Abstract:
A process and associated apparatus to reduce both ferrous (Fe ++ ) iron and ferric (Fe +++ ) iron from an aqueous solution. A pH swing process is described in which a phosphoric acid solution is first added and then a base chemical is added. The combination results in generation and precipitation of iron phosphate. The method and apparatus affords flocculent enhanced settling and removal of the iron precipitates and process suitable buffering of the resulting reduced iron aqueous solution.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application for patent claims priority to U.S. Provisional Patent Application Ser. No. 61/319,000, filed Mar. 30, 2010 and entitled “Aqueous Iron Removal Process and Device” and U.S. Provisional Application Ser. No. 61/328,892, filed Apr. 28, 2010 entitled “Aqueous Iron Removal Process and Apparatus” which are both incorporated by reference herein to the extent permitted by law. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    This invention relates to a chemical based process for the removal of both Ferric (FE +++ ) and especially Ferrous (FE +++ ) iron from aqueous, solutions. 
         [0003]    Iron contamination of water is a prevalent industrial problem. Two types of aqueous iron are possible; Fe +++  (ferric) and Fe ++  (ferrous). Ferric iron is insoluble in most aqueous solutions; precipitating as a solid residue and engendering aqueous discoloration. Prior to process use of a ferric entrained aqueous solution, ferric iron can be settled, chemically coagulated and/or filtered eliminating problems associated with solids deposition and or solution discoloration. In contrast, ferrous iron purveys a dissolved, passive state in aqueous solution. Unfortunately, soluble ferrous iron oxidizes readily into insoluble ferric iron subsequent to contact with oxygen (air). Accordingly, problems associated ferric iron precipitation and discoloration can occur even though an anoxic aqueous solution had been previously treated to remove ferric iron precipitates and discoloration. This problem is especially burdensome with anoxic waters such as water and brine sourced from deep aquifers, oil and gas production operations, mine drainage and similar scenarios. In such oxygen deprived waters the ferrous form of dissolved iron is often present. Eventual contact with oxygen (air) oxidizes the soluble ferrous iron transforming it into the insoluble ferric form with consequential discoloration of the aqueous solution and precipitation of the ferric solid; resulting in detrimental fouling and plugging of pipes, valves, pumps and other process equipment. 
         [0004]    The focus of the invention is to remove both the ferrous and the ferric iron from anoxic brines associated oil and gas production. Plugging of wells, pipelines, tanks, heat exchangers and other process equipment is a prevalent and serious problem associated with iron precipitation and deposition. 
         [0005]    There are numerous filtration appliances, ion exchange media and oxidation processes available in the prior art to remove the offending irons but these methods are hindered by troublesome fouling and plugging with ferric iron and poor removal efficiency of the ferrous iron. The prior art is additionally burdened by solid media expense, consumption and disposal with a corresponding environmental liability. Further, the efficacy of the prior art is hindered by the by the characteristic presence of oils and light hydrocarbons in oil and gas production brines. These materials seriously contaminate, foul and blind the appliances, media and processes of the prior art. Reference the following US patents provide examples of the prior art: U.S. Pat. Nos. 7,481,929 (Wilkins et al.), 7,399,416 (Moller et al.), 6,555,151 (Hu et al.), 6,521,810 (Shapiro et al.), 6,440,300 (Randall et al.), 6,177,015 (Blakey et al.), 6,113,779 (Snee), 5,948,264 (Dreisinger et al.), 5,919,373 (Naaktgeboren) and 5,910,253 (Fuerstenau et al.). 
       BRIEF SUMMARY OF THE INVENTION 
       [0006]    The foregoing discussion focuses on efforts of the prior-art to provide effective means to eliminate ferrous and ferric iron from aqueous solutions, wherein of particular interest, said aqueous solutions are the brines associated with oil and gas production. The prior art fails to address the elimination of these iron materials in an efficient manner. The prior art further demonstrates many other disadvantages due to unreliability, expense and environmental liability associated with spent material disposal concerns. 
         [0007]    The reader who is knowledgeable in the art will clearly recognize the substantial benefits as well as the unique and distinctively superior capabilities afforded by the invention; presenting a cost effective, practical, reliable and environmentally friendly means for removing both ferric and ferrous iron from aqueous solutions. 
         [0008]    The invention described herein provides a simple chemical and pH controlled means to precipitate both ferric and ferrous iron from aqueous solutions; facilitating minimal residual iron content. In summary, a process is provided wherein a ferric and/or ferrous entrained aqueous solution is elevated in pH with a base chemical such as sodium or calcium hydroxide to a pH level rendering precipitation of the ferric iron. In the preferred embodiment a coagulant such as an anionic polymer may be added to the elevated pH mixture to accelerate ferric precipitation. Ferric entrained solids are then separated from the elevated pH solution. 
         [0009]    The elevated pH solution is then buffered with phosphoric acid to facilitate precipitation of the residual ferrous iron. In the preferred embodiment a coagulant such as an anionic polymer may be added to the buffered mixture to accelerate residual iron precipitation. Iron entrained solids are then separated from the elevated pH solution. The buffered, essentially iron free aqueous solution is then conveyed for process use. 
         [0010]    The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention which follows may be better understood. Additional features and advantages of the invention will be described hereinafter, which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the concepts and specific embodiments disclosed herein may be readily utilized as a basis for modifying or designing other structures or processes for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. 
       OBJECTS AND ADVANTAGES 
       [0011]    The invention purveys a chemically staged pH swing process for simple, efficient and cost effective removal of ferric and ferrous iron from an iron entrained aqueous solution. The invention employs addition of base chemical, such as sodium hydroxide, to elevate the pH of an iron bearing solution, followed by pH buffering with phosphoric acid to a lowered or neutral state pH, the effect affording extraction and precipitation of both ferric and ferrous iron as insoluble solids, separable from the solution. The invention provides multiple objects and advantages over the prior art. Some of which are as follows. 
         [0012]    The removal of iron is unimpeded by the presence of oils or hydrocarbons, conveying a distinct advantage over the prior art; auspiciously pertaining to iron removal from oil and gas production brines. In this application the invention proffers elimination of expensive and troublesome equipment required for removal of oils and hydrocarbons prior to the iron extraction practices of the prior art. 
         [0013]    The invention employs a strictly chemical based process eliminating specific appliance or hardware limitations. Since a primary focus of the invention is treatment of very corrosive oil and gas production brines, the expense and impracticality associated with exotic, corrosion resistant materials of construction necessary for appliance of the prior art are not required. 
         [0014]    The invention employs simple and inexpensive chemicals rather than one or more of the ion exchange medias common to the prior art. Such medias are burdened by sensitivity to blinding, fouling and/or poisoning by extraneous salts, metals and other common contaminants entrained in the iron bearing solutions. This is particularly problematic with oil and gas production brines; the focus of the invention. Media life is exceptionally short when treating these brines. Accordingly, the invention purveys a substantially more reliable, longer life, more efficient course for removal of entrained iron than the media based technologies of the prior art. Further, the invention does not beget the disposal expense and associated environmental liabilities burdensome to the media based technologies of the prior art. 
         [0015]    The invention does not require additional chemicals to refurbish media as is a common practice of the prior art. Accordingly the invention eliminates the expense, storage and handling associated with the washing and regeneration chemicals employed by the prior art. Further, since the invention does not require such additional chemicals, the expense and environmental liabilities associated with disposal of spent volumes of these chemicals is eliminated. 
         [0016]    Variations in water constituents can dramatically and negatively affect the performance of many examples of the prior. Such changes are especially common with oil and gas production brines. In contrast to the sensitivity that the prior art often demonstrates to such changes, the invention is robust in accommodating varying constituents. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0017]    In the accompanying drawings, which form a part of the specification and are to be read in conjunction therewith in which like reference numerals are used to indicate like or similar parts in the various views: 
           [0018]      FIG. 1  is a process diagram of an embodiment of the invention employing direct addition of base chemical and phosphoric acid into a receiving vessel; 
           [0019]      FIG. 2  is a process diagram of an embodiment of the invention employing two containment vessels with chemical addition into the confines of the vessels; 
           [0020]      FIG. 3  is a process diagram of an embodiment of the invention employing two vessels with piping conveyance incorporating base chemical and phosphoric acid addition; 
           [0021]      FIG. 4  is a process diagram of an embodiment of the invention employing two vessels with piping conveyance incorporating base chemical and phosphoric acid addition as well as providing pipeline conveyed mixing; 
           [0022]      FIG. 5  is a process diagram of an embodiment of the invention employing two containment vessels with chemical addition, inclusive of agglomeration chemicals into the confines of the vessels; 
           [0023]      FIG. 6  is a process diagram of an embodiment of the invention employing two vessels with piping conveyance incorporating base chemical, phosphoric acid and agglomerating chemicals; 
           [0024]      FIG. 7  is a process diagram of the preferred embodiment of the invention employment two vessels with piping conveyance incorporated base chemical, phosphoric acid and agglomerating chemicals as well as providing pipeline conveyed mixing; and 
           [0025]      FIG. 8  is a process diagram of an embodiment of the invention employing two containment vessels with chemical addition, inclusive of agglomeration chemicals into the confines of the vessels wherein mixing appliances are provided. 
       
    
    
     REFERENCE NUMERALS IN THE DRAWING 
       [0000]    
       
         
           
               1  Containment vessel 
               5  Iron imbued solids 
               10  Iron entrained aqueous solution (brine) feed 
               20  First containment vessel base reaction vessel 
               25  First containment vessel mixing appliance 
               30  Base chemical addition 
               35  Base chemical mixer 
               40  First agglomerating chemical 
               45  First agglomerating chemical mixer 
               50  Ferric fostered solid precipitates 
               60  First containment vessel effluent 
               70  Second containment vessel buffering reaction vessel 
               75  Second containment vessel mixer 
               80  Phosphoric acid entrainment 
               85  Phosphoric acid mixer 
               90  Second agglomerating chemical 
               95  Second agglomerating chemical mixer 
               100  Ferrous fostered solid precipitates 
               110  Low iron content water (brine) 
           
         
       
     
       DETAILED DESCRIPTION OF THE INVENTION 
       [0045]    The making and using of the embodiments illustrated herein are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention. The present invention will be described with respect to the subject embodiments in a specific context, namely as a device and process for reduction of iron in aqueous or brine based solutions. The invention may also be applied, however, to other situations wherein similar iron reduction effects are desired. 
         [0046]    Description—FIG.  1 —Direct to obtaining the effect of the invention a typical embodiment is illustrated on  FIG. 1  and is described as follows. Iron entrained aqueous solution (brine)  10  is conveyed into a containment vessel  1  wherein a pH raising base chemical  30 , such as sodium hydroxide, is added. Ferric iron fostered precipitates separate from solution as an iron bearing insoluble solids discharge  5 . PH buffering phosphoric acid  80  is added into the containment vessel  1 . Ferrous iron fostered precipitates separate from solution as iron bearing insoluble solids discharge  5 . A minimal iron imbued supernatant  110  is conveyed from the containment vessel  1  for process use. 
         [0047]    Description—FIG.  2 —Direct to obtaining the effect of the invention a typical embodiment is illustrated on  FIG. 2  and is described as follows. Iron entrained aqueous solution (brine)  10  is conveyed into a first containment base reaction vessel  20  wherein a pH raising base chemical  30 , such a sodium hydroxide, is added. Ferric iron fostered precipitates separate from solution as iron bearing insoluble solids  50 . A reduced iron effluent  60  egresses the base reaction vessel  20  and having pH buffering phosphoric acid added  80 , mixed  85 , and entrained therein, is conveyed into a second containment buffering reaction vessel  70 . Ferrous iron fostered precipitates separate from solution as iron bearing insoluble solids  100 . A minimal iron imbued supernatant  110  is conveyed from vessel  70  for process use. 
         [0048]    Description—FIG.  3 —Direct to obtaining the effect of the invention another typical embodiment is illustrated on  FIG. 3  and is described as follows. Iron entrained aqueous solution (brine)  10 , having a pH raising base chemical  30 , such as sodium hydroxide, added and entrained therein, is conveyed into a first containment; base reaction vessel  20 . Ferric iron fostered precipitates separate from solution as iron bearing insoluble solids  50 . A reduced iron effluent  60  egresses the base reaction vessel  20  and having pH buffering phosphoric acid added  80 , mixed  85 , and entrained therein, is conveyed into a second containment buffering reaction vessel  70 . Ferrous iron fostered precipitates separate from solution as iron bearing insoluble solids  100 . A minimal iron imbued supernatant  110  is conveyed from vessel  70  for process use. 
         [0049]    Description—FIG.  4 —Direct to obtaining the effect of the invention another typical embodiment is illustrated on  FIG. 4  and is described in the following discussion. Iron entrained aqueous solution (brine)  10  having a pH raising base chemical  30  added, mixed  35 , and entrained therein, is conveyed into a first containment base reaction vessel  20 . Ferric iron fostered precipitates separate from solution as iron bearing insoluble solids  50 . The reduced iron effluent  60  egresses the base reaction vessel  20  and having phosphoric acid added  80 , mixed  85 , and entrained therein, is conveyed at a lowered pH into a second containment buffering reaction vessel  70 . Ferrous iron fostered precipitates separate from solution as iron bearing insoluble solids  100 . A minimal iron imbued supernatant  110  is conveyed from vessel  70  for process use. 
         [0050]    Description—FIG.  5 —Direct to obtaining the effect of the invention another typical embodiment is illustrated on  FIG. 5  and is described in the following discussion. Iron entrained aqueous solution (brine)  10  is conveyed into a first containment base reaction vessel  20  wherein a base chemical  30  is added to increase pH and an agglomerating chemical  40  is added to augment solids precipitation. Ferric iron fostered precipitates separate from solution as iron bearing insoluble solids  50 . The reduced iron effluent  60  egresses the reaction vessel  20  and is conveyed into a second containment pH buffering reaction vessel  70 . PH buffering phosphoric acid  80  and a second agglomeration chemical  90  are added into the buffering reaction vessel  70 . Ferrous iron fostered precipitates separate from solution as iron bearing insoluble solids  100 . A minimal iron imbued supernatant  110  is conveyed from vessel  70  for process use. 
         [0051]    Description—FIG.  6 —Direct to obtaining the effect of the invention another typical embodiment is illustrated on  FIG. 6  and is described as follows. Iron entrained aqueous solution (brine)  10 , having a pH raising base chemical  30 , such as sodium hydroxide, and an agglomeration chemical  40 , such as a metal salt or polymer, added and entrained therein, is conveyed into a first containment base reaction vessel  20 . Ferric iron fostered precipitates separate from solution as iron bearing insoluble solids  50 . A reduced iron effluent  60  egresses the base reaction vessel  20  and after having pH buffering phosphoric acid  80  and a second agglomeration chemical  90 , such as a metal salt or polymer, added and entrained therein, is conveyed into a second containment buffering reaction vessel  70 . Ferrous iron fostered precipitates separate from solution as iron bearing insoluble solids  100 . A minimal iron imbued supernatant  110  is conveyed from vessel  70  for process use. 
         [0052]    Description—FIG.  7 —Direct to obtaining the effect of the invention a preferred embodiment is illustrated on  FIG. 7  and is described as follows. Iron entrained aqueous solution (brine)  10 , having a pH raising base chemical  30 , such as sodium hydroxide, added and mixed  35  and an agglomeration chemical  40 , such as a metal salt or polymer, added and mixed  45 , is conveyed into a first containment base reaction vessel  20 . Ferric iron fostered precipitates separate from solution as iron bearing insoluble solids  50 . A reduced iron effluent  60  egresses the base reaction vessel  20  and after having pH buffering phosphoric acid  80  added and mixed  85  and a second agglomeration chemical  90 , such as a metal salt or polymer, added and mixed  95 , is conveyed into a second containment buffering reaction vessel  70 . Ferrous iron fostered precipitates separate from solution as iron bearing soluble solids  100 . A minimal iron imbued supernatant  110  is conveyed from vessel  70  for process use. 
         [0053]    Description—FIG.  8 —Direct to obtaining the effect of the invention another typical embodiment is illustrated on  FIG. 8  and is described in the following discussion. Iron entrained aqueous solution (brine)  10  is conveyed into a first containment base reaction vessel  20  having a first containment vessel mixing appliance  25  wherein a base chemical  30  is added to increase pH and an agglomerating chemical  40  is added to augment solids precipitation. Vessel mixing appliance  25  may be continuously stirring solution  10  and chemicals  30 ,  40  or may be activated when needed. Ferric iron fostered precipitates separate from solution as iron bearing insoluble solids  50 . The reduced iron effluent  60  egresses the reaction vessel  20  and is conveyed into a second containment pH buffering reaction vessel  70  having a second containment vessel mixer  75 . PH buffering phosphoric acid  80  and a second agglomeration chemical  90  are added into the buffering vessel  70 . Vessel mixer  75  may be continuously stirring effluent  60 , phosphoric acid  80  and chemical  90  or may be activated when needed. Ferrous iron fostered precipitates separate from solution as iron bearing insoluble solids  100 . A minimal iron imbued supernatant  110  is conveyed from vessel  70  for process use. 
         [0054]    In certain embodiments, the invention does not require additional chemicals to refurbish media as is a common practice of the prior art. Accordingly, certain embodiments of the invention eliminate the expense, storage and handling associated with said washing and regeneration chemicals. Further, additional chemicals are not required, the expense and environmental liabilities associated with disposal of spent volumes of these chemicals is eliminated. 
         [0055]    Variations in water constituents can dramatically and negatively affect the performance of many examples of the prior art. Such changes are especially common with oil and gas production brines. In contrast to the sensitivity that the prior art often demonstrates with such changes, the invention is robust in accommodating these changes. 
         [0056]    The making and using of the embodiments illustrated herein are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed herein are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention. The present invention will be described with respect to the subject embodiments in a specific context, namely as a device and process for reduction iron in aqueous or brine based solutions. The invention may also be applied, however, to other situations wherein similar iron reduction effects are desirable. 
         [0057]    Description—FIG.  1 —One embodiment of the present invention is illustrated in  FIG. 1 , wherein iron entrained aqueous solution (brine)  10  is conveyed into an acidic reaction vessel  20  wherein a phosphoric acid solution  30  is added to reduce the pH of the brine. The low pH brine conveys from the acidic reaction vessel  20  into the base reaction vessel  40  wherein a base chemical  50  is added to elevate the pH. Iron phosphate  80  precipitates from the solution in reaction vessel  40  and exits the reaction vessel  40 . The reduced iron supernatant  70  separates from the precipitate and exits the reaction vessel  40  in conveyance to the buffering vessel  90 . Acidic chemical  100  is added in the buffering reaction vessel  90  to lower the pH to a suitable level and the reduced iron precipitant  130  is conveyed to process. 
         [0058]    Description—FIG.  2 —Another embodiment of the present invention is illustrated in  FIG. 2 , wherein iron entrained aqueous solution (brine)  10  is conveyed into a pipeline  25  wherein, while in transit, a phosphoric acid solution  30  is added to reduce the pH of the brine. Further in transit a base chemical  50  is added to elevate the pH. The elevated pH brine then enters a base reaction vessel  40  providing quiescence necessary for settling of precipitating iron phosphate. The reduced iron supernatant  70  separates from the precipitate and exits the base reaction vessel  40 . Iron phosphate  80  separates from the elevated pH brine and exits from the reaction vessel  40 . Reduced iron supernatant  70  conveys via pipeline  95  from the reaction vessel  40 . Acidic chemical  100  is added into the pipeline  95  to lower the pH of the reduced iron brine to create a reduced iron precipitate  130  suitable with suitable pH for conveyance to process. 
         [0059]    Description—FIG.  3 —Another embodiment of the present invention is illustrated in  FIG. 3 , wherein iron entrained aqueous solution (brine)  10  is conveyed into a reaction vessel  20  wherein a phosphoric acid solution  30  is added to reduce the pH of the brine. The lowered pH brine is then conveyed into a second reaction vessel  40  wherein a base chemical  50  is added to raise the pH to afford precipitation of iron phosphate from the brine solution. An additional flocculating chemical  60  is added into the precipitating brine solution in reaction vessel  40  to accelerate and enhance the precipitate settling and separation effects. The settled iron phosphate  80  exits the reaction vessel  40 . The reduced iron supernatant  70  separates from the precipitate and exits the reaction vessel  40  and conveys into buffering vessel  90  wherein an acidic chemical  100  is added to lower the pH of the reduced iron brine to a suitable pH for process use. As a consequence of the reduction of the pH, additional precipitate may form for which the buffering vessel  90  provides quiescence for settling and separation. An additional flocculating chemical  110  is added into buffering vessel  90  to accelerate and enhance the precipitate settling and separation effects. The settled precipitate  120  exits the reaction vessel  90 . The reduced iron precipitate  130  exits the reaction vessel  90  to process. 
         [0060]    Description—FIG.  4 —Another embodiment of the present invention is illustrated in  FIG. 4 , wherein iron entrained aqueous solution (brine)  10  is conveyed into a pipeline  25  wherein, while in transit, a phosphoric acid solution  30  is added to reduce the pH of the brine. A mixing appliance  35 , such as a static pipeline mixer, is provided downstream of the addition of the phosphoric acid solution  30  to enhance mixing of the phosphoric acid into the brine solution. Further in transit down the pipeline  25 , a base chemical  50  is added to the flowing brine to elevate the pH. A mixing appliance  35 , such as a static pipeline mixer, is provided downstream of the addition of the base chemical  50  to enhance mixing and elevation of the flowing brine pH in the pipeline  25 . As a consequence of the elevated pH, iron phosphate precipitate forms in the flowing brine. Further in transit down the pipeline  25  a flocculating chemical  60 , is added to the flowing brine to enhance the precipitation of iron phosphate. A mixing appliance  35 , such as a static pipeline mixer, is provided downstream of the addition of the flocculating chemical  60  to enhance mixing and contacting between precipitates and the flocculating chemical  60 . The elevated pH brine with entrained flocculating precipitates enters a reaction vessel  40  providing quiescence necessary for settling of precipitating iron phosphate. The reduced iron supernatant  70  separates from the precipitate and exits the reaction vessel  40 . Iron phosphate  80  precipitate from the elevated pH brine and exits from the reaction vessel  40 . Reduced iron supernatant  70  with high pH conveys via pipeline  95  from the reaction vessel  40 . Acidic chemical  100  is added into the pipeline  95  to lower the pH of the reduced iron brine to a suitable pH for eventual process use. A mixing appliance  35 , such as a static pipeline mixer, is provided downstream of the addition of the acidic chemical  100  to enhance homogeneous pH reduction. As a consequence of the lowered pH, various precipitates can form in the flowing brine. Further in transit down the pipeline  95 , an additional flocculating chemical  110  is added to the flowing brine to enhance the aggregation of precipitates. A mixing appliance  35 , such as a static pipeline mixer, is provided downstream of the addition of the additional flocculating chemical  110  to enhance mixing and contacting between precipitates and the flocculating chemical. The buffered pH brine with entrained flocculating precipitates enters a buffering vessel  90  providing quiescence necessary for settling of precipitates. The buffered, reduced iron supernatant  130  separates from the precipitate and exits from the buffering vessel  90 . Settled precipitates  120  separate from the buffered pH brine and exit from the buffering vessel  90 . The reduced iron precipitate  130  exits the reaction vessel  90  to process. 
         [0061]    Those skilled in the art recognize that the invention provides a means to efficiently and robustly remove both ferrous (Fe ++ ) iron and ferric (Fe +++ ) iron from an aqueous solution (brine). The advantages over the prior art are substantial and include, among many others: 
         [0062]    Oils and entrained hydrocarbons or grease do not hinder the process; thereby eliminating pretreatment requirements and associated capital, operating and labor expenses. 
         [0063]    Certain embodiments of the invention employ chemicals which minimize the requirement for hardware, appliances and other components prone to damage from the corrosive effects of oil and gas production brines. 
         [0064]    Certain embodiments of the invention employ fluid based chemical reactions; not requiring ion exchange or other type of contacting media. Without the employ of such media the blinding, poisoning and fouling problems associated with the media techniques of the prior art are eliminated. 
         [0065]    Certain embodiments of the invention eliminate the use of the media common to the prior art, thereby eliminating the environmental expense and liabilities associated with disposal of spent media. 
         [0066]    Certain embodiments of the invention do not employ media requiring chemical regeneration. 
         [0067]    Certain embodiments of the invention employ chemicals wherein the dosage is controlled by pH. Such control affords the flexibility of successful iron removal regardless of the customary variations of brine constituents which afflicts oil and gas production brines. 
         [0068]    While the foregoing discussions specify the many advantages inherent to the invention these do not constitute the full scope of the inventions advantages. There are many advantages beyond those defined herein. In a similar manner, the embodiments described in the foregoing are not the only embodiments possible. Other embodiments are possible. 
         [0069]    Embodiments wherein various combinations of sections of the foregoing embodiments are certainly conceivable. Also, in certain embodiments beneficial appliances may be employed. Example of such would be the employ of centrifugal separation devices such as centrifuges or hydrocyclones to accelerate precipitate removal. Filtration devices could also be so used. 
         [0070]    In certain embodiments thermal processes could be also employed. An example would be heating of reaction vessels to expedite pH and mixing reactions. Another possibility would be heating or cooling to expedite the precipitate separation. 
         [0071]    In certain other embodiments electrical coagulation appliances could also be used to accelerate the precipitate agglomeration and separation. Mixing paddles in the reaction and buffering vessels could also be employed to further homogenize the chemical mixtures to assure rapid and complete chemical reactions. 
         [0072]    Those skilled in the art will appreciate that many other additional refinements employing existing art to enhance the performance of the invention; especially in those situations of which one skilled in the art may be especially familiar.