Granule-forming method and waste water treatment method

Patent metadata

Field	Value
Publication number	US-10479710-B2
Application number	US-201616069083-A
Country	US
Kind code	B2
Filing date	Dec 28, 2016
Priority date	Jan 12, 2016
Publication date	Nov 19, 2019
Grant date	Nov 19, 2019

Abstract

A granule-forming method using a semi-batch reaction tank, wherein: operation cycles of a first operation cycle for performing a biological treatment step at a first sludge load and after the first operation cycle, a second operation cycle for performing the biological treatment step at a second sludge load are performed repeatedly; the first sludge load is set so that the soluble BOD concentration in the semi-batch reaction tank at the time of completion of the biological treatment step of the first operation cycle does not decrease to a threshold value or less; and the second sludge load is set so that the soluble BOD concentration in the semi-batch reaction tank at the time of completion of the biological treatment step of the second operation cycle is at or below the threshold value.

First claim

The invention claimed is:

1. A granule-forming method using a semi-batch reaction tank, the method comprising forming granules by repeatedly performing an operation cycle having an introduction step of introducing an organic matter-containing wastewater, a biological treatment step of biologically treating treatment target substances in the organic matter-containing wastewater by using a microbiological sludge, a settling step of allowing the microbiological sludge to settle, and a discharge step of discharging a biologically treated water that has been biologically treated, wherein
the operation cycle includes a first operation cycle for performing the biological treatment step at a first sludge load, and a second operation cycle, performed after the first operation cycle, for performing the biological treatment step at a second sludge load, and
the first sludge load is set such that a soluble BOD concentration inside the semi-batch reaction tank upon completion of the biological treatment step of the first operation cycle does not fall to a threshold value or below, and the second sludge load is set such that a soluble BOD concentration inside the semi-batch reaction tank upon completion of the biological treatment step of the second operation cycle does not exceed a threshold value.

2. The granule-forming method according to claim 1 , wherein a first sludge load/second sludge load ratio is two times or more.

3. The granule-forming method according to claim 1 , wherein
the second sludge load is set such that an ammoniacal nitrogen concentration inside the semi-batch reaction tank upon completion of the biological treatment step of the second operation cycle is 1 mgN/L or less.

4. The granule-forming method according to claim 1 , wherein
a biologically treated water outlet of the semi-batch reaction tank is provided above a wastewater inlet, and the biologically treated water is discharged from the treated water outlet by introducing the organic matter-containing wastewater into the semi-batch reaction tank from the wastewater inlet.

5. The granule-forming method according to claim 1 , the method further comprising supplying the granule to a continuous biological treatment tank.

6. The granule-forming method according to claim 2 , wherein
the second sludge load is set such that an ammoniacal nitrogen concentration inside the semi-batch reaction tank upon completion of the biological treatment step of the second operation cycle is 1 mgN/L or less.

7. The granule-forming method according to claim 2 , wherein
a biologically treated water outlet of the semi-batch reaction tank is provided above a wastewater inlet, and the biologically treated water is discharged from the treated water outlet by introducing the organic matter-containing wastewater into the semi-batch reaction tank from the wastewater inlet.

8. The granule-forming method according to claim 3 , wherein
a biologically treated water outlet of the semi-batch reaction tank is provided above a wastewater inlet, and the biologically treated water is discharged from the treated water outlet by introducing the organic matter-containing wastewater into the semi-batch reaction tank from the wastewater inlet.

Assignees

• Organo Corp

Inventors

• Matsuda Hatsuhiro
• Tomita Masaaki
• Hamamoto Aki
• Miyake Masaki
• Hasebe Yoshiaki
• Eguchi Masahiro

Classifications

• C02F3/10

  Packings; Fillings; Grids (packing elements in general B01J19/30, B01J19/32) · CPC title

• C02F3/12

  Activated sludge processes · CPC title

• C02F3/00

  Biological treatment of water, waste water, or sewage {(C02F1/006 takes precedence)} · CPC title

• C02F2203/004

  comprising a selector reactor for promoting floc-forming or other bacteria · CPC title

• C02F2209/08

  Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD] · CPC title