UASBとDHSリアクターによる嫌気・好気処理システムの染色実廃水への適用

抄録

A system combining Up-flow anaerobic sludge blanket (UASB) and aerobic down-flow hanging sponge (DHS) reactors, which is cost-effective and has low-energy requirements, was applied to an actual dye wastewater treatment. The system performance was investigated for a duration of about 500 days operated in 12 different modes with a HRT of 8 hr for each reactor. The results demonstrated that the actual dye wastewater containing a high concentration of sulfate decreased treatment efficiency because of hydrogen sulfide inhibition in UASB. However, changing to UASB effluent circulation system, in which the effluent was introduced to a desulfurization unit before recycling, effectively improved treatment. As an important finding, the operational mode with the recycling of DHS effluent to the UASB inlet improved the final effluent quality with color removal compared with the UASB-DHS one-through mode. We conclude that the actual dye wastewater that originally contained 1000 mg COD·l^-1, 700 mg BOD·l^-1, and a transparency index of 2.5 cm on average, was effectively treated using the system combining anaerobic/aerobic UASB and DHS reactors, achieving approximately 80% COD removal, more than 95% BOD removal, and of a transparency index over 30 cm.