Adsorption of organic contaminants from water using tailored ACFs

Six activated carbon fibers (ACFs) with different chemical and physical pro perties were prepared by first curing a phenolic resin-coated glass fiber, followed by activation and posttreatment. Their adsorption properties were investigated to evaluate the removal of benzene, toluene, ethylbenzene, and p-xylene (BTEX) and the chemical warfare simulants dissopropylmethyl phosp onate (DIMP) and half mustard (HM) from water. The adsorption isotherms sho wed that ACF SL-2 (activated with CO2/H2O at 800 degreesC) has a higher ads orption capacity for BTEX, DIMP, and HM than other ACFs. This suggests that the high adsorption affinity of SL-2 is related to its higher surface area , larger average micropore size of 11.6 Angstrom (especially effective for the adsorption of DIMP), and lower oxygen content of the surface. The adsor ption isotherms are well represented by the Freundlich equation. For BTEX, the adsorption parameters based on carbon coating showed that, in all cases , ACFs have a higher K value than the best available data obtained on granu lated activated carbon (GAC). The adsorption isotherms of DIMP and Hill on ACFs are also presented.