Patent EA-000561-B1 (EA)
Title: Method for reducing soluable metals from an aqueous phase
Inventor: RASKIN ILYA
IPC: C02F3/32
Filed: 1996-04-16
Abstract: 1. A method for reducing an amount of metal in a metal-containing solution, comprising steps in which metal-containing solution, free of at least one nutrient needed to support plant growth contacting with the bottom part of a terrestrial plant, comprising at least a root biomass of the plant, contacting the second part of the terrestrial plant with a composition comprising at least one nutrient needed to support plant growth and which is absent in the solution, wherein the contact between the first part of the plant and the solution and the contact between the second part and composition maintain during a period of time and under conditions sufficient for growing a plant and for removing, at least, some metal from the solution not adding into it, at least, one nutrient. 2. The method of Claim 1, further comprising separating the terrestrial plant from the solution. 3. The method of Claim 2, further comprising processing the terrestrial plant for its metal content after separating the terrestrial plant from the solution. 4. The method of Claim 1, wherein the step of contacting comprises contacting the solution with the root biomass by growing the terrestrial plant in a receptacle and allowing the root biomass of the terrestrial plant to penetrate through the receptacle into the metal-containing solution, free of plant nutrients. 5. The method of Claim 4, wherein the receptacle is disposed at an air/solution interface of the metal-containing solution. 6. The method of Claim 4, wherein the receptacle is disposed above an air/solution interface of the metal-containing solution. 7. The method of Claim 4, wherein the step of growing comprises incorporating plant nutrients into the receptacle from a plant nutrient source that is external to the metal-containing solution, free of plant nutrients. 8. The method of Claim 4, wherein the receptacle comprises a feeder layer for receiving externally supplied plant nutrients. 9. A method for reducing an amount of metal in a metal-containing solution, comprising: contacting a terrestrial plant or terrestrial plant seed with a receptacle disposed above an air/solution interface of the metal-containing solution, the solution substantially free of one or several plant nutrients needed to support plant growth contacting the solution with the root biomass of the terrestrial plant, growing the root biomass under conditions for the root biomass of the terrestrial plant to remove at least some metal from the solution without adding into the solution one or several nutrients. 10. The method of Claim 9, further comprising separating the terrestrial plant from the solution. 11. The method of Claim 9, wherein the receptacle is disposed at an air/solution interface of the metal-containing solution. 12. The method of Claim 9, wherein the receptacle is disposed above air/solution interface of the metal-containing solution. 13. The method of Claims 1 or 8, wherein the metal is selected from the group consisting of lead, chromium, iron, magnesium, aluminum, mercury, cadmium, cobalt, nickel, molybdenum, copper, arsenic, selenium, zinc, antimony, beryllium, gold, barium, manganese, silver, thallium, tin, scandium, osmium, lanthanum, thorium, tungsten, rhenium, bismuth, germanium, radium, rubidium, strontium, vanadium, yttrium, technecium, ruthenium, palladium, indium, cesium, uranium, plutonium, and cerium and radionuclides thereof. 14. The method of Claim 1, wherein the receptacle is disposed above the metal-containing solution comprising mixtures of metals, or mixtures of metals and common organic pollutants. 15. The method of Claim 1 or 9, wherein a terrestrial plant is characterized by an ability to remove more than one metal. 16. The method of Claim 1or 9, wherein the step of contacting the solution comprises contacting with a terrestrial plant that is selected from the group consisting of sunflower, pea, rye, bean, turfgrasses and members of the Family Brassicaceae, spinach, sorghum, tobacco and corn. 17. The method of Claim 16, wherein the turfgrasses are selected from the group consisting of Colonial bentgrass, Kentucky bluegrass, perennial ryegrass, creeping bentgrass, fescues, lovegrass, Bennudagrass, Buffalograss, centipedegrass, switch grass, lawngrass and coastal panicgrass. 18. The method of Claim 16, wherein the members of the Brassicaceae are selected from the group consisting of Brassica juncea and B. oleracea. 19. The method of Claim 7 or 9, wherein the step of growing comprises incorporating plant nutrients as an aqueous mist or aerosol into the receptacle. 20. The method of Claim 1 or 9, wherein the step of contacting the solution with root biomass of a terrestrial plant comprises contacting with a plant that is capable of depleting, by at least a factor of two, an initial amount of metal from the metal-containing solution. 21. The method of Claim 20, further comprising replacing the root biomass of the terrestrial plant with root biomass of another terrestrial plant, contacting the metal-containing solution, the solution substantially free of one or several plant nutrients needed to support plant growth with root biomass of said another terrestrial plant under conditions sufficient for the root biomass of said another terrestrial plant to continue to remove metal from the solution; providing growth of the root biomass of said another terrestrial plant in the solution not comprising nutrients, the root biomass removes metal. 22. The method of Claim 21, wherein further comprising separating the terrestrial plant from the solution, nutrient free. 23. The method of Claim 17, wherein the step of contacting with a terrestrial plant comprises contacting with a terrestrial plant that is capable of depleting at least 50 % of the initial amount of metal within a time period of no greater than about 8 hours. 24. The method of Claim 20, wherein the metal is selected from the group consisting of cadmium, lead, copper and nickel. 25. The method of Claim 20, wherein the step of contacting the solution with root biomass of a terrestrial plant comprises engaging the terrestrial plant with a receptacle and adding plant nutrients to the receptacle at a concentration and for a time sufficient to allow growth of root biomass through the receptacle and into the metal-containing solution, nutrient free. 26. The method of Claim 20, further comprising processing at least the root biomass of the terrestrial plant for its metal content after separating the root biomass from the solution. 27. The method of Claim 8, wherein a feeder layer selected from the group consisting of soil, humus, sand, clay, charcoal, activated carbon, wood, synthetic materials, and combinations thereof.