Process method for comprehensively treating corn soaking water and obtaining inositol and potassium struvite

Abstract

The invention relates to the technical field of corn soaking water treatment, in particular to a process method for comprehensively treating corn soaking water and obtaining inositol and potassium struvite, which comprises the following steps: treating corn soaking water supernatant as a raw material by first cation and first anion resin columns; the collected desorption solution is subjected to concentration, ultrasonic enzymolysis, decoloration and simulated moving bed chromatographic separation, an obtained inositol phase enters a second cation resin column and a second anion resin column, and an inositol product is obtained through concentration crystallization and drying; adding magnesium chloride hexahydrate into the collected salt phase, adjusting the pH value, filtering, respectively collecting precipitate (potassium struvite) and filtrate, concentrating and crystallizing the filtrate, filtering, and carrying out bipolar membrane electrodialysis treatment on the collected crystallization mother liquor; according to the process method, inositol and potassium struvite products can be obtained, phosphorus and potassium in the corn soaking water are recycled, resource waste is avoided, consumption of a resolving agent (potassium chloride) is reduced, and cost is saved.

Description

Technical Field

[0001] This invention relates to the field of corn soaking water treatment technology, and in particular to a process for comprehensively treating corn soaking water to obtain inositol and potassium struvite. Background Technology

[0002] Corn soaking water is a byproduct of wet corn starch production, containing abundant phosphorus, potassium, magnesium, phytic acid, and other components. Currently, the main treatment of corn soaking water involves cation and anion exchange resin columns. The adsorbed phytic acid is then desorbed, and the potassium phytate solution is hydrolyzed at high temperature. The resulting hydrolysate is then further processed to obtain inositol. However, existing processes do not recover potassium and magnesium ions for the production of potassium struvite, and the regeneration waste liquid generated during the regeneration of cation and anion exchange resin columns is not recycled, resulting in resource waste. Therefore, to address these technical issues, it is necessary to develop a comprehensive process for treating corn soaking water to obtain inositol and potassium struvite. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide a process for comprehensively treating corn soaking water to obtain inositol and potassium struvite, which addresses the shortcomings of the prior art. This process can produce inositol and potassium struvite products. The entire process achieves effective recovery of phosphorus and potassium, avoids resource waste, and reduces the consumption of the desorption agent (potassium chloride).

[0004] To solve the above-mentioned technical problems, the technical solution of the present invention is as follows:

[0005] A process for comprehensively treating corn soaking water to obtain inositol and potassium struvite, the process comprising the following steps:

[0006] (1) The supernatant after corn soaking water is allowed to settle is passed through the first cation exchange resin column, and the collected effluent enters the first anion exchange resin column. After the feeding is completed, potassium chloride solution is used for analysis, and the collected analysis solution is used for later use.

[0007] (2) Take the eluent obtained in step (1), and adjust the pH of the concentrated solution collected after concentration treatment to acidity.

[0008] First, add the chelating agent and stir to mix. Then add phytase and heat to carry out ultrasonic enzymatic hydrolysis. The resulting enzymatic hydrolysate is then ready for use.

[0009] (3) Take the enzymatic hydrolysate from step (2), decolorize it, and filter the resulting decolorized solution for later use;

[0010] (4) Take the decolorizing solution described in step (3) and separate it using a simulated moving bed chromatography system. The resulting inositol phase and salt phase are reserved separately.

[0011] (5) Take the inositol phase described in step (4) and enter the second cation resin column and the second anion resin column in series. The resulting effluent is concentrated, crystallized and dried to obtain the inositol product.

[0012] (6) Take the salt phase described in step (4), add magnesium chloride hexahydrate, adjust the pH to alkaline and stir to mix, filter and collect the filtrate for later use, and dry the collected precipitate to obtain potassium struvite product.

[0013] (7) Take the filtrate from step (6), concentrate and crystallize it, filter the crystallized mother liquor, and then treat it with bipolar membrane electrodialysis to obtain hydrochloric acid and potassium hydroxide solution respectively; hydrochloric acid is used to elute the first cation resin column in step (1) and the second cation resin column in step (5), wherein the eluent collected when hydrochloric acid elutes the first cation resin is concentrated, crystallized and dried to obtain potassium chloride as phytic acid elution agent; the eluent collected when hydrochloric acid elutes the second cation resin column is combined with the filtrate from step (6); the potassium hydroxide solution is used to elute the second anion resin column in step (5), and the collected eluent is combined with the salt from step (4).

[0014] As an improved technical solution, in step (1), the supernatant enters the first cation exchange resin column at a flow rate of 1.5-2 Bv / h, and the effluent enters the first anion exchange resin column at a flow rate of 1.5-2 Bv / h; the concentration of the potassium chloride solution is 12 wt%, and the potassium chloride solution enters the first anion exchange resin column at a flow rate of 0.5-1 Bv / h.

[0015] As an improved technical solution, in step (2), a nanofiltration membrane with a molecular weight cutoff of 300-500 Da is used for concentration treatment; the pH of the concentrate is adjusted to 4.5-5 using potassium hydroxide solution; the chelating agent includes tetrasodium glutamate diacetate and polyaminopolyether methylenephosphonic acid, wherein the amount of tetrasodium glutamate diacetate added is 0.15-0.3 g / L, and the amount of polyaminopolyether methylenephosphonic acid added is 0.2-0.4 ml / L; the temperature is heated to 50-60℃, and ultrasonic enzymatic hydrolysis is performed for 4-6 hours; the power of ultrasonic treatment is 300-500 W.

[0016] As an improved technical solution, activated carbon is added to the enzymatic hydrolysis solution in step (3) for decolorization treatment; the decolorized solution is concentrated under vacuum, and the solid content of the concentrated solution is 40-45 wt%.

[0017] As an improved technical solution, the separation conditions in step (4) using a simulated moving bed chromatography separation system are as follows: operating temperature is 55-65℃, pressure is 3-0.6Mpa, feed flow rate of decolorizing liquid is 0.5Bv / h, and flow rate of mobile phase is 1Bv / h.

[0018] As an improved technical solution, the inositol phase in step (5) enters the second cation resin column and the second anion resin column at a flow rate of 1-1.5 Bv / h.

[0019] As an improved technical solution, the salt phase and the magnesium chloride hexahydrate in step (6) are added at a ratio of 80-120 g / L to the liquid-to-material ratio, and the pH is adjusted to 8.0-10.0.

[0020] As an improved technical solution, the concentration of hydrochloric acid used in step (7) to elute the first cation exchange resin column in step (1) and the second cation exchange resin column in step (5) is 5 wt%.

[0021] After adopting the above technical solution, the beneficial effects of the present invention are:

[0022] This invention uses the supernatant from corn soaking water after settling as raw material. The solution first undergoes adsorption on a first cation exchange resin column (potassium ions are adsorbed). The collected effluent then enters a first anion exchange resin column (phytic acid is adsorbed). Potassium chloride is used to elute the first anion exchange resin column, yielding an eluent containing potassium phytate. This eluent is then concentrated via nanofiltration. The collected concentrate is adjusted to acidic pH, and a chelating agent is added and stirred (to chelate calcium and magnesium ions). Phytase is then added, followed by ultrasonic enzymatic hydrolysis. The resulting hydrolysate (containing inositol and potassium dihydrogen phosphate) is decolorized using activated carbon. The decolorized solution is then separated by simulated moving bed chromatography to obtain an inositol phase and a salt phase. The inositol phase enters a second cation exchange resin column and a second anion exchange resin column connected in series, and is then concentrated. The process involves crystallization and drying to obtain inositol. The collected salt phase is mixed with magnesium chloride hexahydrate to adjust the pH to alkaline. After filtration, the precipitate (which, after drying, becomes potassium struvite) and filtrate are collected separately. The filtrate is then concentrated, crystallized, and filtered again. The collected crystallization mother liquor is then subjected to bipolar membrane electrodialysis to obtain hydrochloric acid and potassium hydroxide solutions. Hydrochloric acid is used to elute the first and second cation exchange resin columns. The eluent collected during hydrochloric acid elution of the first cation exchange resin is concentrated, crystallized, and dried to obtain potassium chloride, which is used as a phytic acid eluent. The eluent collected during hydrochloric acid elution of the second cation exchange resin column is combined with the filtrate from step (6). The potassium hydroxide solution is used to elute the second anion exchange resin column, and the collected eluent is combined with the salt phase. This process yields inositol and potassium struvite products, realizing the recovery of phosphorus and potassium from corn soaking water, avoiding resource waste, reducing the consumption of the eluent (potassium chloride), and saving costs. Detailed Implementation

[0023] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0024] Example 1

[0025] A process for comprehensively treating corn soaking water to obtain inositol and potassium struvite includes the following steps:

[0026] (1) 1000L of supernatant (potassium ions 0.7%, phytic acid 1%, magnesium 0.2%) after corn soaking water has settled and settled is fed into a 100L first cation exchange resin column (packing material Zhengguang-D113) at a flow rate of 1.5 Bv / h. The collected effluent is fed into a 100L first anion exchange resin column (packing material Zhengguang-D314) at a flow rate of 1.5 Bv / h. After feeding, 150L of 12wt% potassium chloride solution is used to precipitate the first anion exchange resin column at a flow rate of 0.5 Bv / h. Then, 150L of water is used for top washing. 300L of the precipitate is collected for later use.

[0027] (2) Take 300L of the eluent from step (1), concentrate it through a nanofiltration membrane with a molecular weight cutoff of 300-500Da, adjust the pH of the collected 90L concentrate to 4.5, first add chelating agent (including tetrasodium glutamate diacetate and polyaminopolyether methylenephosphonic acid, add 13.5g of tetrasodium glutamate diacetate to the eluent at a dosage of 0.15g / L, and add 18ml of polyaminopolyether methylenephosphonic acid to the eluent at a dosage of 0.2ml / L), stir and mix, then add phytase, heat to 50℃ for ultrasonic treatment (300w power), enzymatic hydrolysis reaction for 4h, and the obtained 88L of enzymatic hydrolysate is ready for use;

[0028] (3) Take 88L of the enzymatic hydrolysate from step (2) and decolorize it (add 44g of activated carbon at a dosage of 0.5g / L, heat to 50℃, decolorize for 30min), and filter to obtain 88L of decolorized solution for later use.

[0029] (4) Take 88L of the decolorizing solution from step (3) and separate it using a simulated moving bed chromatography system (containing 6 tandem columns, each with a volume of 30L, the packing material in the column is 001×7 (732 type) styrene-based strong acid cation exchange resin; the operating temperature is 55℃, the pressure is 0.3Mpa, the feed flow rate of the decolorizing solution is 0.5Bv / h, and the flow rate of the mobile phase is 1Bv / h). The resulting 120L of inositol phase and 180L of salt phase are reserved separately.

[0030] (5) Take 120L of inositol phase from step (4) and enter the second cation resin column (resin column volume is 12L, and the packing material in the resin column is Zhengguang-D113) and the second anion resin column (resin column volume is 8L, and the packing material in the resin column is Lx-360) in series at a flow rate of 1Bv / h. Use 12L of water as top feed. The resulting 132L of effluent is vacuum concentrated, cooled and crystallized and dried to obtain the inositol product.

[0031] (6) Take 180L of salt phase from step (4), add magnesium chloride hexahydrate at a ratio of 80g / L, adjust the pH to 8.0, stir and mix, filter and collect 170L of filtrate for later use, and dry the collected precipitate to obtain potassium struvite product.

[0032] (7) Take 170L of filtrate from step (6), concentrate it to a solid content of 65wt%, crystallize and filter it at 30℃, and then treat the collected crystallization mother liquor (potassium chloride mother liquor) with bipolar membrane electrodialysis to obtain hydrochloric acid and potassium hydroxide solution respectively; hydrochloric acid (diluted to 5wt%) is used to elute the first cation resin column in step (1) and the second cation resin column in step (5) (at this time, the second cation resin and the second anion resin column are disconnected in series), wherein the potassium chloride obtained by concentrating, crystallizing and drying the eluent collected when eluting the first cation resin with hydrochloric acid is used as phytic acid elution agent; the eluent collected when eluting the second cation resin column with hydrochloric acid is combined with the filtrate in step (6); the potassium hydroxide solution is used to elute the second anion resin column in step (5) (at this time, the second cation resin and the second anion resin column are disconnected in series), and the collected eluent is combined with the salt in step (4).

[0033] The bipolar membrane electrodialysis treatment employs a standard three-chamber structure: acid chamber-salt chamber-alkali chamber, with the membrane stack consisting of 20 repeating units connected in series. Each unit includes: a cation exchange membrane, an acid chamber partition, a bipolar membrane, an alkali chamber partition, an anion exchange membrane, and a salt chamber partition. Initial feed solutions: Acid and alkali chambers: 1 BV of deionized water is added as the initial receiving solution. Electrolyte chamber: A 2 wt% potassium sulfate solution is circulated and injected to conduct current and maintain electrode stability. Salt chamber (i.e., feed chamber): The recovered potassium chloride mother liquor to be treated is added. The system operates in constant voltage or constant current mode, controlling the operating voltage of each membrane pair to within 1.5V, corresponding to a total stack voltage of 30V.

[0034] Example 2

[0035] A process for comprehensively treating corn soaking water to obtain inositol and potassium struvite includes the following steps:

[0036] (1) 1000L of supernatant (potassium ions 0.7%, phytic acid 1%, magnesium 0.2%) after corn soaking water was allowed to settle and enter a 100L first cation exchange resin column (packing material is Zhengguang-D113) at a flow rate of 1.8 Bv / h. The collected effluent was entered into a 100L first anion exchange resin column (packing material is Zhengguang-D314) at a flow rate of 1.8 Bv / h. After the feeding was completed, 150L of 12wt% potassium chloride solution was used to precipitate the first anion exchange resin column at a flow rate of 0.8 Bv / h. Then, the column was washed with water and 300L of precipitate was collected for later use.

[0037] (2) Take 300L of the eluent from step (1), concentrate it through a nanofiltration membrane with a molecular weight cutoff of 300-500 Da, adjust the pH of the collected 90L concentrate to 4.8, first add chelating agent (including tetrasodium glutamate diacetate and polyaminopolyether methylenephosphonic acid, add 20.7g of tetrasodium glutamate diacetate at a dosage of 0.23g / L, and add 27mL of polyaminopolyether methylenephosphonic acid at a dosage of 0.3ml / L), stir and mix, then add phytase, heat to 55℃ for ultrasonic treatment (400w power), enzymatic hydrolysis reaction for 5h, and the obtained 88L of enzymatic hydrolysate is ready for use;

[0038] (3) Take 88L of the enzymatic hydrolysate from step (2) and decolorize it (add 44g of activated carbon at a dosage of 0.5g / L, heat to 50℃, decolorize for 30min), and filter to obtain 88L of decolorized solution for later use.

[0039] (4) Take 88L of the decolorizing solution from step (3) and separate it using a simulated moving bed chromatography system (containing 6 tandem columns, each with a volume of 30L, the packing material in the column is 001×7 (732 type) styrene-based strong acid cation exchange resin; the operating temperature is 60℃, the pressure is 0.45Mpa, the feed flow rate of the decolorizing solution is 0.5Bv / h, and the flow rate of the mobile phase is 1Bv / h). The resulting 120L of inositol phase and 180L of salt phase are reserved separately.

[0040] (5) Take 120L of inositol phase from step (4) and enter the second cation resin column (resin column volume is 12L, and the packing material in the resin column is Zhengguang-D113) and the second anion resin column (resin column volume is 8L, and the packing material in the resin column is Lx-360) in series at a flow rate of 1.2Bv / h. Use 12L of water as top feed. The resulting 132L of effluent is vacuum concentrated, cooled and crystallized and dried to obtain the inositol product.

[0041] (6) Take 180L of salt phase from step (4), add magnesium chloride hexahydrate at a ratio of 100g / L, adjust the pH to 9.0, stir and mix, filter and collect 172L of filtrate for later use, and dry the collected precipitate to obtain potassium struvite product.

[0042] (7) Take 172L of filtrate from step (6), concentrate it to a solid content of 65wt%, crystallize at 30℃, filter and collect the crystallization mother liquor (potassium chloride mother liquor), and then treat it by bipolar membrane electrodialysis to obtain hydrochloric acid and potassium hydroxide solution respectively; hydrochloric acid (diluted to 5wt%) is used to elute the first cation resin column in step (1) and the second cation resin column in step (5) (at this time, the second cation resin and the second anion resin column are disconnected in series), wherein the eluent collected when hydrochloric acid elutes the first cation resin is concentrated, crystallized and dried to obtain potassium chloride as phytic acid elution agent; the eluent collected when hydrochloric acid elutes the second cation resin column is combined with the filtrate in step (6); potassium hydroxide solution is used to elute the second anion resin column in step (5) (at this time, the second cation resin and the second anion resin column are disconnected in series), and the collected eluent is combined with the salt in step (4).

[0043] The bipolar membrane electrodialysis treatment employs a standard three-chamber structure: acid chamber-salt chamber-alkali chamber, with the membrane stack consisting of 20 repeating units connected in series. Each unit includes: a cation exchange membrane, an acid chamber partition, a bipolar membrane, an alkali chamber partition, an anion exchange membrane, and a salt chamber partition. Initial feed solutions: Acid and alkali chambers: 1 BV of deionized water is added as the initial receiving solution. Electrolyte chamber: A 2 wt% potassium sulfate solution is circulated and injected to conduct current and maintain electrode stability. Salt chamber (feed chamber): The recovered potassium chloride mother liquor to be treated is added. The system operates in constant voltage or constant current mode, controlling the operating voltage of a single membrane pair between 1.5-1.8V, corresponding to a total stack voltage expected to be between 30-36V.

[0044] Example 3

[0045] A process for comprehensively treating corn soaking water to obtain inositol and potassium struvite includes the following steps:

[0046] (1) 1000L of supernatant (potassium ions 0.7%, phytic acid 1%, magnesium 0.2%) after corn soaking water was allowed to settle and enter a 100L first cation exchange resin column (packing material is Zhengguang-D113) at a flow rate of 2Bv / h. The collected effluent was entered into a 100L first anion exchange resin column (packing material is Zhengguang-D314) at a flow rate of 2Bv / h. After the feeding was completed, 150L of 12wt% potassium chloride solution was used to precipitate the first anion exchange resin column at a flow rate of 1Bv / h. Water was used for top washing, and 300L of precipitate was collected for later use.

[0047] (2) Take 300L of the eluent from step (1), concentrate it through a nanofiltration membrane with a molecular weight cutoff of 300-500Da, adjust the pH of the collected 90L concentrate to 5, add chelating agent (including tetrasodium glutamate diacetate and polyaminopolyether methylenephosphonic acid, add 27g of tetrasodium glutamate diacetate at a dosage of 0.3g / L, and add 36mL of polyaminopolyether methylenephosphonic acid at a dosage of 0.4ml / L) and stir to mix, then add phytase, heat to 60℃ for ultrasonic treatment (500w power), and enzymatic hydrolysis reaction for 6h, and the obtained 88L of enzymatic hydrolysate is ready for use;

[0048] (3) Take 88L of the enzymatic hydrolysate from step (2) and decolorize it (add 44g of activated carbon, heat to 50℃, decolorize for 30min), filter and keep the 88L decolorized solution for later use.

[0049] (4) Take 88L of the decolorizing solution from step (3) and separate it using a simulated moving bed chromatography system (containing 6 tandem columns, each with a volume of 30L, the packing material in the column is 001×7 (732 type) styrene-based strong acid cation exchange resin; the operating temperature is 65℃, the pressure is 0.6Mpa, the feed flow rate of the decolorizing solution is 0.5Bv / h, and the flow rate of the mobile phase is 1Bv / h). The resulting 120L of inositol phase and 180L of salt phase are reserved separately.

[0050] (5) Take 120L of inositol phase from step (4) and enter the second cation resin column (resin column volume is 12L, and the packing material in the resin column is Zhengguang-D113) and the second anion resin column (resin column volume is 8L, and the packing material in the resin column is Lx-360) in series at a flow rate of 1.5Bv / h. Use 12L of water for top washing. The resulting 132L of effluent is vacuum concentrated, cooled and crystallized and dried to obtain the inositol product.

[0051] (6) Take 180L of salt phase from step (4), add magnesium chloride hexahydrate at a ratio of 120g / L, adjust the pH to 10.0 and stir to mix. After filtration, collect 175L of filtrate for later use. The collected precipitate is dried to obtain potassium struvite product.

[0052] (7) Take 175L of filtrate from step (6), concentrate it to a solid content of 65wt%, crystallize it at 30℃, filter and collect the crystallization mother liquor (potassium chloride mother liquor), and then treat it by bipolar membrane electrodialysis to obtain hydrochloric acid and potassium hydroxide solution respectively; hydrochloric acid (diluted to 5wt%) is used to elute the first cation resin column in step (1) and the second cation resin column in step (5) (at this time, the second cation resin and the second anion resin column are disconnected in series), wherein the eluent collected when hydrochloric acid elutes the first cation resin is concentrated, crystallized and dried to obtain potassium chloride as phytic acid elution agent; the eluent collected when hydrochloric acid elutes the second cation resin column is combined with the filtrate in step (6); potassium hydroxide solution is used to elute the second anion resin column in step (5) (at this time, the second cation resin and the second anion resin column are disconnected in series), and the collected eluent is combined with the salt in step (4).

[0053] The bipolar membrane electrodialysis treatment employs a standard three-chamber structure: acid chamber-salt chamber-alkali chamber, with the membrane stack consisting of 20 repeating units connected in series. Each unit includes: a cation exchange membrane, an acid chamber partition, a bipolar membrane, an alkali chamber partition, an anion exchange membrane, and a salt chamber partition. Initial feed solutions: Acid and alkali chambers: 1 BV of deionized water is added as the initial receiving solution. Electrolyte chamber: A 2 wt% potassium sulfate solution is circulated and injected to conduct current and maintain electrode stability. Salt chamber (feed chamber): The recovered potassium chloride mother liquor to be treated is added. The system operates in constant voltage or constant current mode, controlling the operating voltage of a single membrane pair between 1.5-1.8V, corresponding to a total stack voltage expected to be between 30-36V.

[0054] To better demonstrate that the process method of the present invention has good technical effects, the following comparative examples are given with reference to Example 2, and the specific experimental data are detailed in Table 1.

[0055] Comparative Example 1

[0056] Unlike Example 2, the chelating agent in step (2) is hydroxyethylidene diphosphate, while the rest of the operation is the same.

[0057] Comparative Example 2

[0058] Unlike Example 2, the chelating agent in step (2) is tetrasodium diacetate of glutamate, while the rest of the operation is the same.

[0059] Comparative Example 3

[0060] Unlike Example 2, in step (2), the pH is adjusted to 6, while the rest of the operation is the same.

[0061] Comparative Example 4

[0062] Unlike Example 2, the pH is adjusted to 4 in step (2), while the rest of the operation is the same.

[0063] Comparative Example 5

[0064] Unlike Example 2, step (2) lacks ultrasonic treatment, but the rest of the operation is the same.

[0065] Comparative Example 6

[0066] Unlike Example 2, in step (6), the pH is adjusted to 11, and the rest of the operation is the same.

[0067] Comparative Example 7

[0068] Unlike Example 2, step (7) is missing; the rest of the operations are the same.

[0069]

[0070] As can be seen from Table 1, the process method of Example 2 of the present invention has better overall yield, production rate and purity of inositol and potassium struvite than other examples and comparative examples, and also reduces the amount of potassium chloride used.

[0071] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A process for comprehensively treating corn soaking water to obtain inositol and potassium struvite, characterized in that, The process includes the following steps: (1) The supernatant after corn soaking water is allowed to settle is passed through the first cation exchange resin column, and the collected effluent enters the first anion exchange resin column. After the feeding is completed, potassium chloride solution is used for analysis, and the collected analysis solution is used for later use. (2) Take the eluent obtained in step (1), and adjust the pH of the concentrated solution collected after concentration treatment to acidity. First, add the chelating agent and stir to mix. Then add phytase and heat to carry out ultrasonic enzymatic hydrolysis. The resulting enzymatic hydrolysate is then ready for use. (3) Take the enzymatic hydrolysate from step (2), decolorize it, and filter the resulting decolorized solution for later use; (4) Take the decolorizing solution described in step (3) and separate it using a simulated moving bed chromatography system. The resulting inositol phase and salt phase are reserved separately. (5) Take the inositol phase described in step (4) and enter the second cation resin column and the second anion resin column in series. The resulting effluent is concentrated, crystallized and dried to obtain the inositol product. (6) Take the salt phase described in step (4), add magnesium chloride hexahydrate, adjust the pH to alkaline and stir to mix, filter and collect the filtrate for later use, and dry the collected precipitate to obtain potassium struvite product. (7) Take the filtrate from step (6), concentrate and crystallize it, filter it, and then treat the crystallized mother liquor by bipolar membrane electrodialysis to obtain hydrochloric acid and potassium hydroxide solution respectively; hydrochloric acid is used to elute the first cation resin column in step (1) and the second cation resin column in step (5), wherein the eluent collected when hydrochloric acid elutes the first cation resin is concentrated, crystallized and dried to obtain potassium chloride as phytic acid elution agent; The eluent collected during the elution of the second cation exchange resin column with hydrochloric acid is combined with the filtrate from step (6); the potassium hydroxide solution is used to eluent the second anion exchange resin column in step (5), and the collected eluent is combined with the salt from step (4).

2. The process for comprehensively treating corn soaking water to obtain inositol and potassium struvite according to claim 1, characterized in that, In step (1), the supernatant enters the first cation exchange resin column at a flow rate of 1.5-2 Bv / h, and the effluent enters the first anion exchange resin column at a flow rate of 1.5-2 Bv / h; the concentration of the potassium chloride solution is 12 wt%, and the potassium chloride solution enters the first anion exchange resin column at a flow rate of 0.5-1 Bv / h.

3. The process for comprehensively treating corn soaking water to obtain inositol and potassium struvite according to claim 1, characterized in that, In step (2), a nanofiltration membrane with a molecular weight cutoff of 300-500 Da is used for concentration treatment; the pH of the concentrate is adjusted to 4.5-5 using potassium hydroxide solution; the chelating agent includes tetrasodium glutamate diacetate and polyaminopolyether methylenephosphonic acid, wherein the amount of tetrasodium glutamate diacetate added is 0.15-0.3 g / L and the amount of polyaminopolyether methylenephosphonic acid added is 0.2-0.4 ml / L; the mixture is heated to 50-60℃ and subjected to ultrasonic enzymatic hydrolysis for 4-6 hours; the power of ultrasonic treatment is 300-500 W.

4. The process for comprehensively treating corn soaking water to obtain inositol and potassium struvite according to claim 1, characterized in that, In step (3), activated carbon is added to the enzymatic hydrolysate for decolorization; the decolorized solution is concentrated under vacuum, and the solid content of the concentrated solution is 40-45 wt%.

5. The process for comprehensively treating corn soaking water to obtain inositol and potassium struvite according to claim 1, characterized in that, In step (4), the separation conditions when using a simulated moving bed chromatography system are as follows: operating temperature is 55-65℃, pressure is 3-0.6Mpa, feed flow rate of decolorizing solution is 0.5Bv / h, and flow rate of mobile phase is 1Bv / h.

6. A process for comprehensively treating corn soaking water to obtain inositol and potassium struvite according to claim 1, characterized in that, The inositol phase described in step (5) is fed into the second cation exchange resin column and the second anion exchange resin column at a flow rate of 1-1.5 Bv / h.

7. The process for comprehensively treating corn soaking water to obtain inositol and potassium struvite according to claim 1, characterized in that, In step (6), the salt phase and the magnesium chloride hexahydrate are added at a ratio of 80-120 g / L to the liquid, and the pH is adjusted to 8.0-10.

0.

8. A process for comprehensively treating corn soaking water to obtain inositol and potassium struvite according to claim 1, characterized in that, In step (7), the concentration of hydrochloric acid used to elute the first cation exchange resin column in step (1) and the second cation exchange resin column in step (5) is 5 wt.

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