Method for treating wastewater and wastewater sludge using a percarboxylic acid

Patent metadata

Field	Value
Publication number	US-2020048118-A1
Application number	US-201716344856-A
Country	US
Kind code	A1
Filing date	Nov 17, 2017
Priority date	Nov 18, 2016
Publication date	Feb 13, 2020
Grant date	—

Abstract

The present invention provides a method for treating wastewater or wastewater sludge, in which method percarboxylic acid is used as an odor controlling agent and/or corrosion controlling agent.

First claim

1 . A method for treating wastewater and/or wastewater sludge, comprising using a treating chemical comprising percarboxylic acid as an odor controlling agent and/or corrosion controlling agent.

2 . The method according to claim 1 , wherein the percarboxylic acid is selected from the group consisting of performic acid, peracetic acid and a combination of thereof.

3 . The method according to claim 1 , wherein performic acid is used as the treating chemical.

4 . The method according to claim 4 , wherein an active concentration of the performic acid is at least 8%, at least 9%, at least 10%, or in a range of 8-14%, calculated as weight to volume.

5 . The method according to claim 1 , wherein the method comprising:
obtaining a wastewater or wastewater sludge stream, and adding the treating chemical comprising percarboxylic acid to the wastewater or wastewater sludge stream.

6 . The method according to claim 5 , wherein the wastewater or the wastewater sludge stream is a stream in municipal wastewater collection or treatment application, municipal sludge collection or treatment application or industrial wastewater application.

7 . The method according to claim 5 , further comprising:
measuring a concentration of dissolved sulfides in the wastewater or wastewater sludge stream prior to the addition of the treating chemical; and adjusting the addition of the treating chemical according to the information obtained about the concentration of the dissolved sulfides.

8 . The method according to claim 7 , wherein a concentration of dissolved sulfides in the wastewater or wastewater sludge stream is measured at a point, to which, the wastewater or wastewater sludge stream is flowed after the addition of the treating chemical.

9 . The method according to claim 7 , further comprising modifying a rate of the addition of the treating chemical to the wastewater or wastewater sludge stream based on the measurement of the concentration of dissolved sulfides.

10 . The method according to 5 , wherein the treating chemical is added continuously to the wastewater or wastewater sludge stream in at least one process location.

11 . The method according to claim 5 , wherein the treating chemical is added into the wastewater or wastewater sludge stream, so as to, bring the level of dissolved sulfides, in particular H 2 S, to a level of less than 5 ppm, less than 2 ppm, or less than 1 ppm in the wastewater stream.

12 . Use of a treating chemical comprising percarboxylic acid, performic acid, peracetic acid or a combination thereof, in odor control of the wastewater or wastewater sludge.

13 . The use of the treating chemical comprising percarboxylic acid, performic acid, peracetic acid or a combination thereof, in corrosion control of wastewater or wastewater sludge collection and treatment processes.

14 . The use according to claim 12 , wherein the treating chemical is performic acid.

15 . The use according to claim 13 , wherein an active concentration of the performic acid is at least 8%, at least 9%, at least 10%, or in a range of 8-14%, calculated as weight to volume.

Assignees

• Kemira Oyj

Inventors

• Allen James Currie
• Mariga Tafadzwa

Classifications

• C02F1/722 Primary

  Oxidation by peroxides · CPC title

• C02F2303/08

  Corrosion inhibition · CPC title

• C02F2303/02

  Odour removal or prevention of malodour · CPC title

• C02F2103/34

  from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 · CPC title

• C02F1/008

  Control or steering systems not provided for elsewhere in subclass C02F · CPC title