A NEW METHOD FOR REGENERATING ACTIVATED CARBON BY THERMAL-DESORPTION WITH LIQUID WATER UNDER SUBCRITICAL CONDITIONS

A new procedure for regenerating activated carbon based on thermal des orption with liquid water under subcritical conditions (300 degrees C and 120 atm) is proposed. The method was assayed with three types of a ctivated carbons exhausted with phenols (phenol and 4-nitrophenol), te xtile dyes (sirius red C.I: 29080 and orange II C.I.: 15510) and pesti cides (carbofuran and atrazine). In all cases, total recovery of the a dsorption capacity was achieved, even after seven regenerations. The m echanism and factors involved in regeneration were investigated using the TPD technique in liquid phase. The differences and advantages of t his procedure as compared with others, such as thermal regeneration or regeneration with supercritical CO2 are discussed. Copyright (C) 1996 Elsevier Science Ltd