Water treatment method and water treatment apparatus

Patent metadata

Field	Value
Publication number	US-11401187-B2
Application number	US-201917253355-A
Country	US
Kind code	B2
Filing date	Jun 20, 2019
Priority date	Jun 22, 2018
Publication date	Aug 2, 2022
Grant date	Aug 2, 2022

Abstract

Provided are: a water treatment method that includes at least a denitrification step for denitrifying water to be treated with a denitrifying bacterium in the presence of a hydrogen donor, wherein the denitrification activity of the denitrifying bacterium can be maintained at a high level and thus the treatment speed can be increased; and a water treatment apparatus. The water treatment method includes at least a denitrification step for passing water to be treated through a biological treatment tank and denitrifying the same with a heterotrophic denitrifying bacterium in the presence of a hydrogen donor, wherein: molybdenum is added to the water to be treated to give a concentration of 0.01-1.0 mgMo/gN; a carrier is added to the biological treatment tank; and the nitrogen load to the carrier is controlled to 1.6 kgN/(m3-carrier·d) or greater.

First claim

The invention claimed is:

1. A water treatment method comprising at least denitrifying that passes a water to be treated through a biological treatment tank to conduct a denitrification treatment by heterotrophic denitrifying bacteria in presence of a hydrogen donor, wherein
0.01 to 1.0 mgMo/gN of molybdenum is allowed to be present in the water to be treated, and
a carrier is added to the biological treatment tank, with a nitrogen loading relative to the carrier set to equal to or more than 1.6 kgN/(m 3 -carrier·d).

2. The water treatment method as claimed in claim 1 , wherein
a molybdenum content in the water to be treated is changed in accordance with a nitrogen loading in the biological treatment tank.

3. A water treatment apparatus comprising
at least a denitrification unit in which a water to be treated is passed through a biological treatment tank to conduct a denitrification treatment by heterotrophic denitrifying bacteria in presence of a hydrogen donor,
a first supply line configured to supply water to be treated, the first supply line being connected to an inlet of the biological treatment tank, and
a second supply line configured to supply molybdenum, the second supply line being connected to the first supply line prior to the inlet of the biological treatment tank,
wherein the second supply line is further configured to supply 0.01 to 1.0 mgMo/gN of molybdenum to the first supply line, and
wherein a carrier is added to the biological treatment tank, with a nitrogen loading relative to the carrier set to equal to or more than 1.6 kgN/(m 3 -carrier·d).

4. The water treatment apparatus as claimed in claim 3 , wherein
the second supply line is further configured to change a molybdenum content in the first supply line in accordance with a nitrogen loading in the biological treatment tank.

Assignees

• Organo Corp

Inventors

• YUI Hironori
• Yamamoto Taichi
• Miyake Masaki
• Hasebe Yoshiaki

Classifications

• Y02W10/10

  Biological treatment of water, waste water, or sewage · CPC title

• C02F2305/06

  Nutrients for stimulating the growth of microorganisms · CPC title

• C02F3/34 Primary

  characterised by the microorganisms used · CPC title

• C02F3/2806

  Anaerobic processes using solid supports for microorganisms · CPC title

• C02F3/305 Primary

  characterised by the denitrification · CPC title