Methods and compositions for remediating cyanuric acid in aqueous liquids

Patent metadata

Field	Value
Publication number	US-12497315-B2
Application number	US-202017770270-A
Country	US
Kind code	B2
Filing date	Oct 14, 2020
Priority date	Oct 28, 2019
Publication date	Dec 16, 2025
Grant date	Dec 16, 2025

Abstract

The present disclosure is generally related to the fields of biology, inorganic chemistry, organic chemistry, molecular biology, enzymology, chlorinated water treatment processes and the like. More particularly, certain embodiments are related to reducing cyanuric acid concentrations in aqueous liquids, such as chlorinated swimming pool water, chlorinated hot tub water and the like.

First claim

The invention claimed is:

1 . A method for remediating cyanuric acid (CYA) in an aqueous liquid comprising at least 1.0 ppm free hypochlorite, the method comprising contacting the liquid with a reductant and an enzyme comprising cyanuric acid hydrolase (CAH) activity, wherein the liquid is first contacted with a reductant followed by an enzyme having CAH activity, or the liquid is simultaneously contacted with a reductant and an enzyme having CAH activity, wherein contacting the liquid with the reductant lowers the free hypochlorite concentration to 0.5 ppm or less.

2 . The method of claim 1 , wherein the liquid is first contacted with a reductant for a sufficient period of time to lower the free hypochlorite concentration in the liquid, followed by contacting the liquid with an enzyme comprising CAH activity.

3 . The method of claim 1 , wherein the enzyme comprising CAH activity is a solid enzyme or a liquid enzyme.

4 . The method of claim 1 , further comprising the addition of an enzyme having BH activity, wherein the enzyme comprising BH activity is a solid enzyme or a liquid enzyme.

5 . The method of claim 4 , wherein the enzyme comprising BH activity is a formulated granule.

6 . The method of claim 1 , wherein the enzyme comprising CAH activity is obtained or derived from a cell selected from the group consisting of M. thermoacetica cell, a Bradyrhizobium diazoefficiens cell, a Bradyrhizobium sp. cell, a Pseudolabrys sp. cell and an Acidovorax citrulli cell.

7 . The method of claim 1 , wherein the enzyme comprising CAH activity comprises an amino acid sequence of SEQ ID NO: 15 near the C-terminus.

8 . The method of claim 1 , wherein the reductant is selected from sulfate, sulfite, thiosulfate, sodium bisulfite, sodium metabisulfite, hydrogen peroxide, potassium iodide, iodate, ferrous iron (salts), copper, nickel, molybdenum, manganese (reduced salts), ascorbate, aldehydes, organosulfur compounds, poly-vinyl-pyrrolidone (PVP), vulcanized rubber, and electrochemical reduction.

9 . The method of claim 1 , wherein the enzyme comprising CAH activity is a formulated granule.

10 . The method of claim 1 , wherein contacting the liquid with the reductant lowers the free hypochlorite concentration to an undetectable level.

Assignees

• Danisco Us Inc
• Regent Of The Univ Of Minnesota

Inventors

• Aukema Kelly Gardner
• Dhaliwal Rajdeep S
• Guo Feng
• Heng Meng Hong
• Hoffmann Katherine
• Latone Jacob Andrew
• Wackett Lawrence Philip
• Whited Gregory M

Classifications

• C12Y305/02015

  Cyanuric acid amidohydrolase (3.5.2.15) · CPC title

• C12N15/52

  Genes encoding for enzymes or proenzymes · CPC title

• C02F2305/00

  Use of specific compounds during water treatment · CPC title

• C02F2103/42

  from bathing facilities, e.g. swimming pools · CPC title

• C02F2101/18

  Cyanides · CPC title