Abstract: An aspect of the present invention provides a wastewater treatment method for treating wastewater containing ammonium nitrogen, including the steps of: oxidizing the ammonium nitrogen in the wastewater to nitrite with nitrifying bacteria in a treatment tank in which the nitrifying bacteria and anaerobic ammonium-oxidizing bacteria having a half-saturation constant of 6.1 mgN/L or more with respect to nitrite coexist; and denitrifying the nitrite formed through the oxidation of the ammonium nitrogen, with the anaerobic ammonium-oxidizing bacteria in the treatment tank, while using the ammonium nitrogen contained in the wastewater as a hydrogen donor.

Abstract: 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.

Abstract: A wastewater treatment method for treating wastewater containing ammonium nitrogen, includes the steps of: charging an unacclimated denitrification carrier containing anaerobic ammonium-oxidizing bacteria into a treatment tank; charging an unacclimated nitrification carrier containing nitrifying bacteria into the treatment tank; acclimating the unacclimated denitrification carrier in the treatment tank under an anaerobic condition; acclimating the unacclimated nitrification carrier in the treatment tank under an aerobic condition, after having acclimated the denitrification carrier; nitriting the ammonium nitrogen in the wastewater to generate nitrite with the acclimated nitrification carrier; and denitrifying the nitrite generated by nitriting the ammonium nitrogen with the acclimated denitrification carrier, while using the ammonium nitrogen in the wastewater as a hydrogen donor.

Abstract: 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.

Abstract: A wastewater treatment method for treating wastewater containing ammonium nitrogen, includes the steps of: charging an unacclimated denitrification carrier containing anaerobic ammonium-oxidizing bacteria into a treatment tank; charging an unacclimated nitrification carrier containing nitrifying bacteria into the treatment tank; acclimating the unacclimated denitrification carrier in the treatment tank under an anaerobic condition; acclimating the unacclimated nitrification carrier in the treatment tank under an aerobic condition, after having acclimated the denitrification carrier; nitriting the ammonium nitrogen in the wastewater to generate nitrite with the acclimated nitrification carrier; and denitrifying the nitrite generated by nitriting the ammonium nitrogen with the acclimated denitrification carrier, while using the ammonium nitrogen in the wastewater as a hydrogen donor.

Abstract: An aspect of the present invention provides a wastewater treatment method for treating wastewater containing ammonium nitrogen, including the steps of: oxidizing the ammonium nitrogen in the wastewater to nitrite with nitrifying bacteria in a treatment tank in which the nitrifying bacteria and anaerobic ammonium-oxidizing bacteria having a half-saturation constant of 6.1 mgN/L or more with respect to nitrite coexist; and denitrifying the nitrite formed through the oxidation of the ammonium nitrogen, with the anaerobic ammonium-oxidizing bacteria in the treatment tank, while using the ammonium nitrogen contained in the wastewater as a hydrogen donor.