Use of Keplerate type polyoxymolybdates for decontaminating aquatic environments

Abstract

Use of Keplerate type polyoxomolybdates of the general structure Mo.sub.72M.sub.30, wherein M is selected from the group consisting of Fe, Cr, V or Mo.sub.2, for decontaminating aqueous media (water) from inorganic and organic pollutants.

Claims

1. A method comprising decontaminating aqueous media from inorganic and organic pollutants with a Keplerate type polyoxomolybdate of the general structure Mo.sub.72M.sub.30, wherein M is selected from the group consisting of Fe, Cr, V or Mo.sub.2, in combination with electromagnetic radiation having a wavelength exceeding 400 nm wherein the Keplerate type polyoxomolybdate is used in combination with a persulfate as an oxidizing agent.

2. The method in accordance with claim 1 wherein M is Fe.

3. The method in accordance with claim 1 wherein the electromagnetic radiation is sunlight.

4. The method in accordance with claim 1 wherein the aqueous media are selected from process waters of textile finishing, dye production, chemical synthesis, petrochemical synthesis or pharmaceutical synthesis or from waste water collecting systems in hospitals or urban environments.

5. The method in accordance with claim 1 wherein the pollutant is selected from organic pollutants.

6. The method in accordance with claim 5 wherein the organic pollutant is selected from pharmaceutically active ingredients, agricultural active ingredients, peptides or aromatic organic compounds.

7. The method in accordance with claim 5 wherein the organic pollutant is selected from pharmaceutically active ingredients and agriculturally active ingredients.

8. The method in accordance with claim 1 wherein the pollutant is selected from inorganic pollutants.

9. The method in accordance with claim 1 wherein the pollutant is a dyestuff.

10. A process for the decontamination of aqueous environments, the process comprising: adding a Keplerate type polyoxomolybdate of the general structure Mo.sub.72M.sub.30, wherein M is selected from the group consisting of Fe, Cr, V or Mo.sub.2, and a persulfate as an oxidizing agent to the aqueous environment forming an aqueous solution/slurry, and thereafter, irradiating the aqueous solution/slurry with electromagnetic radiation having a wavelength exceeding 400 nm.

11. A process for the decontamination of aqueous environments, the process comprising: flowing an aqueous solution comprising a persulfate as an oxidizing agent over a selected carrier while irradiating the aqueous solution with electromagnetic radiation having a wavelength exceeding 400 nm, wherein the selected carrier comprises a Keplerate type polyoxomolybdate of the general structure Mo.sub.72M.sub.30, wherein M is selected from the group consisting of Fe, Cr, V or Mo.sub.2, supported on a solid support.

Description

EXAMPLES

(1) 0.1 g Mo.sub.72Fe.sub.30, synthesized in accordance with Müller et al. Angew. Chem. Int. Ed. 39, 1612-1614 (2000), 2 grams of sodium persulfate, 20 ml of water and the substrate to be treated in accordance with the data given in Table 1 were irradiated in a quartz glass reactor with a Xe-lamp using a filter excluding radiation of wavelengths of less than 420 nm (thereby filtering out the UV radiation). The decomposition of the substrate was monitored by measuring the CO.sub.2 evolution at the upper end of the reactor with CG/MS. In addition, for some of the experiments, chromatographic (HPLC) or spectrophotometric (UV/VIS) measurements were carried out to show the degradation of the substrates. Table 1 shows the results obtained.

(2) TABLE-US-00001 TABLE 1 Duration of Degree of Conc irradiation degradation Pollutant (ppm) (h) % Analytical method Urea 2000 4 96 GC, GC-MS Ureic acid 1500 8 90 GC, GC-MS HPLC Pharmaceuticals.sup.1 600 4 94 GC, GC-MS HPLC 1,10-phenanthroline 1000 8 86 GC, GC-MS Tripeptide 1500 4 81 GC, GC-MS Escherichia coli 1000 12 >99 GC, GC-MS Benzene 2200 12 20 GC-MS Pyrene 1000 12 62 GC-MS Acetonitrile 2000 8 35 GC-MS Potassium hexacyanoferrate 2500 8 89 GC-MS Decamethylcyclopentasiloxane 4800 16 41 GC-MS Silicone oil 4800 18 24 GC-MS Fe(III)pththalocyanine chloride 1000 12 87 GC-MS Hematoporphyrine 1000 12 77 GC-MS Methylene blue 1000 8 97 GC-MS HPLC C.I Basic violet 3 1000 8 81 GC-MS HPLC Melamine 2000 12 83 GC-MS Pentafluorophenol 1500 8 85 GC-MS HPLC p-Nitrophenol 1250 12 74 GC-MS HPLC Triethanolamine 2800 8 42 GC-MS Methyl viologen 1000 12 77 GC-MS .sup.1Mixture of dichlofenac, carbamezipine and sulfo methaxol (200 ppm each)

(3) The results show that the use of POM in accordance with the present invention can be successfully applied to a great variety of different pollutants.

Example 2

(4) A dye contained in the leafs of canna lilies was extracted and degraded under the conditions in Example 1. The color change observed was proof of the successful degradation.

(5) The POM catalyst can also immobilized, thereby opening the possibility of a continuous operation. Examples showed that a simple LED emitting light in the visible range was sufficient to achieve the desired degradation.