A resource utilization method for creatine organic high-salt wastewater

Abstract

The present application discloses a method for resource utilization of creatine organic high-salt wastewater, which belongs to the technical field of resource utilization of organic high-salt wastewater. Creatine production wastewater is pretreated with an adsorbent, and then the pretreated wastewater is catalytically oxidized. The wastewater treated with catalytic oxidation is evaporated and concentrated. The steam in the concentration is condensed and then passed through a reverse osmosis membrane to obtain pure water for reuse. Industrial-grade sodium chloride and sodium sulfate are obtained by evaporation, cooling, crystallization and washing. The catalyst can effectively promote the catalytic oxidation of organic matter in the wastewater. The method provided by the present invention can realize the resource utilization of organic high-salt wastewater generated in creatine production. The recycled water, sodium chloride and sodium sulfate have high purity, less chemical wastewater is generated, and the method is environmentally friendly. The method is simple and low in cost, which is conducive to large-scale industrial application.

Description

Technical Field

[0001] The present application belongs to the technical field of resource utilization of organic high-salt wastewater, and in particular, relates to a resource utilization method of creatine organic high-salt wastewater. Background Art

[0002] With the rapid development of my country's health and wellness food industry, the market demand for creatine products has been huge in recent years. There are few domestic production enterprises and they are small in scale. Creatine monohydrate has been in short supply. Therefore, the development of creatine monohydrate production is of great significance to alleviating the shortage of creatine monohydrate. However, a large amount of organic high-salt wastewater is generated during the production of creatine monohydrate, which is difficult to dispose of. The high-salt wastewater has a large output, a wide range of sources, a complex chemical composition and high environmental pollution. Although many important research progress has been made so far, the recovery and utilization of organic high-salt wastewater resources is still a key and urgent task. The resource utilization of organic high-salt wastewater must not only solve the problem of efficient and low-cost removal of organic matter in wastewater, but also solve the problem of comprehensive utilization of inorganic salts and water resources.

[0003] The organic high-salt wastewater generated in creatine production has a complex composition. In addition to a large amount of inorganic salts, it also contains organic matter that has an adverse effect on the recovery of inorganic salts and water resources. In order to achieve efficient recovery and utilization of high-salt wastewater resources, the organic matter must be removed first; the currently developed methods are physical and chemical methods, Fenton oxidation method, iron-carbon micro-electrolysis-Fenton oxidation method, photocatalysis-catalytic wet oxidation method, ozone-photocatalytic oxidation method, electrocatalytic oxidation-ozonation method, etc., which can overcome the shortcomings of a single method by coupling the advantages of multiple treatment methods and significantly improve the removal efficiency of organic matter and heavy metal ions in wastewater.

[0004] Common technologies for separating and recovering inorganic salts include evaporation, electrodialysis, reverse osmosis, microfiltration, nanofiltration, etc. Crystallization is the process of separating solids from gas / liquid / solid phases in the form of crystals. It can convert inorganic salts from dissolved ions in high-salt wastewater into solid forms and separate them. Other process technologies cannot directly separate solid inorganic salts. A method of reducing the solubility of inorganic salts by cooling and crystallizing them. By adding an anti-solvent that is miscible with water to water, the solubility of inorganic salts in the system is reduced, so that they are crystallized. Using the dissolution crystallization method, ethanol is used as the anti-solvent to extract Na with a purity of 97% from polytetrahydrofuran wastewater. 2 HPO 4 , the salt recovery rate is as high as 93% (Desalination and Water Treatment, 2016, Vol. 57, pp. 382-387).

[0005] Invention patent CN114105389B discloses a method for resource utilization of coking high-salt wastewater, including the steps of subjecting the coking wastewater to concentration to form a concentrated brine and subjecting it to nanofiltration treatment to obtain a sodium sulfate concentrate and nanofiltration water; subjecting the nanofiltration water to high-pressure reverse osmosis treatment to obtain a sodium chloride concentrate; and adding ammonium bicarbonate and ammonia and carbon dioxide generated by the decomposition of ammonium bicarbonate to the sodium chloride concentrate to obtain sodium bicarbonate and ammonium chloride, respectively. Sodium bicarbonate is used as a raw material for dry flue gas desulfurization, while ammonium chloride can be used as one of the formula raw materials in agricultural fertilizers or compound fertilizers, thereby effectively realizing the resource recovery and utilization of coking high-salt wastewater; to date, many methods for resource utilization of organic high-salt wastewater have been developed, but there is a lack of in-depth research on the resource utilization of wastewater generated in the field of creatine monohydrate. Summary of the invention

[0006] The present application provides a method for resource utilization of creatine organic high-salt wastewater, which solves the problems of high cost of removing organic matter and poor recovery effect in creatine organic high-salt wastewater, as well as comprehensive utilization of inorganic salts and water resources.

[0007] The present application embodiment provides a method for resource utilization of creatine organic high-salt wastewater, which specifically includes the following steps:

[0008] Step 1, creatine organic high-salt wastewater is adsorbed by an adsorbent to obtain pretreated wastewater;

[0009] Step 2, adjusting the pH value of the pretreated wastewater, adding a hydrophobic FeMn@C catalyst and hydrogen peroxide, ultrasonicating, and filtering to obtain a wastewater mother liquor;

[0010] The preparation method of the hydrophobic FeMn@C catalyst comprises: dissolving a soluble polymer in an organic solvent, adding an iron source and a manganese source, stirring for reaction, and post-treating to obtain the hydrophobic FeMn@C catalyst;

[0011] Step 3, concentrating the wastewater mother liquor, condensing the wastewater generated during the concentration process, and treating the condensed water with a reverse osmosis membrane to obtain purified water, sodium chloride and concentrated wastewater mother liquor;

[0012] Step 4: Cooling and crystallizing the concentrated wastewater mother liquor to obtain sodium sulfate.

[0013] In one embodiment,

[0014] The adsorbent in step 1 is one of HZSM-5 molecular sieve, activated carbon, Beta molecular sieve, alumina or Y molecular sieve. Preferably, the adsorbent is HZSM-5 molecular sieve.

[0015] In one embodiment,

[0016] In step 2, the pH value is 3-8, and the ultrasonic time is 2-6 hours. Preferably, the pH value is 5, and the ultrasonic time is 4 hours.

[0017] In one embodiment,

[0018] In step 2, the soluble polymer is one of soluble polytetrafluoroethylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer or ethylene-chlorotrifluoroethylene copolymer; the organic solvent is one of dimethylformamide, methanol, ethanol or n-hexane. Preferably, the soluble polymer is soluble polytetrafluoroethylene and the organic solvent is dimethylformamide.

[0019] In one embodiment,

[0020] In step 2, the iron source is one of ferric nitrate, ferric chloride or ferric acetate, and the manganese source is one of manganese nitrate, manganese chloride or manganese sulfate. Preferably, the iron source is ferric nitrate and the manganese source is manganese nitrate.

[0021] In one embodiment,

[0022] In step 2, the molar ratio of the iron source to the manganese source is 1:0.5-2. Preferably, the molar ratio of the iron source to the manganese source is 1:1.

[0023] In one embodiment,

[0024] In step 2, the ratio of the hydrophobic FeMn@C catalyst to hydrogen peroxide is 1:20-80, preferably, the ratio of the hydrophobic FeMn@C catalyst to hydrogen peroxide is 1:30.

[0025] In one embodiment,

[0026] The stirring time in step 2 is 1-5 hours, and the specific steps of the post-treatment are: rotary drying at 80°C for 6 hours, and then calcining at 400-600°C in a nitrogen atmosphere for 3-8 hours, preferably, calcining at 500°C in a nitrogen atmosphere for 5 hours.

[0027] In one embodiment,

[0028] The concentration temperature in step 3 is 100-140°C; the crystallization temperature in step 4 is 10°C, preferably, the concentration temperature is 140°C.

[0029] In one embodiment,

[0030] The sodium chloride in step 3 and the sodium sulfate in step 4 are washed with a cleaning solvent to obtain industrial grade sodium chloride and industrial grade sodium sulfate respectively; the cleaning solvent is one of methanol, ethanol, n-hexane or dimethylformamide.

[0031] The present application provides a method for resource utilization of creatine organic high-salt wastewater, wherein creatine production wastewater is pretreated with an adsorbent, and then the pretreated wastewater is catalytically oxidized, the catalyst used is a prepared FeMn catalyst coated with a hydrophobic carbon layer, the wastewater treated with catalytic oxidation is evaporated and concentrated, the steam in the concentration is condensed and then passed through a reverse osmosis membrane to obtain pure water for reuse, sodium chloride is obtained by evaporation and crystallization, sodium sulfate is obtained by cooling and crystallization, and the obtained sodium chloride and sodium sulfate are washed to obtain industrial-grade sodium chloride and sodium sulfate; the catalyst in the present application uses a FeMn catalyst coated with a hydrophobic carbon layer, which can effectively promote the catalytic oxidation of organic matter in the wastewater; the method provided by the present invention can realize the resource utilization of organic high-salt wastewater generated in creatine production, the recovered water, sodium chloride and sodium sulfate are of high purity, less chemical wastewater is generated, it is environmentally friendly, the method is simple, the cost is low, and it is conducive to large-scale industrial application. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative labor.

[0033] Figure 1 This is a TEM image of the catalyst in Example 1. DETAILED DESCRIPTION

[0034] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clear, the present application is further described in detail. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0035] Example 1

[0036] A method for resource utilization of creatine organic high-salt wastewater, specifically comprising the following steps:

[0037] Step 1, adsorbing the creatine organic high-salt wastewater with an adsorbent, wherein the selected adsorbent is HZSM-5 molecular sieve, to obtain pretreated wastewater;

[0038] Step 2, preparation of hydrophobic FeMn@C catalyst: firstly, dissolve soluble polytetrafluoroethylene in dimethylformamide, add ferric nitrate and manganese nitrate (the molar ratio of n(Fe):n(Mn) is 1:1), stir for 1-5h, dry at 80℃ rotary evaporation for 6h, and then calcine at 500℃ in nitrogen atmosphere for 5h to obtain a hydrophobic FeMn@C catalyst, such as Figure 1 As shown;

[0039] The pH of the pretreated wastewater was adjusted to 5, and a hydrophobic FeMn@C catalyst and hydrogen peroxide were added, followed by ultrasonic treatment for 4 hours, with the mass ratio of the catalyst to the hydrogen peroxide being 1:30, and the catalyst and the wastewater were separated by suction filtration to obtain a wastewater mother liquor;

[0040] Step 3: adding the wastewater mother liquor into the reactor and stirring, concentrating at 140° C., condensing the wastewater generated during the concentration process, and treating the condensed water with a reverse osmosis membrane to obtain purified water for recycling; since the solubility of sodium chloride is not greatly affected by temperature, and the sodium chloride concentration in the wastewater mother liquor is relatively high, the sodium chloride in the wastewater mother liquor is supersaturated during the evaporation and concentration process, and the sodium chloride can be obtained by separation, and a concentrated wastewater mother liquor is also obtained; the obtained sodium chloride is washed with methanol to obtain industrial-grade sodium chloride;

[0041] Step 4: Cool the concentrated wastewater mother liquor and crystallize it at 10°C to obtain sodium sulfate. Wash the sodium sulfate with ethanol to obtain industrial-grade sodium sulfate, thereby realizing resource utilization of organic high-salt wastewater.

[0042] Example 2

[0043] A method for resource utilization of creatine organic high-salt wastewater, specifically comprising the following steps:

[0044] Step 1, adsorbing the creatine organic high-salt wastewater with an adsorbent, wherein the selected adsorbent is activated carbon, to obtain pretreated wastewater;

[0045] Step 2, preparation of hydrophobic FeMn@C catalyst: firstly, polyvinylidene fluoride was dissolved in dimethylformamide, and ferric nitrate and manganese nitrate (the molar ratio of n(Fe):n(Mn) was 1:0.5) were added, stirred for 3 hours, dried by rotary evaporation at 50°C for 12 hours, and then calcined at 600°C in a nitrogen atmosphere for 4 hours to obtain a hydrophobic FeMn@C catalyst;

[0046] The pH of the pretreated wastewater was adjusted to 3, and a hydrophobic FeMn@C catalyst and hydrogen peroxide were added, followed by ultrasonic treatment for 4 hours, with the mass ratio of the catalyst to the hydrogen peroxide being 1:20, and the catalyst and the wastewater were separated by suction filtration to obtain a wastewater mother liquor;

[0047] Step 3: adding the wastewater mother liquor into the reactor and stirring, concentrating at 100° C., condensing the wastewater generated during the concentration process, and treating the condensed water with a reverse osmosis membrane to obtain purified water for recycling; since the solubility of sodium chloride is not greatly affected by temperature, and the sodium chloride concentration in the wastewater mother liquor is relatively high, the sodium chloride in the wastewater mother liquor is supersaturated during the evaporation and concentration process, and the sodium chloride can be obtained by separation, and a concentrated wastewater mother liquor is also obtained; the obtained sodium chloride is washed with n-hexane to obtain industrial-grade sodium chloride;

[0048] Step 4: Cool the concentrated wastewater mother liquor and crystallize it at 10°C to obtain sodium sulfate. Wash the sodium sulfate with methanol to obtain industrial-grade sodium sulfate, thereby realizing resource utilization of organic high-salt wastewater.

[0049] Example 3

[0050] A method for resource utilization of creatine organic high-salt wastewater, specifically comprising the following steps:

[0051] Step 1, adsorbing the creatine organic high-salt wastewater with an adsorbent, wherein the selected adsorbent is Beta molecular sieve, to obtain pretreated wastewater;

[0052] Step 2, preparation of hydrophobic FeMn@C catalyst: firstly, dissolve ethylene-tetrafluoroethylene copolymer in dimethylformamide, add ferric nitrate and manganese nitrate (the molar ratio of n(Fe):n(Mn) is 1:2), stir for 2 hours, dry by rotary evaporation at 60°C for 24 hours, and then calcine at 500°C in a nitrogen atmosphere for 5 hours to obtain a hydrophobic FeMn@C catalyst;

[0053] The pH of the pretreated wastewater was adjusted to 6, and a hydrophobic FeMn@C catalyst and hydrogen peroxide were added and ultrasonicated for 4 hours, with the mass ratio of the catalyst to the hydrogen peroxide being 1:30. The catalyst and the wastewater were separated by suction filtration to obtain a wastewater mother liquor;

[0054] Step 3, adding the wastewater mother liquor into the reactor and stirring, concentrating at 140° C., condensing the wastewater generated during the concentration process, and treating the condensed water with a reverse osmosis membrane to obtain purified water for recycling; since the solubility of sodium chloride is not greatly affected by temperature, and the sodium chloride concentration in the wastewater mother liquor is relatively high, the sodium chloride in the wastewater mother liquor is supersaturated during the evaporation and concentration process, and the sodium chloride can be obtained by separation, and a concentrated wastewater mother liquor is also obtained; the obtained sodium chloride is washed with ethanol to obtain industrial-grade sodium chloride;

[0055] Step 4: Cool the concentrated wastewater mother liquor and crystallize it at 10°C to obtain sodium sulfate. Wash the sodium sulfate with ethanol to obtain industrial-grade sodium sulfate, thereby realizing resource utilization of organic high-salt wastewater.

[0056] Example 4

[0057] A method for resource utilization of creatine organic high-salt wastewater, specifically comprising the following steps:

[0058] Step 1, adsorbing the creatine organic high-salt wastewater with an adsorbent, wherein the selected adsorbent is alumina, to obtain pretreated wastewater;

[0059] Step 2, preparation of hydrophobic FeMn@C catalyst: firstly, dissolve ethylene-chlorotrifluoroethylene copolymer in dimethylformamide, add ferric chloride and manganese sulfate (the molar ratio of n(Fe):n(Mn) is 1:1), stir for 3 hours, dry by rotary evaporation at 70°C for 24 hours, and then calcine at 550°C in a nitrogen atmosphere for 5 hours to obtain a hydrophobic FeMn@C catalyst;

[0060] The pH of the pretreated wastewater was adjusted to 5, and a hydrophobic FeMn@C catalyst and hydrogen peroxide were added, followed by ultrasonic treatment for 3 hours, with the mass ratio of the catalyst to the hydrogen peroxide being 1:80, and the catalyst and the wastewater were separated by suction filtration to obtain a wastewater mother liquor;

[0061] Step 3, adding the wastewater mother liquor into the reactor and stirring, concentrating at 100° C., condensing the wastewater generated during the concentration process, and treating the condensed water with a reverse osmosis membrane to obtain purified water for recycling; since the solubility of sodium chloride is not greatly affected by temperature, and the sodium chloride concentration in the wastewater mother liquor is relatively high, the sodium chloride in the wastewater mother liquor is supersaturated during the evaporation and concentration process, and the sodium chloride can be obtained by separation, and a concentrated wastewater mother liquor is also obtained; the obtained sodium chloride is washed with dimethylformamide to obtain industrial-grade sodium chloride;

[0062] Step 4: Cool the concentrated wastewater mother liquor and crystallize it at 10°C to obtain sodium sulfate. Wash the sodium sulfate with methanol to obtain industrial-grade sodium sulfate, thereby realizing resource utilization of organic high-salt wastewater.

[0063] Example 5

[0064] A method for resource utilization of creatine organic high-salt wastewater, specifically comprising the following steps:

[0065] Step 1, adsorbing the creatine organic high-salt wastewater with an adsorbent, wherein the selected adsorbent is Y molecular sieve, to obtain pretreated wastewater;

[0066] Step 2, preparation of hydrophobic FeMn@C catalyst: firstly, polyvinylidene fluoride was dissolved in dimethylformamide, and ferric acetate and manganese chloride (the molar ratio of n(Fe):n(Mn) was 1:0.5) were added, stirred for 1 hour, dried by rotary evaporation at 70°C for 6 hours, and then calcined at 400°C in a nitrogen atmosphere for 3 hours to obtain a hydrophobic FeMn@C catalyst;

[0067] The pH of the pretreated wastewater was adjusted to 3, and a hydrophobic FeMn@C catalyst and hydrogen peroxide were added and ultrasonicated for 2 hours, the mass ratio of the catalyst to the hydrogen peroxide was 1:20, and the catalyst and the wastewater were separated by suction filtration to obtain a wastewater mother liquor;

[0068] Step 3: adding the wastewater mother liquor into the reactor and stirring, concentrating at 100° C., condensing the wastewater generated during the concentration process, and treating the condensed water with a reverse osmosis membrane to obtain purified water for recycling; since the solubility of sodium chloride is not greatly affected by temperature, and the sodium chloride concentration in the wastewater mother liquor is relatively high, the sodium chloride in the wastewater mother liquor is supersaturated during the evaporation and concentration process, and the sodium chloride can be obtained by separation, and concentrated wastewater mother liquor is also obtained; the obtained sodium chloride is washed with ethanol to obtain industrial-grade sodium chloride;

[0069] Step 4: Cool the concentrated wastewater mother liquor and crystallize it at 10°C to obtain sodium sulfate. Wash the sodium sulfate with n-hexane to obtain industrial-grade sodium sulfate, thereby realizing resource utilization of organic high-salt wastewater.

[0070] Example 6

[0071] A method for resource utilization of creatine organic high-salt wastewater, specifically comprising the following steps:

[0072] Step 1, adsorbing the creatine organic high-salt wastewater with an adsorbent, wherein the selected adsorbent is activated carbon, to obtain pretreated wastewater;

[0073] Step 2, preparation of hydrophobic FeMn@C catalyst: firstly, polyvinylidene fluoride was dissolved in dimethylformamide, and ferric nitrate and manganese nitrate (the molar ratio of n(Fe):n(Mn) was added thereto, stirred for 1 hour, dried by rotary evaporation at 70°C for 12 hours, and then calcined at 500°C in a nitrogen atmosphere for 8 hours to obtain a hydrophobic FeMn@C catalyst;

[0074] The pH of the pretreated wastewater was adjusted to 8, and the hydrophobic FeMn@C catalyst and hydrogen peroxide were added and ultrasonicated for 6 hours, the mass ratio of the catalyst to the hydrogen peroxide was 1:60, and the catalyst and the wastewater were separated by suction filtration to obtain a wastewater mother liquor;

[0075] Step 3: adding the wastewater mother liquor into the reactor and stirring, concentrating at 130° C., condensing the wastewater generated during the concentration process, and treating the condensed water with a reverse osmosis membrane to obtain purified water for recycling; since the solubility of sodium chloride is not greatly affected by temperature, and the sodium chloride concentration in the wastewater mother liquor is relatively high, the sodium chloride in the wastewater mother liquor is supersaturated during the evaporation and concentration process, and the sodium chloride can be obtained by separation, and concentrated wastewater mother liquor is also obtained; the obtained sodium chloride is washed with ethanol to obtain industrial-grade sodium chloride;

[0076] Step 4: Cool the concentrated wastewater mother liquor and crystallize it at 10°C to obtain sodium sulfate. Wash the sodium sulfate with ethanol to obtain industrial-grade sodium sulfate, thereby realizing resource utilization of organic high-salt wastewater.

[0077] Example 7

[0078] The difference between this embodiment and embodiment 1 is that the organic solution dimethylformamide in step 2 is replaced by ethanol, and the remaining operations are the same.

[0079] Example 8

[0080] The difference between this embodiment and embodiment 1 is that the organic solution dimethylformamide in step 2 is replaced by methanol, and the remaining operations are the same.

[0081] Example 9

[0082] The difference between this embodiment and embodiment 1 is that the organic solution dimethylformamide in step 2 is replaced by n-hexane, and the other operations are the same.

[0083] Comparative Example 1

[0084] A method for resource utilization of creatine organic high-salt wastewater, specifically comprising the following steps:

[0085] Step 1, preparation of hydrophobic FeMn@C catalyst: firstly, dissolve soluble polytetrafluoroethylene in dimethylformamide, add ferric nitrate and manganese nitrate (the molar ratio of n(Fe):n(Mn) is 1:1), stir for 1-5h, dry by rotary evaporation at 80°C for 6h, and then calcine at 500°C in a nitrogen atmosphere for 5h to obtain a hydrophobic FeMn@C catalyst;

[0086] The pH of the creatine organic high-salt wastewater was adjusted to 5, and a hydrophobic FeMn@C catalyst and hydrogen peroxide were added, and then ultrasonicated for 4 hours, with the mass ratio of the catalyst to the hydrogen peroxide being 1:30, and the catalyst and the wastewater were separated by suction filtration to obtain a wastewater mother liquor;

[0087] Step 2: Add the wastewater mother liquor into the reactor and stir, concentrate at 140°C, condense the wastewater generated during the concentration process, and treat the condensed water with a reverse osmosis membrane to obtain purified water for recycling; since the solubility of sodium chloride is not greatly affected by temperature, and the sodium chloride concentration in the wastewater mother liquor is relatively high, the sodium chloride in the wastewater mother liquor is supersaturated during the evaporation and concentration process, and the sodium chloride can be obtained by separation, and concentrated wastewater mother liquor is also obtained; the obtained sodium chloride is washed with methanol to obtain industrial-grade sodium chloride;

[0088] Step 3: Cool the concentrated wastewater mother liquor and crystallize it at 10°C to obtain sodium sulfate. Wash the sodium sulfate with ethanol to obtain industrial-grade sodium sulfate, thereby realizing resource utilization of organic high-salt wastewater.

[0089] Comparative Example 2

[0090] A method for resource utilization of creatine organic high-salt wastewater, specifically comprising the following steps:

[0091] Step 1, adsorbing the creatine organic high-salt wastewater with an adsorbent, wherein the selected adsorbent is HZSM-5 molecular sieve, to obtain pretreated wastewater;

[0092] Step 2: Add the pretreated wastewater into the reactor and stir, concentrate at 140°C, condense the wastewater generated during the concentration process, and treat the condensed water with a reverse osmosis membrane to obtain purified water for recycling; since the solubility of sodium chloride is not greatly affected by temperature, and the sodium chloride concentration in the wastewater mother liquor is relatively high, the sodium chloride in the wastewater mother liquor is supersaturated during the evaporation and concentration process, and the sodium chloride can be obtained by separation, and a concentrated wastewater mother liquor is also obtained; the obtained sodium chloride is washed with methanol to obtain industrial-grade sodium chloride;

[0093] Step 3: Cool the concentrated wastewater mother liquor and crystallize it at 10°C to obtain sodium sulfate. Wash the sodium sulfate with ethanol to obtain industrial-grade sodium sulfate, thereby realizing resource utilization of organic high-salt wastewater.

[0094] Comparative Example 3

[0095] A method for resource utilization of creatine organic high-salt wastewater, specifically comprising the following steps:

[0096] Step 1, adsorbing the creatine organic high-salt wastewater with an adsorbent, wherein the selected adsorbent is HZSM-5 molecular sieve, to obtain pretreated wastewater;

[0097] Step 2, preparation of hydrophobic FeMn@C catalyst: firstly, dissolve soluble polytetrafluoroethylene in dimethylformamide, add ferric nitrate and manganese nitrate (the molar ratio of n(Fe):n(Mn) is 1:1), stir for 1-5h, dry by rotary evaporation at 80°C for 6h, and then calcine at 500°C in a nitrogen atmosphere for 5h to obtain a hydrophobic FeMn@C catalyst;

[0098] The pH of the pretreated wastewater was adjusted to 5, and a hydrophobic FeMn@C catalyst and hydrogen peroxide were added, followed by ultrasonic treatment for 4 hours, with the mass ratio of the catalyst to the hydrogen peroxide being 1:30, and the catalyst and the wastewater were separated by suction filtration to obtain a wastewater mother liquor;

[0099] Step 3: Add the wastewater mother liquor into the reactor and stir, concentrate at 140°C, condense the wastewater generated during the concentration process, and treat the condensed water with a reverse osmosis membrane to obtain purified water for recycling.

[0100] Table 1 Chemical oxygen demand and salt content in wastewater after treatment with different catalysts in Examples 1-6

[0101]

[0102]

[0103] Table 2 Chemical oxygen demand and salt content in wastewater after treatment in Comparative Examples 1-3

[0104]

[0105] The present application provides a method for resource utilization of creatine organic high-salt wastewater, comprising the following steps: adsorbing the creatine organic high-salt wastewater with an adsorbent to obtain pretreated wastewater; adjusting the pH value of the pretreated wastewater, adding a hydrophobic FeMn@C catalyst and hydrogen peroxide, ultrasonicating, and filtering to obtain a wastewater mother liquor; the preparation method of the hydrophobic FeMn@C catalyst is: dissolving a soluble polymer in an organic solvent, adding an iron source and a manganese source, stirring the reaction, and post-treating to obtain a hydrophobic FeMn@C catalyst; concentrating the wastewater mother liquor, condensing the wastewater generated during the concentration process, and treating the condensed water with a reverse osmosis membrane to obtain purified water, sodium chloride, and concentrated wastewater mother liquor; cooling and crystallizing the concentrated wastewater mother liquor to obtain sodium sulfate; the method for resource utilization of creatine production organic high-salt wastewater provided by the present application is to adsorb the creatine production wastewater with an adsorbent The wastewater is pretreated, and then the pretreated wastewater is catalytically oxidized. The catalyst used is a FeMn catalyst coated with a prepared hydrophobic carbon layer. The wastewater treated with catalytic oxidation is evaporated and concentrated. The steam in the concentration is condensed and then passed through a reverse osmosis membrane to obtain pure water for reuse. Evaporation and crystallization can obtain sodium chloride. Cooling and crystallization can obtain sodium sulfate. The obtained sodium chloride and sodium sulfate are washed to obtain industrial-grade sodium chloride and sodium sulfate. The catalyst in the present application uses a FeMn catalyst coated with a hydrophobic carbon layer, which can effectively promote the catalytic oxidation of organic matter in the wastewater. The method provided by the present invention can realize the resource utilization of organic high-salt wastewater generated in creatine production, and the recovered water, sodium chloride and sodium sulfate have high purity, less chemical wastewater is generated, and it is environmentally friendly. The method is simple and low in cost, which is conducive to large-scale industrial application.

[0106] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0107] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. A method for resource utilization of creatine organic high-salt wastewater, characterized in that: The specific steps include: Step 1, creatine organic high-salt wastewater is adsorbed by an adsorbent to obtain pretreated wastewater; Step 2, adjusting the pH value of the pretreated wastewater, adding a hydrophobic FeMn@C catalyst and hydrogen peroxide, ultrasonicating, and filtering to obtain a wastewater mother liquor; The preparation method of the hydrophobic FeMn@C catalyst comprises: dissolving a soluble polymer in an organic solvent, adding an iron source and a manganese source, stirring for reaction, and post-treating to obtain the hydrophobic FeMn@C catalyst; The soluble polymer is one of soluble polytetrafluoroethylene, polyvinylidene fluoride, ethylene-tetrafluoroethylene copolymer or ethylene-chlorotrifluoroethylene copolymer; the organic solvent is one of dimethylformamide, ethanol, methanol or n-hexane; the molar ratio of the iron source to the manganese source is 1:0.5-2; The stirring time is 1-5 hours, and the specific steps of the post-treatment are: rotary drying at 80°C for 6 hours, and then calcining at 400-600°C in a nitrogen atmosphere for 3-8 hours; Step 3, concentrating the wastewater mother liquor, condensing the wastewater generated during the concentration process, and treating the condensed water with a reverse osmosis membrane to obtain purified water, sodium chloride and concentrated wastewater mother liquor; Step 4: Cooling and crystallizing the concentrated wastewater mother liquor to obtain sodium sulfate.

2. The method for resource utilization of creatine organic high-salt wastewater according to claim 1, characterized in that: The adsorbent in step 1 is one of HZSM-5 molecular sieve, activated carbon, Beta molecular sieve, alumina or Y molecular sieve.

3. The method for resource utilization of creatine organic high-salt wastewater according to claim 1, characterized in that: In step 2, the pH value is 3-8, and the ultrasonic time is 2-6 hours.

4. The method for resource utilization of creatine organic high-salt wastewater according to claim 1, characterized in that: In step 2, the iron source is one of ferric nitrate, ferric chloride or ferric acetate, and the manganese source is one of manganese nitrate, manganese chloride or manganese sulfate.

5. The method for resource utilization of creatine organic high-salt wastewater according to claim 1, characterized in that: In step 2, the mass ratio of the hydrophobic FeMn@C catalyst to hydrogen peroxide is 1:20-80.

6. The method for resource utilization of creatine organic high-salt wastewater according to claim 1, characterized in that: The concentration temperature in step 3 is 100-140°C; the crystallization temperature in step 4 is 10°C.

7. The method for resource utilization of creatine organic high-salt wastewater according to claim 1, characterized in that: The sodium chloride in step 3 and the sodium sulfate in step 4 are washed with a cleaning solvent to obtain industrial grade sodium chloride and industrial grade sodium sulfate respectively; the cleaning solvent is one of methanol, ethanol, n-hexane or dimethylformamide.

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