SORPTION CHARACTERISTICS OF BIOLOGICAL POWDERED ACTIVATED CARBON IN BPAC-MF (BIOLOGICAL POWDERED ACTIVATED CARBON-MICROFILTRATION) SYSTEM FOR REFRACTORY ORGANIC REMOVAL

The sorption characteristic of biological powdered activated carbon (B PAC) were investigated in a hybrid membrane process which was accompli shed by introducing powdered activated carbon (PAC) into a crossflow m icrofiltration system and seeding microorganisms. This combined proces s a as designated BPAC-MF and could be an alternative system for recla mation of secondary sewage effluent. Experiments were carried out to i dentify the ability of BPAC to remove various dissolved refractory org anic matter in secondary sewage effluents such as peptone, beef extrac t, lauryl sulfate, humic acid, tannin, lignin and gum arabic. Adsorpti on test by fresh powdered activated carbon (PAC) showed significantly different adsorption characteristics for each organic substance. These adsorption characteristics were identified by the analysis of gel per meable chromatography (GPC). The sorptive capacity of BPAC was almost four times higher than that of fresh PAC. This phenomenon could be exp lained from the sorption capacity of PAC and BPAC for each substance. For the hardly adsorbable refractory organics, humic acid and gum arab ic, the sorption capacity of bPAC was 12.1 and 8.7 mg/g respectively. These values are significantly high compared with 3.6 and 0.2 mg/g obt ained by PAC. It was estimated that the enhanced sorption capacity of BPAC was due to the stimulation of activated carbon adsorption by biol ogical effect. (C) 1997 IAWQ. Published by Elsevier Science Ltd.