Method for treating water containing organic matter using ion exchange and ballasted flocculation

Patent metadata

Field	Value
Publication number	US-9957182-B2
Application number	US-201514959711-A
Country	US
Kind code	B2
Filing date	Dec 4, 2015
Priority date	Dec 5, 2014
Publication date	May 1, 2018
Grant date	May 1, 2018

Abstract

Method for treating water, containing organic matter characterized in that it comprises a step of adsorption of the organic matter contained in said water, in which this water is put into contact with an amagnetic ion-exchanging resin in an infinitely stirred tank ( 1 ); the filtering of the mixture of water and resin within the tank ( 1 ) and the discharging of filtered water from this tank, the filtering being implemented through at least one screen ( 4 ) provided within the tank ( 1 ) enabling the resin to be contained in the infinitely stirred tank; the periodic cleansing of the screen ( 4 ) consisting of the separation, from this screen, of the saturated resin that has collected thereon; the drawing off ( 18 ) of saturated resin from the tank ( 1 ); the regenerating ( 6 ) of at least a part of the saturated resin thus drawn off; the recycling ( 7 ) of said resin thus regenerated in the tank ( 1 ); a step of ballasted coagulation/flocculation ( 12, 13 ) and separation ( 14 ) comprising the addition of coagulant reagent ( 12 b ), flocculent reagent ( 13 b ) and microballast ( 21 ) to the filtered water coming from the tank ( 1 ) leading to the formation of flocs; the separation of the formed flocs from a clarified water ( 16 ); and the discharging ( 16 ) of the clarified water; and the discharging ( 17 ) of the sludges formed by the separated flocs.

First claim

The invention claimed is:

1. A method for treating water containing organic matter comprising:
contacting the organic matter contained in the water with an amagnetic ion exchange resin in a stirred tank and adsorbing the organic matter onto the resin;
filtering the mixture of water and resin within the tank and discharging the filtered water from the tank;
said filtering being implemented through at least one screen in the tank and wherein the filtering of the water in the tank is such that the resin is contained within the tank and some used resin is collected on the screen;
periodically cleaning the at least one screen and separating from the screen used resin that is collected on the screen;
removing the used resin from the tank;
regenerating at least a portion of the used resin removed from the tank;
recycling at least a portion of the regenerated resin to the tank;
directing the filtered water to a downstream ballasted flocculation and separation system;
in the ballasted flocculation and separation system, adding a coagulant reagent, a flocculant reagent and a microballast to the filtered water which causes the formation of flocs;
separating the formed flocs from a clarified water;
discharging the clarified water from the ballast flocculation and separation system; and
wherein the flocs form a part of sludge and the method includes discharging the sludge from the ballasted flocculation and separation system.

2. The method of claim 1 wherein cleaning the screen includes injecting a fluid into and through the screen where the injected fluid flows in a direction generally counter to the direction of flow of the filtered water.

3. The method of claim 1 wherein the regeneration of the used resin comprises the elution of the organic matter adsorbed on this resin by passage of an eluent on said resin and the recovery of an eluate, said eluate being fractioned into at least one fraction highly charged with organic matter and at least one fraction not highly charged with organic matter, said fraction highly charged with organic matter being discharged and said fraction not highly charged with organic matter being recycled as an eluent.

4. The method according to claim 1 , characterized in that the separation of said flocs is done by flotation.

5. The method according to claim 1 , characterized in that the separation of said flocs is done by lamellar or non-lamellar decantation.

6. The method according to claim 1 , characterized in that said resin is an anionic resin.

7. The method of claim 1 further including maintaining the concentration of resin in the water in the tank in the range of 100-200 ml of resin per liter of water.

8. The method of claim 1 wherein regenerating the resin includes employing a brine as an eluent.

9. The method of claim 8 wherein the eluent is NaCl.

10. The method of claim 1 wherein recycling the regenerated resin includes providing a resin renewal rate in the tank of 2-4 ml of resin per liter of water.

11. The method of claim 1 wherein organic matter and suspended solids are removed from the water through the processes in the tank and the ballasted flocculation and separation system such that the clarified water leaving the ballasted flocculation and separation system includes an organic matter content expressed in TOC of 1 mgC/L and a turbidity in NTU below 1.

Assignees

• Veolia Water Solutions & Tech

Inventors

• Sauvignet Philippe
• Gaid Abdelkader

Classifications

• B01D21/0084

  Enhancing liquid-particle separation using the flotation principle (flotation in general B03D1/00) · CPC title

• C02F2001/422

  using anionic exchangers · CPC title

• C02F2101/30

  Organic compounds · CPC title

• C02F1/5245

  using basic salts, e.g. of aluminium and iron · CPC title

• C02F1/42

  by ion-exchange (ion-exchange in general B01J) · CPC title