Wastewater treatment method and wastewater treatment apparatus

摘要

A nitrification carrier having made nitrifying bacteria dominant therein and a denitrification carrier having made anaerobic ammonium-oxidizing bacteria dominant therein are mixed in a treatment tank. Both of a nitrification reaction with the nitrification carrier and a denitrification reaction with denitrification carrier are allowed to proceed in the treatment tank to decompose ammonium nitrogen in wastewater to nitrogen gas. The ratio of the bacterial loads of the nitrifying bacteria and the anaerobic ammonium-oxidizing bacteria can be easily controlled by immobilizing the nitrifying bacteria and the anaerobic ammonium-oxidizing bacteria on different carriers from each other (nitrification carrier and denitrification carrier) and by controlling the volume ratio (ratio of the feeding amounts) of the nitrification carrier and the denitrification carrier.