Treatment system comprising wood-based organic material and its use in wastewater treatment, and method for removing dissolved organic compounds from wastewater

Patent metadata

Field	Value
Publication number	US-12116294-B2
Application number	US-202017618815-A
Country	US
Kind code	B2
Filing date	Jun 12, 2020
Priority date	Jun 14, 2019
Publication date	Oct 15, 2024
Grant date	Oct 15, 2024

Abstract

A treatment system for removing dissolved organic compounds from wastewater, which comprises a water-soluble cationic polymer, and wood-based organic material having an average particle size <10 mm. The invention relates also use of said treatment system for COD removal in the treatment of wastewaters, and a method for removing dissolved organic compounds from wastewater.

First claim

The invention claimed is:

1. A method to treat wastewater originating from pulp and/or paper mill, the method comprising:
obtaining wastewater from the pulp and/or paper mill;
providing a water-soluble synthetic cationic polymer and/or cationic bio-based polymer;
providing wood-based organic material in a form of powder, flakes, chips, sticks and/or other particles having an average particle size <10 mm;
preparing a blend of the wood-based organic material and the water-soluble synthetic cationic polymer and/or cationic bio-based polymer;
providing an Al and/or Fe based inorganic metal coagulant;
combining the Al and/or Fe based inorganic metal coagulant and the blend of the wood-based organic material and the water-soluble synthetic cationic polymer and/or cationic bio-based polymer in a weight ratio of 4:1-1:10; and
adding into the wastewater the combined Al and/or Fe based inorganic metal coagulant and the blend of the wood-based organic material and the water-soluble synthetic cationic polymer and/or cationic bio-based polymer.

2. The method according to claim 1 , wherein the wood-based organic material comprises saw dust, wood bark, mechanically grinded wood particles, wood flour, wood powder or any combination of them.

3. The method according to claim 1 , wherein the average particle size of the wood-based organic material is <5 mm.

4. The method according to claim 1 , wherein the average particle size of the wood-based organic material is in a range of 0.010-10 mm.

5. The method according to claim 1 , wherein a weight ratio of the wood-based organic material and the synthetic cationic polymer and/or cationic bio-based polymer is 0.5:1-5:1, calculated by using active amount of the synthetic cationic polymer and/or cationic bio-based polymer, respectively.

6. The method according to claim 1 , wherein a weight ratio of the Al and/or Fe based inorganic metal coagulant and the blend of wood-based organic material and the synthetic cationic polymer and/or cationic biobased polymer is 4:1-1:4, calculated by using active metal content and active amount of the synthetic cationic polymer and/or cationic biobased polymer.

7. The method according to claim 1 , wherein the synthetic cationic polymer comprises polyamine, polyvinylamine, polyethyleneimine, polydicyandiamide (polyDCD), polydiallyldimethylammonium chloride (polyDADMAC), poly(acryloyloxyethyl trimethylammonium chloride) (polyADAM-Cl), poly (methacryloyloxyethyl trimethylammonium chloride) (polyMADAM-Cl), poly (acrylamido-N-propyltrimethylammonium chloride) (polyAPTAC), poly (methacrylamidopropyltrimethylammonium chloride) (polyMAPTAC) and/or a copolymer of (meth)acrylamide and cationic monomers selected from diallyl dimethylammonium chloride (DADMAC), acryloyloxyethyl trimethylammonium chloride (ADAM-Cl), methacryloyloxyethyltrimethylammonium chloride (MADAM-Cl), acrylamide-N-propyltrimethylammonium chloride (APTAC) and/or methacrylamidopropyltrimethylammonium chloride (MAPTAC).

8. The method according to claim 7 , wherein the synthetic cationic polymer comprises polyamine and/or polydiallyldimethylammonium chloride (polyDADMAC).

9. The method according to claim 1 , wherein the cationic bio-based polymer comprises cationic starch having degree of substitution (DS) value at least 0.3.

10. The method according to claim 1 , wherein the Al and/or Fe based inorganic metal coagulant comprises aluminium sulphate, polyaluminium chloride, iron sulphate, ferric chloride or any combination of them.

11. The method according to claim 1 , wherein the coagulant is added to wastewater after biological treatment step of the wastewater and prior to tertiary treatment.

12. The method according to claim 1 , wherein pH of the wastewater is adjusted <7 prior to addition of the coagulant.

13. The method according to claim 3 , wherein the average particle size of the wood-based organic material is in a range of 0.050-5 mm.

14. The method according to claim 5 , wherein the weight ratio of the wood-based organic material and the synthetic cationic polymer and/or cationic bio-based polymer is 1:1-3:1 calculated by using active amount of the synthetic cationic polymer and/or cationic bio-based polymer, respectively.

15. The method according to claim 14 , wherein the weight ratio of the wood-based organic material and the synthetic cationic polymer and/or cationic bio-based polymer is 1:1-2:1 calculated by using active amount of the synthetic cationic polymer and/or cationic bio-based polymer, respectively.

16. The method according to claim 6 , wherein the weight ratio of the Al and/or Fe based inorganic metal coagulant and the blend of wood-based organic material and the synthetic cationic polymer and/or cationic biobased polymer is 1:1-1:4, calculated by using active metal content and active amount of the synthetic cationic polymer and/or cationic biobased polymer.

17. The method according to claim 9 , wherein the cationic bio-based polymer comprises cationic starch having degree of substitution (DS) value at least 0.4.

18. The method according to claim 12 , wherein pH of the wastewater is adjusted into a range of 3-6 prior to addition of the coagulant.

Assignees

• Kemira Oyj

Inventors

• Halttunen Sakari
• Penttinen Matias
• Ahlgren Jonni
• Härkönen Susann
• Shestakova Marina

Classifications

• C02F2209/08

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

• C02F2103/28

  from the paper or cellulose industry · CPC title

• C02F1/66

  by neutralisation; pH adjustment (for degassing C02F1/20; using ion-exchange C02F1/42; for flocculation or precipitation of suspended impurities C02F1/52; for removing dissolved compounds C02F1/58) · CPC title

• C02F1/56

  Macromolecular compounds · CPC title

• B03D2201/002

  Coagulants and Flocculants · CPC title