Abstract:
A contaminated water disinfectant and method including a quantity of substantially dry soluble alkali metal ferrate (VI) particles. A porous sealed packet contains the particles in a quantity sufficient to disinfect a predetermined quantity of contaminated water by oxygenation. A quantity of substantially dry insoluble inert particles are also contained within said packet and are of sufficient weight to cause the packet to at least partially sink into the contaminated water. The packet is formed of a porous sheet material capable of passing oxygen and water therethrough while preventing undissolved ferrate and inert particles from passing from the packet and entering the water.

Description:
BACKGROUND OF THE INVENTION 
     1. Scope of Invention 
     This invention relates generally to the use of ferrates of alkali metals for disinfecting contaminated water, and more particularly to a combination of such ferrates contained in dry particle form within a porous packet. 
     2. Prior Art 
     The utilization of ferrates as a catalytic agent has been exploited with respect to both novel uses and economy of manufacture. An early U.S. Pat. No. 2,455,696 to Moseman Fischer-Tropsch teaches catalysts that are prepared by reacting Fe(OH) 3  with an alkali metal hydroxide and an oxidizing agent to form alkali metal ferrate, after which a mixture of ferrate and powdered iron or iron oxide is heated in the presence of air. 
     Schreyer, in U.S. Pat. No. 2,536,703 teaches alkali metal ferrates prepared by oxidizing ferrate hydroxide in a strong caustic solution with chlorine gas for use as a deodorizing agent for caustic solutions. In U.S. Pat. No. 2,728,695, Harrison teaches the use of ferrites applied to metallic surfaces for corrosion protection. Mills, in U.S. Pat. No. 2,758,090 teaches the use of orthophosphates and metaphosphates to stabilize ferrates. The unique production of potassium ferrate is also disclosed. In another Harrison U.S. Pat. No. 2,835,553, an alkali metal carbonate is reacted with ferric oxide to yield an alkali metal ferrate (III). From that, an alkali metal ferrate (IV) and then ferrate (VI) are prepared. 
     BeMiller, in U.S. Pat. No. 3,632,802 teaches the use of alkali metal ferrates to oxidize starch and cellulose. Preparation of ferrates are shown by reacting potassium hydroxide, ferric nitrate and chlorine. 
     The use of ferrates by Rainer in U.S. Pat. No. 4,246,910 teaches an alkali earth metal ferrate form added to cigarette filters to remove hydrogen cyanide and ammonia. In U.S. Pat. No. 4,304,760, Mein has disclosed potassium ferrate (VI) and a process for removing potassium hydroxide from the crystallized potassium ferrate (VI). Thompson, a co-inventor herein, in U.S. Pat. No. 4,385,045, teaches a method of producing alkali metal ferrates by dry reactions at high temperatures either in a vacuum or in an inert gas atmosphere. 
     In the Deininger U.S. Pat. No. 4,405,573, the making of potassium ferrate by reacting pure potassium hydroxide, chlorine and a ferric salt in the presence of a ferrate-stabilizing compound is taught. Two additional Deininger U.S. Pat. Nos. 4,435,256 and 4,435,257 also disclose processes for preparing potassium ferrate (VI) by electrochemical methods. 
     Another of co-applicant Thompson&#39;s U.S. Pat. No. 4,535,974 provides further dry technique technology in producing alkali metal ferrates using hematite and magnetite at controlled elevated temperatures. U.S. Pat. No. 4,551,326 also invented by Thompson is a continuation of the previously referenced U.S. Pat. No. 4,385,045. 
     In two U.S. Pat. Nos. 4,500,499 and 4,606,843, Kaczur teaches the production of highly pure alkali metal or alkaline earth metal ferrates by an extraction process and by vacuum drying a crude ferrate cake of an alkali metal or alkaline earth metal ferrate with at least one alkali metal or alkaline or earth metal hydroxide followed by high temperature drying with heated CO 2  gas. 
     In another patent to Deininger, U.S. Pat. No. 4,983,306, a process for treating water to remove transuranic elements using an alkali or alkaline earth metal ferrate is there taught. A water soluble salt added to the alkaline earth ferrate is also taught to enhance removal efficiency. Deininger also reviews many prior art processes for the use of ferrate in U.S. Pat. No. 5,202,108 which generally teaches another process for producing ferrate utilizing beta-ferric oxide. Moreover, in U.S. Pat. No. 5,217,584, Deininger further teaches yet another process for producing ferrate employing beta-ferric oxide. 
     Stable ferrates having the formula MFe,XO 4  in which M is two atoms of either Na or K or one atom of Ca or Ba, X being selected from the group consisting of Al, Si, P, S, CL, Mo, Mn, Cr and mixtures thereof, are prepared by reacting MOH and an oxide with a compound of Fe and X. 
     Johnson, in U.S. Pat. No. 5,746,994 teaches ferrates which are produced by oxidizing Fe 3+  to FeO 4   2−  with monoperoxosulfate in the presence of KOH or NaOH. The availability of ferrates under the trademark TRUCLEAR by Analytical Development Corporation for water purification and waste water treatment are disclosed. 
     A significant limitation in the use of an alkali metal ferrate in dry or granular form is that, because it is substantially lighter than water, these particles will simply float atop the water to no avail in effecting decontamination thereof. Additionally, after chemically reacting with the water, a non-toxic residue is left in the water in the form of iron oxide particles and other inert impurities which increases the turbidity of the contaminated water and will not decompose thereafter. By the present invention, highly effective alkali metal ferrate (VI) particles, combined with predetermined amounts of an inert insoluble particle material such as clean, dry sand in a uniformly blended mixture with the alkali ferrate (VI) within a porous sealed packet overcome the above limitations in utilizing ferrates (VI) for water decontamination. 
     BRIEF SUMMARY OF THE INVENTION 
     This invention is directed to a contaminated water disinfectant and method including a quantity of substantially dry soluble alkali metal ferrate (VI) particles. A porous sealed packet contains the particles in a quantity sufficient to disinfect a predetermined quantity of contaminated water by oxygenation. A quantity of substantially dry insoluble inert particles are also contained within said packet and are of sufficient weight to cause the packet to at least partially sink into the contaminated water. The packet is formed of a porous sheet material capable of passing oxygen and water therethrough while preventing undissolved ferrate and inert particles from passing through the sides of the packet and entering the water. 
     It is therefore an object of this invention to provide an effective utilization of alkali metal ferrates (VI) in dry particle form for water decontamination and disinfectant. 
     It is another object of this invention to provide a porous packet for disinfecting contaminated water including dry particles of an alkali metal ferrate in combination with inert insoluble particles which cause the packet to sink within the contaminated water for heightened oxygen discharge decontaminating effectiveness. 
     It is still another object of this invention to provide, in combination, a dry mixture of alkali metal ferrate (VI), e.g. potassium ferrate, and dry beach sand within a porous packet, the combination having a density greater than that of the contaminated water so that the packet will sink to the bottom of the contaminated water to maximize the effective release of disinfecting quantities of oxygen from the packet. 
     In accordance with these and other objects which will become apparent hereinafter, the instant invention will now be described with reference to the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevation schematic view of the invention in use within a container of contaminated water. 
     FIG. 2 is a side elevation view of the invention of FIG.  1 . 
     FIG. 3 is an end elevation schematic section view of FIG.  2 . 
     FIG. 4 is an enlarged segment in cross section of a packet similar to that of FIG. 2 having a lighter density just sufficient to submerge only a portion of the packet. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to the drawings, the invention in FIGS. 1 to  3  is shown generally at numeral  10  in the form of a packet  12  which is formed of porous sheet material containing dry particles  16 . The preferred range of porosity of the porous material forming the packet  12  is in the range of 0.2 to 10 microns, 5 microns being preferred. The preferred form of the porous sheet material is a synthetic plastic, preferably polyester, e.g. spinbonded polyester under the trademark REEMAY®, series 2000, #2275 or #2200. Paper filter material may also be used, although paper filter material is very hygroscopic and can prematurely absorb excess amounts of water to the detriment of the functioning of the packet as described herebelow. 
     The primary features of the porous sheet material forming the packet  12  as depicted in FIG. 3 are a porosity sufficient to allow water to pass into the packet  12  for oxygen to escape from the packet  12  through the porous material, and for any remaining undissolved particles  16  described herebelow to be retained within the packet  12 . 
     A uniform mixture of dry loose particles  16  are placed within the packet  12  and then sealed therein along seal lines  14 . The particles  16  represent a mixture of an alkali metal ferrate (VI) and a quantity of dry beach sand. Typically, ferrate (VI) only needs to be about 50% pure, containing other insoluble inert impurities such as iron oxide. Ferrate (VI) has a chemical formula of FeO 4   −2 . The preferred form of the alkali metal cation combined with the ferrate (VI) is one that dissolves in water, namely, Li, Na, K, Rb and Cs. Potassium K is preferred for both economy and manufacturing ease and availability. 
     The intent of this invention is to disinfect contaminated water with oxygen O released from the packet  12 . By placing one of the inventions  10  into a container C filled with contaminated water W as seen in FIG. 1, purifying and disinfecting oxygen O is released from the packet  12  in the direction of the arrows B into the contaminated water W. The presence of the dry beach sand mixed with the alkali metal ferrate (VI) within the mixture  16  insures by adequate presence of the inert insoluble sand particles that the packet  10 , when dropped into the water W, will preferably sink to the bottom of the container C in the direction of arrow A in FIG.  1 . 
     When the packet  12  is at the bottom of the container C, the oxygen O is released by the following chemical formula: 
     
       
         4K 2 FeO 4 +10H 2 O→4Fe(OH) 2 +30 2 ↑+8KOH  (1) 
       
     
     The liberated oxygen is dispersed uniformly upwardly into the contaminated water W in the direction of arrows B. 
     The preferred source of dry ferrate (Vl) is described in one of co-applicant&#39;s previous U.S. Pat. No. 4,545,974. Utilization of ferrate (VI) in its dry form is preferred due to its stability in packet form, substantially reduced cost, and the elimination of chlorinated hydrocarbons as a side product within the contaminated water. Residue left within the packet  12  after water disinfection is typically in the form of iron oxide and potassium oxide, both of which are non-toxic. However, the limited porosity of the sheet material forming the packet  12  as above described prevents this residue from entering into the now disinfected water, which residue would otherwise increase the turbidity and cloudiness thereof. 
     What the present invention accomplishes on an overall basis is the reduction of biological oxygen demand (B.O.D.) and chemical oxygen demand (C.O.D.). By substantially reducing these two factors present in the contaminated water, the disinfected water is ready for consumption and, when in sufficiently concentrated form as below described by example, may also serve as a wound disinfectant. 
     EXAMPLE 1 
     A mixture of 0.25 g potassium ferrate (VI) (K 2 FeO 4 ) particles with 1.75 g of clean dry sand (2.0 g total) in a small tea bag approximately 1″ square will disinfect five (5) gallons of contaminated water killing all bacteria contained therein. This example mixture contains sufficient inert sand to cause the packet  12  to sink to the bottom of the container C as depicted in FIG. 1 for optimal disinfecting oxygen O release. 
     EXAMPLE 2 
     A larger mixture of 7 g of potassium ferrate (VI) particles plus 93 g of clean dry sand (100 g total) uniformly mixed was prepared. Two (2) g of this dry mixture in packet form will purify one gallon of water. 
     EXAMPLE 3 
     A mixture of 0.25 g ferrate (VI) plus 1.75 g of clean dry sand in a packet  14  placed into one gallon of contaminated water will produce a disinfectant wash for wounds. TIME FACTOR 
     When the invention is utilized in shade or unlit areas at room temperature, the disinfecting process above described will take approximately ten (10) hours. The color of the contaminated water will first turn to purple due to the presence of Fe 6+  and then to brown Fe 3+  when the oxygen release is completed. However, when the same reaction is caused to occur in sunlight, the reaction time is reduced to about 1 to 1¼ hours. 
     It is also here noted as shown in Example 2 above that the addition of clean dry sand also serves as an effective dilutent of the potassium ferrate (VI) so that, when mixed in larger quantities at desired proportions, smaller packet sized portions of that uniform mixture may be more accurately prepared to effect the desired controlled disinfecting of predetermined volumes of contaminated water. 
     The preferred embodiment of the invention is shown generally at numeral  10  in FIGS. 1 to  3  wherein a quantity of clean dry sand or more generally inert, insoluble particles, are added in sufficient quantity to cause the packet  12  to sink to the bottom of the container C. However, as shown in FIG. 4, the dry particle mixture  16 ′ of potassium ferrate (VI) and dry sand may include only a sufficient amount of the dry sand particles to cause the packet  12 ′ to become partially submerged in the contaminated water W so that oxygen is liberated in the direction of arrows E at or near the surface of the contaminated water. Again, this embodiment is not preferred, but is nonetheless useful in effecting water decontamination as above described. 
     While the instant invention has been shown and described herein in what are conceived to be the most practical and preferred embodiments, it is recognized that departures may be made therefrom within the scope of the invention, which is therefore not to be limited to the details disclosed herein, but is to be afforded the full scope of the claims so as to embrace any and all equivalent apparatus and articles.