抄録
Solvent extraction was performed to characterize adsorbed materials on activated carbon and to evaluate a effective method of regeneration of the carbon, which was used in night soil treatment process. The exhaused carbon was extracted by the Soxhlet apparatus with three kinds of organic solvents (i.e., ethanol, chloroform, hexane), and dry-weight, COD, UV and IR spectrum and HPLC were measured. The amount of each solvent extract increased as the following order ; hexane < < chloroform < ethanol. The ethanol extract almost consisted of acidic components and the hexane extracted only small amount of neutral compounds. It was assumed that the most components of the adsorbed materials on the carbon were acidic. Based on these results, regeneration of carbon was investigated in column exctraction experiments using NaOH and/or H2SO4 solution. 0.1N -NaOH solution extracted 14.5mgCOD/g-AC, which was about 8 times larger than O.1N -H2SO4 extract. In this case, the major part of extracts was desorbed by small amount of solvent (12.5ml/g-AC). Two-step extraction with 0.1N -NaOH and 0.1N -H2SO4 brought about 71.8% regeneration rate, which was measured by iodine sorption capacity. It was found that there was a linear relation between the absorbance at 240nm and extracted COD or regeneration rate.
