PENTACHLOROPHENOL ADSORPTION AND DESORPTION CHARACTERISTICS OF GRANULAR ACTIVATED CARBON .1. ISOTHERMS

The adsorption/desorption of pentachlorophenol (PCP) with Calgon F300 granular activated carbon (GAG) was studied and modelled. A modified R adke-Prausnitz (1972) isotherm model, incorporating a temperature- and pH-dependent proportionality constant, was found to best describe the observed PCP adsorption and desorption. The modified isotherm is vali d in the ranges 4 less than or equal to pH less than or equal to 11 an d 10 less than or equal to T less than or equal to 60 degrees C. The a ctivation energy of PCP adsorption was calculated to be 5.2 kJ/mol. At 30 degrees C, PCP adsorbed strongly, and the rate of subsequent desor ption was very low. However, the amount of PCP desorbed could be incre ased significantly by increasing the temperature to 60 degrees C. Copy right (C) 1996 Elsevier Science Ltd