System and method for maintaining water quality in large water bodies

• US 9,470,008 B2
• Filed: 12/09/2014
• Issued: 10/18/2016
• Est. Priority Date: 12/12/2013
• Status: Active Grant

• Current Assignee: Crystal Image Technology Incorporated
• Original Assignee: Crystal Lagoons (Curacao) B.V. (Crystal Lagoons Corp.)
• Inventors: Fischmann, Fernando Benjamin
• Primary Examiner(s): Keyworth, Peter
• Application Number:
  US14/564,957
• Publication Number:
  US 20150166361A1
• Time in Patent Office: 679 Days
• US Class Current: 1/1
• CPC Class Codes: C02F 1/001 Processes for the treatment of water whereby the filtration technique is of importance C02F1/44 takes precedence; construction of filters in general B01D24/00 - B01D41/00
• CPC Class Codes: C02F 1/008 Control or steering systems not provided for elsewhere in subclass C02F
• CPC Class Codes: C02F 1/40 Devices for separating or removing fatty or oily substances or similar floating material cleaning or keeping clear the surface of open water from oil or like materials E02B15/04; devices in sewers for separating liquid or solid substances from sewage E03F5/14, e.g. for use in drains leading to the sewer E03F5/16
• CPC Class Codes: C02F 1/52 by flocculation or precipitation of suspended impurities C02F1/463 takes precedence
• CPC Class Codes: C02F 1/5245 using basic salts, e.g. of aluminium and iron
• CPC Class Codes: C02F 1/5263 using natural chemical compounds
• CPC Class Codes: C02F 1/5272 using specific organic precipitants
• CPC Class Codes: C02F 1/5281 Installations for water purification using chemical agents
• CPC Class Codes: C02F 1/56 Macromolecular compounds
• CPC Class Codes: C02F 1/76 with halogens or compounds of halogens C02F1/4674 takes precedence
• CPC Class Codes: C02F 2001/007 Processes including a sedimentation step
• CPC Class Codes: C02F 2103/007 Contaminated open waterways, rivers, lakes or ponds
• CPC Class Codes: C02F 2103/42 from bathing facilities, e.g. swimming pools
• 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 2209/008 comprising telecommunication features, e.g. modems or antennas
• CPC Class Codes: C02F 2209/06 pH
• CPC Class Codes: C02F 2209/08 Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD]
• CPC Class Codes: C02F 2209/11 Turbidity
• CPC Class Codes: C02F 2209/15 N03-N
• CPC Class Codes: C02F 2209/18 PO4-P
• CPC Class Codes: C02F 2209/22 : O2
• CPC Class Codes: C02F 2209/29 : Chlorine compounds
• CPC Class Codes: C02F 2209/36 : Biological material, e.g. enzymes or ATP
• CPC Class Codes: C02F 2209/44 : Time
• CPC Class Codes: C02F 2303/04 : Disinfection
• 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
• CPC Class Codes: E04H 4/1209 : Treatment of water for swimming pools filters B01D
• CPC Class Codes: E04H 4/1281 : Devices for distributing chemical products in the water of swimming pools
• CPC Class Codes: E04H 4/16 : specially adapted for cleaning
• CPC Class Codes: E04H 4/1654 : Self-propelled cleaners

Abstract

The present application relates to an innovative and optimized method and system for maintaining water quality in water bodies such as excavated inland structures and floating structures with bottoms comprising flexible membranes, using a simplified economic filtration system and degreasing system that requires much smaller filtration equipment than conventional centralized filtration systems and provides for consumption of significantly lower amounts of energy. The method of the invention allows activating a chemical application system, mobile suctioning device, and/or degreasing system based on information regarding turbidity, the color of the bottom of the water body, and amount of greases on the surface water layer of the water body, to adjust the water quality parameters within their limits.

Claims

1. A method for treating large water bodies for recreational uses, including large artificial excavated or floating structures with bottoms comprising flexible membranes, wherein the method comprises:

(a) applying an effective amount of a flocculant to water in the water body to maintain turbidity of the water below 2 NTU, wherein the flocculant flocculates suspended solids in the water into particles that settle to the bottom of the water body;

(b) monitoring to determine the color of the bottom of the water body, receiving information regarding the color of the bottom and activating a mobile suctioning device to adjust the color within a set limit by suctioning settled particles from the bottom of the water body;

(c) operating the mobile suctioning device to maintain an increase in a black component of the color of the bottom below 30% based on the CMYK scale, wherein the mobile suction device moves on the bottom of the water body and suctions a portion of water from the bottom of the water body containing settled particles, wherein the device is capable of moving and cleaning at a rate of 10,000 m² per 24 hours, and wherein operating the mobile suctioning device does not re-suspend more than 30% of the settled particles in the area on the bottom of the water body cleaned by the mobile suction device;

(d) filtering the water suctioned by the mobile suction device and returning the filtered water to the water body, wherein the water suctioned by the mobile suction device does not exceed 10% of the total water volume of the water body in a 24 hour interval; and

(e) operating a degreasing system to maintain a surface water layer having less than about 20 mg/L of floating greases within a top-most 1 cm of the surface water layer, wherein greases from the surface water layer flow into the degreasing system and are removed by a separation unit comprising a degreaser, and the water that has passed through the degreaser is returned to the water body.

2. The method of claim 1, further comprising adding a chlorine-based additive to maintain at least a minimum free residual chlorine level in the water, where the minimum free residual chlorine level is at least the value resulting from the following equation:

Minimum Free Residual Chlorine Level=(0.3−

0.002(WQI−

100))ppm.

3. The method of claim 1, wherein the water body has a surface area of at least 7,000 m³.

4. The method of claim 1, wherein the flexible membrane has a thickness between about 0.1 mm and about 5 mm.

5. The method of claim 1, wherein the flexible membrane comprises rubber, plastic, Teflon, low density polyethylene, high density polyethylene, polypropylene, nylon, polystyrene, polycarbonate, polyethylene terephthalate, polyamides, PVC, acrylics, or a combination thereof.

6. The method of claim 1, wherein the suctioning device is supported over brushes to avoid damaging the bottom of the artificially constructed structures.

7. The method of claim 1, wherein the suctioning device is a self-propelled device.

8. The method of claim 1, wherein the suctioning device allows concentration of suctioning power at suction points distributed along the bottom of the device, therefore providing higher suctioning efficiency and avoiding re-suspending the settled materials and debris found on the bottom.

9. The method of claim 1, further comprising receiving information regarding the turbidity of the water and applying flocculants to adjust the turbidity below a set limit.

10. The method of claim 1, wherein the turbidity is determined by empirical methods, analytical methods, or algorithms based on experience.

11. The method of claim 1, wherein a control system activates the application of additives, the operation of the suctioning device, and the operation of the degreaser system.

12. The method of claim 11, wherein the control system is an automated system that processes information.

13. The method of claim 11, wherein the control system may be operated on site.

14. The method of claim 11, wherein the control system may be operated remotely through an interne connection or other information-exchange system.

15. The method of claim 11, wherein the control system receives information regarding the turbidity of the water and activates the flocculant application to adjust the turbidity within a set limit.

16. The method of claim 1, wherein the flocculant comprises synthetic polymers comprising quaternary ammonium-containing polymers or polycationic multivalent cations;

aluminum salts;

calcium oxide;

calcium hydroxide;

ferrous sulphate;

ferric chloride;

polyacrylamide;

sodium aluminate;

sodium silicate;

natural agents comprising chitosan, gelatin, guar gum, alginates, or moringa seeds;

starch derivatives;

or combinations thereof.

17. The method of claim 1, wherein flocculant comprises algaecide properties.

18. The method of claim 1, wherein the flocculant is dispensed into the water by a chemical application system comprising at least one selected from the group consisting of injectors, sprinklers, dispensers, manual application, and piping.

19. The method of claim 2, further comprising receiving information regarding the free residual chlorine level in the water.

20. The method of claim 2, wherein the minimum free residual chlorine level is determined by empirical methods, analytical methods, or algorithms based on experience.

21. The method of claim 2, wherein a control system activates the chlorine-based additive application.

22. The method of claim 2, wherein the chlorine-based additive is dispensed into the water by a chemical application system comprising at least one selected from the group consisting of injectors, sprinklers, dispensers, manual application, and piping.

23. The method of claim 18, wherein the chemical application system is disposed to provide homogeneity to the water body, wherein water quality between two different locations differs less than 20% for periods of time longer than 4 hours.

24. The method of claim 1, further comprising receiving information regarding the color of the bottom of the water body and activating the mobile suctioning device to adjust the color within a set limit by suctioning settled particles from the bottom of the water body.

25. The method of claim 1, wherein the color is determined by an empirical methods, sensory methods, analytical methods, or algorithms based on experience.

26. The method of claim 1, wherein the color of the bottom of the structure is determined using a colorimeter.

27. The method of claim 1, wherein operation of the mobile suctioning device is activated based on an amount of impurities that have settled onto the bottom of the water body and affect the color of the bottom, the amount of settled impurities corresponding to an amount of turbidity removed from the water.

28. The method of claim 11, wherein the control system receives information regarding the color of the bottom of the water body and activates the operation of a suctioning device to adjust the color within a set limit.

29. The method of claim 11, wherein the control system receives information regarding amount of floating greases and activates the operation of the degreasing system to adjust the amount of floating greases within a set limit.

30. The method of claim 1, wherein the degreasing system comprises skimmers to provide the surface water flow into the separation unit.

31. The method of claim 1, wherein the degreaser comprises an overflow apparatus for separating oils and greases from the water.

32. The method of claim 1, wherein the degreasing system comprises one or more screens for retaining large debris and a degreaser for separating water from oils and greases through overflow.

33. The method of claim 1, wherein the degreasing system comprises a filter.

34. The method of claim 1, wherein the method is applied to a bathing zone within the water body.

35. The method of claim 2, wherein the minimum residual chlorine level is maintained continuously within the water body.

36. The method of claim 2, wherein the minimum residual chlorine level is maintained for a period of time within the water body.

37. The method of claim 2, wherein the minimum residual chlorine level is maintained when the water body is in use.

38. The method of claim 1, wherein the impurities comprise suspended solids, organic matter, inorganic matter, bacteria, or algae.

39. The method of claim 1, wherein the water body comprises an excavated structure having a bottom and walls to contain the water and a non-permeable flexible membrane covering the bottom of the water body, the bottom having a slope that is about 20% or less and the walls having a slope that is greater than about 45%.

40. The method of claim 39, wherein soil forming the bottom of the excavated structure is compacted soil, the soil being compacted to at least 80% of its relative density (RD) if a passage rate of the soil forming the bottom of the excavated structure through N°

200 mesh is less than 12%.

41. The method of claim 39, wherein soil forming the bottom of the excavated structure is compacted soil, the soil being compacted to at least 85% of its maximum dry density (MDD) if a passage rate of the soil forming the bottom of the excavated structure through N°

200 mesh is greater than 12%.

42. The method of claim 1, wherein the bottom comprises a colored material with a white, yellow, or blue color.