A biological treatment method for developer waste liquid

Abstract

The present invention discloses a biological treatment method for developer waste liquid, specifically: first, the dissolved photoresist in the developer waste liquid is removed through acid precipitation and flotation processes, and then the organic nitrogen in the developer waste liquid is converted into ammonia nitrogen through an anaerobic biological method. In the anaerobic biological method, hydrogen-producing bacteria are enriched in the anaerobic bioreactor by adding a hydrogen-producing agent, thereby inhibiting the growth of methanogens; finally, the ammonia nitrogen in the developer waste liquid is converted into nitrogen gas for discharge through an anaerobic biological method. The anaerobic biological method places a short-range nitrification process and an anaerobic ammonia oxidation process in the same reactor for autotrophic biological denitrification. The biological treatment method for developer waste liquid of the present invention has the advantages of low agent consumption, low sludge production, low greenhouse gas production, and no secondary pollutants. The generated hydrogen can be reused as clean energy, while effectively reducing operating costs, thereby achieving low-carbon, high-efficiency, and energy-saving treatment of high-concentration developer waste liquid.

Description

Technical Field

[0001] The invention relates to a biological treatment method for developing waste liquid. Background Art

[0002] During the photolithography process in LCD panel production, a developer is required to dissolve and remove unexposed areas of the photoresist. Tetramethylammonium hydroxide (TMAH), with the molecular formula (CH3)4NOH, is a strong organic base with corrosive and biotoxic properties. It is one of the most commonly used developers in the electronics industry. After removing the photoresist during the photolithography process, a high-concentration developer wastewater is generated, with TMAH concentrations typically ranging from 10,000 to 24,000 mg / L.

[0003] Existing developer wastewater treatment processes primarily utilize a combination of flotation / sedimentation, advanced oxidation, and biological treatment. This involves first removing the photoresist from the developer wastewater, then converting TMAH into ammonia nitrogen through chemical or biological methods, and finally removing the ammonia nitrogen. Advanced oxidation methods include Fenton, Fe-C, O3 / O3+H2O2, UV+S2O8, and wet oxidation, which can treat TMAH wastewater of various concentrations. However, they generally suffer from high investment and operating costs, as well as harsh reaction conditions (such as high temperature and high pressure). Biological methods can be divided into aerobic and anaerobic biological methods, and their operating costs are far lower than those of physicochemical methods. Aerobic biological methods, such as the multi-stage AO process, are currently the most commonly used treatment process for TMAH wastewater from LCD panels. However, they have strict limits on the influent TMAH concentration (TMAH < 1000 mg / L), making it difficult to treat large quantities of high-concentration TMAH wastewater. Furthermore, the aerobic biological treatment system (multi-stage AO) also suffers from high chemical consumption and high sludge production during the treatment process. Anaerobic biological methods have relatively broad requirements for influent TMAH (1,000 to 10,000 mg / L). Studies have shown that anaerobic biological methods can degrade TMAH at a rate more than five times that of aerobic biological methods, with total organic carbon removal and organic nitrogen ammoniation rates both exceeding 95%. However, existing anaerobic biological methods for treating TMAH wastewater produce large amounts of the greenhouse gas CH4. Summary of the Invention

[0004] Purpose of the invention: The purpose of the present invention is to provide a method for treating developer wastewater with low chemical consumption, low sludge production and low greenhouse gas generation.

[0005] Technical solution: The biological treatment method for developer waste liquid described in the present invention specifically comprises the following steps: first, removing the dissolved photoresist in the developer waste liquid through acid precipitation and flotation processes; then, converting the organic nitrogen in the developer waste liquid into ammonia nitrogen through an anaerobic biological method; wherein, in the anaerobic biological method, hydrogen-producing bacteria are enriched in the anaerobic bioreactor by adding a hydrogen-producing agent, thereby inhibiting the growth of methanogens; finally, converting the ammonia nitrogen in the developer waste liquid into nitrogen gas for discharge through a facultative biological method; and placing the short-range nitrification process and the anaerobic ammonium oxidation process in the same reactor for autotrophic biological denitrification.

[0006] In the anaerobic biological method, the developer waste liquid for removing the photoresist is pumped into the anaerobic bioreactor via a lifting pump. The temperature of the developer waste liquid entering the anaerobic bioreactor is 32-38°C. Disodium hydrogen phosphate, trace elements and hydrogen-producing agents are added to the developer waste liquid. Anaerobic granular sludge is added to the anaerobic bioreactor (sludge is added first, and then wastewater is introduced). The amount of sludge added is 22-25 g / L. The volumetric load of the anaerobic bioreactor is 6-9 kg TMAH / (m 3 d), rising flow rate 4.5-7m / h; the gas produced by the anaerobic bioreactor enters the carbonic acid absorption tank through the water seal tank, and after the CO2 is removed, it enters the gas collection system. The effluent of the anaerobic bioreactor enters the facultative aerobic bioreactor for treatment.

[0007] The amount of sodium dihydrogen phosphate added to the developer waste liquid is 0.4-0.5% of the mass of tetramethylammonium hydroxide in the waste liquid; each liter of trace elements includes 1000mg MgSO4·7H2O, 100mg / L NaCl, 100mg / L Na2MO4·2H2O, 100mg / L CaCl2·2H2O and 150mgMnSO4·7H2O, and the solvent is water; the amount of trace elements added is 0.5L / m 3 (It means adding 0.5L trace elements to every cubic meter of developing waste liquid); the dosage of hydrogen generating agent is 1L / m 3 .

[0008] Each liter of the hydrogen-producing agent includes 0.1 kg of nano-iron particles, 0.08 kg of Na2S, 0.16 kg of Na2S2O3, 0.2 kg of industrial caramel, 0.04 kg of starch and 0.12 kg of L-cysteine, and the solvent is water.

[0009] The nano iron particles are prepared by the following method: adding ground siderite (grinding is only to accelerate the dissolution rate of siderite in sulfuric acid) to sulfuric acid at a solid-liquid ratio of 1:8-10, stirring for reaction, and filtering; mixing the filtrate, water and anhydrous methanol (the role of anhydrous methanol in the system is to provide a suitable reaction environment for the subsequent reduction reaction) at a volume ratio of 1:0.5:1.3-1.7 to obtain a mixed solution; adding glycerol fatty acid ester to the mixed solution (the role of glycerol fatty acid ester in the system is: a dispersant to prevent the nano iron particles formed by the subsequent reduction reaction from aggregating, so that The particle dispersion is higher), and the dosage of glycerol fatty acid ester is 25-50 mg / L; then the solution is heated to 45-60°C, and hydrazine hydrate is added at a concentration of 8-16 g / L (the amount of hydrazine hydrate added is 8-16 g / L, and hydrazine hydrate is a reducing agent to reduce iron ions to elemental iron). Continuous mechanical stirring is carried out, and after stirring, it is filtered (filtration is performed using a PVDF filter membrane with a nominal pore size of 40 nm). The nano-iron particles obtained by filtration are repeatedly rinsed with water and anhydrous methanol, and then dried in an environment of 70-80°C to obtain nano-iron particles with an average particle size of 40-100 nm. This method uses glycerol fatty acid ester as a dispersant, and the resulting nano-iron particles are more uniform, less likely to aggregate into lumps, and can be quickly utilized by microorganisms. This avoids the problem of nano-iron particles easily agglomerating during the drying process prepared by conventional liquid-phase reduction methods.

[0010] In the facultative aerobic biological method, the developing waste liquid treated by the anaerobic biological method is pumped into the facultative aerobic bioreactor via a lifting pump. The temperature of the developing waste liquid entering the facultative aerobic bioreactor is 30-35°C. Sodium carbonate and trace elements are added to the developing waste liquid. The pH of the developing waste liquid is adjusted to 7.7-8.5 by sodium carbonate. The dosage of the trace elements is 0.5L / m 3 ; Add short-cut nitrification granular sludge and anaerobic ammonium oxidation granular sludge to the facultative aerobic bioreactor, the total amount of the two sludges added is 20-25g / L; the volume load of the facultative aerobic bioreactor is 0.9-1.4kg NH3-N / (m 3 d) External reflux ratio of 40-70%, rising flow rate of 3-7 m / h; nitrogen produced by the facultative aerobic bioreactor is directly discharged, and the effluent of the facultative aerobic bioreactor enters the subsequent biological system for deep treatment.

[0011] The facultative aerobic bioreactor includes a water distribution zone, a micro-aerobic zone, an oxygen-limited zone and a two-phase separation zone, and a screen is provided between the micro-aerobic zone and the oxygen-limited zone; the micro-aerobic zone is filled with suspended filler A; an aeration port is provided at the bottom of the micro-aerobic zone, and the dissolved oxygen concentration in the micro-aerobic zone is 0.5-1.0 mg / L; short-range nitrifying bacteria are enriched on the suspended filler A; a filamentous filler B is provided in the oxygen-limited zone, and one end of the filamentous filler B is fixed on the screen; four aeration ports are provided on the side wall of the oxygen-limited zone, and the dissolved oxygen concentration in the oxygen-limited zone is 0.1-0.2 mg / L; the micro-aerobic zone performs a short-range nitrification reaction, converting part of the ammonia nitrogen in the influent into nitrite nitrogen, thereby relieving the inhibition of high-concentration ammonia nitrogen on anaerobic ammonia-oxidizing bacteria; the oxygen-limited zone simultaneously performs a short-range nitrification reaction and an anaerobic ammonia oxidation reaction, converting nitrite nitrogen into nitrogen gas, thereby completing the removal of nitrogen-containing pollutants.

[0012] The preparation method of the suspension filler A specifically comprises the following steps:

[0013] (1) Modification of polyurethane sponge filler: The polyurethane sponge is added to a mixed solution of sulfuric acid, nitric acid and hydrogen peroxide and soaked (the purpose of the first soaking is to use the strong oxidizing property of the mixed solution of sulfuric acid, nitric acid and hydrogen peroxide to destroy the surface and internal structure of the polyurethane sponge, so that the supramolecular hydrogel is more easily loaded into the polyurethane sponge filler). After soaking, the polyurethane sponge is taken out and placed in an enzyme solution to remove the residual hydrogen peroxide. After soaking, the polyurethane sponge is taken out and dried at room temperature to obtain a modified polyurethane sponge filler;

[0014] (2) Sodium hyaluronate and chitosan are added to deionized water, stirred to obtain a mixed solution, and the pH of the mixed solution is adjusted to 8-9.5; polycarbodiimide and N-hydroxysuccinimide are added to the mixed solution (polycarbodiimide and N-hydroxysuccinimide are activated cross-linking agents, under the action of which sodium hyaluronate and chitosan undergo polymerization reaction and solvent exchange reaction to form supramolecular hydrogel) to carry out activation reaction, and then aminocyclodextrin is added after the reaction (aminocyclodextrin has a cavity structure, and combines with supramolecular hydrogel to form supramolecular cyclodextrin hydrogel with adsorption, which is easier to capture and load microorganisms), and the supramolecular hydrogel aqueous solution is formed after rapid stirring; the modified polyurethane sponge filler is placed in the supramolecular hydrogel aqueous solution with a solid-liquid ratio of 1:3-4, and the supramolecular hydrogel is attached to the inside of the modified polyurethane sponge filler by rapid stirring, and the polyurethane sponge filler loaded with supramolecular hydrogel is obtained after freeze-drying;

[0015] (3) taking a glucose oxidase aqueous solution with a mass concentration of 25 to 28%, adjusting the pH of the glucose oxidase aqueous solution to 4 to 5, adding the polyurethane sponge filler of step (2) with a solid-liquid ratio of 1:1 to 2, rapidly stirring and drying at room temperature, wherein the glucose oxidase is embedded in the microporous structure of the supramolecular hydrogel under acidic conditions to form an immobilized slow-release enzyme group.

[0016] The preparation method of the filamentous filler B specifically comprises the following steps: the solid-liquid ratio mentioned below refers to 1 g corresponding to 1 L;

[0017] (1) Grinded chalcopyrite and siderite are mixed in a mass ratio of 1:1.26-1.44 (chalcopyrite provides copper, siderite provides iron, and large pieces of ore are ground into small stones to facilitate the subsequent rapid dissolution of chalcopyrite and siderite), and added to a mixture of sulfuric acid, nitric acid and acetic acid with a solid-liquid ratio of 1:8-12. After reaction, the mixture is filtered; the filtrate, oxalic acid, ethanol and triethanolamine are mixed in a volume ratio of 15:2:2:1, stirred rapidly, and filtered to obtain a beige gel (generating a copper-iron compound gel); the gel is washed and dried, and then calcined at 350°C, 500°C and 850°C respectively (the purpose of calcining at different temperatures is: the calcination process gradually increases the temperature, which can gradually change the apparent morphology of the formed nano-copper-iron particles, which is conducive to a better induction and stimulation effect on microorganisms. At the same time, the gradual increase in temperature during calcination can make the formed nano-copper-iron particles more magnetic), thereby obtaining magnetic nano-copper-iron particles.

[0018] (2) The polyacrylonitrile fiber bundle is placed in a hydroxylamine hydrochloride solution with a pH of 5 to 7 (the purpose of soaking is to destroy the surface structure of the fiber bundle and make the nano-copper iron particles easier to load). After soaking, the fiber bundle is taken out and dried; magnetic nano-copper iron particles are added to deionized water with a solid-liquid ratio of 1:10 to 15, and then the modified fiber bundle is added. The amount of fiber bundle added is: 1m 2 The fiber bundle is reacted at 80°C (the purpose of the high temperature reaction is to fix the nano copper and iron particles on the fiber bundle). After the reaction, the fiber bundle is taken out, cleaned and then calcined at 200°C to fix the magnetic nano copper and iron particles on the fiber bundle to obtain filamentous filler B.

[0019] Beneficial effects: Compared with the existing technology, the present invention has the following significant technical effects: the biological treatment method of the developer waste liquid of the present invention has the advantages of low chemical consumption, low sludge production, low greenhouse gas generation, and no secondary pollutants. The generated hydrogen can be reused as clean energy, while effectively reducing the operating costs and realizing low-carbon, high-efficiency and energy-saving treatment of high-concentration developer waste liquid; the TOC removal rate of the developer waste liquid treated by the method of the present invention is greater than 95%, the ammonia nitrogen removal rate is greater than 95%, and the total nitrogen removal rate is greater than 90%. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of the structure of the anaerobic bioreactor;

[0021] Figure 2 Schematic diagram of the structure of the facultative aerobic bioreactor;

[0022] Figure 3is the total organic carbon removal rate during the operation of the anaerobic bioreactor;

[0023] Figure 4 is the ammonia nitrogen conversion rate during the operation of the anaerobic bioreactor;

[0024] Figure 5 It is the removal rate of total nitrogen and ammonia nitrogen during the operation of the aerobic bioreactor. DETAILED DESCRIPTION

[0025] The biological treatment method for developer waste liquid of the present invention first removes dissolved photoresist in the developer waste liquid through acid precipitation and flotation processes, then converts organic nitrogen in the developer waste liquid into ammonia nitrogen through an anaerobic biological method, wherein hydrogen-producing agents are added in the anaerobic biological method to enrich hydrogen-producing bacteria in the anaerobic bioreactor and inhibit the growth of methanogens; finally, the ammonia nitrogen in the developer waste liquid is converted into nitrogen gas for discharge through a facultative biological method, wherein the facultative biological method places a short-range nitrification process and an anaerobic ammonium oxidation process in the same reactor for autotrophic biological denitrification; the method specifically comprises the following steps:

[0026] (1) Acid precipitation-flotation: The developer wastewater with a TMAH concentration of 0.05-2.38% is put into the regulating tank, and hydrochloric acid is added to the regulating tank to adjust the pH of the developer wastewater to 5.5-6.8. At this pH value, TMAH is converted into TMA + Under neutral conditions, the photoresist dissolved in the developer waste liquid is precipitated; the neutral developer waste liquid passes through the coagulation tank and the flocculation tank in turn, PAC is added in the coagulation tank, the PAC dosage is 100-350 mg / L, so that the precipitated photoresist is destabilized and condensed to form flocs, and PAM is added in the flocculation tank, the PAM dosage is 3-5 mg / L, so that the small flocs are formed into larger flocs. The developer waste liquid after chemical coagulation treatment enters the flotation device, which adopts the internal circulation jet pressurized dissolved air method to supply air, and the dissolved The air-water pressure is 0.3-0.4 MPa, and the air-solid ratio is 1-2.5%. Solid-liquid separation is achieved by an air flotation device to remove photoresist flocs from the developer waste liquid. The developer waste liquid from which the photoresist has been removed is transported to an intermediate water tank I via a water pump. If the TMAH concentration in the developer waste liquid is greater than 1.8%, dilution water (domestic sewage or reverse osmosis concentrated water) is added to the intermediate water tank I to dilute the developer waste liquid to a TMAH concentration of less than or equal to 1.8%. If the TMAH concentration in the developer waste liquid is less than or equal to 1.8%, no dilution is required.

[0027] (2) Anaerobic biological method: add disodium hydrogen phosphate, trace elements and hydrogen-generating agent to the developing wastewater in the intermediate water tank I. The dosage of sodium dihydrogen phosphate is m(TMAH):m(PO4-P)=240, and the dosage of trace elements is 0.5L / m 3(Trace elements per liter include 1000mg MgSO4·7H2O, 100mg / L NaCl, 100mg / L Na2MO4·2H2O, 100mg / L CaCl2·2H2O and 150mgMnSO4·7H2O, the solvent is water). Sodium dihydrogen phosphate and trace elements provide some nutrients necessary for the growth of anaerobic microorganisms; the dosage of hydrogen production agent is 1L / m 3 The hydrogen-producing agent is used to maintain a suitable environment for the growth of hydrogen-producing anaerobic microorganisms; the developing wastewater in the intermediate water tank I is pumped into the anaerobic bioreactor (Bio-UiSA) through a lifting pump to remove TMA + The middle water tank I is equipped with a steam heating pipe to maintain the inlet water temperature at 32-38°C. An insulation layer is provided outside the reactor. Anaerobic granular sludge is added to Bio-UiSA at a sludge addition rate of 22-25 g / L. The volumetric load of Bio-UiSA is 6-9 kg TMAH / (m 3 d) With an upward flow rate of 4.5 to 7 m / h, the gas produced by Bio-UiSA (mainly H2 and CO2) enters the carbonic acid absorption tank through the water seal tank. After the CO2 is removed, it enters the gas collection system. The effluent from the anaerobic bioreactor enters the facultative aerobic bioreactor for treatment.

[0028] (3) Short-cut nitrification-anaerobic ammonium oxidation: The effluent from Bio-UiSA enters the intermediate water tank II. The C / N ratio of the effluent from Bio-UiSA is between 0.25 and 0.4. Sodium carbonate and trace elements are added to the intermediate water tank II. The dosage of sodium carbonate is m(TN):m(Na2CO3)=0.8~1. Sodium carbonate provides the carbon source necessary for the growth of short-cut nitrifying bacteria and regulates the alkalinity of the wastewater. The dosage of trace elements is 0.5L / m 3 , adjust the pH of the wastewater in the intermediate water tank II to 7.7-8.5, and send it to the facultative aerobic bioreactor (Bio-HiSA) through the lifting pump to carry out short-term nitrification-anaerobic ammonium oxidation reaction. During the short-term nitrification-anaerobic ammonium oxidation reaction, ammonia nitrogen is used as the electron donor and nitrite nitrogen is used as the electron acceptor to achieve autotrophic biological denitrification; the intermediate water tank II is equipped with a steam heating pipe to maintain the inlet water temperature at 30-35°C, and an insulation layer is provided outside the reactor. A two-phase separator is provided on the top of the Bio-HiSA reactor to effectively separate mud and water. The amount of mud added to the reactor is 20-25g / L. The volume load of Bio-HiSA is 0.9-1.4kg NH3-N / (m 3 d) External reflux ratio of 40-70% (the larger the external reflux ratio, the greater the rising flow velocity), rising flow velocity of 3-7 m / h (the greater the rising flow velocity, the better the fluidization state), the nitrogen produced by Bio-HiSA can be directly discharged, and the Bio-HiSA effluent enters the subsequent biological system for deep treatment.

[0029] like Figure 1 As shown, the anaerobic bioreactor includes a water distribution area and two layers of three-phase separation areas at the bottom of the reactor. The two layers of three-phase separation areas are located at the top and middle of the reactor respectively. An exhaust port I is also provided at the top of the reactor, and the exhaust port I is connected to an external gas production collection device through a pipe. A spiral reaction zone is provided between the water distribution area and the three-phase separation area, as well as between the two layers of three-phase separation areas. The spiral reaction zone uses staggered baffles to make the water flow in the spiral reaction zone form a deflection, so that the water flow rotates and rises. The angle between the baffle and the side wall of the reactor is 45 to 65 degrees. An exhaust port II is provided below the baffle, that is, at the position where the baffle forms an angle with the side wall of the reactor. The exhaust port II is connected to an external gas production collection device through a pipe. The provision of the exhaust port II here can effectively prevent the formation of reaction dead corners in the reactor; the water flow in the spiral reaction zone rotates and rises, so that the entire reactor reaches a state of local vortex and overall push flow. At the same time, the reactor adopts two layers of three-phase separation zones, which can improve the mud, water and gas three-phase separation effect on the one hand, and effectively prevent sludge loss on the other hand. If the reactor only has a top layer of three-phase separation zone, it is easy to cause sludge overflow (being carried out of the reactor by gas). The anaerobic bioreactor used in the present invention has a high TMAH treatment load (6-9 kg TMAH / (m 3 d)) has the advantages of high tolerance to influent TMAH concentration (TMAH < 18,000 mg / L) and high TMAH (tetramethylammonium hydroxide) treatment efficiency (TOC removal rate > 95%, ammonia nitrogen conversion rate nearly 100%). This is because a spiral reaction zone is set up in the reactor, and an exhaust port II is provided below the baffle to avoid the formation of dead corners, effectively increasing the mud-water contact effect in the reactor and making the mud-water mixing more complete, thereby achieving high TMAH treatment efficiency in the reactor and high tolerance to influent TMAH concentration.

[0030] The hydrogen-producing agent used in the anaerobic biological reaction process of the present invention is: per liter of hydrogen-producing agent, it includes 0.1kg nano-iron particles, 0.08kg Na2S, 0.16kg Na2S2O3, 0.2kg industrial caramel, 0.04kg starch and 0.12kg L-cysteine, and the solvent is water.

[0031] The preparation method of nano-iron particles is a liquid-phase chemical reduction method. The ground siderite is added to sulfuric acid with a mass concentration of 20% and a solid-liquid ratio of 1:8. After stirring for 1 hour, it is filtered. The filtrate, deionized water and anhydrous methanol are mixed in a volume ratio of 1:0.5:1.3, and glycerol fatty acid ester is added. The dosage of glycerol fatty acid ester is 25 mg / L. Then the solution is heated to 45°C and a hydrazine hydrate solution with a concentration of 4 moL / L is added. The solution is continuously mechanically stirred for 1 hour and filtered. The nano-iron particles obtained by filtration are repeatedly rinsed with deionized water and anhydrous methanol 5 times, and then placed in a 70°C environment for drying for 12 hours.

[0032] In hydrogen-producing agents, nano-iron particles promote the synthesis of ferredoxin, accelerating the decarboxylation of pyruvate to produce hydrogen and the oxidation and reduction of coenzyme I (which are intermediate products of the microbial reaction). Furthermore, the porous surface structure of the nano-iron particles increases their specific surface area, endowing them with adsorption properties that promote and maintain granulation of anaerobic sludge and prevent its aggregation and formation of flocs. Furthermore, the porous structure of the nano-iron particles forms numerous micro-batteries on their surface, triggering electrochemical corrosion reactions that slowly release hydrogen into the system, enhancing hydrogen production. Na₂S and Na₂S₂O₃ enrich hydrogen-producing bacteria within the reactor, which rely on sulfur as a key growth element, while inhibiting the growth of methanogens, thereby relieving the inhibitory effect of methanogens on hydrogen-producing bacteria. Industrial caramel and starch provide reducing sugars, which rapidly enrich hydrogen-producing bacteria during the reactor startup phase and maintain their activity during operation. L-cysteine acts as a reducing agent, controlling the ORP within the reactor to -400 to -300 mV, creating a suitable environment for anaerobic hydrogen production. The reactor uses hydrogen-producing agents to create a hydrogen-producing environment, making it suitable for the survival of hydrogen-producing bacteria and enhancing their hydrogen production.

[0033] like Figure 2 As shown, the facultative aerobic bioreactor includes, from bottom to top, a water distribution zone, a microaerobic zone, an oxygen-limited zone, and a two-phase separation zone. A screen is provided between the microaerobic zone and the oxygen-limited zone. The microaerobic zone is filled with suspended filler A. The volume of the suspended filler A is 10-15% of the volume of the microaerobic zone. A screen is provided at the top of the microaerobic zone to prevent the loss of the suspended filler A. An aeration port is provided at the bottom of the microaerobic zone. An online dissolved oxygen detector is also provided in the microaerobic zone. The dissolved oxygen concentration in the microaerobic zone is controlled at 0.5-1.0 mg / L. Short-range nitrifying bacteria can be enriched on the suspended filler A. A filamentous filler B is provided in the oxygen-limited zone. One end of the filamentous filler B is fixed to the screen and is rotated every 10 cm. 2 A filamentous filler B is provided, and the length of filamentous filler B is 2.8m; four aeration ports are provided on the side wall of the oxygen-limited zone, and an online dissolved oxygen detector is also provided in the oxygen-limited zone. The dissolved oxygen concentration in the oxygen-limited zone is controlled to be 0.1-0.2mg / L. A short-range nitrification reaction is carried out in the micro-aerobic zone to convert part of the ammonia nitrogen in the influent into nitrite nitrogen, thereby relieving the inhibition of high-concentration ammonia nitrogen on anaerobic ammonia-oxidizing bacteria; a short-range nitrification-anaerobic ammonia-oxidation reaction is carried out in the oxygen-limited zone to complete the removal of nitrogen-containing pollutants. The facultative oxygen bioreactor of the present invention can convert ammonia nitrogen into nitrogen gas in the same reactor, thereby realizing efficient denitrification by autotrophic organisms, that is, denitrification can be achieved in the same reactor. The facultative oxygen bioreactor of the present invention has the advantages of extremely fast startup speed (about 14-28d) and high nitrogen load. This advantage is due to the high activity of microorganisms, fast mold hanging, and high nitrogen removal efficiency.

[0034] The preparation method of the suspended filler A specifically comprises the following steps:

[0035] (1) Modification of polyurethane sponge filler: The main structure of the suspended filler A is an ordinary polyurethane cubic sponge filler with a side length of 3 mm. The polyurethane sponge is added to a mixed solution of sulfuric acid, nitric acid and hydrogen peroxide and soaked. The mass concentrations of sulfuric acid and nitric acid are both 15%, and the mass concentration of hydrogen peroxide is 3%. After soaking for 1 hour, the sponge is taken out and then placed in an enzyme solution to remove residual hydrogen peroxide. The mass concentration of the enzyme is 2%. After soaking for 0.5 hour, the sponge is taken out and dried at room temperature for 24 hours. A modified polyurethane sponge filler with good loading performance and the ability to adsorb large molecular substances can be obtained.

[0036] (2) Sodium hyaluronate and chitosan are added to deionized water, with the dosage of sodium hyaluronate being 5 g / L and the dosage of chitosan being 0.5 g / L, and the mixture is stirred evenly. Sodium hydroxide is added to adjust the pH value of the solution to 8, and polycarbodiimide and N-hydroxysuccinimide are added to the solution for activation reaction, with the reaction time being 0.6 h, the dosage of polycarbodiimide being 3 g / L, and the dosage of N-hydroxysuccinimide being 1 g / L, and then aminocyclodextrin is added, with the dosage of aminocyclodextrin being 35 g / L, and the mixture is rapidly stirred for 12 h to form a supramolecular hydrogel aqueous solution; the modified polyurethane sponge filler of step (1) is placed in the supramolecular hydrogel aqueous solution, with a solid-liquid ratio of 1:3, and the supramolecular hydrogel is attached to the inside of the modified polyurethane sponge filler after rapid stirring for 4 h, and the modified polyurethane sponge filler is freeze-dried for 2 h to complete the supramolecular hydrogel loading;

[0037] The sodium hyaluronate-chitosan supramolecular hydrogel loaded with suspended filler A allows short-range nitrifying bacteria in the microaerobic zone to adhere to the filler (aminocyclodextrin has a cavity structure, and when combined with the supramolecular hydrogel, the resulting supramolecular cyclodextrin hydrogel has extremely strong adsorption properties, making it easier to capture and load microorganisms), accelerating the passive biofilm formation process of short-range nitrifying bacteria. At the same time, the supramolecular hydrogel can induce and promote the secretion of large amounts of EPS (short-range nitrifying bacteria have the characteristic of passive biofilm formation. The supramolecular hydrogel proposed in the present invention has the functions of capturing, adsorbing, and inducing, which can fix short-range nitrifying bacteria in the filler. Under the guidance of the supramolecular hydrogel, the short-range nitrifying bacteria fixed in the filler accelerate the secretion of EPS (extracellular polymeric substances)). This allows more short-range nitrifying bacteria to adhere and aggregate, quickly forming a stable biofilm with short-range nitrifying bacteria as the main functional bacteria within the filler. Therefore, the addition of suspended filler A can initiate the short-range nitrification reaction in the microaerobic zone in a very short time, effectively shortening the reactor startup time.

[0038] (3) A 25% glucose oxidase aqueous solution was taken, the pH was adjusted to 4-5, and a modified polyurethane sponge filler loaded with supramolecular hydrogel was added at a solid-liquid ratio of 1:1-2. After rapid stirring for 2 hours, the mixture was taken out and dried at room temperature to obtain a suspended filler A. In the suspended filler A, glucose oxidase was embedded in the microporous structure of the supramolecular hydrogel under acidic conditions to form an immobilized slow-release enzyme group; the immobilized slow-release enzyme group can slowly release glucose oxidase in water, effectively reducing the toxic effects of free ammonia and metal ions on short-range nitrifying bacteria. (Glucose oxidase is modified by combining with free ammonia and metal ions to reduce their impact on microorganisms) to maintain a suitable growth environment for short-range nitrifying bacteria; at the same time, the slow-release glucose oxidase can combine with calcium and magnesium ions in the water to reduce the risk of calcification of biofilm, activated sludge and suspended fillers in an environment with high alkalinity. After calcification, the microorganisms lose their activity, which reduces the treatment effect of the bioreactor and can even cause the bioreactor to collapse in severe cases. The slow-release period of the immobilized slow-release enzyme group is 190 to 230 days. After the slow-release effect disappears, the immobilization reaction can be carried out again.

[0039] The preparation method of the filamentous filler B specifically comprises the following steps:

[0040] (1) Preparation of magnetic nano-copper iron particles: ground chalcopyrite and siderite were mixed in a mass ratio of 1:1.26, added to a mixture of sulfuric acid, nitric acid and acetic acid, with a mass concentration of 15% sulfuric acid, 3% nitric acid and 6% acetic acid, and a solid-liquid ratio of 1:8, stirred for 2 hours and then filtered; the filtrate, oxalic acid, ethanol and triethanolamine were mixed in a volume ratio of 15:2:2:1, rapidly stirred for 2 hours and then filtered to obtain a beige gel, which was repeatedly rinsed with deionized water and anhydrous methanol for 5 times and then dried at 80°C for 2 hours; then placed in a muffle furnace and calcined at 350°C, 500°C and 850°C for 1 hour each to obtain magnetic nano-copper iron particles;

[0041] (2) The carrier of the filamentous filler B is a lightweight polyacrylonitrile fiber bundle. The fiber bundle is first placed in a hydroxylamine hydrochloride solution with a pH of 5 to 7, where the mass concentration of hydroxylamine hydrochloride is 6%. After soaking for 5 hours, the fiber bundle is placed at room temperature and dried for 12 hours. Magnetic nano-copper iron particles are added to deionized water with a solid-liquid ratio of 1:10, and then the fiber bundle is added thereto. The reaction temperature is controlled to 80°C, and the fiber bundle is rapidly stirred for 8 hours. The fiber bundle is taken out, and the unloaded magnetic nano-copper iron particles are rinsed with deionized water. The fiber bundle is then placed in a muffle furnace and calcined at 200°C for 2 hours to fix the magnetic nano-copper iron particles on the fiber bundle. After cooling to room temperature, the fiber bundle is cut into pieces of appropriate length to obtain the filamentous filler B.

[0042] The filamentous filler B has a large specific surface area and a loose and porous surface structure, which is conducive to the active biofilm formation of anaerobic ammonium oxidizing bacteria. The magnetic nano-copper-iron particles loaded on the filler can form numerous small magnetic fields in the reactor, causing the anaerobic ammonium oxidizing bacteria to produce a microbial magnetic effect, greatly improving the activity of the anaerobic ammonium oxidizing bacteria and effectively shortening the reactor startup time. The nano-copper in the magnetic nano-copper-iron particles can inhibit nitrite oxidizing bacteria and prevent them from competing with anaerobic ammonium oxidizing bacteria, while also catalyzing the secretion of autoinducers (C6-HSL, C8-HSL) by anaerobic ammonium oxidizing bacteria, thereby improving the denitrification efficiency of anaerobic ammonium oxidizing bacteria. The bottom end of the filamentous filler B is fixed on the screen, while the upper end is not fixed. Under the shear force of water, the EPS secreted by anaerobic ammonium oxidizing bacteria is quickly released, which can not only accelerate the formation of anaerobic ammonium oxidizing biofilm, but also granulate the flocculent sludge in a faster time in the oxygen-limited zone. The granular sludge formed in the oxygen-limited zone is mainly composed of short-range nitrifying bacteria on the outside and anaerobic ammonium oxidizing bacteria on the inside. Finally, a mud film coexistence system is formed in the oxygen-limited zone, which converts nitrogen-containing pollutants into nitrogen gas and realizes denitrification in the same reactor.

[0043] The specific application of the treatment method of the present invention is: the amount of developing wastewater in a certain liquid crystal panel factory is 60m 3 / d, and its water quality is as follows:

[0044] Table 1 shows the water quality of the developer wastewater from a certain LCD panel factory.

[0045] pH TMAH (mg / L) TOC (mg / L) TN (mg / L) <![CDATA[NH3-N(mg / L)]]> 13.4 22300～23800 9970～11860 3430～3670 ＜16

[0046] For the developer waste liquid, the treatment method of the present invention comprises the following steps:

[0047] (1) Acid precipitation-flotation: The developer waste liquid with a TMAH concentration of 22300-23800 mg / L enters the regulating tank, and hydrochloric acid is added to it to adjust its pH to 5.7-6.8. The neutral developer waste liquid passes through the coagulation tank and flocculation tank in turn. PAC is added in the coagulation tank at a dosage of 100-350 mg / L to destabilize the precipitated photoresist and condense to form flocs. PAM is added in the flocculation tank at a dosage of 100-350 mg / L. 5mg / L, so that the fine flocs form larger flocs. The developer waste liquid after chemical coagulation treatment enters the flotation device, which adopts the internal circulation jet pressurized dissolved air method to supply air, with the dissolved air water pressure of 0.3-0.4MPa and the gas-solid ratio of 1.3-1.5%. The developer waste liquid with the photoresist removed is transported to the intermediate water tank I by a water pump, and the RO concentrated water of the recycling water system is added to the intermediate water tank I to dilute the developer waste liquid to a TMAH mass concentration of 1.6-1.8%;

[0048] (2) Anaerobic: Add disodium hydrogen phosphate, trace elements and hydrogen-producing agents to the intermediate water tank I. The dosage of sodium dihydrogen phosphate is m(TMAH):m(PO4-P)=240, and the dosage of trace elements is 0.5L / m3 , the dosage of hydrogen production agent is 1L / m 3 , adjust the pH to make the inlet pH 5.5-6.2; the developing waste liquid in the intermediate water tank I is pumped into the anaerobic bioreactor through the lifting pump, the inlet water temperature is 32-35℃, and an insulation layer is provided outside the reactor. Anaerobic granular sludge is added to the anaerobic bioreactor at a sludge addition rate of 23.5g / L. The volumetric load of the anaerobic bioreactor is 7.75kg TMAH / (m 3 ·d), with an upward flow rate of 4.5-5.8 m / h. The gas produced by the anaerobic bioreactor enters the carbonic acid absorption tank through the water seal tank and then enters the gas collection system. During the stable operation period, the V(H2):V(CH4):V(CO2) in the gas produced is 12:1:7, and the hydrogen production rate is 187 mL H2 / (gTVS·h). The total organic carbon removal rate and ammonia nitrogen conversion rate during the operation of the anaerobic bioreactor are shown in Figure 2. Figures 3-4 ;

[0049] (3) Short-cut nitrification-anaerobic ammonium oxidation: The effluent from the anaerobic bioreactor enters the intermediate water tank II, into which sodium carbonate and trace elements are added. The sodium carbonate dosage is m(TN):m(Na2CO3)=1, and the trace element dosage is 0.5L / m 3 The pH of the wastewater in the intermediate water tank II is 7.7-8.2, and it is pumped into the facultative aerobic bioreactor through a lifting pump. The intermediate water tank II is equipped with a steam heating pipe to maintain the inlet water temperature at 32-35°C, and an insulation layer is provided outside the reactor. The residual sludge from the secondary sedimentation tank is added to the facultative aerobic bioreactor at a rate of 22.4 g / L. The volumetric load of the facultative aerobic bioreactor is 1.17 kg NH3-N / (m 3 d), with an upward flow rate of 3 to 7 m / h; the microaerobic zone of the facultative aerobic bioreactor is provided with suspended filler A (the volume of suspended filler A is 15% of the volume of the microaerobic zone), and the dissolved oxygen concentration in the microaerobic zone is within the range of 0.5 to 1.0 mg / L; the oxygen-limited zone is provided with filamentous filler B, which is fixed on the screen (every 10 cm 2 1 is set), its length is 2.8m; the dissolved oxygen concentration in the oxygen-limited zone is within the range of 0.1-0.2mg / L; the nitrogen produced by the facultative aerobic bioreactor can be discharged directly, and the effluent of the facultative aerobic bioreactor enters the subsequent water treatment system; the total nitrogen and ammonia nitrogen removal rates during the operation of the facultative aerobic bioreactor are shown in Figure 2. Figure 5 .

Claims

1. A biological treatment method for developer wastewater, characterized in that: Specifically, the dissolved photoresist in the developer wastewater is first removed through acid precipitation and flotation processes, and then the organic nitrogen in the developer wastewater is converted into ammonia nitrogen through an anaerobic biological process. In the anaerobic biological process, hydrogen-producing agents are added to enrich hydrogen-producing bacteria in the anaerobic bioreactor, inhibiting the growth of methanogens. Finally, the ammonia nitrogen in the developer wastewater is converted into nitrogen gas for discharge through an anaerobic biological process. The facultative biological process places the short-range nitrification process and the anaerobic ammonium oxidation process in the same reactor for autotrophic biological denitrification. The reactor of the facultative anaerobic biological process comprises a water distribution zone, a micro-aerobic zone, an oxygen-limited zone and a two-phase separation zone, wherein a screen is provided between the micro-aerobic zone and the oxygen-limited zone; the micro-aerobic zone is filled with a suspended filler A; and the preparation method of the suspended filler A comprises the following steps: (1) Modification of polyurethane sponge filler: The polyurethane sponge is added to a mixed solution of sulfuric acid, nitric acid and hydrogen peroxide and soaked. The polyurethane sponge is taken out after soaking and placed in an enzyme solution to remove the residual hydrogen peroxide. The polyurethane sponge is taken out after soaking and dried at room temperature to obtain a modified polyurethane sponge filler. (2) Sodium hyaluronate and chitosan are added to deionized water, stirred to obtain a mixed solution, and the pH of the mixed solution is adjusted to 8-9.5; polycarbodiimide and N-hydroxysuccinimide are added to the mixed solution for activation reaction, and aminocyclodextrin is added after the reaction, and the solution is rapidly stirred to form a supramolecular hydrogel aqueous solution; the modified polyurethane sponge filler is placed in the supramolecular hydrogel aqueous solution with a solid-liquid ratio of 1:3-4, and the solution is rapidly stirred to allow the supramolecular hydrogel to adhere to the inside of the modified polyurethane sponge filler, and the polyurethane sponge filler loaded with supramolecular hydrogel is obtained after freeze-drying; (3) Take a glucose oxidase aqueous solution with a mass concentration of 25-28%, adjust the pH of the glucose oxidase aqueous solution to 4-5, add the polyurethane sponge filler of step (2) with a solid-liquid ratio of 1:1-2, stir rapidly and dry at room temperature, and the glucose oxidase is embedded in the microporous structure of the supramolecular hydrogel under acidic conditions to form an immobilized slow-release enzyme group.

2. The biological treatment method for developer wastewater according to claim 1, wherein: In the anaerobic biological method, the developer waste liquid for removing the photoresist is pumped into the anaerobic bioreactor via a lifting pump. The developer waste liquid entering the anaerobic bioreactor has a temperature of 32-38°C. Disodium hydrogen phosphate, trace elements and a hydrogen-producing agent are added to the developer waste liquid. Anaerobic granular sludge is added to the anaerobic bioreactor in an amount of 22-25 g / L. The volumetric load of the anaerobic bioreactor is 6-9 kg TMAH / (m 3 d), with an upward flow rate of 4.5-7 m / h; the gas produced by the anaerobic bioreactor enters the carbonic acid absorption tank through the water seal tank, where the CO2 is removed and then enters the gas collection system. The effluent from the anaerobic bioreactor enters the facultative aerobic bioreactor for treatment.

3. The biological treatment method for developer wastewater according to claim 2, wherein: The dosage of sodium dihydrogen phosphate in the developer waste liquid is 0.4~0.5% of the mass of tetramethylammonium hydroxide in the waste liquid; each liter of trace elements includes 1000mgMgSO4·7H2O, 100mg / L NaCl, 100mg / L Na2MO4·2H2O, 100mg / L CaCl2·2H2O and 150mgMnSO4·7H2O, and the solvent is water; the dosage of trace elements is 0.5L / m 3 ; The dosage of hydrogen production agent is 1L / m 3 .

4. The biological treatment method for developer wastewater according to claim 2, wherein: Each liter of the hydrogen-producing agent includes 0.1 kg of nano-iron particles, 0.08 kg of Na2S, 0.16 kg of Na2S2O3, 0.2 kg of industrial caramel, 0.04 kg of starch and 0.12 kg of L-cysteine, and the solvent is water.

5. The biological treatment method for developer wastewater according to claim 4, characterized in that: The nano iron particles are prepared by the following method: adding ground siderite to sulfuric acid at a solid-liquid ratio of 1:8-10, stirring for reaction, and filtering; mixing the filtrate, water, and anhydrous methanol at a volume ratio of 1:0.5:1.3-1.7 to obtain a mixed solution; adding glycerol fatty acid ester to the mixed solution, with the dosage of glycerol fatty acid ester being 25-50 mg / L; then heating the solution to 45-60°C, adding hydrazine hydrate, continuously stirring, and filtering after stirring; repeatedly rinsing the filtered nano iron particles with water and anhydrous methanol, and then drying in an environment of 70-80°C to obtain nano iron particles with an average particle size of 40-100 nm.

6. The biological treatment method for developer wastewater according to claim 1, wherein: In the anaerobic biological method, the developing waste liquid treated by the anaerobic biological method is pumped into the anaerobic bioreactor via a lifting pump. The temperature of the developing waste liquid entering the anaerobic bioreactor is 30-35°C. Sodium carbonate and trace elements are added to the developing waste liquid. The pH of the developing waste liquid is adjusted to 7.7-8.5 by sodium carbonate. The dosage of the trace elements is 0.5L / m 3 ; Add short-cut nitrification granular sludge and anaerobic ammonium oxidation granular sludge into the facultative aerobic bioreactor, the amount of sludge added is 20~25g / L; the volume load of the facultative aerobic bioreactor is 0.9~1.4kg NH3-N / (m 3 d) External recirculation ratio of 40-70%, rising velocity of 3-7 m / h; nitrogen produced by the facultative aerobic bioreactor is directly discharged, and the effluent of the facultative aerobic bioreactor enters the subsequent biological system for deep treatment.

7. The biological treatment method for developer wastewater according to claim 1, wherein: An aeration port is provided at the bottom of the micro-aerobic zone, and the dissolved oxygen concentration in the micro-aerobic zone is 0.5-1.0 mg / L; short-range nitrifying bacteria are enriched on the suspended filler A; a filamentous filler B is provided in the oxygen-limited zone, and one end of the filamentous filler B is fixed to the barrier; four aeration ports are provided on the side wall of the oxygen-limited zone, and the dissolved oxygen concentration in the oxygen-limited zone is 0.1-0.2 mg / L. The micro-aerobic zone undergoes a short-range nitrification reaction, converting part of the ammonia nitrogen in the influent into nitrite nitrogen, thereby relieving the inhibition of high-concentration ammonia nitrogen on anaerobic ammonia-oxidizing bacteria; the oxygen-limited zone simultaneously undergoes a short-range nitrification reaction and an anaerobic ammonia oxidation reaction, converting nitrite nitrogen into nitrogen gas, thereby completing the removal of nitrogen-containing pollutants.

8. The biological treatment method for developer wastewater according to claim 7, characterized in that: The preparation method of the filamentous filler B specifically comprises the following steps: (1) Grinded chalcopyrite and siderite were mixed in a mass ratio of 1:1.26-1.44 and added to a mixture of sulfuric acid, nitric acid and acetic acid at a solid-liquid ratio of 1:8-12. After reaction, the mixture was filtered. The filtrate, oxalic acid, ethanol and triethanolamine were mixed in a volume ratio of 15:2:2:1, stirred rapidly and filtered to obtain a beige gel. The gel was washed and dried and then calcined at 350°C, 500°C and 850°C to obtain magnetic nano-copper iron particles. (2) Place the polyacrylonitrile fiber bundle in a hydroxylamine hydrochloride solution with a pH of 5-7, soak it, remove the fiber bundle, and dry it; add magnetic nano-copper iron particles into deionized water with a solid-liquid ratio of 1:10-15, then add the modified fiber bundle, and react at 80°C. After the reaction, remove the fiber bundle, wash it, and then calcine it at 200°C to fix the magnetic nano-copper iron particles on the fiber bundle to obtain filamentous filler B.

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