adsorption isotherms of MTBE over the chloromethylated polymer and nonpolar porous polymer could be well described by Langmuir adsorption model,