• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    METHOD FOR TREATING AND RECOVERING RESIDUAL WATER PHOSPHATE COMPOUNDS CONTAINING PHOSPHATE. A method for treating and recovering phosphate compounds from wastewater containing phosphate. The method includes the steps of: (a) removing residual water fluoride; (b) recovering a phosphate compound from the aqueous residue maintaining the supersaturation conditions for the phosphate compound and (c) refining the residual water. A silica removal step can optionally be performed after step (a) and before step (b).
    公开号:BR112012029278B1
    申请号:R112012029278-1
    申请日:2011-05-18
    公开日:2020-06-30
    发明作者:Pierre Cote；Ahren Britton；R4Am Prasad Melahalli Sathyanarayana；Rhonda Maria Hyslop
    申请人:Ostara Nutrient Recovery Tecnologies Inc.；
    IPC主号:
    专利说明:

    [0001] [0001] This application claims the benefit under 35 U.S.C. §119 of United States conditional patent application No. 61 / 346,002, which is hereby incorporated by reference. Technical Field
    [0002] [0002] The invention relates to the treatment of phosphate-containing waste water, such as phosphogipsite reservoir water, and the recovery of useful phosphate compounds, such as struvite, during treatment. Foundations
    [0003] [0003] Phosphogipsite is a by-product of processing phosphate rock into phosphoric acid fertilizer. The production of 1 ton of phosphoric acid generates approximately 4 to 5 tonnes of phosphogipsite. Phosphogipsite is essentially a waste product. Phosphogipsite may have a low level of radioactivity that prevents its use in various applications.
    [0004] [0004] Phosphogipsite is typically stored being made into paste and stacked in large piles, which can be up to hundreds of feet high, in outdoor storage locations. The water that permeates through the batteries forms reservoirs. In 2005, there were 24 piles of phosphogipsite in Florida alone, containing 1.2 billion tons of phosphogipsite and 50 billion gallons (189,270,600 m 3 ) of reservoir water (Perpich et al, 2005).
    [0005] [0005] In active phosphoric acid fertilizer plants, such reservoirs are typically used as reservoirs for process water for use in a closed arc. Reservoir water is toxic and needs to be treated before it can be discharged. In addition, closed cells continue to produce leachate containing contaminants that require treatment.
    [0006] [0006] The reservoir water associated with phosphogipsite cells is strongly acidic and contains numerous contaminants including large amounts of phosphates. The data collected from different sources are summarized in Table 1. The column with the heading “Representative Value” contains results from a composite of 18 samples from 6 different plants that represent the composition of fresh saturated reservoir water (Kennedy et al., 1991). The reported phosphorus concentration of 6,600 ppm when P is equivalent to 20,220 ppm of PO 4 or 0.22 Mol / L. Reservoir water also contains significant amounts of ammonia (ammonia is often added to phosphoric acid in phosphoric acid plants for the manufacture of di-ammonium phosphate) and magnesium.
    [0007] [0007] Reservoir water treatment chemistry is relatively complex. The reservoir water can contain ten main components that can form numerous soluble species and precipitate when the pH is changed and cations are added. When indicated by the data under the column with the heading “Range” in Table 1, the composition of reservoir water can vary significantly.
    [0008] [0008] A cost-effective and efficient process for treating phosphate-containing waste water while recovering commercially useful phosphate compounds should be desirable. summary
    [0009] [0009] The following embodiments and their aspects are described and illustrated in conjunction with drugs and methods that are understood to be exemplary and illustrative, not limiting with respect to the scope. In various embodiments, one or more of the problems described above have been reduced or eliminated, while other embodiments are directed to other improvements.
    [0010] [00010] In one aspect, a method for treating and recovering phosphate compounds, waste water containing phosphate, is provided. The method comprising: (a) removing fluoride from waste water; (b) recovering a phosphate compound from the aqueous residue by maintaining the supersaturation conditions for the phosphate compound and (c) refining the residual water.
    [0011] [00011] Step (a) can comprise fluoride precipitation. Fluoride precipitation may comprise increasing the pH of the residual water around pH 3 to 4. Increasing the pH of the residual water may comprise adding the base containing calcium with calcium in an amount to satisfy the stoichiometric requirements to precipitate the fluoride. The calcium-containing base can be lime. Fluoride can be precipitated as fluorite. The increase in the pH of the residual water may further comprise addition to one or more calcium-free bases with cations in an amount to satisfy the stoichiometric requirements to precipitate the phosphate compound. The one or more calcium-free bases can be selected from the group consisting of magnesium oxide, magnesium hydroxide, ammonium hydroxide and anhydrous ammonia.
    [0012] [00012] The phosphate compound can comprise struvite or a struvite analog such as iron ammonium phosphate.
    [0013] [00013] The maintenance of supersaturation conditions in step (b) may comprise one or more of: maintaining a supersaturation ratio of 2 to 5; maintaining a pH at least around pH 5; Controllably introduce magnesium and / or ammonium and maintain a higher phosphate concentration than magnesium and ammonia concentrations. Sturvite can be recovered in the form of crystals and aggregates ranging in size from 1 to 5 mm.
    [0014] [00014] Silica can be removed from the aqueous residue of step (a) if the residual water from step (a) comprises a silica concentration greater than 100 ppm. Removing the silica may comprise hydrolyzing the silica by increasing the pH. Increasing the pH to hydrolyze the silica may comprise adding the base comprising cations in an amount to satisfy the stoichiometric requirements to precipitate the phosphate compound. The base can be selected from the group consisting of magnesium oxide, magnesium hydroxide, ammonium hydroxide and anhydrous ammonia.
    [0015] [00015] Refining step (c) may comprise increasing the pH around pH 8 to 10. Step (c) may comprise removal of ammonia using a process selected from the group consisting of chlorination of the breaking point , withdrawal, biological nitrification and biological denitrification.
    [0016] [00016] The refining step (c) may comprise subjecting the waste water from step (b) to a dual stage membrane treatment comprising: (i) a first membrane treatment to obtain a first concentrate comprising bivalent ions and a first permeate comprising monovalent ions and (ii) a second membrane treatment for the first permeate to obtain a second concentrate comprising monovalent ions and a second permeate comprising effluent. The first concentrate can be recirculated to step (a). The first membrane treatment may comprise nanofiltration. The second membrane treatment may comprise reverse osmosis. Prior to the two-stage membrane treatment, the pH can be lowered around pH 3 to 5 and the solids placed in suspension can be removed by filtration. Ammonia can be removed from the second permeate by subjecting the second permeate to ion exchange. The ammonia-containing regeneration liquid from the ion exchange can be recirculated to step (b).
    [0017] [00017] Before step (b), the residual water can be subjected to a first membrane treatment to obtain a first concentrate comprising bivalent ions and a first permeate comprising monovalent ions, in which the first concentrate defines the feed for the step (b). Residual water from (b) can be recirculated to step (a). The first permeate can be subjected to a second membrane treatment to obtain a second concentrate comprising monovalent ions and a second permeate comprising effluent. The first membrane treatment may comprise nanofiltration. The second membrane treatment may comprise reverse osmosis. Prior to the two-stage membrane treatment, the pH can be lowered around pH 3 to 5 and the solids placed in suspension can be removed by filtration. Ammonia can be removed from the second permeate by subjecting the second permeate to ion exchange. The ammonia-containing regeneration liquid from the ion exchange can be recirculated to step (b).
    [0018] [00018] In addition to the exemplary aspects and embodiments described above, additional aspects and embodiments will become evident by reference to the drawings and by studying the following detailed descriptions. Brief Description of Drawings
    [0019] [00019] The accompanying drawings illustrate non-limiting embodiments of the invention.
    [0020] [00020] Figure 1 is a flow chart illustrating a process for treating waste water containing phosphate according to an embodiment of the present invention.
    [0021] [00021] Figure 2 is a block diagram illustrating a process for the treatment of waste water containing phosphate according to another embodiment of the present invention.
    [0022] [00022] Figure 3 is a flow chart illustrating a process for the treatment of waste water containing phosphate according to an embodiment of the present invention.
    [0023] [00023] Figure 4 is a block diagram illustrating a process for the treatment of waste water containing phosphate according to another embodiment of the present invention.
    [0024] [00024] Figure 5 is a flow chart illustrating a process for treating waste water containing phosphate according to an embodiment of the present invention.
    [0025] [00025] Figure 6 is a block diagram illustrating a process for the treatment of waste water containing phosphate according to another embodiment of the present invention. description
    [0026] [00026] Throughout the following description, specific details are presented in order to provide a more complete understanding of the invention. However, the invention can be practiced without these particulars. In other examples, well-known elements have been shown or described in detail to avoid unnecessarily obscuring the invention, hence the specification and drawings should be considered in an illustrative rather than a restrictive sense.
    [0027] [00027] Some embodiments of the invention relate to methods of treating waste water containing phosphate while simultaneously recovering commercially useful phosphate compounds. The bases are used to neutralize the acidity of the waste water containing phosphate. Base cations are used to remove contaminants and recover phosphate compounds. Excess cations can be recirculated to maximize contaminant removal and recovery of phosphate compounds.
    [0028] [00028] Some embodiments of the invention relate to treatment processes in which the phosphate-containing waste water is phosphogipsite reservoir water and the phosphate compound is recovered in the form of granular struvite. These embodiments coincide with an aspect of the invention having significant commercial utility. The scope of the invention, however, is not limited to these embodiments.
    [0029] [00029] Figure 1 illustrates, in general, a waste water treatment process 1 according to an embodiment of the invention. In process 1, phosphate-containing wastewater from a wastewater source goes through a fluoride removal step 10, an optional silica removal step 20, a phosphate recovery step 30 and a refinement step 40. The residual water can, for example, be phosphoglypsite reservoir water. The phosphate recovery step 30 produces the phosphate compounds in a commercially useful manner. Refining stage 40 produces treated effluent ready for discharge.
    [0030] [00030] Figure 2 illustrates another embodiment of the invention following process 1, but more specifically exemplifying the treatment of phosphogipsite reservoir water and struvite recovery.
    [0031] [00031] The fluoride removal step 10 comprises increasing the pH of the waste water with one or more bases to a desired pH that promotes the precipitation of contaminants, such as fluoride and / or sulfates, but not phosphate precipitation. In some embodiments, the pH can be raised from pH 3.0 to 4.0. In some embodiments the degree to which the pH is high can vary with the composition of the waste water. The fluoride removal step 10 results in relatively dense precipitates that settle well. The precipitates can, for example, be sedimented and separated in a reservoir, a clarifier, a separation tank or the like.
    [0032] [00032] The base used in the fluoride removal step 10 can be a base containing calcium. The calcium-containing base can be added in such an amount that the calcium added to any pre-existing calcium in the residual water results in a concentration of calcium ions sufficient to cause the precipitation of compounds, such as fluorite, calcium fluorosilicate, sodium sulfate calcium and others while it is insufficient to precipitate significant amounts of calcium phosphate. This can be achieved by adding sufficient calcium in a residual water solution at a rate such that the product of the calcium ion concentration, the concentration of an ionic species containing fluorine and the concentrations of any other components of a calcium salt exceed ok sp for the calcium salt without being so high in order to cause significant precipitation of calcium phosphate. The total amount of calcium added in step 10 is desirably sufficient to cause the fluoride charge to precipitate in the waste water in step 10. For example, a stoichiometric amount of calcium can be introduced during step 10. As shown in Figure 2, the The calcium-containing base may comprise lime, including calcium oxides, carbonates and hydroxides. In other embodiments, the calcium-containing base may be a compound other than lime.
    [0033] [00033] Alternatively or additionally, one or more calcium-free bases can be added to increase the pH sufficiently for fluoride precipitation in the fluoride removal step 10. In some embodiments, the calcium-free base can be selected on the basis of a phosphate compound that is desired to be recovered in the phosphate recovery step 30. For example, if the phosphate compound to be recovered is or comprises struvite, as shown in Figure 2, the appropriate calcium-free bases can include bases containing magnesium and / or ammonium, such as magnesium oxide, magnesium hydroxide, ammonium hydroxide and anhydrous ammonia.
    [0034] [00034] Bases containing magnesium and / or ammonia can be added to simultaneously raise the pH of the waste water and increase the concentration of magnesium and / or ammonia cations to facilitate the production of struvite in a subsequent step. For example, magnesium oxide can be used to add magnesium in an amount sufficient to raise a concentration of magnesium ions or towards the desired concentration to precipitate struvite later. The addition of a base containing magnesium may also assist in the removal of fluoride ions to promote precipitation of fluoride such as saddle (MgF 2 ).
    [0035] [00035] In some embodiments, a mixture of two or more calcium-free bases can be used to raise the pH in the fluoride removal step 10. The bases can be added in a sequence that counts for pH dependent differences in the solubility of the bases. For example, the base with better dissolution at a lower pH can be added before the base with lower dissolution at the lower pH. For example, if magnesium oxide and ammonium hydroxide are used, then magnesium oxide can be added first (because their dissolution is better at the lower pH) and then added ammonium hydroxide nearby to achieve the desired pH for removal fluoride.
    [0036] [00036] Following the fluoride removal step 10, process 1 can include a silica removal step 20. Silica removal may be desirable in some embodiments to prevent silica gel formation, which can interfere with recovering the phosphate compounds (e.g., struvite crystallization) in the phosphate recovery step 30. In some embodiments, the silica can be removed by adding the base to hydrolyze the silica and then allow the silica to settle. Step 20 can conveniently be performed in a sedimentation tank or the like. Sedimented silica can be removed. In some embodiments, the silica can be hydrolyzed by adding a base to justify an optimum pH for the subsequent phosphate recovery step 30. In some embodiments, the pH can be at least about 5 before the step phosphate recovery system 30.
    [0037] [00037] One or more bases containing cations (for example, magnesium and / or ammonia) that will intensify the precipitation of the phosphate recovery step 30 can be used to raise the pH for the silica removal step 20. As shown in Figure 2, the pH can be raised to a pH of about 7.5 in the silica removal step 20. In some embodiments a suitable flocculant can be added after the silica hydrolysis further to promote silica aggregation and sedimentation.
    [0038] [00038] The silica removal step 20 is not necessary in some embodiments. Since the formation of silica gel tends to occur only at the highest silica concentrations (for example, Si> 100 ppm), embodiments of the invention for processing wastewater with low silica concentrations cannot require the silica removal step. Even if the silica concentration is highly sufficient for gel formation, the hydraulic retention time for gel formation is typically on the order of hours. In contrast, the hydraulic retention time for phosphate precipitation in the phosphate recovery step 30 may be shorter than this. For example, the hydraulic retention time for struvite formation is typically less than 1 hour, although with a high concentration feed the hydraulic retention time can be significantly longer in the embodiments incorporating the recirculation as described below. The formation of silica gel and the need for removal of silica prior to the phosphate recovery step 30 can therefore therefore be avoided even in some embodiments that process the waste water with the highest silica concentrations. In some embodiments where the silica is not removed prior to the phosphate recovery step 30, the silica is hydrolyzed during the phosphorus recovery step 30 and eventually removed downstream.
    [0039] [00039] The silica removal step 20 is followed by the phosphate recovery step 30. As shown in Figure 2, the phosphate can in some embodiments be recovered in the form of struvite, struvite analogs, or other phosphate compounds , for example, according to the methods and mechanisms described by Koch et al. in U.S. 7,622,047, incorporated herein by reference. If the waste water was not treated by the silica removal step 20 (and therefore the pH did not rise since the fluoride removal step 10), then a suitable base can be added to the waste water at an initial point in the phosphate recovery 30 to raise the pH to a desired level for precipitation of the desired phosphate compounds. As shown in Figure 2, ammonium hydroxide (or another base containing ammonium and / or magnesium) can, for example, be used to raise the pH for the phosphate recovery step 30 to raise the pH. The pH can be raised between pH 7.0 to 8.0, for example, to pH 7.5.
    [0040] [00040] Supersaturation conditions for the phosphate compound are maintained to recover the desired phosphate compounds during the phosphate recovery step 30. Maintaining the supersaturation conditions may, for example, include: maintaining a supersaturation ratio of 2 to 5 for struvite; maintaining an adequate pH, for example, to control the introduction of the base and / or the removal of air; maintain the phosphate concentration higher than the concentrations of other components of the phosphate compound; and / or controlling the introduction of the compounds comprising at least one of the other components of the desired phosphate compound.
    [0041] [00041] The supersaturation conditions for struvite can be determined in relation to the product of the struvite solubility K sp given by: K sp = [Mg 2+ ] eq [NH 4 + ] eq [PO 4 3- ] eq where the activities of different species (ie [Mg 2+ ] eq , [NH 4 + ] eq and [PO 4 3- ] eq ) are respectively measured as magnesium, ammonia and orthophosphate soluble in equilibrium. Supersaturation ratio (SSR) can be given by: SSR = [Mg 2+ ] [NH 4 + ] [PO 4 3- ] / K sp .
    [0042] [00042] The increase in SSR leads to struvite crystallization.
    [0043] [00043] In the case of struvite recovery, the "other components" mentioned above are magnesium and ammonia. During the recovery of struvite in the embodiment illustrated in Figure 2, sodium hydroxide is added to control the pH and magnesium chloride is added to control the magnesium concentration. Struvite recovery can be run lean in magnesium and / or ammonia in some embodiments. Struvite can be recovered in the form of solid granules ranging in size from 1 to 5 mm in some embodiments.
    [0044] i O tempo de retenção hidráulica durante de recuperação estruvita pode ser estendida visto que o água de reservatório de fosfogipsita tende a ter uma concentração de fósforo muito maior comparado a água residual municipal e formação de grânulo é a taxa limitante. Este pode ser atingido, por exemplo, pelo aumento da razão de reciclagem (uma proporção da água residual que é reciclada à água residual que sai da etapa de recuperação de fosfato 30). ii A amônia pode ser adicionada na forma de hidróxido de amônio (ou altemativamente como cloreto de amônia ou amônio de anidro mais cáustico para o ajuste de pH). iii A taxa de fluxo de alimentação de água de reservatório de fosfogipsita pode ser diminuída com relação à taxa de fluxo da água residual sendo reciclada na etapa de remoção de fosfato 30 para atingir a razão de supersaturação desejada de 2-5. iv O fosfato pode ser mantido em excesso como para minimizar as quantidades de magnésio e amônio perde no efluente final. [00044] The methods described in US 7,622,047 can be modified and / or selected to optimize the phosphate recovery step 30 in several ways including one or more of the following. i The hydraulic retention time during struvite recovery can be extended as the phosphogipsite reservoir water tends to have a much higher phosphorus concentration compared to municipal waste water and granule formation is the limiting rate. This can be achieved, for example, by increasing the recycling ratio (a proportion of the waste water that is recycled to the waste water that leaves the phosphate recovery step 30). ii Ammonia can be added in the form of ammonium hydroxide (or alternatively as ammonium chloride or more caustic anhydrous ammonium for pH adjustment). iii The flow rate of phosphogipsite reservoir water supply can be decreased in relation to the flow rate of waste water being recycled in the phosphate removal step 30 to achieve the desired 2-5 supersaturation ratio. iv Phosphate can be kept in excess as to minimize the amounts of magnesium and ammonium lost in the final effluent.
    [0045] [00045] Following the phosphate recovery step 30 the residual water undergoes refining step 40 before being discharged as treated effluent. In some embodiments, refining step 40 may involve one or more chemical steps.
    [0046] [00046] In the embodiment shown in Figure 2, refining step 40 includes raising the pH of the waste water from the struvite production step to about pH 8-10. This may comprise the addition of a base such as lime. The elevated pH causes precipitation of the remaining solutes including any phosphate, sulfate, calcium, magnesium and heavy trace metals. Refining step 40 can also include an ammonia removal step. As shown in Figure 2, ammonia can be removed to lower the pH to about pH 7.0 and subject the breakpoint chloride to residual water. Other suitable methods for removing ammonia include withdrawal, biological nitrification, biological denitrification and others. The ammonia removal step may not be necessary if the struvite recovery step is run lean on ammonia. After refining step 40, the treated effluent can be discharged.
    [0047] [00047] Figure 3 illustrates in general a wastewater treatment process 100 according to another embodiment of the invention. The fluoride removal step 110, silica removal step 120 and phosphate recovery step 130 of process 100 can be similar to the corresponding steps of process 1.
    [0048] [00048] Figure 4 illustrates a further embodiment of the invention following process 100, but more specifically exemplifying the treatment of phosphogipsite reservoir water and struvite recovery. Following the phosphate recovery step 130, waste water in process 100 is refined by membranes 150, 160 in refining step 140. As shown in Figure 4, before the membrane treatment before the waste water pH membrane treatment can be decreased to about pH 3.05.0 to prevent flaking of the membranes, as well as to reduce silica hydrolysis and the risk of contamination of the membrane. This may be particularly desirable in cases where the silica removal step is not carried out upstream. Before the membrane treatment, the residual water can be pre-filtered to remove the suspended solids and to reduce the sediment density index. Decreasing the pH and / or pre-filtration before the membrane treatment is optional in some embodiments.
    [0049] [00049] First membrane stage 150 can be configured to reject bivalent ions (for example, phosphate, sulfate, magnesium) and allowed direct monovalent ion flows (for example, sodium, chloride, fluoride, ammonia) to the second membrane stage 160. The first membrane stage can, for example, comprise a reverse osmosis (RO) or nanofiltration membrane (NC). In some embodiments, the low pH concentrates (current A) of the first membrane stage 150 can be recirculated to the fluoride removal step 110. As shown in Figure 4, recirculation of current A differs from the bivalent ions of the discharged and in instead of the results in: additional precipitation of the residual components in the fluoride removal step (for example, removal of the sulfate as calcium sulfate in the fluoride removal step); and additional recovery of the desired components (for example, phosphate and magnesium as struvite) in the phosphate recovery step.
    [0050] [00050] Second stage of membrane 160 can be configured to reject monovalent ions (eg, sodium, chloride, fluoride). As shown in Figure 4, the second membrane stage can comprise a reverse osmosis (RO) membrane. The permeate pH from the first membrane stage can be adjusted to pH 7.5 - 8.0 before the second membrane stage to promote fluoride rejection and obtain the permeate that can be discharged directly. In some embodiments, the second stage of the membrane concentrates (stream B) containing more monovalent ions (sodium, chloride, fluoride) can be released back to the residual water source (eg, phosphogipsite pile) or the removal step fluoride.
    [0051] [00051] An ion exchange resin bed (IX) 170 can be provided to remove ammonia from the second stage of the membrane permeate prior to discharge as treated effluent. The ion exchange regeneration liquid containing ammonia (stream C) can be recirculated to the phosphate recovery step 130 to provide pH and ammonia adjustment for the recovery of the phosphate compounds.
    [0052] [00052] Figure 5 illustrates in general the waste water treatment process 200 according to another embodiment of the invention. The fluoride removal step 210, silica removal step 220 and phosphate recovery step 230 of process 200 are similar to the corresponding steps of process 1 and first membrane stage 250, second membrane stage 260 and exchange resin bed ion ion 270 are similar to the corresponding characteristics of process 100. Figure 6 illustrates a further embodiment of the invention by following process 200, but exemplifying the treatment more specifically of phosphogipsite reservoir water and struvite recovery.
    [0053] [00053] Following the silica removal step 220, residual water is directed to the first membrane stage 250. In a similar manner to process 100, the residual water can be acidified and pre-filtered before the first membrane stage 250. The concentrate from the first membrane stage is fed from the phosphate recovery step 230. This concentrate for containing more of the phosphate at about twice the concentration compared to the feed for the phosphate recovery step in process 1 and 100. The concentrated phosphate it can improve the conditions for the recovery of phosphate compounds in some cases. The other elements of the processes illustrated in Figures 5 and 6, including the three recirculation streams A, B and C, are similar to those described above in relation to process 100, with the exception that in process 200 current A is generated in the recovery step phosphate instead of concentrate from the first membrane stage in process 100.
    [0054] [00054] The recirculation of the concentrate A streams, containing, for example, excess magnesium and concentrate of the C stream, containing, for example, excess ammonia, in the upstream steps may even result in the complete recovery of these components in the phosphate compounds recovered, for example, as struvite.
    [0055] i. Os métodos para remoção de amônia descritos para a etapa de remoção de amônia do processo 1 e o método de troca de íon para a remoção de amônia nos processos 100 e 200 são trocáveis. ii. O processo 1 pode ser modificado para fornecer a recirculação. Por exemplo, amônia recuperada na etapa de remoção de amônia pode ser recirculada à etapa de recuperação de fosfato 30. iii. Os dois estágios do tratamento de membrana podem ser substituídos com uma membrana simples (por exemplo, osmose reversa apenas) ou mais do que duas membranas (por exemplo, os dois estágios do tratamento de membrana precedido pelas membranas de microfiltração e/ou ultrafiltração). iv. As características individuais de várias formas de realização divulgadas neste podem ser combinadas com uma outra para criar as formas de realização do exemplo adicional. Por exemplo, o estágio de refino 40 da Figura 1 pode ser expandido para compreender o tratamento de membrana, como mostrado na Figura 3 ou Figura 4 ou outros processos de refino mecânico, v Algumas formas de realização podem produzir os análogos estruvita tal como fosfato de amônio de ferro, em que os compostos Fe correspondentes são substituídos pelos compostos Mg durante o processamento. [00055] As it will be apparent that person skilled in the art in light of the foregoing disclosure, many changes and modifications are possible in the practice of this invention without diverging from the spirit or scope of this. For example: i. The ammonia removal methods described for the process 1 ammonia removal step and the ion exchange method for ammonia removal in processes 100 and 200 are exchangeable. ii. Process 1 can be modified to provide recirculation. For example, ammonia recovered in the ammonia removal step can be recirculated to the phosphate recovery step 30. iii. The two stages of membrane treatment can be replaced with a single membrane (for example, reverse osmosis only) or more than two membranes (for example, the two stages of membrane treatment preceded by microfiltration and / or ultrafiltration membranes). iv. The individual characteristics of various embodiments disclosed in this can be combined with one another to create the embodiments of the additional example. For example, refining stage 40 in Figure 1 can be expanded to include membrane treatment, as shown in Figure 3 or Figure 4 or other mechanical refining processes, v Some embodiments can produce struvite analogs such as iron ammonium phosphate, in which the corresponding Fe compounds are replaced by Mg compounds during processing.
    [0056] [00056] The following example provides the results of the laboratory scale test of some embodiments of the invention. EXAMPLE 1
    [0057] [00057] Crude reservoir water samples were tested in three stages: 1) F removal with Ca, 2) pH increase and 3) struvite precipitation.
    [0058] [00058] In stage 1, CaCC 3 and Ca (OH) 2 samples of 2L and 3L of reservoir water were added, mixed for 60 minutes, pelleted for 30 minutes, then filtered and the supernatants analyzed to evaluate the effect of the addition bases both in pH and in F and PO 4 concentrations. Ca (OH) 2 was added in both solid and paste form (results shown for paste form only). Ca: F molar ratios of 0.5 and 0.6 for both reagents were tested, respectively representing the stoichiometric amount and an amount in excess of 20%.
    [0059] [00059] Both CaCO 3 reagents and Ca (OH) 2 reagents raise the pH between about 2.5 to 3.5 after 1 hour of mixing. CaCO 3 may be preferred in some embodiments. The results tested showed that with CaCO 3 the removal of F in 0.6 Ca: F molar ratio was less than with Ca (OH) 2 the 0.6 Ca: F molar ratio but PO 4 and NH 3 are lost. if. For the remaining stages, CaCO 3 the 0.6 Ca: F molar ratio was used.
    [0060] [00060] 24 hours after the end of the test, more solids have precipitated in the filtered supernatant and the concentration of SO 4 has decreased along with the concentration of Ca, indicating the formation of gypsum.
    [0061] [00061] In stage 2, Mg (OH) 2 was added (in the form of paste 40% of the weight form) the samples of 500 ml and 1250 ml of the supernatant of stage 1 in molar ratios Mg: P of 0.8, 0.9 and 1.0, to raise the pH of the solution closer to the pH required by the precipitation of and also to place the Mg ions in the solution. Also, MgCl 2 was added at a ratio of 1.0 Mg: P to compare the effects of adding a non-basic Mg source at this stage.
    [0062] [00062] The Mg compounds were added immediately after the completion of a repeated stage 1 test, to prevent loss of Ca through gypsum precipitation. The solutions were mixed for 60 minutes and pelleted for 15 minutes.
    [0063] [00063] Mg (OH) 2 raised the pH to 4.5 to 5.5 and caused the closest complete removal (> 90%) of both Ca and F. A substantial amount of PO 4 was also removed, but the The remaining quantity was still high and sufficient for struvite downstream production. A substantial amount of the added Mg was also removed at this stage. MgCl 2 does not raise the pH, but it slowly lowers it and has a much lesser effect on the removal of F or loss of P. Increasing the molar ratio of Mg: P from 0.8 to 1.0 increases removal F only by 2.8% but PO 4 losses increase by 11.5%. 0.8 Mg: P was selected for use in stage 3.
    [0064] [00064] In stage 3, NH 4 OH was added to the 500 mL samples of the stage 2 supernatant in the N: P molar ratios of 0.8 and 1.0, then NaOH was used to raise the pH above 7.0 . As the Mg: P ratio was approximately 0.5: 1 due to the loss of Mg in stage 2, a P recovery close to 50% should be expected if P is mainly struvite formation. Mg was removed 99%, showing that the reaction proceeds as far as it should give the Mg limits and the removal of P was close to 58%. The precipitation of Struvite in the residual water is limited as well as MgCl 2 and other sources of soluble Mg can be added.
    [0065] [00065] A total pH test was also conducted. 250 mL of the reservoir water sample was placed in a beaker. The blade of a suspended mixer was placed in the sample and rotated at 70 rpm. 6.95 g of CaCO 3 was added to obtain a 0.6 Ca: F ratio. The pH was monitored every 15 minutes. The pH was recorded 60 minutes ago.
    [0066] [00066] 3.95 g of Mg (OH) 2 in paste form in 5.4 g of water were added to obtain a 1: 1 Mg: P ratio, based on the previous pot test result from Example 1. The pH was monitored every 15 minutes. The pH was recorded in 60 minutes.
    [0067] [00067] 2.16 g of dry base / 7.17 g of 30% NH 4 OH by weight was slowly added to obtain a 1: 1 NH 4 OH: P based on P after precipitation of CaCO 3 .
    [0068] [00068] Kennedy, G.A., Soroczak, M.M. and Clayton, J.D., "Chemistry of Gypsum Pond Systems", Florida Institute of Phosphate Research (FIPR) Project # 85-05-025R, 1991.
    [0069] [00069] Perpich, B, Jr., Soule, C., Zamani, S. Timchak, L., Uebelhoer, G., Nagghappan, L. and Helwick, R., “Mobile Agua residual Treatment Helps Remediate Concentrated Acidic Process Water at Fertilizer Plant ”, Florida Water Resources Journal, July 2005.
    权利要求:
    Claims (21)
    [0001]
    Method for treating and recovering phosphate compounds from wastewater, characterized by the fact that the method comprises: (a) measure, precipitate and remove fluoride from wastewater by increasing the pH of wastewater by adding a base containing calcium with a stoichiometric amount of calcium to precipitate fluoride, where the pH does not promote the precipitation of phosphates, and then further increasing the pH of the wastewater by adding one or more calcium-free bases. (b) recover struvite from the residual fluoride water that was removed by maintaining the struvite's supersaturation conditions; and (c) refining waste water, wherein step (c) comprises subjecting the waste water from step (b) to a membrane treatment system to obtain a concentrate and a permeate comprising treated effluent.
    [0002]
    Method according to claim 1, characterized in that the membrane treatment system comprises a two-stage membrane treatment.
    [0003]
    3. Method according to claim 2, characterized in that the two-stage membrane treatment comprises: (i) a first membrane treatment to obtain a first concentrate comprising bivalent ions and a first permeate comprising monovalent ions; and (ii) a second membrane treatment for the first permeate to obtain a second concentrate comprising monovalent ions and a second permeate comprising effluent.
    [0004]
    Method according to claim 3, characterized by the fact that the first concentrate is recirculated to step (a).
    [0005]
    Method according to claim 3 or 4, characterized in that the first membrane treatment comprises nanofiltration.
    [0006]
    Method according to any of claims 3 to 5, characterized in that the second membrane treatment comprises reverse osmosis.
    [0007]
    Method according to any one of claims 2 to 6, characterized in that it comprises lowering the pH around pH 3 to 5 before the two-stage membrane treatment.
    [0008]
    Method according to any one of claims 2 to 7, characterized in that it comprises removing solids put into suspension by filtration before the treatment of two-stage membrane.
    [0009]
    Method according to any one of claims 3 to 6, characterized in that it comprises removing ammonia from the second permeate.
    [0010]
    Method according to claim 9, characterized in that the removal of ammonia comprises subjecting the second permeate to ion exchange.
    [0011]
    Method according to claim 10, characterized by the fact that the liquid containing ammonia from the ion exchange is recirculated up to step (b).
    [0012]
    Method according to claim 1 or 2, characterized by the fact that before step (b) the residual water is subjected to a first membrane treatment to obtain a first concentrate comprising bivalent ions and a first permeate comprising monovalent ions, where the first concentrate defines the feed for step (b).
    [0013]
    Method according to claim 12, characterized in that the waste water from step (b) is recirculated to step (a).
    [0014]
    Method according to claim 12 or 13, characterized in that the first permeate is subjected to a second membrane treatment to obtain a second concentrate comprising monovalent ions and a second permeate comprising effluent.
    [0015]
    Method according to any one of claims 12 to 14, characterized in that the first membrane treatment comprises nanofiltration.
    [0016]
    Method according to claim 14, characterized in that the second membrane treatment comprises reverse osmosis.
    [0017]
    Method according to any one of claims 12 to 16, characterized in that it comprises decreasing the pH around pH 3 to 5 before the first membrane treatment.
    [0018]
    Method according to any of claims 12 to 17, characterized in that it comprises removing suspended solids by filtration before the first membrane treatment.
    [0019]
    Method according to claim 14, characterized in that it comprises removing ammonia from the second permeate.
    [0020]
    Method according to claim 19, characterized in that the removal of ammonia comprises subjecting the second permeate to ion exchange.
    [0021]
    Method according to claim 20, characterized by the fact that the liquid containing ammonia from the ion exchange is recirculated up to step (b).
    类似技术:
    公开号 | 公开日 | 专利标题
    BR112012029278B1|2020-06-30|method for treating and recovering phosphate compounds from wastewater
    BR112014006571B1|2020-09-29|METHOD FOR THE TREATMENT OF WASTE WATERS CONTAINING PHOSPHATE
    CN105565573B|2019-01-25|The device and method of desulfurization wastewater zero discharge treatment
    US20120160770A1|2012-06-28|Process for Reducing the Sulfate Concentration in a Wastewater Stream
    CN105084589A|2015-11-25|Treatment method and system for wet magnesium desulphurization wastewater
    US20140367335A1|2014-12-18|Method For Removing Mercury And Selenium From Sulfate-Containing Waste Water
    AU2010201962A1|2010-12-09|Salt purification process
    JP2013230414A|2013-11-14|Recovery process of phosphorus and recovery apparatus of the phosphorus
    SE1750319A1|2017-03-17|Method for treating an effluent supersaturated with calcium carbonate in the presence of phosphonate precipitation-inhibiting products
    CN106458672A|2017-02-22|Method for barium and norm removal from produced water
    Banerjee et al.2015|An innovative process to reduce sulfate in membrane concentrate enhances mine water recovery
    RU2104938C1|1998-02-20|Method for extraction of rare-earth elements of phosphogypsum
    US7081204B2|2006-07-25|Remediation of barium, bicarbonate and alkalinity in ground water
    JP2007007530A|2007-01-18|Waste water treatment method and waste water treatment apparatus
    JP2016140818A|2016-08-08|Phosphorus recovery apparatus and method
    CN212403770U|2021-01-26|Multistage crystallization precipitation treatment system for wastewater desalination
    ES2836877A1|2021-06-28|A suitable procedure for the recovery of phosphorus from organic waste and a system for its implementation |
    JP2003154372A|2003-05-27|Method and apparatus for removing sulfate ion and method for treating wastewater
    Rom et al.2020|Kinetics of CaCO3 precipitation in seeded aeration softening of brackish water desalination concentrate
    Noshadi et al.2015|Determining the optimal ZLD method for Ca and SiO2 removal from RO systems effluent
    BR112021003131A2|2021-05-11|methods and systems for treating water containing phosphogypsum
    WO2009045100A1|2009-04-09|Method and device for purifying a liquid
    Song et al.2011|The removal of high NH3-N concentration in landfill leachate by chemical precipitation
    BR112015003530B1|2021-10-19|METHOD FOR REMOVING SULFATE, CALCIUM AND/OR OTHER SOLUBLE METALS FROM WASTE WATER.
    RU2323164C1|2008-04-27|Process of treating waste water to remove sulfate ions
    同族专利:
    公开号 | 公开日
    MX339660B|2016-06-03|
    CA2799294A1|2011-11-24|
    US10196289B2|2019-02-05|
    MX2012013322A|2013-04-03|
    US20190106348A1|2019-04-11|
    BR112012029278B8|2020-07-21|
    CN102947229A|2013-02-27|
    CA2799294C|2021-11-23|
    BR112012029278A2|2016-07-26|
    MA34312B1|2013-06-01|
    US20130062289A1|2013-03-14|
    WO2011143775A1|2011-11-24|
    US10486994B2|2019-11-26|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    US3551332A|1969-06-16|1970-12-29|Int Minerals & Chem Corp|Purification of fluorine-containing industrial waste waters|
    US3700415A|1970-02-18|1972-10-24|Kerr Mc Gee Chem Corp|Vanadium recovery from wet process phosphoric acid using neutral organophosphorus extractants|
    US3725265A|1971-01-22|1973-04-03|Grace W R & Co|Purification of waste water|
    GB1601669A|1975-03-07|1981-11-04|Occidental Petroleum Corp|Recovery of fluorine and phosphate values from waste water|
    CA1045258A|1974-04-03|1978-12-26|Ronald J. Hirko|Recovery of fluorine and phosphate values from waste water|
    US4639359A|1985-12-16|1987-01-27|International Minerals & Chemical Corp.|Process of removing cationic impurities from wet process phosphoric acid|
    FR2669619B1|1990-11-26|1993-01-08|Elf Aquitaine|PROCESS FOR THE DISPOSAL OF AMMONIA FROM WASTEWATER.|
    CA2186963C|1996-10-01|1999-03-30|Riad A. Al-Samadi|High water recovery membrane purification process|
    KR19990011049A|1997-07-21|1999-02-18|오덕춘|Treatment method of phosphate wastewater by struvite precipitation|
    TW534894B|1998-04-22|2003-06-01|Fujitsu Ltd|Treatment process for fluorine-containing water|
    CN1978336B|1999-01-15|2014-09-03|纳尔科化学公司|Composition and method for simultaneously precipitating metal ions from semiconductor wastewater|
    US6652758B2|2000-09-26|2003-11-25|Ionics, Incorporated|Simultaneous ammonia and fluoride treatment for wastewater|
    US6758977B2|2001-10-25|2004-07-06|Imc Global Operations Inc.|Purification of phosphoric acid plant pond water|
    CA2382813C|2002-04-22|2008-09-02|Kenneth Haggerty|Process for recovery of nutrients from wastewater effluent|
    WO2004024637A1|2002-09-13|2004-03-25|North Carolina State University|Apparatus and method for removing phosphorus from waste lagoon effluent|
    WO2004067139A1|2003-01-31|2004-08-12|Ebara Corporation|Method and apparatus for removing ion in fluid by crystallization|
    US20060196835A1|2003-01-31|2006-09-07|Ebara Corporation|Method and apparatus for removing ions in liquid through crystallization method|
    AU2004315614B2|2004-02-13|2010-07-15|The University Of British Columbia|Fluidized bed wastewater treatment|
    US7560031B1|2005-12-14|2009-07-14|Dr. Phosphate, Inc.|Process for treating pond water|
    US7635236B2|2006-03-30|2009-12-22|Auburn University|In situ remediation of inorganic contaminants using stabilized zero-valent iron nanoparticles|
    US20080053909A1|2006-09-06|2008-03-06|Fassbender Alexander G|Ammonia recovery process|
    KR101019200B1|2008-02-11|2011-03-03|엔텍스|Nitrogen-rich waste water treatment method and method for producing struvite|
    US20110127223A1|2009-12-02|2011-06-02|Veolia Water North America Operating Services, Llc|Process for treating pond water|CA2834690A1|2010-05-13|2011-11-17|Multiform Harvest Inc.|Process and system for recovering phosphorus from wastewater|
    WO2012030857A2|2010-08-30|2012-03-08|Multiform Harvest, Inc.|Methods and systems for recovering phosphorus from wastewater including digestate recycle|
    US9334166B2|2011-02-03|2016-05-10|Multiform Harvest Inc.|Methods and compositions for chemical drying and producing struvite|
    WO2013153531A1|2012-04-11|2013-10-17|Universidade Do Minho|Nanoporous, aluminium-supported alumina membrane, method for producing same and use thereof|
    WO2013153587A1|2012-04-11|2013-10-17|Ｊｆｅエンジニアリング株式会社|Method and device for treating accompanying water from well|
    CN102633384A|2012-04-20|2012-08-15|瓮福（集团）有限责任公司|Method for preparing phosphoric acid by recycling phosphorus from phosphorus-containing wastewater|
    US9663375B2|2012-07-21|2017-05-30|K-Technologies, Inc.|Processes for the recovery of fluoride and silica products and phosphoric acid from wet-process phosphoric acid facilities and contaminated waste waters|
    US8999007B2|2013-07-12|2015-04-07|Ostara Nutrient Recovery Technologies Inc.|Method for fines control|
    CN112094064A|2013-10-14|2020-12-18|瑟登帝石膏公司|struvite-K and potassium gypsum composition for building materials|
    US9422193B2|2013-08-12|2016-08-23|Certainteed Gypsum, Inc.|Struvite-K and syngenite composition for use in building materials|
    US10479728B2|2013-08-12|2019-11-19|Certainteed Gypsum, Inc.|Struvite-K and Syngenite composition for use in building materials|
    CN103951141B|2014-05-08|2015-12-30|东莞市环境科学研究所|A kind of garbage leachate treatment process and treatment unit|
    SG11201609957RA|2014-06-26|2017-01-27|Kurita Water Ind Ltd|Method and device for treating fluoride-containing water|
    CN104973712A|2014-10-23|2015-10-14|铜陵县明晋生产力促进中心有限公司|Treatment method and treatment device of phosphogypsum waste water|
    EP3093274A4|2015-03-19|2016-11-16|Mitsubishi Heavy Ind Ltd|Water treatment system and power generation apparatus|
    US10464852B2|2016-05-13|2019-11-05|University Of Maryland, Baltimore County|Phosphorus extraction and recovery system |
    CN106241763B|2016-08-11|2018-09-25|贵阳开磷化肥有限公司|A kind of phosphor ammonium slurry filter device and its filter method|
    US20180282189A1|2017-03-31|2018-10-04|University Of South Florida|Struvite precipitation and microbial fuel cell for recovery of nutrients and energy from digester effluent|
    WO2018206092A1|2017-05-09|2018-11-15|Helmholtz-Zentrum Für Umweltforschung Gmbh - Ufz|Method for recovering phosphorus from wastewater containing phosphorus and associated sewage plant|
    EP3495327A1|2017-12-06|2019-06-12|Ovivo Inc.|Treatment of fluoride-containing wastewater|
    WO2020041458A1|2018-08-21|2020-02-27|Evoqua Water Technologies Llc|Methods and systems for treating phosphogypsum-containing water|
    CN109300386B|2018-11-28|2021-03-16|贵州大学|Experimental device for treating polluted karst underground water of leachate in phosphogypsum yard|
    US10787380B1|2019-01-15|2020-09-29|Paul Baskis|Biosolids concentrator and digester system and method|
    CN110104848A|2019-06-17|2019-08-09|武汉兴天宇环境股份有限公司|A kind of ardealite dump leaching wastewater treatment method|
    CN110563198A|2019-09-04|2019-12-13|广西长润环境工程有限公司|Chemical fertilizer wastewater treatment method and treatment equipment|
    CN110467168A|2019-09-19|2019-11-19|中南大学|The recovery method of titanium pigment in a kind of ardealite|
    CN112794488A|2019-11-14|2021-05-14|西南科技大学|Method for synergistic harmless treatment of electrolytic manganese slag leachate and phosphogypsum leachate|
    CN112062343A|2020-09-08|2020-12-11|湖北美辰环保股份有限公司|MAP method-based harmless recycling treatment method for phosphogypsum yard leachate|
    法律状态:
    2018-04-10| B06F| Objections, documents and/or translations needed after an examination request according [chapter 6.6 patent gazette]|
    2019-02-26| B06T| Formal requirements before examination [chapter 6.20 patent gazette]|
    2019-12-10| B06A| Patent application procedure suspended [chapter 6.1 patent gazette]|
    2020-04-14| B09A| Decision: intention to grant [chapter 9.1 patent gazette]|
    2020-06-30| B16A| Patent or certificate of addition of invention granted [chapter 16.1 patent gazette]|Free format text: PRAZO DE VALIDADE: 20 (VINTE) ANOS CONTADOS A PARTIR DE 18/05/2011, OBSERVADAS AS CONDICOES LEGAIS. |
    2020-07-21| B16C| Correction of notification of the grant [chapter 16.3 patent gazette]|Free format text: REF. RPI 2582 DE 30/06/2020 QUANTO AO TITULAR E AO INVENTOR. |
    优先权:
    申请号 | 申请日 | 专利标题
    US34600210P| true| 2010-05-18|2010-05-18|
    US61/346002|2010-05-18|
    PCT/CA2011/050311|WO2011143775A1|2010-05-18|2011-05-18|Treatment of phosphate-containing wastewater|
    [返回顶部]