Process for the removal of endocrine disrupting compounds

1. A process for the removal of an endocrine disrupting compound (EDC) from an aqueous medium, comprising (a) contacting the aqueous medium with (i) surface treated natural calcium carbonate or an aqueous suspension comprising surface treated calcium carbonate having a pH of greater than 6.0 measured at 20° C., so that the surface-treated natural calcium carbonate absorbs an EDC wherein the surface treated calcium carbonate is formed by treating natural calcium carbonate with carbon dioxide and one or more acids, wherein the carbon dioxide is formed in situ by the acid treatment and/or is supplied from an external source; and (b) separating the surface-treated natural calcium carbonate with absorbed EDC from the aqueous medium.

2. The process according to claim 1 , wherein the surface treated natural calcium carbonate is prepared as an aqueous suspension having a pH of greater than 6.5, measured at 20° C.

3. The process according to claim 1 , wherein the natural calcium carbonate is marble, calcite, chalk and dolomite, limestone or mixtures thereof.

4. The process according to claim 1 , wherein the acid has a pK a at 25° C. of 2.5 or less.

5. The process according to claim 4 , wherein the acid is hydrochloric acid, sulphuric acid, sulphurous acid, hydrosulphate, phosphoric acid, oxalic acid or mixtures thereof.

6. The process according to claim 1 , wherein the natural calcium carbonate is treated with the acid and the carbon dioxide in the presence of at least one silicate and/or silica, aluminum hydroxide, earth alkali metal aluminate, magnesium oxide, or mixtures thereof.

7. The process according to claim 6 , wherein the at least one silicate is an aluminum silicate, a calcium silicate or an alkali metal silicate.

8. The process according to claim 1 , wherein the surface treated natural calcium carbonate has a specific surface area of from 5 m 2 /g to 200 m 2 /g, measured using nitrogen and the BET method according to ISO 9277.

9. The process according to claim 1 , wherein the surface treated natural calcium carbonate has a mean grain diameter d 50 of from 0.1 to 50 μm measured according to the sedimentation method.

10. The process according to claim 1 , wherein the aqueous suspension of surface treated natural calcium carbonate is stabilized with one or more dispersants.

11. The process according to claim 1 , wherein the surface treated natural calcium carbonate is used in powder form and/or in the form of granules.

12. The process according to claim 1 , wherein the surface treated calcium carbonate is contacted with the aqueous medium at a dosage (weight-based) of 10 2 to 10 9 times the mass of EDC.

13. The process according to claim 1 , wherein the pH of the aqueous medium is adjusted to a value of >6 before being brought into contact with the surface treated natural calcium carbonate.

14. The process according to claim 1 , wherein the EDC is an endogenous hormone, 17β-estradiol (E2), estrone (El), estriol (E3), testosterone, dihydro testosterone, a phyto hormone, a myco hormone, β-sitosterol, genistein, daidzein, zeraleon, a drug, 17α-ethinylestradiol (EE2), mestranol (ME), diethylstilbestrol (DES), an industrial chemical, 4-nonyl phenol (NP), 4-tert-octyl phenol (OP), bisphenol A (BPA), tributyltin (TBT), methylmercury, a phthalates, PAK or PCB.

15. The process according to claim 1 , wherein activated carbon is brought into contact with the aqueous medium.

16. The process according to claim 15 , wherein activated carbon is brought into contact with the aqueous medium prior to contacting the aqueous medium with the surface treated calcium carbonate.

17. The process according to claim 15 , wherein the activated carbon has a grain size of 0.1 μm to 5 mm.

18. The process according to claim 15 , wherein the weight ratio of the surface treated natural calcium carbonate to the activated carbon is from 1:1 to 100:1.

19. The process according to claim 1 , wherein the surface-treated natural calcium carbonate is prepared as an aqueous suspension having a pH of greater than 7.0, measured at 20° C.

20. The process according to claim 1 , wherein the surface-treated natural calcium carbonate is prepared as an aqueous suspension having a pH of greater than 7.5, measured at 20° C.

21. The process according to claim 1 , wherein the surface-treated natural calcium carbonate has a specific surface area of from 20 m 2 /g to 80 m 2 /g, measured using nitrogen and the BET method according to ISO 9277.

22. The process according to claim 1 , wherein the surface-treated natural calcium carbonate has a specific surface area of from 30 m 2 /g to 60 m 2 /g, measured using nitrogen and the BET method according to ISO 9277.

23. The process according to claim 1 , wherein the surface-treated natural calcium carbonate has a mean grain diameter d 50 of from 0.5 to 25 μm, measured according to the sedimentation method.

24. The process according to claim 1 , wherein the surface-treated natural calcium carbonate has a mean grain diameter d 50 of from 0.8 to 20 μm, measured according to the sedimentation method.

25. The process according to claim 1 , wherein the surface-treated natural calcium carbonate has a mean grain diameter d 50 of from 1.0 to 10 μm, measured according to the sedimentation method.

26. The process according to claim 1 , wherein the surface-treated calcium carbonate is contacted with the aqueous medium at a dosage (weight-based) of 2·10 4 to 10 6 times the mass of EDC.

27. The process according to claim 1 , wherein the surface-treated calcium carbonate is contacted with the aqueous medium at a dosage (weight-based) of 10 4 to 3·10 5 times the mass of EDC.

28. The process according to claim 1 , wherein the pH of the aqueous medium is adjusted to a value of >6.5 before being brought into contact with the surface-treated natural calcium carbonate.

29. The process according to claim 1 , wherein the pH of the aqueous medium is adjusted to a value of >7 before being brought into contact with the surface-treated natural calcium carbonate.

30. The process according to claim 15 , wherein the activated carbon has a grain size of 10 μm to 2 mm.

31. The process according to claim 15 , wherein the activated carbon has a grain size of 0.1 μm to 0.5 mm.

32. The process according to claim 15 , wherein the activated carbon has a grain size of 0.3 μm.

33. The process according to claim 15 , wherein the weight ratio of the surface-treated natural calcium carbonate to the activated carbon is from 5:1 to 80:1.

34. The process according to claim 15 , wherein the weight ratio of the surface-treated natural calcium carbonate to the activated carbon is from 10:1 to 70:1.

35. The process according to claim 15 , wherein the weight ratio of the surface-treated natural calcium carbonate to the activated carbon is from 20:1 to 50:1.

36. The process according to claim 15 , wherein the weight ratio of the surface-treated natural calcium carbonate to the activated carbon is from 30:1.

37. The process according to claim 15 , wherein the weight ratio of the surface-treated natural calcium carbonate to the activated carbon is from 50:1.

38. The process according to claim 1 , wherein the carbon dioxide is formed in situ by the acid treatment.

39. The process according to claim 1 , wherein the carbon dioxide is supplied from an external source.