BLUNN ADAM JUSTIN (AU)
| US20050175758A1 | 2005-08-11 | |||
| GB1445754A | 1976-08-11 | |||
| GB899284A | 1962-06-20 | |||
| US20100252509A1 | 2010-10-07 | |||
| US6579977B1 | 2003-06-17 | |||
| RU2291113C1 | 2007-01-10 | |||
| AU2010295857A1 | 2012-03-08 | |||
| TW200938494A | 2009-09-16 | |||
| JP2002192186A | 2002-07-10 | |||
| TWI320029B | 2010-02-01 | |||
| MX2008012759A | 2010-04-05 | |||
| GR1006922B | 2010-07-30 | |||
| CN101508426A | 2009-08-19 | |||
| CZ21197A3 | 1997-10-15 | |||
| JPS58161926A | 1983-09-26 | |||
| RU2334802C2 | 2008-09-27 | |||
| US6512110B1 | 2003-01-28 | |||
| DE19850286A1 | 2000-05-04 | |||
| DE19753196A1 | 1999-07-08 | |||
| DE19859746A1 | 2000-06-29 | |||
| US6579977B1 | 2003-06-17 | |||
| US6761272B1 | 2004-07-13 | |||
| US20070093654A1 | 2007-04-26 | |||
| GB1001603A | 1965-08-18 |
| Claims 1. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions comprising reacting one or more biomass based cellulose containing raw materials with dilute phosphoric acid where the reaction mixture containing said cellulose containing materials is heated to a reaction temperature and after completion of the reaction time, separation of the dilute phosphoric acid solution from the remaining insoluble raw material, neutralisation of the solution by means of a suitable neutralising agent resulting in precipitation of the modified cellulose, and then separating, washing and removing excess water from the resultant precipitate. 2. A process tor producing a cellulose based sorbent material comprising reacting one or more biomass based cellulose containing raw materials with dilute phosphoric acid where the reaction mixture containing said cellulose containing materials is heated to a reaction temperature and after completion of the reaction time, separation of the dilute phosphoric acid solution from the remaining insoluble raw material, neutralisation of the solution by means of a suitable neutralising agent resulting in precipitation of the modified cellulose, and then filtering, washing and drying the resultant precipitate. 3. A process for producing a cellulose based sorbent material in accordance with claim 1 or 2 in which the concentration of the phosphoric acid is in the range of approximately lg/1 to 80g/l. 4. A process for producing a cellulose based sorbent material in accordance with daim 1 or 2 in which the concentration of the phosphoric acid is in the range of approximately 2g/l to 40g/l. 5- A process for producing a cellulose based sorbent material in accordance with any one of claims 1 to 4 wherein the reaction mixture is heated to reaction temperature for at least 2 minutes. 6. A process for producing a cellulose based sorbent material in accordance with any one of claims 1 to 4 wherein the reaction mixture is heated to reaction temperature for at least 5 minutes. 7. A process for producing a cellulose based sorbent material in accordance with any one of claims 1 to 4 wherein the reaction mixture is heated to reaction temperature for at least 1 hour. 8. A process for producing a cellulose based sorbent material tn accordance with any one of claims 1 to 4 wherein the reaction mixture is heated to reaction temperature for up to 4 hours. 9. A process for producing a cellulose based sorbent material in accordance with any one of claims 1 to 8 in which the ratio of cellulosic feedstock to dilute phosphoric acid is in the range of part feedstock to 5 parts dilute phosphoric acid up to 1 part feedstock to 40 parts of dilute phosphoric acid. 10. A process for producing a cellulose based sorbent material In accordance with any one of claims 1 to 8 in which the ratio of cellulosic feedstock to dilute phosphoric acid is in the range of part feedstock to 2 parts dilute phosphoric aoid up to 1 part feedstock to 80 parts of dilute phosphoric acid. 11. A process for producing a cellulose based sorbent material in accordance with any one of claims 1 to 10 wherein the neutralisation agent used to neutralize the solution Is caustic soda. 12. A process for producing a cellulose based sorbent material in accordance with any one of claims 1 to 11 wherein the solution is neutralized to approximately pH 7. 13. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Mercury. 14. A process for producing a oellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Cadmium. 15. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Chromium. 16. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Copper. 17. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Zinc. 18. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and otner aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Iron. 19. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Bismuth. 20. A prooesB for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Selenium. 21. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Tin. 22. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Cobalt 23. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions In accordance with any one of claims 1 to 12 wherein at least one contaminant contains Nickel. 24. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Vanadium. 26. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Manganese. 26. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Uranium. 27. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions In accordance with any one or claims 1 to 12 wherein at least one contaminant contains Thorium. 28. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Arsenic. 29. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Lead. 30. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions in accordance with any one of claims 1 to 12 wherein at least one contaminant contains Ammonia. 31. A process for producing a cellulose based sorbent material for the removal of water soluble contaminants from water and other aqueous solutions substantially as hereinbefore described with reference to the examples. 32. A cellulose based sorbent product manufactured in accordance with the process in any one of claims 1 to 13. 33. A cellulose based sorbent product manufactured in accordance with the process in any one of claims 1 to 13 In which the product is in the form of a powder. 34. A cellulose based sorbent product manufactured in accordance with the process In any one of claims 1 to 13 in which the product Is In the form of a slurry. 35. A method for the removal of water soluble contaminants from water and other aqueous solution by contacting a sorbent product manufactured in accordance with the process in any one of claims 1 to 13 with the contaminated water or aqueous solution by mixing and then separating the product and the treated water or aqueous solution. 36. A method in accordance with claim 17 In which Seperation b effected by allowing the product to settle and decanting the supernatant treated water or aqueous solution. 37. A method in accordance with claim 17 in which separation is effected by filtration 38. A method in accordance with claim 17 in which separation is effected by some other method of solid liquid separation. 39. A method for the removal of water soluble contaminants from water and other aqueous solutions by utilising the sorbent product manufactured In accordance with the process in any one of claims 1 to 13 as an active component In a filter. 40. A method for the removal of water soluble contaminants from water and other aqueous solutions by utilising the sorbent product manufactured In accordance with the process in any one of claims 1 to 13 as an active component in a permeable reactive barrier. 41. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Mercury. 42. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Cadmium. 43. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one oontaminant contains Chromium. 44. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Copper. 45. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Zinc. 46. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Iron. 47. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Bismuth. 48. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Selenium. 4Θ. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Tin. 50. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Cobalt. 51. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Nickel. 52. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Vanadium. 53. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Manganese. 54. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Uranium. 55. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Thorium. 56. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Arsenic. 57. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Lead. 58. A method for the removal of water soluble contaminants from water and other aqueous solutions wherein at least one contaminant contains Ammonia. |
Field of the Invention
This invention relates to a chemical process for synthesising a modified cellulose phosphate powder from biomass sou roes of oetlulose Including, but not limited to, algae, bagasse, and waste paper.
This invention further relates to the application of the cellulose phosphate powder for use in removel of various contaminants or chemical species from water. Including but not limited to Mercury, Cadmium, Chromium, Copper, Zinc, Iron, Bismuth, Selenium, Tin, Cobalt, Nickel, Vanadium, Manganese, Uranium, Thorium, Arsenic, Load and Ammonia.
Backoround of the Invention
This Invention has particular application in near neutral pH aqueous solutions that are contaminated with various water soluble species. Typical species include those containing transition metals, and also other contaminants containing ammonia, arsenic, and selenium. At low concentrations these contaminants are soluble in water and often have toxicological, clinical or environmental impacts. At low concentrations, many contaminants are difficult to separate from water. The existing solutions for removal of trace level contaminants, particularly those utilized in industrial applications, include the use of ion exchange resins, activated carbon or alumina, or titanium dioxide, reverse osmosis, chemical precipitation, or biological filtration. Each of these works with only specific contaminants. However none of these options is satisfactory for all contaminants. Further, other limitations of these processes include insufficient removal of particular contaminants, impractical application for large volumes, and high expense. Often a combination of two or more techniques is necessary, and creates process engineering difficulties.
Summary of the Invention
The present invention involves creating a modified cellulose based powder by reacting a biomass based celiuloslc raw material with dilute phosphoric acid at elevated temperature. The cellulosic raw material is partially dissolved and then the remaining insoluble raw material is separated from the dilute phosphoric add solution. The clear phosphoric acid solution is then neutralized with subsequent precipitation of the modified cellulose, followed by , separating, washing and removal of excess water prior to use. The resulting product is a sorbent powder. (Wherever the term "sorbent* is used in this specification, this shall be Interpreted to mean adsorbent However, It is to be understood that the product may also have absorbent properties.) The sorbent product, which may be in the form of a powder or a slurry, is particularly useful for removal of low levels of contaminants from water and aqueous solutions. The solid residue resulting from extraction is then inert and non flammable, and the remaining filtrate is discarded, or may be processed for recovery of unreacted phosphoric acid .
As a sorbent for trace contaminants, the method of application includes but is not limited to contacting the sorbent product with the contaminated water or aqueous solution by mixing and then separating either by allowing the product to settle and decanting the supernatant treated water or solution, or by filtering, or some other method of solid liquid separation.
Additionally the sorbent product can be used as an active component in a filter or permeable reactive barrier
Detailed Description of the Preferred Embodiments
The synthesis of the sorbent powder is performed by utilizing a ceilulosic feedstock. This may include but is not Hmfted to algae, bagasse, and favourably, waste paper. The ceilulosic feedstock is then mixed with dilute phosphoric acid (typically in the concentration range from approximately 2g/\ up to 40 g/l but may also be In the range 1g/I up to 80g/[), and heated to reaction temperature for at least 2 minutes, but more preferably at least 5 minutes, up to 4 hours. The heating may be performed by conventional means, but may also include alternative heating technologies for water Including microwave heating. The ratio of ceilulosic feedstock to dilute phosphoric acid may typically be between a ratio of 1 part feedstock to 5 parts dilute phosphoric acid, up to 1 part feedstock to 40 parts of dilute phosphoric acid. However, this ratio may also foreseeabiy be in the range of 1 part feedstock to 2 parts dilute phosphoric acid , up to 1 part feedstock to 80 parts of dilute phosphoric acid. This is more of a practical issue rather than a technical limit. The yield of sorbent from feedstock ranges from 4% by weight up to 40% by weight depending upon the feedstock used, the dilute acid concentration and volume, and the temperature and heating time of the synthesis.
Following reaction of the feedstock with dHute phosphoric acid, the remaining solids and the solution are separated by any suitable means. Simple filtering has been shown to be effective. The solid residue consists of insoluble end unreactive ceilulosic -feedstock. This residue is non flammable and, based upon this characteristic, may be useful as a tire retardant and in insulation products. Subsequent to the initial solid liquid separation, the filtrate or supernatant la neutralized to pH 7 with any suitable neutraizing agent but preferably caustic soda. As the neutralization is performed, a fine precipitate develops in solution which settles easily and filters easily. This precipitate is the object of the process and is recovered by filtering or other suitable solid liquid separation technique. The precipitate is then washed with water to remove any remaining salts, and excess water removed. Accordingly, the product may be a dried powder or may be in the form of a slurry.
The application of the sorbent product for treatment of low level water contaminants is performed by simple mixing of the sorbent product with water. Contact and mixing time may typically be between approximately 5 minutes and 2 hours. However, this range may be greater and foreseeably may be between approximately 2 minutes and 24 hours, with dose rate determined by total load of contaminants and capacity of the sorbent for a given contaminant. Following mixing of the sorbent and the water to be treated, solid liquid separation is performed by any suitable means including but not limited to tittering, centrifugation, and decanting. Additionally the sorbent can be utilized as a filter bed with the contaminated water passed through the filter bed with removal of various contaminants taking place within the filter bed.
The use of cellulose phosphate derivatives has been described in prior art patents DE19850286 <A1); DE19753198 (A1); DE19859746 (A1); US6579977 (B1); US6761272 (51); U82007093664 (At); GB1001603 (A). In these patents all cellulose feedstocks described are prepared via several steps which include caustic pulping, further pulp preparation, and derlvattsatlon with complex and expensive phosphate reagents. In the above prior art documents, derivabsation is performed In organic solvents which increase the safety risks and expense of producing a cellulose phosphate derivative. Further, additional dertvatJeatlon is needed to achieve satisfactory performance for trace contaminant removal and this usually includes but is not limited to addition of amine or nitrogen species to effect an improved functionality of the cellulose derivative.
The present invention provides an alternative and more cost effective solution for the removal of the abovementioned contaminants from water. The cellulose phosphate product has different physical characteristics and improved performance as water treatment product, particularly for trace contaminants, in addition, the cellulose phosphate of the present invention has a Fourier Transformation Infrared spectrum that shows significant differences from conventional cellulose phosphate esters and ethers. The process described in the present invention utilizes a different method of synthesis to previously taught approaches and otters a number of advantages including greater simplicity, tower risk and production costs. This results In a product with affinity for a range of contaminants (the affinity of which may vary according to the contaminant) without the need for further functionalization.
The following examples are provided in order to illustrate the process:
[Example 1: 3.128 g of waste paper was reacted with 120 mis of 8% w/v phosphoric acid at 104 degrees C for 2hours 43 minutes. The resultant mixture was cooled, separated by filtering end the residue washed and dried. 2.206 g of residue was recovered. The filtrate and washings were neutralized with 40 g/l caustic soda to a pH of 7.0, the resultant precipitated powder was filtered and washed and dried to give a final weight of 0.845 g of sorbent powder. 0.5g of this powder was added to a 1 litre water sample with 24 hours mixing and the resultant change in composition was:
Example 2: 2.003 g of bagasse was reacted with 100 mis of 8% w/v phosphoric acid at 100 degrees C for 3 hours and 15 minutes. The resultant mixture was cooled separated by filtering and the residue washed and dried. 1.782 g of residue was recovered. The filtrate and washings were neutralized with 40 g/l caustic soda to a pH of 7.0, the resultant precipitated powder was filtered and washed and dried to give a final weight of 0.241 g of sorbent powder.
Example 3: 1.030 g of dried filamentous algae was reacted with 100 mis of 8% w/v phosphoric acid at 100 degrees C for 3 hours and 15 minutes. The resultant mixture was cooled separated by filtering and the residue washed and- dried. 0.962 g of residue was recovered. The filtrate end washings were neutralized with 40 g/l caustic soda to a pH of 7.0, the resultant precipitated powder was filtered and washed and dried to give a final weight of 0.073 g of sorbent powder.
(Example 4: 1170 g of waste paper was boiled with 23.3 litres of 4.4% w/v phosphoric acid for 2 hours. The resultant mixture was cooled separated by deoanting end then filtering and the residue washed and dried. The filtrate and washings were neutralized with 80 g/l caustic soda to a pH of 6.5, the resultant precipitated powder was filtered and washed and dried to give a final weight of 221 g of sorbent powder. 339 mg of this powder was prepared as a column filter and 100 ml of contaminated water was passed through the filter. The resultant change in water composition was:
The invention enables the reduction of a range of trace contaminants from contaminated water sources with near neutral pH. without any toxic or aesthetic reduction In water quality. This invention has particular application in dilute waste water treatment, or environmental water treatment
Accordingly the Invention has both commercial and environmental advantages. It will of course be realised that while the foregoing has been given by way of illustrative example of this invention, all such and other modifications and variations thereto as would be apparent to persons skilled In the art are deemed to fall within the broad scope and ambit of this invention as Is herein set forth.