Adsorption of Halogenated Hydrocarbons from Gaseous Streams by Amberlite XAD-4 Resin and Activated Carbon: Equilibria

摘要

Single-solute adsorption equilibria have been measured for the adsorption of the gaseous solutes chloroform, chlorobenzene, and 1,1,1-trichloroethane onto Amberlite XAD-4 resin. For 1,1,1-trichloroethane the adsorption equilibrium has also been measured with activated carbon Norit ROW 0.8 SUPRA as a sorbent. Temperature was varied between 20 and 120 deg C ,whereas nitrogen was used as a dilutant. All obtained experimental data could be fitted satisfactorily with two different temperature dependent Freundlich equations, one derived by Halsey (1952) and another derived in this work. Adsorption of the halogenated hydrocarbons onto Amberlite XAD-4 as well as Norit ROW 0.8 SUPRA proved to be completely reversible. The adsorption capacity of Amberlite CAD-4 was found to decrease exponentially with increasing temperature, whereas the capacity of Norit ROW 0.8 SUPRA decreased in a linear way and at a much lower rate, reflecting the bad regeneration characteristics of activated carbon sorbents. The obtained data for the adsorption of gaseous chloroform and 1,1,1-trichloroethane onto Amberlite XAD-4 resin agreed surprisingly well with data that were earlier obtained with these same hydrocarbons being adsorbed from water, in which they were dissolved, by nonwetted Amberlite XAD-4 particles. When plotted against the partial pressure of the solutes ,equal adsorption capacities were found, indicating that, at least at 20 deg C , the presence of water vapor inside the pores of the nonwetted resin particles does not affect the adsorption capacity of these particles with respect to the halogenated hydrocarbons in concern.