Method for the removal of submicron particulates from chlorinated water by sequentially adding a cationic polymer followed by adding an anionic polymer

1. A method for removing submicron particulates from water containing a halogenating agent, comprising:

(a) adding chitosan to water comprising submicron particulates and a halogenating agent to provide chitosan-treated water;

(b) adding a soluble, anionic polymer comprising alginate to the chitosan-treated water to provide polymer-treated water;

(c) allowing flocs comprising submicron particulates to form in the polymer-treated water; and

(d) filtering the flocs to remove the submicron particulates from the water.

2. The method of claim 1 , wherein the chitosan is in solution when added to the water.

3. The method of claim 2 , wherein the solution comprises acetic acid.

4. The method of claim 1 , further comprising adding at least one of sodium hexametaphosphate, sodium carboxymethylcellulose, pectin, polyacrylic acid, anionic polysaccharide, carrageenan, or polyacrylamide.

5. The method of claim 4 , wherein the polymer concentration in the water is about 5 ppb to about 100 ppm by weight.

6. The method of claim 1 , wherein the water is in a swimming pool, spa, water park, or hot tub.

7. The method of claim 1 , comprising filtering the flocs in at least one of a sand, cartridge, or diatomaceous earth filter.

8. The method of claim 1 , further comprising adding an inorganic aluminum coagulant.

9. The method of claim 8 , wherein the inorganic aluminum coagulant is aluminum sulfate or polyaluminum chloride.

10. The method of claim 8 , wherein the inorganic aluminum coagulant concentration in the water is about 50 ppb to about 100 ppm by weight.

11. The method of claim 1 , further comprising adding a ferric salt coagulant to the water.

12. The method of claim 11 , wherein the ferric salt coagulant is ferric sulfate or ferric chloride.

13. The method of claim 11 , wherein the ferric salt coagulant concentration in the water is about 50 ppb to about 100 ppm by weight.

14. The method of claim 1 , wherein the chitosan concentration in the water is about 5 ppb to about 100 ppm by weight.

15. The method of claim 1 , wherein the halogenating agent comprises at least one of sodium hypochlorite, calcium hypochlorite, chlorine, hypochlorous acid, bromine, hypobromous acid, N-chlorosuccinimide, sodium hypobromite, pyridinium bromide, perbromide, N-bromosuccinimide, chloramine-T, chlorhexadine, dichlorodimethylhydantoin, bromochlorodimethylhydantoin, dibromodimethylhydantoin, dichloroisocyanurate, or trichloroisocyanurate.

16. The method of claim 1 , wherein the halogenating agent concentration in the water is about 1 ppm to about 50 ppm by weight.

17. The method of claim 1 , wherein the halogenating agent concentration in the water is about 2 ppm to about 20 ppm by weight.

18. The method of claim 1 , wherein the submicron particulates further comprise a nonpolar hydrocarbon.

19. The method of claim 1 , wherein the submicron particulates further comprise oil.

20. The method of claim 1 , wherein the submicron particulates include particles in the range from about 0.5 microns to less than 1 micron.

21. The method of claim 1 , wherein the submicron particulates include particles in the range of from about 0.3 microns to less than 0.5 microns.

22. The method of claim 1 , wherein the submicron particulates include particles in the range of from about 0.2 microns to about 0.3 microns.

23. The method of claim 1 , wherein the submicron particulates include particles less than 0.5 microns.

24. The method of claim 1 , wherein step (b) follows step (a).

25. The method of claim 1 , wherein step (b) is performed about 4 hours to about 8 hours after performing step (a).

26. The method of claim 1 , wherein the water comprises a biguanide.

27. A method for clarifying water, comprising:

to water containing about 2 ppm to about 20 ppm by weight of a halogenating agent and submicron particulates, adding chitosan to reach a concentration in the water of about 5 ppb to about 100 ppm by weight;

followed by adding to the water, a soluble, anionic polymer comprising alginate to reach a concentration in the water of about 5 ppb to about 100 ppm by weight; and

filtering the water to remove flocs comprising submicron particulates, to clarify said water.

28. A method for clarifying water, comprising:

to water containing about 2 ppm to about 20 ppm by weight of a halogenating agent and submicron particulates, adding a soluble, cationic polymer comprising chitosan to reach a concentration in the water of about 5 ppb to about 100 ppm by weight;

followed by adding to the water, a soluble, anionic polymer or anionic salt comprising alginate to reach a concentration in the water of about 5 ppb to about 100 ppm by weight; and

filtering the water to remove flocs comprising submicron particulates, to clarify said water.

29. A method for removing submicron particulates from water, comprising:

adding a soluble, cationic polymer comprising chitosan to water containing a halogenating agent and submicron particulates;

allowing dispersal of the soluble, cationic polymer to occur in the water;

followed by adding a soluble, anionic polymer or anionic polymer salt comprising alginate to the water; and

filtering the water to remove flocs comprising submicron particulates.

30. A method for clarifying water in a swimming pool, comprising:

adding a soluble, cationic polymer comprising chitosan to water containing submicron particulates in a swimming pool;

allowing the soluble, cationic polymer to disperse throughout the water in the swimming pool;

followed by adding a soluble, anionic polymer or anionic salt comprising alginate to the water in the swimming pool; and

filtering the water of the swimming pool to remove the flocs comprising submicron particulates formed from the cationic polymer and the anionic polymer, to clarify said water.