Green treatment process for methanol production wastewater

Abstract

The present application belongs to the technical field of sewage treatment, and particularly relates to a green treatment process for methanol production sewage, comprising the following steps: modifying zeolite with lanthanum by using KH-550, PEG-DGE and phytic acid, soaking in a potassium chloride solution, packing into a column tube after washing and drying to obtain an adsorption column; reacting porous microspheres treated by carboxylation with manganese nitrate and iron nitrate, performing hydrophobic treatment by using C8TES after heat treatment and reactivation treatment, and packing into a column tube to obtain a reaction column; adjusting the pH value of effluent from a methanol production sewage treatment system and then feeding into the adsorption column to obtain low-ammonia-nitrogen effluent, and simultaneously feeding the low-ammonia-nitrogen effluent and ozone into the reaction column to obtain purified effluent. When the effluent from the methanol production sewage treatment system still contains a high content of ammonia nitrogen and phenolic compounds, the present application can effectively remove the ammonia nitrogen and phenolic compounds for a long time, and further reduce the ammonia nitrogen content and COD value.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment technology, and in particular relates to a green treatment process for methanol production wastewater. Background Technology

[0002] The production of methanol from coal generates a large amount of wastewater, which has a high ammonia nitrogen content and contains phenolic compounds (such as phenol), organic acids (such as formic acid and acetic acid), and oxygenated organic alcohols (such as methanol). Current technology typically employs a wastewater treatment system to treat methanol production wastewater: ferrous sulfate is first added to the wastewater to chemically precipitate sulfides and other pollutants. The precipitate is then discharged, and the supernatant is treated through a Fenton reaction and an A / O tank to remove ammonia nitrogen and organic matter, yielding effluent. When wastewater quality fluctuates, the biological system in the A / O tank responds slowly and recovers gradually, reducing the removal capacity of ammonia nitrogen and phenolic compounds. This can easily lead to slight exceedances of ammonia nitrogen and COD levels in the effluent (10 mg / L < ammonia nitrogen < 60 mg / L, 60 mg / L < COD < 180 mg / L). If the excessive effluent is directly returned to the original influent, it will increase the system load, further reducing the efficiency of denitrification and organic matter removal, causing the effluent to continue to exceed the standards. This not only reduces the overall treatment efficiency but may also cause problems such as waste of reagents and increased energy consumption, violating the principles of green, low-carbon, and efficient resource utilization.

[0003] Chinese patent document CN120271189B discloses a method for treating ammonia nitrogen wastewater, including the following steps: adding a composite modified zeolite material to the ammonia nitrogen wastewater for adsorption, then adding a composite photocatalyst for photocatalytic treatment, adjusting to neutrality, and then performing resin adsorption treatment to complete the treatment of ammonia nitrogen wastewater; the preparation steps of the composite modified zeolite material are as follows: adding zeolite to sodium chloride solution and stirring, then allowing it to stand, centrifuging, washing, drying, and calcining to obtain the composite modified zeolite material. When using the aforementioned patent to treat effluent with slightly excessive ammonia nitrogen and COD values, the addition of ferrous sulfate for chemical precipitation during the wastewater treatment process results in the presence of ferrous ions in the effluent. Under ferrous ion and aerobic conditions, phenol is prone to oxidation and polymerization, generating polyphenol polymers that deposit on the surface of the composite modified zeolite, clogging the pores and reducing the ammonia nitrogen treatment effect. This is not conducive to further reducing the ammonia nitrogen content in the effluent. The unremoved ammonia nitrogen, acting as a hydroxyl radical scavenger, will consume the free radicals generated subsequently for the degradation of phenolic compounds, reducing the phenolic compound treatment effect and hindering further reduction of the COD value in the effluent. Summary of the Invention

[0004] This invention provides a green treatment process for methanol production wastewater. When the effluent from the methanol production wastewater treatment system still contains high levels of ammonia nitrogen and phenolic compounds, this invention can effectively remove ammonia nitrogen and phenolic compounds for a long period of time, further reducing its ammonia nitrogen content and COD value.

[0005] To solve the above problems, the present invention adopts the following technical solution:

[0006] A green treatment process for methanol production wastewater includes the following steps:

[0007] S1. Lanthanum-modified zeolite was treated with KH-550, PEG-DGE and phytic acid, then soaked in potassium chloride solution, washed and dried to obtain composite modified zeolite, and the composite modified zeolite was packed into a column tube to obtain an adsorption column.

[0008] S2. The carboxylated porous microspheres were dispersed in deionized water, dissolved in manganese nitrate and ferric nitrate, heated to react, allowed to stand for aging, filtered, washed, dried and then subjected to heat treatment and reactivation treatment in sequence. Subsequently, hydrophobic treatment was performed using C8TES to obtain functional microspheres. The functional microspheres were then packed into a column to obtain a reaction column.

[0009] S3. Adjust the pH value of the effluent from the methanol production wastewater treatment system and pass it into the adsorption column to obtain low ammonia nitrogen effluent. Pass the low ammonia nitrogen effluent and ozone into the reaction column at the same time to obtain purified effluent.

[0010] Lanthanum-modified zeolite was treated with KH-550 (γ-aminopropyltriethoxysilane) to introduce amino groups onto the zeolite surface. The epoxy groups of PEG-DGE (polyethylene glycol diglycidyl ether) and the amino groups underwent a ring-opening reaction. Phosphate groups of phytic acid molecules were linked to lanthanum ions in the zeolite through coordinate bonds, resulting in a composite modified zeolite with a surface rich in hydroxyl and phosphate groups. When the effluent from a methanol production wastewater treatment system was passed through an adsorption column composed of this composite modified zeolite, the hydrophilic layer composed of hydrophilic hydroxyl and phosphate groups on the surface of the composite modified zeolite effectively repelled hydrophobic phenolic compounds, inhibiting their adhesion to the surface. This facilitated the rapid diffusion of ammonium ions to the ion exchange sites of the composite modified zeolite, thus enhancing its effectiveness. Zeolite can effectively adsorb ammonium ions through ion exchange, further reducing the ammonia nitrogen content in the effluent and obtaining low-ammonia nitrogen effluent. The low-ammonia nitrogen effluent is then fed into a reaction column composed of functional microspheres, while ozone is introduced into the reaction column. The functional microspheres contain iron-manganese oxides formed by iron and manganese ions, and the surface of the functional microspheres has a hydrophobic layer formed by C8TES (n-octyltriethoxysilane). The hydrophobic layer can promote the diffusion of phenolic compounds into the functional microspheres through hydrophobic interactions, increasing the local concentration of phenolic compounds. This allows the hydroxyl radicals generated by the iron-manganese oxides catalyzing ozone to efficiently decompose phenolic compounds, further reducing the COD of the low-ammonia nitrogen effluent, and thus obtaining purified effluent with compliant ammonia nitrogen content and COD value.

[0011] In the composite modified zeolite, phosphate groups can chelate residual ferrous ions in the water and ferric ions generated by ferrous ions under the action of dissolved oxygen. This inhibits the generation of hydroxyl radicals by ferric ions and ferrous ions through a Fenton-like reaction, preventing the hydrophilic layer from being degraded by hydroxyl radicals and improving the service life of the composite modified zeolite. At the same time, the chelating effect of phytic acid can effectively prevent ferrous ions from entering the reaction column, prevent ferrous ions from reacting with ozone to generate hydroxyl radicals, protect the hydrophobic layer from being damaged by hydroxyl radicals, and improve the service life of the functional microspheres.

[0012] Furthermore, the lanthanum-modified zeolite is prepared by the following method: clinoptilolite is dispersed in deionized water, oxalic acid solution is added to adjust the pH to 2-3, the mixture is stirred at 300-400 rpm for 1-2 hours, filtered, and washed with deionized water until the wash solution is neutral. Then, the mixture is dispersed in deionized water, lanthanum chloride is added to dissolve it, sodium hydroxide solution is added dropwise to adjust the pH to 5.5-6, the mixture is stirred at 80-100 rpm for 1-2 hours, filtered, and washed with deionized water to obtain the lanthanum-modified zeolite.

[0013] Further, in step S1, the lanthanum-modified zeolite is washed with anhydrous ethanol and dispersed in anhydrous ethanol. KH-550 and deionized water are added, and acetic acid solution is added dropwise to adjust the pH to 5-6. The mixture is stirred at 300-400 rpm for 2-3 hours, filtered, washed with anhydrous ethanol and DMF (N,N-dimethylformamide), dispersed in DMF, and PEG-DGE and phytic acid are added and mixed. The mixture is heated to 60-65℃ under an inert atmosphere and stirred at 80-100 rpm for 3-4 hours, filtered, washed with DMF and deionized water, and then soaked in a 5-6 wt% potassium chloride solution for 12-16 hours. After filtration, the mixture is washed with deionized water and anhydrous ethanol and dried at 40-50℃ and 10-20 kPa for 8-10 hours to obtain the composite modified zeolite; the M of the PEG-DGE... n It is 280-300 g / mol.

[0014] Oxalic acid can dissolve iron and other metal ions in clinoptilolite. Under pH conditions of 5.5-6, lanthanum ions from lanthanum chloride are loaded onto clinoptilolite through ion exchange, resulting in lanthanum-modified zeolite, which provides a basis for the fixation of phytic acid molecules on the surface of lanthanum-modified zeolite. The lanthanum-modified zeolite is treated with KH-550 to introduce primary amino groups onto its surface. A ring-opening reaction occurs between the primary amino groups and the epoxy groups of PEG-DGE, generating secondary amino groups and introducing hydroxyl groups. The phosphate groups of phytic acid form coordinate bonds with lanthanum ions and interact with hydroxyl groups through hydrogen bonds, enhancing the adhesion stability of phytic acid on the surface of lanthanum-modified zeolite and preventing it from detaching under water erosion. The treated lanthanum-modified zeolite is then immersed in potassium chloride solution to improve its adsorption capacity for ammonium ions. After washing and drying, a composite modified zeolite is obtained.

[0015] Furthermore, the composite modified zeolite comprises the following raw materials in parts by weight: 48-53 parts of clinoptilolite, 19-24 parts of lanthanum chloride, 2.8-3.3 parts of KH-550, 1.9-2.4 parts of PEG-DGE, 0.4-0.5 parts of phytic acid, and 500-550 parts of 5-6wt% potassium chloride solution.

[0016] Furthermore, the porous microspheres are prepared by the following method: A water-soluble phenolic resin prepolymer is mixed with deionized water, and PMMA microspheres and PEO-PPO-PEO triblock copolymer are added and mixed to obtain a slurry; the slurry is added to dimethyl silicone oil at a constant temperature of 8-10℃, stirred at 10000-11000 rpm for 25-35 min, heated to 98-103℃, stirred at 4000-5000 rpm for 2-3 h, and then heated further. Stir at 1000-2000 rpm for 3-4 hours at 155-162℃, cool, filter, wash with petroleum ether, transfer to an inert atmosphere, heat to 295-305℃ and hold for 2-3 hours, heat to 650-660℃ and hold for 1.5-2 hours, cool, and obtain porous microspheres; the solid content of the water-soluble phenolic resin prepolymer is 40%-50%, and the viscosity of the dimethyl silicone oil at 25℃ is 100-120 cst.

[0017] The slurry composed of water-soluble phenolic resin prepolymer, deionized water, PMMA microspheres (polymethyl methacrylate microspheres), and PEO-PPO-PEO triblock copolymer (polyoxyethylene-polyoxypropylene-polyoxyethylene triblock copolymer) is hydrophilic, while dimethyl silicone oil is highly hydrophobic. The PEO-PPO-PEO triblock copolymer in the slurry, due to its amphiphilic nature, can act as an emulsifier. Under continuous high shear conditions of 10000-11000 rpm, the slurry can be dispersed into multiple aqueous droplets. Under gradient heating conditions of 98-103℃ and 155-162℃, the water in the aqueous droplets gradually evaporates, and the water-based phenolic resin prepolymer undergoes a gelation reaction, forming an organic cross-linked network encapsulating the PMMA microspheres and the PEO-PPO-PEO triblock copolymer. After filtration and washing, the microspheres are placed in an environment of 295-305℃. At this temperature, the PMMA microspheres and PEO-PPO-PEO triblock copolymer decompose, forming pores in the organic cross-linked network. Subsequently, the temperature is raised to 650-660℃ in an inert atmosphere, and the organic cross-linked network carbonizes, resulting in porous microspheres with a rich pore structure. The carbon skeleton surface of the porous microspheres is nonpolar, which can effectively adsorb and enrich phenolic compounds in low ammonia nitrogen effluent through π-π interactions, thus improving ozone oxidation efficiency. Due to the addition of PMMA microspheres, the porous microspheres have a large specific surface area, which is beneficial to increasing the loading of iron and manganese oxides, while improving mass transfer efficiency and promoting the rapid penetration of ozone bubbles and low ammonia nitrogen effluent through the entire functional microsphere, thereby improving the treatment effect of functional microspheres on phenolic compounds.

[0018] Furthermore, the porous microspheres were carboxylated using the following method: the porous microspheres were dispersed in a 9-13 wt% nitric acid solution, heated to 57-63℃, stirred at 300-400 rpm for 3-4 hours, filtered, and washed with deionized water until the washing solution was neutral, thus completing the carboxylation treatment of the porous microspheres.

[0019] Furthermore, the porous microspheres comprise the following raw materials in parts by weight: 75-82 parts of water-soluble phenolic resin prepolymer, 200-210 parts of deionized water, 30-34 parts of PMMA microspheres, 7-10 parts of PEO-PPO-PEO triblock copolymer, and 1045-1055 parts of dimethyl silicone oil.

[0020] Carboxyl groups can be introduced onto porous microspheres through oxidation by nitric acid solution. The operation is simple and provides a functional group basis for subsequent loading of iron and manganese ions.

[0021] Further, in step S2, the carboxylated porous microspheres are dispersed in deionized water, dissolved with manganese nitrate and ferric nitrate, and the pH is adjusted to 3-3.5 by adding nitric acid solution dropwise. The temperature is raised to 60-65℃, stirred at 300-400 rpm for 5-6 hours, allowed to stand for 12-14 hours, filtered, washed with deionized water, and then kept at 70-80℃ and 50-60 kPa for 6-8 hours, followed by incubation at 280-290℃ for 2 hours. After cooling for 5-3 hours, the mixture is placed in a plasma generator and reactivated for 17-22 seconds under conditions of oxygen flow rate of 30-35 sccm and radio frequency power of 90-100W. Then, it is placed in a fluidized bed reactor and a nitrogen gas flow rate of 5-8 cm / s is introduced. The inlet temperature is controlled at 127-130℃ and the outlet temperature is controlled at 122-125℃. The vaporized C8TES is introduced and maintained for 25-35 minutes. After cooling, functional microspheres are obtained.

[0022] Under pH conditions of 3-3.5, carboxyl groups on porous microspheres combine with iron and manganese ions, achieving effective loading of iron and manganese ions onto the microspheres. At a high temperature of 280-290℃, iron and manganese ions form iron-manganese oxides, yielding the microsphere precursor. This provides a catalytic basis for the generation of hydroxyl radicals from ozone, which then decomposes phenolic compounds. The microsphere precursor is reactivated using oxygen plasma to introduce hydroxyl groups onto its surface. Under an inert atmosphere, vaporized C8TES undergoes hydrolysis in the presence of trace amounts of moisture on the microsphere precursor surface. The hydrolysis products condense with the hydroxyl groups on the microsphere precursor surface, thus forming a hydroxyl radical on the microsphere precursor. A hydrophobic layer is formed on the microsphere to obtain functional microspheres. When the functional microspheres come into contact with low ammonia nitrogen wastewater and ozone, phenolic compounds can preferentially accumulate in the hydrophobic layer through hydrophobic interactions and further diffuse into the interior of the functional microspheres. Iron and manganese oxides catalyze the decomposition of ozone to generate hydroxyl radicals, thereby efficiently oxidizing and degrading the accumulated phenolic compounds. At the same time, the hydrophobic layer can reduce the direct contact between the aqueous phase and the internal iron and manganese oxides, inhibit the dissolution of iron and manganese oxides, and extend the service life of the functional microspheres. The hydrophobic layer can also effectively block hydrophilic ammonium ions from entering the interior of the functional microspheres, avoid side reactions with hydroxyl radicals, reduce the ineffective consumption of free radicals, and improve the oxidative degradation efficiency of phenolic compounds.

[0023] Furthermore, the functional microspheres comprise the following raw materials in parts by weight: 42-47 parts porous microspheres, 0.3-0.4 parts manganese nitrate, 0.2-0.3 parts ferric nitrate, and 0.5-0.6 parts C8TES.

[0024] Furthermore, in step S3, acetic acid solution is added to the effluent of the methanol production wastewater treatment system to adjust the pH value to 6.3-6.7, and the solution is introduced into the adsorption column at a rate of 3.8-4.2 BV / h. When the concentration of ammonia nitrogen in the effluent is 8%-11% of the feed liquid, the feed is stopped to obtain low ammonia nitrogen effluent. Ozone with a concentration of 20-30 mg / L is introduced into the reaction column at a rate of 0.2-0.3 L / min, while the low ammonia nitrogen effluent is introduced at a rate of 3.8-4.2 BV / h to obtain purified effluent.

[0025] The present invention has the following beneficial effects:

[0026] The effluent from the methanol production wastewater treatment system is passed into an adsorption column composed of composite modified zeolite. The hydrophilic layer on the surface of the composite modified zeolite, composed of hydroxyl and phosphate groups, effectively repels phenolic compounds and inhibits their adhesion to the surface. This facilitates the rapid diffusion of ammonium ions, accelerates the adsorption rate of ammonia nitrogen by the composite modified zeolite, and further reduces the ammonia nitrogen content in the effluent, resulting in low-ammonia nitrogen effluent. The low-ammonia nitrogen effluent and ozone are then simultaneously fed into a reaction column composed of functional microspheres. The hydrophobic layer on the surface of the functional microspheres, composed of C8TES, allows phenolic compounds to preferentially diffuse into the interior of the microspheres through hydrophobic interactions, increasing the local concentration of phenolic compounds. The iron and manganese oxides inside the functional microspheres catalyze the ozone to generate hydroxyl radicals. These hydroxyl radicals can efficiently decompose phenolic compounds, further reducing the COD of the low-ammonia nitrogen effluent, thus obtaining purified effluent with compliant ammonia nitrogen content and COD value. Detailed Implementation

[0027] Preparation Example 1

[0028] Add 82g of water-soluble phenolic resin prepolymer with a solid content of 40% to 210g of deionized water, stir at 1000rpm for 20min, then add 33g of PMMA microspheres with a particle size of 5μm and 9g of... The PEO-PPO-PEO triblock copolymer (model: poloxamer 407) was stirred at 5000 rpm for 15 min to obtain a slurry. 155 g of the slurry was slowly added to 1050 g of dimethyl silicone oil (viscosity 100 cst at 25 °C) at a constant temperature of 8 °C. The mixture was stirred at 10000 rpm for 35 min, and then slowly heated to 100 °C while stirring at 5000 rpm for 2 h. The mixture was then slowly heated to 155 °C while stirring at 2000 rpm for 3 h. After cooling, the mixture was filtered, washed three times with petroleum ether, and placed in a tube furnace. Under a nitrogen atmosphere, the temperature was slowly increased to 305 °C and held for 3 h. The temperature was then slowly increased to 660 °C and held for 1.7 h. The mixture was then naturally cooled to room temperature to obtain porous microspheres.

[0029] Preparation Example 2

[0030] Add 80g of water-soluble phenolic resin prepolymer with a solid content of 45% to 205g of deionized water, stir at 1000rpm for 20min, then add 34g of PMMA microspheres with a particle size of 5μm and 10g of... The PEO-PPO-PEO triblock copolymer (model: poloxamer 407) was stirred at 5000 rpm for 15 min to obtain a slurry. The slurry was slowly added to 1055 g of dimethyl silicone oil (viscosity 110 cst at 25 °C) at a constant temperature of 9 °C. The mixture was stirred at 11000 rpm for 25 min, and then slowly heated to 103 °C with stirring at 5000 rpm. The mixture was stirred at 4000 rpm for 3 h, and then slowly heated to 159 °C with stirring at 2000 rpm. The mixture was stirred at 1000 rpm for 4 h, cooled, filtered, washed three times with petroleum ether, and placed in a tube furnace. Under a nitrogen atmosphere, the temperature was slowly increased to 295 °C and held for 2.5 h. The temperature was then slowly increased to 650 °C and held for 1.5 h. The mixture was then naturally cooled to room temperature to obtain porous microspheres.

[0031] Preparation Example 3

[0032] Add 75g of water-soluble phenolic resin prepolymer with a solid content of 50% to 200g of deionized water, stir at 1000rpm for 20min, then add 30g of PMMA microspheres with a particle size of 5μm and 7g of... The PEO-PPO-PEO triblock copolymer (model: poloxamer 407) was stirred at 5000 rpm for 15 min to obtain a slurry. The slurry was slowly added to 1045 g of dimethyl silicone oil (viscosity 120 cst at 25 °C) at a constant temperature of 10 °C. The mixture was stirred at 10500 rpm for 30 min, then slowly heated to 98 °C under stirring at 5000 rpm and stirred at 4500 rpm for 2.5 h. The mixture was then slowly heated to 162 °C under stirring at 2000 rpm and stirred at 1500 rpm for 3.5 h. After cooling, the mixture was filtered, washed three times with petroleum ether, and placed in a tube furnace. Under a nitrogen atmosphere, the mixture was slowly heated to 300 °C and held for 3 h. The mixture was then slowly heated to 655 °C and held for 2 h. After naturally cooling to room temperature, porous microspheres were obtained.

[0033] Example 1

[0034] Add 50g of clinoptilolite with a particle size of 1mm to 600g of deionized water, stir at 2000rpm for 25min, add 30wt% oxalic acid solution to adjust the pH to 2.5, stir at 300rpm for 2h, filter, wash with deionized water until the eluent is neutral, add to 550g of deionized water, stir at 2000rpm for 25min, add 20g of lanthanum chloride, stir at 300rpm for 10min, add 1wt% sodium hydroxide solution dropwise to adjust the pH to 6, stir at 80rpm for 2h, filter, wash 4 times with deionized water to obtain lanthanum-modified zeolite; wash the lanthanum-modified zeolite 3 times with anhydrous ethanol, add to 500g of anhydrous ethanol, stir at 2000rpm for 25min, add 3g KH-550 and 2g of deionized water, add 5wt% acetic acid solution dropwise to adjust the pH to 5, stir at 300rpm for 3h, wash 3 times with anhydrous ethanol, wash 3 times with DMF, add to 450g of... In DMF, stir at 1000 rpm for 20 minutes, then add 2g M. n PEG-DGE at a concentration of 280 g / mol and 0.4 g of phytic acid were mixed, stirred at 300 rpm for 15 min, heated to 60 °C under nitrogen protection, stirred at 80 rpm for 4 h, filtered, washed twice with DMF, washed twice with deionized water, added to 500 g of 5 wt% potassium chloride solution, stirred at 200 rpm and soaked for 12 h, filtered, washed with deionized water until the eluent was free of chloride ions, washed twice with anhydrous ethanol, and dried at 50 °C and 20 kPa for 8 h to obtain composite modified zeolite. The composite modified zeolite was packed into a column using a wet packing method to obtain an adsorption column.

[0035] 45g of porous microspheres were added to 500g of 10wt% nitric acid solution and ultrasonically dispersed at 500W for 30min. The mixture was then heated to 60℃ and stirred at 350rpm for 3.5h. After filtration, the microspheres were washed with deionized water until the eluent was neutral, completing the carboxylation treatment. The carboxylated microspheres were then added to 500g of deionized water and stirred at 1500rpm for 10min. 0.3g of manganese nitrate and 0.24g of ferric nitrate were added, and the mixture was stirred at 500rpm for 25min. The pH was adjusted to 3.5 by adding 5wt% nitric acid solution dropwise. The mixture was then heated to 60℃ and stirred at 300rpm for 6h. After standing for 12h, the mixture was filtered and washed with deionized water. Next, the microspheres were kept at 80℃ and 60kPa for 6 hours, then removed and kept at 280℃ for 3 hours. After cooling to room temperature, they were placed in a plasma generator, and oxygen was introduced at a flow rate of 35 sccm. The radio frequency power was controlled at 90W, and oxygen plasma reactivation treatment was performed for 17 seconds. After removal, the microspheres were placed in a fluidized bed reactor, and nitrogen gas was introduced at a flow rate of 5 cm / s. The inlet temperature was controlled at 128℃, and the outlet temperature was controlled at 122℃. 0.5g of vaporized C8TES was introduced and kept for 25 minutes. After cooling to room temperature, functional microspheres were obtained. The functional microspheres were then packed into a column to obtain a reaction column.

[0036] Acetic acid solution was added to the effluent of the methanol production wastewater treatment system to adjust the pH to 6.5. The solution was then introduced into the adsorption column at a rate of 4 BV / h. Feeding was stopped when the concentration of ammonia nitrogen in the effluent was 10% of that in the feed solution, resulting in low-ammonia nitrogen effluent. Ozone at a concentration of 20 mg / L was introduced into the reaction column at a rate of 0.2 L / min, while the low-ammonia nitrogen effluent was introduced at a rate of 4 BV / h, resulting in purified effluent.

[0037] The porous microspheres used in this embodiment were prepared in Preparation Example 1.

[0038] Example 2

[0039] Add 48g of clinoptilolite with a particle size of 1mm to 600g of deionized water, stir at 2000rpm for 25min, add 30wt% oxalic acid solution to adjust the pH to 2.5, stir at 300rpm for 2h, filter, wash with deionized water until the eluent is neutral, add to 550g of deionized water, stir at 2000rpm for 25min, add 19g of lanthanum chloride, stir at 300rpm for 10min, add 1wt% sodium hydroxide solution dropwise to adjust the pH to 6, stir at 80rpm for 2h, filter, wash 4 times with deionized water to obtain lanthanum-modified zeolite; wash the lanthanum-modified zeolite 3 times with anhydrous ethanol, add to 500g of anhydrous ethanol, stir at 2000rpm for 25min, add 3.1g KH-550 and 2.2g of deionized water, add 5wt% acetic acid solution dropwise to adjust the pH to 5, stir at 300rpm for 3h, wash 3 times with anhydrous ethanol, wash 3 times with DMF, add to 450g of... In DMF, stir at 1000 rpm for 20 minutes, then add 2.3g M. n PEG-DGE at a concentration of 280 g / mol and 0.47 g of phytic acid were mixed, stirred at 300 rpm for 15 min, heated to 60 °C under nitrogen protection, stirred at 80 rpm for 4 h, filtered, washed twice with DMF, washed twice with deionized water, added to 525 g of 6 wt% potassium chloride solution, stirred at 200 rpm and soaked for 12 h, filtered, washed with deionized water until the eluent was free of chloride ions, washed twice with anhydrous ethanol, and dried at 50 °C and 20 kPa for 8 h to obtain composite modified zeolite. The composite modified zeolite was packed into a column using a wet packing method to obtain an adsorption column.

[0040] 42g of porous microspheres were added to 500g of 10wt% nitric acid solution and ultrasonically dispersed at 500W for 30min. The mixture was then heated to 60℃ and stirred at 350rpm for 3.5h. After filtration, the microspheres were washed with deionized water until the eluent was neutral, completing the carboxylation treatment. The carboxylated microspheres were then added to 500g of deionized water and stirred at 1500rpm for 10min. 0.32g of manganese nitrate and 0.3g of ferric nitrate were added, and the mixture was stirred at 500rpm for 25min. The pH was adjusted to 3.5 by adding 5wt% nitric acid solution dropwise. The mixture was then heated to 60℃ and stirred at 300rpm for 6h. After standing for 12h, the microspheres were filtered and washed with deionized water. Next, the microspheres were kept at 80℃ and 60kPa for 6 hours, then removed and kept at 280℃ for 3 hours. After cooling to room temperature, they were placed in a plasma generator, and oxygen was introduced at a flow rate of 35 sccm. The radio frequency power was controlled at 90W, and oxygen plasma was used for reactivation treatment for 17 seconds. After removal, the microspheres were placed in a fluidized bed reactor, and nitrogen gas was introduced at a flow rate of 5 cm / s. The inlet temperature was controlled at 128℃, and the outlet temperature was controlled at 122℃. 0.54g of vaporized C8TES was introduced and kept for 25 minutes. After cooling to room temperature, functional microspheres were obtained. The functional microspheres were then packed into a column to obtain a reaction column.

[0041] Acetic acid solution was added to the effluent of the methanol production wastewater treatment system to adjust the pH to 6.3. The solution was then introduced into the adsorption column at a rate of 4 BV / h. Feeding was stopped when the concentration of ammonia nitrogen in the effluent was 10% of that in the feed solution, resulting in low-ammonia nitrogen effluent. Ozone at a concentration of 20 mg / L was introduced into the reaction column at a rate of 0.2 L / min, while the low-ammonia nitrogen effluent was introduced at a rate of 4 BV / h, resulting in purified effluent.

[0042] The porous microspheres used in this embodiment were prepared in Preparation Example 1.

[0043] Example 3

[0044] Add 53g of clinoptilolite with a particle size of 1mm to 600g of deionized water, stir at 2000rpm for 25min, add 30wt% oxalic acid solution to adjust the pH to 2, stir at 350rpm for 1.5h, filter, wash with deionized water until the eluent is neutral, add to 550g of deionized water, stir at 2000rpm for 25min, add 20g of lanthanum chloride, stir at 300rpm for 10min, add 1wt% sodium hydroxide solution dropwise to adjust the pH to 5.5, stir at 100rpm for 1h, filter, wash 4 times with deionized water to obtain lanthanum-modified zeolite; wash the lanthanum-modified zeolite 3 times with anhydrous ethanol, add to 500g of anhydrous ethanol, stir at 2000rpm for 25min, add 2.9g of KH-550 and 2.1g of deionized water, add 5wt% acetic acid solution dropwise to adjust the pH to 5.5, stir at 350rpm for 2.5h, wash 3 times with anhydrous ethanol, wash 3 times with DMF, add to 450g of... In DMF, stir at 1000 rpm for 20 minutes, then add 2.4 g M. n PEG-DGE at a concentration of 290 g / mol and 0.49 g of phytic acid were mixed, stirred at 300 rpm for 15 min, heated to 63 °C under nitrogen protection, stirred at 90 rpm for 3.5 h, filtered, washed twice with DMF, washed twice with deionized water, added to 550 g of 5.5 wt% potassium chloride solution, stirred at 150 rpm and soaked for 16 h, filtered, washed with deionized water until the eluent was free of chloride ions, washed twice with anhydrous ethanol, and dried at 40 °C and 10 kPa for 10 h to obtain composite modified zeolite. The composite modified zeolite was packed into a column using a wet packing method to obtain an adsorption column.

[0045] 45g of porous microspheres were added to 500g of 13wt% nitric acid solution and ultrasonically dispersed at 500W for 30min. The temperature was raised to 57℃ and stirred at 400rpm for 3h. After filtration, the microspheres were washed with deionized water until the eluent was neutral, completing the carboxylation treatment. The carboxylated microspheres were then added to 500g of deionized water and stirred at 1500rpm for 10min. 0.36g of manganese nitrate and 0.2g of ferric nitrate were added and stirred at 500rpm for 25min. The pH was adjusted to 3.2 by adding 5wt% nitric acid solution dropwise. The temperature was raised to 63℃ and stirred at 400rpm for 5h. After standing for 13h, the microspheres were filtered and washed four times with deionized water. The microspheres were incubated at 70℃ and 50kPa for 8 hours, then removed and incubated at 290℃ for 2.8 hours. After cooling to room temperature, they were placed in a plasma generator, and oxygen was introduced at a flow rate of 30 sccm. The radio frequency power was controlled at 100W, and oxygen plasma was used for reactivation treatment for 20 seconds. The microspheres were then removed and placed in a fluidized bed reactor, and nitrogen gas was introduced at a flow rate of 7 cm / s. The inlet temperature was controlled at 127℃, and the outlet temperature was controlled at 123℃. 0.53g of vaporized C8TES was introduced and maintained for 35 minutes. After cooling to room temperature, functional microspheres were obtained. The functional microspheres were then packed into a column to obtain a reaction column.

[0046] Acetic acid solution was added to the effluent of the methanol production wastewater treatment system to adjust the pH to 6.5. The solution was then introduced into the adsorption column at a rate of 3.8 BV / h. Feeding was stopped when the concentration of ammonia nitrogen in the effluent was 11% of that in the feed solution, resulting in low-ammonia nitrogen effluent. Ozone at a concentration of 30 mg / L was introduced into the reaction column at a rate of 0.3 L / min, while the low-ammonia nitrogen effluent was introduced at a rate of 4.2 BV / h, resulting in purified effluent.

[0047] The porous microspheres used in this embodiment were prepared in Preparation Example 2.

[0048] Example 4

[0049] 49g of clinoptilolite with a particle size of 1mm was added to 600g of deionized water and stirred at 2000rpm for 25min. The pH was adjusted to 2 by adding 30wt% oxalic acid solution, and the mixture was stirred at 350rpm for 1.5h. The mixture was filtered, washed with deionized water until the eluent was neutral, added to 550g of deionized water, and stirred at 2000rpm for 25min. 24g of lanthanum chloride was added, and the mixture was stirred at 300rpm for 10min. The pH was adjusted to 5.5 by adding 1wt% sodium hydroxide solution, and the mixture was stirred at 100rpm for 1h. The mixture was filtered, washed four times with deionized water to obtain lanthanum-modified zeolite. The lanthanum-modified zeolite was washed three times with anhydrous ethanol and then added to 500g of anhydrous ethanol. The mixture was stirred at 2000rpm for 25min, added 2.8g of KH-550 and 1.8g of deionized water, and the pH was adjusted to 5.5 by adding 5wt% acetic acid solution. The mixture was stirred at 350rpm for 2.5h, washed three times with anhydrous ethanol and three times with DMF, and then added to 450g of deionized water. In DMF, stir at 1000 rpm for 20 minutes, then add 1.9 g M. n PEG-DGE at a concentration of 290 g / mol and 0.5 g of phytic acid were mixed, stirred at 300 rpm for 15 min, heated to 63 °C under nitrogen protection, stirred at 90 rpm for 3.5 h, filtered, washed twice with DMF, washed twice with deionized water, added to 530 g of 5 wt% potassium chloride solution, stirred at 150 rpm and soaked for 16 h, filtered, washed with deionized water until the eluent was free of chloride ions, washed twice with anhydrous ethanol, and dried at 40 °C and 10 kPa for 10 h to obtain composite modified zeolite. The composite modified zeolite was packed into a column using a wet packing method to obtain an adsorption column.

[0050] 47g of porous microspheres were added to 500g of 13wt% nitric acid solution and ultrasonically dispersed at 500W for 30min. The mixture was then heated to 57℃ and stirred at 400rpm for 3h. After filtration, the microspheres were washed with deionized water until the eluent was neutral, completing the carboxylation treatment. The carboxylated microspheres were then added to 500g of deionized water and stirred at 1500rpm for 10min. 0.3g of manganese nitrate and 0.25g of ferric nitrate were added, and the mixture was stirred at 500rpm for 25min. The pH was adjusted to 3.2 by adding 5wt% nitric acid solution dropwise. The mixture was then heated to 63℃ and stirred at 400rpm for 5h. After standing for 13h, the microspheres were filtered and washed four times with deionized water. The microspheres were incubated at 70℃ and 50kPa for 8 hours, then removed and incubated at 290℃ for 2.8 hours. After cooling to room temperature, they were placed in a plasma generator, and oxygen was introduced at a flow rate of 30 sccm. The radio frequency power was controlled at 100W, and oxygen plasma was used for reactivation treatment for 20 seconds. The microspheres were then removed and placed in a fluidized bed reactor, and nitrogen gas was introduced at a flow rate of 7 cm / s. The inlet temperature was controlled at 127℃, and the outlet temperature was controlled at 123℃. 0.6g of vaporized C8TES was introduced and maintained for 35 minutes. After cooling to room temperature, functional microspheres were obtained. The functional microspheres were then packed into a column to obtain a reaction column.

[0051] Acetic acid solution was added to the effluent of the methanol production wastewater treatment system to adjust the pH to 6.5. The solution was then introduced into the adsorption column at a rate of 3.8 BV / h. Feeding was stopped when the concentration of ammonia nitrogen in the effluent was 11% of that in the feed solution, resulting in low-ammonia nitrogen effluent. Ozone at a concentration of 30 mg / L was introduced into the reaction column at a rate of 0.3 L / min, while the low-ammonia nitrogen effluent was introduced at a rate of 4.2 BV / h, resulting in purified effluent.

[0052] The porous microspheres used in this embodiment were prepared in Preparation Example 2.

[0053] Example 5

[0054] Add 50g of clinoptilolite with a particle size of 1mm to 600g of deionized water, stir at 2000rpm for 25min, add 30wt% oxalic acid solution to adjust the pH to 3, stir at 400rpm for 1h, filter, wash with deionized water until the eluent is neutral, add to 550g of deionized water, stir at 2000rpm for 25min, add 23g of lanthanum chloride, stir at 300rpm for 10min, add 1wt% sodium hydroxide solution dropwise to adjust the pH to 5.7, stir at 90rpm for 1.5h, filter, wash 4 times with deionized water to obtain lanthanum-modified zeolite; wash the lanthanum-modified zeolite 3 times with anhydrous ethanol, add to 500g of anhydrous ethanol, stir at 2000rpm for 25min, add 3.3g KH-550 and 1.9g of deionized water, add 5wt% acetic acid solution dropwise to adjust the pH to 6, stir at 400rpm for 2h, wash 3 times with anhydrous ethanol, wash 3 times with DMF, add to 450g of... In DMF, stir at 1000 rpm for 20 minutes, then add 2.2g M. n PEG-DGE (300 g / mol) and phytic acid (0.44 g) were mixed and stirred at 300 rpm for 15 min. The mixture was then heated to 65 °C under nitrogen protection and stirred at 100 rpm for 3 h. After filtration, the mixture was washed twice with DMF and twice with deionized water. It was then added to 510 g of 6 wt% potassium chloride solution and stirred at 180 rpm for 14 h. After filtration, the mixture was washed with deionized water until the eluent was free of chloride ions and washed twice with anhydrous ethanol. The mixture was then dried at 45 °C and 15 kPa for 9 h to obtain a composite modified zeolite. The composite modified zeolite was then packed into a column using a wet packing method to obtain an adsorption column.

[0055] 43g of porous microspheres were added to 500g of 9wt% nitric acid solution and ultrasonically dispersed at 500W for 30min. The mixture was then heated to 63℃ and stirred at 300rpm for 4h. After filtration, the microspheres were washed with deionized water until the eluent was neutral, completing the carboxylation treatment. The carboxylated microspheres were then added to 500g of deionized water and stirred at 1500rpm for 10min. 0.35g of manganese nitrate and 0.27g of ferric nitrate were added, and the mixture was stirred at 500rpm for 25min. The pH was adjusted to 3 by adding 5wt% nitric acid solution dropwise. The mixture was then heated to 65℃ and stirred at 350rpm for 5.5h. After standing for 14h, the microspheres were filtered and washed four times with deionized water. The microspheres were incubated at 75℃ and 55kPa for 7 hours, then removed and incubated at 285℃ for 2.5 hours. After cooling to room temperature, they were placed in a plasma generator, and oxygen was introduced at a flow rate of 32 sccm. The radio frequency power was controlled at 95W, and oxygen plasma reactivation treatment was performed for 22 seconds. The microspheres were then removed and placed in a fluidized bed reactor, and nitrogen gas was introduced at a flow rate of 8 cm / s. The inlet temperature was controlled at 130℃, and the outlet temperature was controlled at 125℃. 0.57g of vaporized C8TES was introduced and maintained for 30 minutes. After cooling to room temperature, functional microspheres were obtained. The functional microspheres were then packed into a column to obtain a reaction column.

[0056] Acetic acid solution was added to the effluent of the methanol production wastewater treatment system to adjust the pH to 6.7. The solution was then introduced into the adsorption column at a rate of 4.2 BV / h. Feeding was stopped when the concentration of ammonia nitrogen in the effluent was 8% of that in the feed solution, resulting in low-ammonia nitrogen effluent. Ozone at a concentration of 25 mg / L was introduced into the reaction column at a rate of 0.25 L / min, while the low-ammonia nitrogen effluent was introduced at a rate of 3.8 BV / h, resulting in purified effluent.

[0057] The porous microspheres used in this embodiment were prepared in Preparation Example 3.

[0058] Example 6

[0059] Add 52g of clinoptilolite with a particle size of 1mm to 600g of deionized water, stir at 2000rpm for 25min, add 30wt% oxalic acid solution to adjust the pH to 3, stir at 400rpm for 1h, filter, wash with deionized water until the eluent is neutral, add to 550g of deionized water, stir at 2000rpm for 25min, add 21g of lanthanum chloride, stir at 300rpm for 10min, add 1wt% sodium hydroxide solution dropwise to adjust the pH to 5.7, stir at 90rpm for 1.5h, filter, wash four times with deionized water to obtain lanthanum-modified zeolite; wash the lanthanum-modified zeolite three times with anhydrous ethanol, add to 500g of anhydrous ethanol, stir at 2000rpm for 25min, add 3g KH-550 and 2.2g of deionized water, add 5wt% acetic acid solution dropwise to adjust the pH to 6, stir at 400rpm for 2h, wash three times with anhydrous ethanol, wash three times with DMF, add to 450g of... In DMF, stir at 1000 rpm for 20 minutes, then add 2.3g M. n PEG-DGE (300 g / mol) and phytic acid (0.42 g) were mixed and stirred at 300 rpm for 15 min. The mixture was then heated to 65 °C under nitrogen protection and stirred at 100 rpm for 3 h. After filtration, the mixture was washed twice with DMF and twice with deionized water. It was then added to 520 g of 5.5 wt% potassium chloride solution and stirred at 180 rpm for 14 h. After filtration, the mixture was washed with deionized water until the eluent was free of chloride ions. It was then washed twice with anhydrous ethanol and dried at 45 °C and 15 kPa for 9 h to obtain a composite modified zeolite. The composite modified zeolite was then packed into a column using a wet packing method to obtain an adsorption column.

[0060] 44g of porous microspheres were added to 500g of 9wt% nitric acid solution and ultrasonically dispersed at 500W for 30min. The mixture was then heated to 63℃ and stirred at 300rpm for 4h. After filtration, the microspheres were washed with deionized water until the eluent was neutral, completing the carboxylation treatment. The carboxylated microspheres were then added to 500g of deionized water and stirred at 1500rpm for 10min. 0.4g of manganese nitrate and 0.29g of ferric nitrate were added, and the mixture was stirred at 500rpm for 25min. The pH was adjusted to 3 by adding 5wt% nitric acid solution dropwise. The mixture was then heated to 65℃ and stirred at 350rpm for 5.5h. After standing for 14h, the microspheres were filtered and washed four times with deionized water. The microspheres were incubated at 75℃ and 55kPa for 7 hours, then removed and incubated at 285℃ for 2.5 hours. After cooling to room temperature, they were placed in a plasma generator, and oxygen was introduced at a flow rate of 32 sccm. The radio frequency power was controlled at 95W, and oxygen plasma reactivation treatment was performed for 22 seconds. The microspheres were then removed and placed in a fluidized bed reactor, and nitrogen gas was introduced at a flow rate of 8 cm / s. The inlet temperature was controlled at 130℃, and the outlet temperature was controlled at 125℃. 0.55g of vaporized C8TES was introduced and maintained for 30 minutes. After cooling to room temperature, functional microspheres were obtained. The functional microspheres were then packed into a column to obtain a reaction column.

[0061] Acetic acid solution was added to the effluent of the methanol production wastewater treatment system to adjust the pH to 6.7. The solution was then introduced into the adsorption column at a rate of 4.2 BV / h. Feeding was stopped when the concentration of ammonia nitrogen in the effluent was 8% of that in the feed solution, resulting in low-ammonia nitrogen effluent. Ozone at a concentration of 25 mg / L was introduced into the reaction column at a rate of 0.25 L / min, while the low-ammonia nitrogen effluent was introduced at a rate of 3.8 BV / h, resulting in purified effluent.

[0062] The porous microspheres used in this embodiment were prepared in Preparation Example 3.

[0063] The present invention also includes comparative examples and related experiments.

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 6 is that phytic acid was not added during the preparation of the composite modified zeolite. Other operating steps and reaction conditions were the same as in Example 6, resulting in purified effluent.

[0066] Comparative Example 2

[0067] The difference between this comparative example and Example 6 is that PEG-DGE was not added during the preparation of the composite modified zeolite. Other operating steps and reaction conditions were the same as in Example 6, resulting in purified effluent.

[0068] Comparative Example 3

[0069] The difference between this comparative example and Example 6 is that C8TES was not added during the preparation of the functional microspheres. Other operating steps and reaction conditions were the same as in Example 6, resulting in purified effluent.

[0070] Comparative Example 4

[0071] The difference between this comparative example and Example 6 is that PMMA microspheres were not added during the preparation of the porous microspheres. Other operating steps and reaction conditions were the same as in Example 6, resulting in purified effluent.

[0072] Deep purification test

[0073] Ammonium chloride, phenol, ferrous sulfate, and calcium chloride were added to deionized water to achieve concentrations of 67 mg / L for ammonium ions, 75 mg / L for phenol, 10 mg / L for ferrous ions, and 10 mg / L for calcium ions. A 5 wt% acetic acid solution was added dropwise to adjust the pH to 6.5. This solution was used to simulate the effluent from a methanol production wastewater treatment system, where the ammonia nitrogen content was approximately 51.96 mg / L and the COD value was approximately 178.5 mg / L.

[0074] 40g of the composite modified zeolite prepared in each example and comparative example was used to prepare an adsorption column, and 40g of the functional microspheres prepared in each example and comparative example was used to prepare a reaction column. 5.5L of effluent from a methanol production wastewater treatment system was introduced into each adsorption column at a rate of 4 BV / h to obtain low ammonia nitrogen effluent. The low ammonia nitrogen effluent was then introduced into the reaction column at a rate of 4 BV / h, while ozone at a concentration of 20 mg / L was introduced into the reaction column at a rate of 0.2 L / min to obtain purified effluent. 500g of 20wt% potassium chloride solution was introduced into the adsorption column at a rate of 2 BV / h for desorption treatment. Subsequently, deionized water was introduced to wash the adsorption column until the washing liquid was free of chloride ions. This was considered as the completion of the first adsorption-desorption cycle of the composite modified zeolite. The composite modified zeolite was recycled multiple times. The effluent from the adsorption columns of each embodiment and comparative example flowed only into the reaction column prepared in conjunction with that embodiment and comparative example. The ammonia nitrogen content (mg / L) and COD value (mg / L) of the purified effluent were measured after the 1st, 10th, 50th, 100th and 200th cycles. The results are shown in Table 1.

[0075] Table 1

[0076]

[0077] Table 1 shows that after 200 cycles of the composite modified zeolite, the purified effluent from Examples 1 to 6 still exhibits low ammonia nitrogen content and COD value (ammonia nitrogen content ≤ 10 mg / L, COD value ≤ 60 mg / L), meeting emission standards. This indicates that the series treatment using an adsorption column composed of composite modified zeolite and a reaction column composed of functional microspheres can effectively remove ammonium ions and phenolic compounds from the effluent of the methanol production wastewater treatment system over a long period. Compared to Comparative Example 1, after 200 cycles of the composite modified zeolite, the purified effluent from Example 6 still exhibits low ammonia nitrogen content and COD value. This indicates that the addition of phytic acid during the preparation of the composite modified zeolite effectively chelates ferrous and ferric ions in the effluent of the methanol production wastewater treatment system, protecting the composite modified zeolite from interference by ferrous ions, preventing them from penetrating the adsorption column, reducing interference from ferrous ions on the functional microspheres, and ensuring the long-term stable operation of the adsorption and reaction columns. Compared to Comparative Example 2, after 200 cycles of the composite modified zeolite, the purified effluent from Example 6 still exhibits low ammonia nitrogen content and COD value. The ammonia nitrogen content and COD value indicate that the addition of PEG-DGE during the preparation of the composite modified zeolite can improve the hydrophilicity of the composite modified zeolite surface, effectively inhibit the adsorption of phenolic compounds on the surface of the composite modified zeolite, and improve the adsorption effect of the composite modified zeolite on ammonium ions. The introduction of PEG-DGE can also prevent phytic acid from falling off the surface of the composite modified zeolite, avoid the inflow of ferrous ions into the reaction column, and ensure the long-term stable operation of the reaction column. Compared with Comparative Example 3, the purified effluent of Example 6 still has a low COD value after 200 cycles of composite modified zeolite recycling, indicating that C8TES can introduce a hydrophobic layer on the surface of functional microspheres, accelerate the enrichment and decomposition rate of phenolic compounds, inhibit the dissolution of iron and manganese oxides inside the functional microspheres, and improve the service life of the functional microspheres. Compared with Comparative Example 4, the purified effluent of Example 6 always has a low COD value, indicating that the introduction of PMMA microspheres increases the porosity and iron and manganese oxide loading of the functional microspheres, accelerates the mass transfer efficiency and treatment efficiency of phenolic compounds, and improves the removal effect of phenolic compounds.

Claims

1. A green treatment process for methanol production wastewater, characterized in that, Includes the following steps: S1. Lanthanum-modified zeolite was treated with KH-550, PEG-DGE and phytic acid, then soaked in potassium chloride solution, washed and dried to obtain composite modified zeolite, and the composite modified zeolite was packed into a column tube to obtain an adsorption column. S2. The carboxylated porous microspheres were dispersed in deionized water, dissolved with manganese nitrate and ferric nitrate, heated to react, allowed to stand for aging, filtered, washed, and dried, and then subjected to heat treatment and reactivation treatment in sequence. Subsequently, hydrophobic treatment was performed using C8TES to obtain functional microspheres. The functional microspheres were packed into a column to obtain a reaction column. The porous microspheres were prepared as follows: water-soluble phenolic resin prepolymer was mixed with deionized water, PMMA microspheres and PEO-PPO-PEO triblock copolymer were added and mixed to obtain a slurry; the slurry was added to dimethyl silicone oil at a constant temperature of 8-10℃, 1000 Stir at 0-11000 rpm for 25-35 min, heat to 98-103℃, stir at 4000-5000 rpm for 2-3 h, heat to 155-162℃, stir at 1000-2000 rpm for 3-4 h, cool, filter, wash with petroleum ether, transfer to an inert atmosphere, heat to 295-305℃, hold for 2-3 h, heat to 650-660℃, hold for 1.5-2 h, cool, and porous microspheres are obtained; the solid content of the water-soluble phenolic resin prepolymer is 40%-50%, and the viscosity of dimethyl silicone oil at 25℃ is 100-120 cst; Carboxylated porous microspheres were dispersed in deionized water, dissolved with manganese nitrate and ferric nitrate, and the pH was adjusted to 3-3.5 by adding nitric acid solution dropwise. The temperature was raised to 60-65℃, stirred at 300-400 rpm for 5-6 hours, and allowed to stand for 12-14 hours. After filtration and washing with deionized water, the microspheres were kept at 70-80℃ and 50-60 kPa for 6-8 hours, and then kept at 280-290℃ for 2.5-3 hours. After cooling, the microspheres were placed in a plasma generator and reactivated for 17-22 seconds under conditions of oxygen flow rate of 30-35 sccm and radio frequency power of 90-100 W. The microspheres were then placed in a fluidized bed reactor, and a nitrogen gas flow rate of 5-8 cm / s was introduced. The inlet temperature was controlled at 127-130℃ and the outlet temperature at 122-125℃. The vaporized C8TES was introduced and maintained for 25-35 minutes. After cooling, the functional microspheres were obtained. S3. Adjust the pH value of the effluent from the methanol production wastewater treatment system and pass it into the adsorption column to obtain low ammonia nitrogen effluent. Pass the low ammonia nitrogen effluent and ozone into the reaction column at the same time to obtain purified effluent.

2. The green treatment process for methanol production wastewater according to claim 1, characterized in that, The lanthanum-modified zeolite was prepared by dispersing clinoptilolite in deionized water, adding oxalic acid solution to adjust the pH to 2-3, stirring at 300-400 rpm for 1-2 hours, filtering, washing with deionized water until the wash solution was neutral, dispersing in deionized water, adding lanthanum chloride to dissolve, adding sodium hydroxide solution dropwise to adjust the pH to 5.5-6, stirring at 80-100 rpm for 1-2 hours, filtering, and washing with deionized water to obtain the lanthanum-modified zeolite.

3. The green treatment process for methanol production wastewater according to claim 2, characterized in that, In step S1, lanthanum-modified zeolite is washed with anhydrous ethanol and dispersed in anhydrous ethanol. KH-550 and deionized water are added, and acetic acid solution is added dropwise to adjust the pH to 5-6. The mixture is stirred at 300-400 rpm for 2-3 hours, filtered, washed with anhydrous ethanol and DMF, dispersed in DMF, and then PEG-DGE and phytic acid are added and mixed. The mixture is heated to 60-65℃ under an inert atmosphere and stirred at 80-100 rpm for 3-4 hours, filtered, washed with DMF and deionized water, and then soaked in a 5-6 wt% potassium chloride solution for 12-16 hours, filtered, washed with deionized water and anhydrous ethanol, and then dried at 40-50℃ and 10-20 kPa for 8-10 hours to obtain composite modified zeolite; the M of PEG-DGE... n It is 280-300 g / mol.

4. The green treatment process for methanol production wastewater according to claim 3, characterized in that, The composite modified zeolite comprises the following raw materials in parts by weight: 48-53 parts of clinoptilolite, 19-24 parts of lanthanum chloride, 2.8-3.3 parts of KH-550, 1.9-2.4 parts of PEG-DGE, 0.4-0.5 parts of phytic acid, and 500-550 parts of 5-6wt% potassium chloride solution.

5. The green treatment process for methanol production wastewater according to claim 1, characterized in that, The porous microspheres were carboxylated using the following method: the porous microspheres were dispersed in a 9-13 wt% nitric acid solution, heated to 57-63℃, stirred at 300-400 rpm for 3-4 hours, filtered, and washed with deionized water until the washing solution was neutral, thus completing the carboxylation treatment of the porous microspheres.

6. The green treatment process for methanol production wastewater according to claim 1, characterized in that, The porous microspheres comprise the following raw materials in parts by weight: 75-82 parts of water-soluble phenolic resin prepolymer, 200-210 parts of deionized water, 30-34 parts of PMMA microspheres, 7-10 parts of PEO-PPO-PEO triblock copolymer, and 1045-1055 parts of dimethyl silicone oil.

7. The green treatment process for methanol production wastewater according to claim 1, characterized in that, The functional microspheres comprise the following raw materials in parts by weight: 42-47 parts porous microspheres, 0.3-0.4 parts manganese nitrate, 0.2-0.3 parts ferric nitrate, and 0.5-0.6 parts C8TES.

8. The green treatment process for methanol production wastewater according to claim 1, characterized in that, In step S3, acetic acid solution is added to the effluent of the methanol production wastewater treatment system to adjust the pH value to 6.3-6.

7. The solution is then introduced into the adsorption column at a rate of 3.8-4.2 BV / h. Feeding is stopped when the concentration of ammonia nitrogen in the effluent is 8%-11% of the feed solution, resulting in low-ammonia nitrogen effluent. Ozone at a concentration of 20-30 mg / L is introduced into the reaction column at a rate of 0.2-0.3 L / min, while the low-ammonia nitrogen effluent is introduced at a rate of 3.8-4.2 BV / h, resulting in purified effluent.

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