Abstract
Biological expanded-bed GAC (granular activated carbon) reactor was applied to treat artificial wastewater which contains high concentration of pentachlorophenol (PCP) as well as acetic acid. Organic loading was changed from 0.64 to 11g CODcr/(kg GAC·Eday) by changing concentration of organics (PCP concentration from 100 to 800mg/L and acetic acid from 500 to 2000mg/L) and hydraulic retention time from 2.2 to 0.43 days based on expanded-bed volume. The operation of the reactor was successfully started without any dilution of the wastewater and the reactor could respond without any deterioration of treatment efficiency to shock load by the adsorption ability of GAC used as attached medium. COD and PCP removal efficiencies were kept more than 95% and 99% respectively. Biomass in the reactor was from 0.10 to 0.22mgDNA/gGAC, which corresponds to 1700-3900mgVSS/L based on the expanded-bed volume.
