METHOD OF TREATING WATER EFFLUENT FROM PURGING OR CLEANING STEAM GENERATOR CIRCUITS, AND A MOBILE UNIT ENABLING THE METHOD TO BE IMPLEMENTED

• US 20090261039A1
• Filed: 04/15/2009
• Published: 10/22/2009
• Est. Priority Date: 04/18/2008
• Status: Active Grant

• Current Assignee: Veolia Water Solutions & Technologies Support
• Original Assignee: Veolia Eau - Compagnie Generale des Eaux (Veolia Environnement SA)
• Inventors: Paillard, Herve, Bonnefoy, Joseph, Benedittis, Jerome De
• Granted Patent: US 8,679,342 B2
• Time in Patent Office: Days
• US Class Current: 210/638
• CPC Class Codes: B01D 61/025 Reverse osmosis; Hyperfiltration
• CPC Class Codes: C02F 1/04 by distillation or evaporation
• CPC Class Codes: C02F 1/441 by reverse osmosis
• CPC Class Codes: C02F 1/66 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 Class Codes: C02F 2101/101 Sulfur compounds
• CPC Class Codes: C02F 2101/105 Phosphorus compounds
• CPC Class Codes: C02F 2101/16 Nitrogen compounds, e.g. ammonia
• CPC Class Codes: C02F 2101/301 Detergents, surfactants
• CPC Class Codes: C02F 2101/303 Complexing agents
• CPC Class Codes: C02F 2103/023 Water in cooling circuits
• CPC Class Codes: C02F 2201/008 Mobile apparatus and plants, e.g. mounted on a vehicle for biological treatment C02F2203/008
• CPC Class Codes: C02F 2303/24 Separation of coarse particles, e.g. by using sieves or screens
• CPC Class Codes: C02F 9/00 Multistage treatment of water, waste water or sewage

Abstract

The invention relates to a method of treating water effluent from purging or cleaning steam generator circuits.

In characteristic manner, the following steps are performed:

• • filtering the raw effluent to separate insoluble matter from the filtered effluent; and
  • concentrating the filtered effluent to below the solubility limit of the dissolved species so as to obtain a liquid concentrate, the concentration step including at least evapo-concentration treatment and reverse osmosis treatment;
  • the pH of the effluent being adjusted to a value in the range 5 to 6.5.

Claims

1. A method of treating water effluent from purging or cleaning steam generator circuits, wherein the following steps are performed:

filtering the raw effluent to separate insoluble matter from the filtered effluent; and

concentrating the filtered effluent to below the solubility limit of the dissolved species so as to obtain a liquid concentrate, the concentration step including at least evapo-concentration treatment and reverse osmosis treatment;

the pH of the effluent being adjusted to a value in the range 5 to 6.5.

2. A method according to claim 1, wherein the pH of the effluent is adjusted upstream from the reverse osmosis treatment.

3. A method according to claim 1, wherein the pH is adjusted upstream from the evapo-concentration treatment.

4. A method according to claim 1, wherein the pH is adjusted upstream from the filtering step.

5. A method according to claim 1, wherein the evapo-concentration treatment is performed on the osmosis concentrate.

6. A method according to claim 1, wherein the reverse osmosis treatment is performed on the evapo-concentration distillate.

7. A method according to claim 1, wherein the concentration step further comprises treatment by ion exchange resin on the permeate of the reverse osmosis treatment.

8. A method according to claim 1, wherein the concentration step further comprises prior treatment by ion exchange resin that is implemented before any other treatment of the concentration step.

9. A method according to claim 1, wherein the following additional step is implemented:

the liquid concentrate is dried to form a dry concentrate.

10. A method according to claim 1, wherein the reverse osmosis treatment is performed in a single stage.

11. A method according to claim 1, wherein the reverse osmosis treatment is performed in two stages, with the second reverse osmosis stage being fed with the permeate from the first stage.

12. A method according to claim 11, wherein the pH of the effluent is adjusted between the two reverse osmosis stages.

14. A mobile unit according to claim 1, further including a module for treatment by ion exchange resin, the module having an inlet for regeneration solution, an inlet for liquid to be treated, and an outlet for eluate, and an outlet for filtrate.

13. A mobile unit for treating water effluent from purging or cleaning steam generator circuits, wherein the unit comprises:

an inlet duct suitable for being connected to a vessel containing the effluent;

a filter module suitable for separating insoluble matter from the filtered effluent;

an evapo-concentration treatment module having an inlet, a distillate outlet, and a concentrate outlet;

a reverse osmosis treatment module having an inlet, a permeate outlet, and a concentrate outlet;

a pH adjustment module having an inlet and an outlet;

at least one outlet duct for delivering treated effluent; and

pipes interconnecting the inlet ducts, the outlet ducts, and the inlets and outlets of the various modules, and valves enabling said pipes to be opened and closed.