Method for treating high-ammonia-nitrogen wastewater in electronic industry

Abstract

The invention discloses a method for treating high-ammonia-nitrogen wastewater in the electronic industry, which can realize quick start of a short-cut nitrification system on one hand, and can synchronously realize half-quantity nitrosation of the high-ammonia-nitrogen wastewater and accumulation of low-concentration nitrate nitrogen on the other hand. According to the present invention, the ammonia nitrogen concentration of the system inlet water is 1200-1400 mg / L, such that the ratio of the outlet water ammonia nitrogen to the nitrite nitrogen can be rapidly achieved to be 0.9-1.1, and the nitrate nitrogen accumulation amount is less than 50 mg / L so as to provide the reaction substrate with the suitable concentration and the suitable ratio for the subsequent anaerobic ammonia oxidation treatment unit;

Description

Technical Field

[0001] The present invention relates to a method for treating high ammonia nitrogen wastewater in the electronics industry. Background Art

[0002] During the production process of the electronics industry, a large amount of high-concentration ammonia nitrogen wastewater is generated, and its main pollutants are ammonia nitrogen and hydrogen peroxide (both with a concentration of 1000 - 1500 mg / L). Currently, most of the high ammonia nitrogen wastewater in the electronics industry is treated by stripping and catalytic oxidation processes. Conventional stripping and catalytic processes have problems such as high operating costs, large consumption of chemical agents, easy generation of secondary pollution (generating a large amount of ammonium sulfate), and frequent replacement of rusted and caked equipment, which greatly increases the operation and maintenance costs. Since the high ammonia nitrogen wastewater only contains ammonia water and hydrogen peroxide and almost no organic matter exists, it is very suitable for autotrophic biological nitrogen removal processes. However, although the current short-cut nitrification-anaerobic ammonia oxidation process can achieve efficient treatment of high ammonia nitrogen wastewater under low energy consumption conditions, the growth rate of autotrophic microorganisms is slow and the system startup period is long, thus seriously affecting the stable operation of the whole plant wastewater system. Summary of the Invention

[0003] Object of the Invention: The object of the present invention is to provide a method for treating high ammonia nitrogen wastewater in the electronics industry, which can simultaneously achieve efficient removal of hydrogen peroxide and semi-quantitative nitrification of high-concentration ammonia nitrogen, and can quickly start the short-cut nitrification process and rapidly enter the stable operation stage.

[0004] Technical Solution: The method for treating high ammonia nitrogen wastewater in the electronics industry according to the present invention includes the following steps:

[0005] (1) Removal of H 2 O 2 : Add hydrogen peroxide catalase to the high ammonia nitrogen wastewater with a pH of 8.5 - 9.0. After the reaction, the wastewater enters the activated carbon filter, and the activated carbon filter deeply removes H 2 O 2 ;

[0006] (2) The water outlet of the activated carbon filter enters the inlet pool I, and inhibitor A, IPA, and trace elements are added to the inlet pool I; among them, inhibitor A is added intermittently, and the dosage per addition is 6 - 12 mg / L; it is added once every 1 day, and the addition time each time lasts for 32 - 36 min; the dosage of IPA (isopropanol) makes COD / NH 4 + -N be 0.8 - 1.0; the dosage of trace elements is 0.5 L / m 3 ;

[0007] (3) The water in the inlet pond I enters the reactor I, and the packing area of the reactor I is filled with modified bioactive packing; during the operation of the reactor I, it operates in the mode of reaction → rapid drainage → slow water inlet, and the ratio of the reaction time: drainage time: water inlet time of the reactor I is 1:1:3 - 3.5;

[0008] (4) The water discharged from the reactor I enters the reactor II. During the operation of the reactor II, inhibitor B and CaCl are added to it. 2 Among them, inhibitor B is a mixed solution of dimethyl sulfoxide (DMSO) and hydroxylamine. Inhibitor B is added intermittently. The dosage of DMSO each time is 7.5 - 10 mg / L, the dosage of hydroxylamine each time is 5 mg / L, and it is added once every 3 days, and the addition time each time lasts for 20 - 24 h; CaCl 2 is added continuously, and its dosage is 20 - 24 mg / L; the pH in the reactor II is 7.0 - 7.5, and the DO is 0.4 - 0.6 mg / L; after the reaction, the water discharged from the reactor II enters the subsequent anaerobic ammonium oxidation treatment unit.

[0009] Among them, in step (1), the hydrogen peroxide catalase is enzyme; the dosage of enzyme is m(enzyme):m(H 2 O 2 ) = 0.2 - 0.3, and stir and react for 45 - 60 min; after the reaction, the residual concentration of H 2 O 2 is less than 2 mg / L.

[0010] Among them, in step (2), the inhibitor A is paracetamol (APAP); the composition of the trace elements is: MgSO 4 ·7H 2 O 1000 mg / L, NaCl 100 mg / L, Na 2 MO 4 ·2H 2 O 100 mg / L and MnSO 4 ·7H 2 O 150 mg / L.

[0011] Among them, in step (3), the filling rate of the modified bioactive packing (the ratio of the volume of the added packing to the volume of the packing area) is 30 - 40%.

[0012] Among them, in step (3), the modified bioactive packing is prepared by the following method, and the specific steps are as follows:

[0013] (3.1) Modification of polyurethane sponge filler: The polyurethane sponge filler is modified with strong oxidizing substances to obtain a modified polyurethane sponge filler capable of adsorbing macromolecular substances. Through surface oxidation modification, the specific surface area and hydrophilicity of the sponge filler are increased, and the subsequent microbial attachment ability is enhanced.

[0014] (3.2) Immerse the modified polyurethane sponge filler in the mixed solution, take it out after immersion, and solidify it at room temperature to obtain the modified bioactive filler. Among them, the mixed solution is composed of PVA solution and activated sludge dispersion. The mixing volume ratio of the two is 1:3.5 - 4; the MLSS of the activated sludge is 2000 - 5000 mg / L.

[0015] Among them, the activated sludge dispersion is prepared by the following method: The residual sludge (solid content rate 1%) in Reactor II is over-aerated for 2 - 3 h at DO 7 - 8 mg / L, and the sludge flocs are disintegrated by the agitation of the gas and endogenous respiration. After the aeration ends, precipitate for 4 h; take the lower-layer activated sludge and mix it with the PVA solution.

[0016] Among them, the PVA solution is prepared by the following method: Mix PVA (polyvinyl alcohol) and deionized water in a mass ratio of 1:9, and then add a cross-linking agent (sodium alginate) accounting for 20% of the mass of PVA, and stir at 80 - 90 °C for 4 - 5 h to completely dissolve PVA, obtaining a PVA solution with a mass concentration of 10%. After cross-linking of PVA and sodium alginate, a biological carrier is formed. The PVA-sodium alginate cross-linking product is a biological carrier used to increase the microbial biomass on the polyurethane sponge, and it is mixed with activated sludge to form microbial pellets loaded on the polyurethane sponge.

[0017] Among them, in step (3), in each operation cycle, the ratio of reaction time: drainage time: influent time is 1:1:3.

[0018] Among them, in step (4), the influent and aeration are carried out at the bottom of Reactor II, and the effluent is discharged from the upper part. A stirrer is provided in Reactor II, and the hydraulic shear strength in Reactor II is 1200 - 1400 N / m2.

[0019] Among them, in steps (3) and (4), the internal temperature of Reactor I and Reactor II is 30 - 32 °C.

[0020] The present invention adopts a combined process of "enzymatic catalysis of hydrogen peroxide decomposition + shortcut nitrification". Hydrogen peroxide is efficiently removed through enzymatic reactions, and half - nitritation of high - ammonia - nitrogen wastewater is rapidly achieved under low - energy - consumption conditions through autotrophic biological reactions, effectively reducing the accumulation of nitrate nitrogen. The modified biological active filler of the present invention uses the AOB bacteria enriched in reactor II as the strain, and the raw materials for preparing the modified biological active filler are prepared by the embedding method (the sludge and PVA are cross - linked to form activated sludge pellets, which are used to provide stable AOB bacteria for the sponge filler). During the startup and operation of reactor I, the active filler slowly releases auto - inducers into the water, accelerating the synthesis and secretion of AOB EPS, improving the "passive" film - hanging speed of AOB bacteria, and enabling the AOB bacteria to quickly form a film. At the same time, the PVA carrier has a unique three - dimensional network structure with high porosity, creating a suitable growth environment for functional bacteria, quickly forming a biofilm, and shortening the reactor startup period. At the same time, reactor I operates in a mode of reaction → rapid drainage → slow water inlet. Without the need for aeration, an aerobic - anoxic alternating environment is created inside reactor I in a short time. An inhibitor A (paracetamol) is added to inlet pond I, and an intermittent dosing mode is adopted. Without affecting the activity of AOB, the activity of NOB is quickly inhibited, reducing the accumulation amount of nitrate nitrogen. Using organic waste liquid (IPA) as the organic carbon source, the DO concentration and C / N ratio (C / N ratio of 0.9 - 1.2) are both within the appropriate range, and the shortcut nitrification - denitrification reaction in reactor I can be quickly achieved. Part of the ammonia nitrogen is converted into nitrite nitrogen, and part of the nitrite nitrogen is converted into nitrogen gas, effectively relieving the inhibition of high - concentration ammonia nitrogen on the subsequent treatment unit. Reactor II further inhibits the activity of NOB by intermittently adding inhibitor B (a mixed solution of dimethyl sulfoxide and hydroxylamine), reducing the accumulation amount of nitrate nitrogen. Under the action of appropriate hydraulic shear strength and Ca 2+ Accelerate the sludge granulation process, and the flocculent sludge becomes granular sludge in a short time, greatly improving the sludge activity. Coupled with appropriate ammonia - nitrogen concentration, temperature and dissolved oxygen concentration, AOB is quickly enriched, realizing the rapid startup of the shortcut nitrification process in reactor II.

[0021] Beneficial effects: Compared with the prior art, the present invention has the following remarkable effects: On the one hand, the treatment method of the present invention can realize the rapid startup of the shortcut nitrification system, and on the other hand, it can simultaneously realize half - nitritation of high - ammonia - nitrogen wastewater and the accumulation of low - concentration nitrate nitrogen. For the system with an influent ammonia - nitrogen concentration of 1200 - 1400 mg / L, it can quickly achieve an effluent ammonia - nitrogen to nitrite - nitrogen ratio of 0.9 - 1.1, and the accumulation amount of nitrate nitrogen is less than 50 mg / L, providing a reaction substrate with an appropriate concentration and ratio for the subsequent anaerobic ammonium oxidation treatment unit. Brief Description of the Drawings

[0022] Figure 1 It is the process flow chart of the treatment method of the present invention;

[0023] Figure 2 Schematic structural diagram of the shortcut nitrification reactor I;

[0024] Figure 3 Schematic structural diagram of the shortcut nitrification reactor II. Detailed implementation manners

[0025] Example 1

[0026] The high ammonia nitrogen wastewater of a certain chip factory, with a water volume of 40 m 3 / d, and its water quality is as follows:

[0027] pH <![CDATA[NH 3 -N (mg / L)]]> TN (mg / L) <![CDATA[H 2 O 2 (mg / L)]]> TOC (mg / L) 10～11 1200～1400 1200～1400 500～1500 ＜10

[0028] As Figure 1 shown, the above high ammonia nitrogen wastewater is treated by the treatment method of the present invention, and the specific steps are as follows:

[0029] (1) pH adjustment: The high ammonia nitrogen wastewater enters the pH adjustment tank from the wastewater adjustment tank, and sulfuric acid is added to adjust the pH of the wastewater to 8.5 - 9.0; a relatively high influent pH can effectively save the usage amount of alkalinity substances in the shortcut nitrification process;

[0030] (2) H 2 O 2 removal: Enzyme (catalase) is added to the reaction tank, and the dosage of the enzyme is m(enzyme):m(H 2 O 2 ) = 0.25, and the reaction is stirred for 50 min; after the reaction, the residual concentration of H 2 O 2 is less than 2 mg / L;

[0031] (3) Activated carbon filtration: After the H 2 O 2 is removed in the reaction tank, the wastewater enters the activated carbon filter, and the activated carbon filter deeply removes the H 2 O 2 in the wastewater; the effluent H 2 O 2 of the activated carbon filter is not detected;

[0032] (4) Shortcut nitrification: The effluent of the activated carbon filter enters the inlet tank I (the effective volume of the inlet tank I is 20 m 3 ), and then enters the shortcut nitrification reactor I; inhibitor A, IPA and trace elements are added to the inlet tank I. Inhibitor A is added intermittently. Inhibitor A is acetaminophen (APAP), and the dosage per time is 10 mg / L, and it is added once every 1 day, and the dosing time for each dosing cycle is 32 - 36 min; IPA is taken from the IPA waste liquid in the factory, and according to COD / NH 4 +-N dosing in proportion, continuous dosing, so that the COD / NH 4 + -N ratio is 0.8 - 1.0; trace elements (the trace element composition is MgSO 4 ·7H 2 O 1000mg / L, NaCl 100mg / L, Na 2 MO 4 ·2H 2 O 100mg / L, MnSO 4 ·7H 2 O 150mg / L) dosing amount is 0.5L / m 3 , continuous dosing; the inlet pond I is equipped with heating pipes, and the shortcut nitrification reactor I is equipped with a heat preservation layer, controlling the temperature in the reactor I to be 30 - 32 °C;

[0033] As Figure 2 shown, the packing area of the reactor I is filled with modified bioactive packing, and the filling rate of the modified bioactive packing is 35% (the ratio of the packing volume to the packing area volume); the operation mode of the reactor I is reaction → rapid drainage → slow water inlet: rapidly drain water from the bottom of the reactor I until it is emptied, and drain the water to the inlet pond I; then spray water into the reactor I from the top, and the water inlet volume is 20m 3 / cycle; each operation cycle is 3h, and the reaction time: drainage time: water inlet time ratio of each operation cycle is 1:1:3; through the above operation mode, an aerobic - anoxic alternating environment can be created in the reactor I in a short time, so as to realize the rapid occurrence of shortcut nitrification and denitrification reactions, that is, part of the ammonia nitrogen is converted into nitrite nitrogen, and part of the nitrite nitrogen is converted into nitrogen; at the same time, by adding the inhibitor APAP of NOB, the nitrification reaction is inhibited, and the accumulation amount of nitrate nitrogen is reduced; the start - up period of the reactor I is 16d, at this time the ammonia nitrogen removal rate of the effluent is about 36%, the total nitrogen removal rate is about 16%, the nitrite nitrogen accumulation rate is about 20%, and the nitrate accumulation amount is less than 40mg / L;

[0034] The effluent of the shortcut nitrification reactor I enters the inlet pond II, and then enters the shortcut nitrification reactor II; the inlet pond II is equipped with heating pipes, and the reactor II is equipped with a heat preservation layer, controlling the internal temperature of the reactor II to be 30 - 32 °C; As Figure 3 shown, water enters and is aerated at the bottom of the reactor II, and water exits at the upper part, and a stirrer is installed in the reactor II; the hydraulic shear strength in the reactor II is 1400Pa;

[0035] During the operation of the reactor II, inhibitor B, Na 2 CO 3 and CaCl 2, Inhibitor B is a mixed solution of dimethyl sulfoxide (DMSO) and hydroxylamine. Inhibitor B is added intermittently. The dosage of DMSO each time is 10 mg / L, and the dosage of hydroxylamine each time is 5 mg / L. DMSO is taken from the in-plant DMSO waste liquid and added once every 3 days, and the addition time each time lasts for 24 h; Na 2 CO 3 Adjust the pH inside Reactor II to stabilize it within the range of 7.0 - 7.5; CaCl 2 The dosage is 24 mg / L and it is added continuously; the DO inside Reactor II is controlled within the range of 0.4 - 0.6 mg / L; by adding NOB inhibitors, NOB inhibition is quickly achieved, making the nitrification reaction inside Reactor II tend to stop and reducing the accumulation amount of nitrate nitrogen; under the action of appropriate hydraulic shear strength and Ca 2+ , the sludge granulation process is accelerated, the flocculent sludge becomes granular sludge in a short time, and the sludge activity is greatly improved; at the same time, under the appropriate influent ammonia nitrogen concentration (the ammonia nitrogen concentration of the effluent from Reactor I), temperature, and dissolved oxygen concentration, AOB is rapidly enriched, effectively realizing the rapid startup of the shortcut nitrification process; the startup period of Reactor II is 13 d. At this time, the accumulation amount of nitrate nitrogen in the effluent is less than 50 mg / L, and the ratio of ammonia nitrogen to nitrite nitrogen in the effluent is 0.9 - 1.1.

[0036] Among them, the modified bioactive filler is prepared by the following method:

[0037] (1.1) Modification of the polyurethane sponge filler: The main structure of the filler is a polyurethane cubic sponge filler with a side length of 3 - 5 mm; the sponge filler is added to a mixed solution of sulfuric acid, nitric acid, and hydrogen peroxide for soaking (the purpose of 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, making it easier for active substances to be loaded onto the polyurethane sponge filler); in the mixed solution, the mass concentration of sulfuric acid is 20%, the mass concentration of nitric acid is 15%, and the mass concentration of hydrogen peroxide is 6%; after soaking for 1 h, it is taken out, and then the sponge filler is placed in an enzyme solution to remove the residual hydrogen peroxide. In the enzyme solution, the mass concentration of the enzyme is 4.5%. After soaking for 0.5 h, it is taken out and dried at room temperature for 24 h to obtain a modified polyurethane sponge filler that can adsorb macromolecular substances;

[0038] (1.2) Mix PVA (polyvinyl alcohol) and deionized water in a mass ratio of 1:9, and then add a cross-linking agent (sodium alginate) accounting for 20% of the mass of PVA. Stir at 80 - 90 °C for 4 - 5 h to completely dissolve PVA, obtaining a 10% mass concentration PVA solution; Over-aerate the excess sludge (solid content 1%) in Reactor II for 2 - 3 h (DO is about 7 - 8 mg / L), use the agitation of gas and endogenous respiration to disintegrate the sludge flocs, precipitate for 4 h after aeration ends, take the lower layer of activated sludge and mix it with the 10% mass concentration PVA solution (the mixing volume ratio of the two is 1:3.5), and mix evenly at 30 - 40 °C to obtain a mixed solution; Place the modified polyurethane sponge filler in the mixed solution, take it out after 10 - 15 s, and solidify at room temperature for 3 - 4 h to obtain the modified bioactive filler.

[0039] Comparative Example 1

[0040] Compared with Example 1, the only difference in Comparative Example 1 is that a commercially available conventional biological filler (polyurethane composite filler, purchased from Suzhou Shuiliyang Environmental Technology Co., Ltd.) is selected and filled in Reactor I, and the remaining reaction conditions are the same. Specifically:

[0041] The high ammonia nitrogen wastewater from a certain chip factory has a water volume of 40 m 3 / d, and its water quality is as follows:

[0042] pH <![CDATA[NH 3 -N (mg / L)]]> TN (mg / L) <![CDATA[H 2 O 2 (mg / L)]]> TOC (mg / L) 10～11 1200～1400 1200～1400 500～1500 ＜10

[0043] The specific steps are as follows:

[0044] (1) pH adjustment: The high ammonia nitrogen wastewater enters the pH adjustment tank from the wastewater adjustment tank, and sulfuric acid is added to adjust the pH of the wastewater to 8.5 - 9.0;

[0045] (2) H 2 O 2 removal: Add enzyme (catalase) to the reaction tank, and the dosing amount of the enzyme is m(enzyme):m(H 2 O 2 ) = 0.25, stir and react for 50 min; After the reaction ends, the residual concentration of H 2 O 2 is less than 2 mg / L;

[0046] (3) Activated carbon filtration: After removing H 2 O 2 in the reaction tank, the wastewater enters the activated carbon filter, and the activated carbon filter deeply removes H 2 O 2 in the wastewater; The effluent of the activated carbon filter does not detect H 2 O 2 ;

[0047] (4) Shortcut nitrification: The effluent from the activated carbon filter enters the inlet pond I and then enters the shortcut nitrification reactor I; inhibitor A, IPA, and trace elements are added to the inlet pond I. Inhibitor A is added intermittently. Inhibitor A is paracetamol (APAP), and the dosage per addition is 10 mg / L. It is added once every 1 day, and the dosing time for each dosing cycle is 32 - 36 min; IPA is taken from the IPA waste liquid in the factory and dosed according to the COD / NH 4 + -N ratio, and is added continuously to make the COD / NH 4 + -N ratio 0.8 - 1.0; the dosage of trace elements (the trace element composition is MgSO 4 ·7H 2 O 1000 mg / L, NaCl 100 mg / L, Na 2 MO 4 ·2H 2 O 100 mg / L, MnSO 4 ·7H 2 O 150 mg / L) is 0.5 L / m 3 , and is added continuously; the inlet pond I is equipped with a heating pipeline, and the shortcut nitrification reactor I is equipped with a heat preservation layer, and the temperature inside the reactor I is controlled at 30 - 32 °C;

[0048] The packing area of the reactor I is filled with bioactive packing, and the filling rate of the bioactive packing is 35% (the ratio of the packing volume to the packing area volume); the operation mode of the reactor I is reaction → rapid drainage → slow water inlet: drain quickly from the bottom of the reactor I until it is emptied, and drain to the inlet pond I; then spray water into the reactor I from the top, and the water inflow is 20 m 3 / cycle; each operation cycle is 3 h, and the ratio of the reaction time: drainage time: water inlet time for each operation cycle is 1:1:3; the start-up period of the reactor I is 30 d, at this time the ammonia nitrogen removal rate of the effluent is about 25%, the total nitrogen removal rate is about 10%, the nitrite nitrogen accumulation rate is about 12%, and the nitrate accumulation amount is less than 80 mg / L;

[0049] The effluent from the shortcut nitrification reactor I enters the inlet pond II and then enters the shortcut nitrification reactor II; the inlet pond II is equipped with a heating pipeline, and the reactor II is equipped with a heat preservation layer, and the temperature inside the reactor II is controlled at 30 - 32 °C; the hydraulic shear strength inside the reactor II is 1400 Pa; during the operation of the reactor II, inhibitor B, Na 2 CO 3 and CaCl 2, Inhibitor B is a mixed solution of dimethyl sulfoxide (DMSO) and hydroxylamine. Inhibitor B is added intermittently. The dosage of DMSO each time is 10 mg / L, and the dosage of hydroxylamine each time is 5 mg / L. DMSO is taken from the in-plant DMSO waste liquid and added once every 3 days, with each addition lasting for 24 h; Na 2 CO 3 Adjust the pH inside Reactor II to be stable within the range of 7.0 - 7.5; CaCl 2 The dosage is 24 mg / L and it is added continuously; the DO inside Reactor II is controlled at 0.4 - 0.6 mg / L; the start-up period of Reactor II is 22 d. At this time, the accumulated amount of nitrate nitrogen in the effluent is less than 90 mg / L, and the ratio of ammonia nitrogen to nitrite nitrogen in the effluent is 0.8 - 1.1.

[0050] Comparative Example 2

[0051] Compared with Example 1, the only difference in Comparative Example 2 is that the operation mode of Reactor I is not reaction → rapid drainage → slow water inlet, but continuous water inlet (water inlet while draining). The ratio of reaction time: drainage time: water inlet time for each operation cycle is 3:0.5:0.5, and the other reaction conditions are the same. Specifically:

[0052] The high ammonia nitrogen wastewater from a chip factory has a water volume of 40 m 3 / d, and its water quality is as follows:

[0053] pH <![CDATA[NH 3 -N (mg / L)]]> TN (mg / L) <![CDATA[H 2 O 2 (mg / L)]]> TOC (mg / L) 10～11 1200～1400 1200～1400 500～1500 ＜10

[0054] The specific steps are as follows:

[0055] (1) pH adjustment: The high ammonia nitrogen wastewater enters the pH adjustment tank from the wastewater adjustment tank, and sulfuric acid is added to adjust the pH of the wastewater to 8.5 - 9.0;

[0056] (2) H 2 O 2 removal: Enzyme (catalase) is added to the reaction tank. The dosage ratio of enzyme is m(enzyme):m(H 2 O 2 ) = 0.25, and it is stirred and reacted for 50 min; after the reaction, the residual concentration of H 2 O 2 is less than 2 mg / L;

[0057] (3) Activated carbon filtration: After the H 2 O 2 is removed in the reaction tank, the wastewater enters the activated carbon filter, and the activated carbon filter deeply removes the H 2 O 2 in the wastewater; the H 2 O 2 is not detected in the effluent of the activated carbon filter;

[0058] (4) Short-cut nitrification: The effluent from the activated carbon filter enters the inlet pond I and then enters the short-cut nitrification reactor I; inhibitor A, IPA and trace elements are added to the inlet pond I. Inhibitor A is added intermittently. Inhibitor A is paracetamol (APAP), and the dosage per addition is 10 mg / L, added once every 1 day, and the dosing time for each dosing cycle is 32 - 36 min; IPA is taken from the IPA waste liquid in the factory and dosed according to the COD / NH 4 + -N ratio, added continuously to make the COD / NH 4 + -N ratio 0.8 - 1.0; the dosage of trace elements (the trace element composition is MgSO 4 ·7H 2 O 1000 mg / L, NaCl 100 mg / L, Na 2 MO 4 ·2H 2 O 100 mg / L, MnSO 4 ·7H 2 O 150 mg / L) is 0.5 L / m 3 , added continuously; the inlet pond I is equipped with a heating pipeline, and the short-cut nitrification reactor I is equipped with a heat preservation layer, controlling the temperature in the reactor I to be 30 - 32 °C;

[0059] The packing area of the reactor I is filled with modified bioactive packing, and the filling rate of the modified bioactive packing is 35% (the ratio of the packing volume to the packing area volume); the operation mode of the reactor I is: continuous water inlet, and the ratio of the reaction time: drainage time: water inlet time for each operation cycle is 3:0.5:0.5, and the water inlet volume is 20 m 3 / cycle; each operation cycle is 3 h, the start-up period of the reactor I is 35 d, at this time the ammonia nitrogen removal rate of the effluent is about 19%, the total nitrogen removal rate is about 6%, the nitrite nitrogen accumulation rate is about 8%, and the nitrate accumulation amount is less than 100 mg / L;

[0060] The effluent from the short-cut nitrification reactor I enters the inlet pond II and then enters the short-cut nitrification reactor II; the inlet pond II is equipped with a heating pipeline, and the reactor II is equipped with a heat preservation layer, controlling the internal temperature of the reactor II to be 30 - 32 °C; the hydraulic shear strength in the reactor II is 1400 Pa; during the operation of the reactor II, inhibitor B, Na 2 CO 3 and CaCl 2, Inhibitor B is a mixed solution of dimethyl sulfoxide (DMSO) and hydroxylamine. Inhibitor B is added intermittently. The dosage of DMSO each time is 10 mg / L, and the dosage of hydroxylamine each time is 5 mg / L. DMSO is taken from the in-plant DMSO waste liquid and is added once every 3 days, with each addition lasting for 24 hours; Na 2 CO 3 Adjust the pH inside Reactor II to make it stable within the range of 7.0 - 7.5; CaCl 2 The dosage is 24 mg / L and it is added continuously; the DO inside Reactor II is controlled at 0.4 - 0.6 mg / L; the start-up period of Reactor II is 24 days. At this time, the accumulated amount of nitrate nitrogen in the effluent is about 120 mg / L, and the ratio of ammonia nitrogen to nitrite nitrogen in the effluent is 1.3 - 1.5.

[0061] Comparative Example 3

[0062] Compared with Example 1, the only difference in Comparative Example 3 is that calcium chloride is not continuously added and there is no stirring device in Reactor II, and the other reaction conditions are the same. Specifically:

[0063] The high ammonia-nitrogen wastewater from a certain chip factory has a flow rate of 40 m 3 / d, and its water quality is as follows:

[0064] pH <![CDATA[NH 3 -N (mg / L)]]> TN (mg / L) <![CDATA[H 2 O 2 (mg / L)]]> TOC (mg / L) 10～11 1200～1400 1200～1400 500～1500 ＜10

[0065] The specific steps are as follows:

[0066] (1) pH adjustment: The high ammonia-nitrogen wastewater enters the pH adjustment tank from the wastewater adjustment tank, and sulfuric acid is added to adjust the pH of the wastewater to 8.5 - 9.0;

[0067] (2) H 2 O 2 removal: Enzyme (catalase) is added to the reaction tank. The dosage of the enzyme is m(enzyme):m(H 2 O 2 ) = 0.25, and it is stirred and reacted for 50 minutes; after the reaction ends, the residual concentration of H 2 O 2 is less than 2 mg / L;

[0068] (3) Activated carbon filtration: After H 2 O 2 is removed in the reaction tank, the wastewater enters the activated carbon filter, and the activated carbon filter deeply removes H 2 O 2 in the wastewater; the effluent of the activated carbon filter does not detect H 2 O 2 ;

[0069] (4) Short-cut nitrification: The effluent from the activated carbon filter enters the inlet tank I and then enters the short-cut nitrification reactor I; inhibitor A, IPA, and trace elements are added to the inlet tank I. Inhibitor A is added intermittently. Inhibitor A is acetaminophen (APAP), and the dosage per addition is 10 mg / L, added once every 1 day, and the dosing time for each dosing cycle is 32 - 36 min; IPA is taken from the in-plant IPA waste liquid, dosed according to the COD / NH 4 + -N ratio, added continuously to make the COD / NH 4 + -N ratio 0.8 - 1.0; the dosage of trace elements (the trace element composition is MgSO 4 ·7H 2 O 1000 mg / L, NaCl 100 mg / L, Na 2 MO 4 ·2H 2 O 100 mg / L, MnSO 4 ·7H 2 O 150 mg / L) is 0.5 L / m 3 , added continuously; the inlet tank I is equipped with a heating pipeline, and the short-cut nitrification reactor I is equipped with a heat preservation layer, controlling the temperature inside the reactor I to be 30 - 32 °C;

[0070] The packing area of the reactor I is filled with bioactive packing, and the filling rate of the bioactive packing is 35% (the ratio of the packing volume to the packing area volume); the operation mode of the reactor I is reaction → rapid drainage → slow water inlet: rapidly drain water from the bottom of the reactor I until it is emptied, and drain the water to the inlet tank I; then spray water into the reactor I from the top, and the water inflow is 20 m 3 / cycle; each operation cycle is 3 h, and the ratio of the reaction time: drainage time: water inlet time for each operation cycle is 1:1:3; the start-up period of the reactor I is 16 d, at this time the ammonia nitrogen removal rate of the effluent is about 36%, the total nitrogen removal rate is about 16%, the nitrite nitrogen accumulation rate is about 20%, and the nitrate accumulation amount is less than 40 mg / L;

[0071] The effluent from the short-cut nitrification reactor I enters the inlet tank II and then enters the short-cut nitrification reactor II; the inlet tank II is equipped with a heating pipeline, and the reactor II is equipped with a heat preservation layer, controlling the internal temperature of the reactor II to be 30 - 32 °C; during the operation of the reactor II, inhibitor B and Na 2 CO 3 are added. Inhibitor B is a mixed solution of dimethyl sulfoxide (DMSO) and hydroxylamine. Inhibitor B is added intermittently. The dosage of DMSO per addition is 10 mg / L, and the dosage of hydroxylamine per addition is 5 mg / L. DMSO is taken from the in-plant DMSO waste liquid, added once every 3 days, and the dosing time for each addition lasts for 24 h; Na 2 CO3 Adjust the pH inside Reactor II to stabilize it within the range of 7.0 - 7.5; control the DO inside Reactor II at 0.4 - 0.6 mg / L; the start-up period of Reactor II is 25 days. At this time, the accumulated amount of nitrate nitrogen in the effluent is about 150 mg / L, and the ratio of ammonia nitrogen to nitrite nitrogen in the effluent is 1.6 - 1.8.

Claims

1. A method for treating high-ammonia nitrogen wastewater in the electronics industry, characterized in that: The steps include: (1) Removal of H2O2: Hydrogen peroxide catalytic decomposition enzyme is added to high ammonia nitrogen wastewater, and after the reaction, the wastewater enters the activated carbon filter; (2) The effluent from the activated carbon filter enters the water inlet pool I, and inhibitor A, IPA and trace elements are added to the water inlet pool I; inhibitor A is added intermittently, and the dosage each time is 6-12 mg / L; the dosage of IPA is such that COD / NH4 + -N is 0.8~1.0; the dosage of trace elements is 0.5~0.6L / m 3 ; (3) The water from the water inlet pool I enters the reactor I, and the filler area of ​​the reactor I is filled with modified biologically active fillers; during the operation of the reactor I, the reaction → fast drainage → slow water inlet mode is adopted, and the ratio of the reaction time of the reactor I: drainage time: water inlet time is 1:1:3-3.5; (4) The effluent from reactor I enters reactor II. During the operation of reactor II, inhibitor B and CaCl2 are added thereto. Inhibitor B is a mixed solution of DMSO and hydroxylamine. Inhibitor B is added intermittently, and the dosage of DMSO and hydroxylamine is 7.5-10 mg / L and 5-5.5 mg / L respectively. CaCl2 is added continuously to ensure that the dosage is 20-24 mg / L. The pH in reactor II is 7.0-7.5, and the DO is 0.4-0.6 mg / L. After the reaction, the effluent from reactor II enters the subsequent anaerobic ammonia oxidation treatment unit.

2. The processing method according to claim 1, characterized in that: In step (1), the pH of the high ammonia nitrogen wastewater is 8.5-9.

0.

3. The processing method according to claim 1, characterized in that: In step (1), the hydrogen peroxide catalytic decomposition enzyme is an enzyme; the dosage of the enzyme is m(enzyme):m(H2O2)=0.2-0.3, and the reaction is stirred for 45-60 minutes.

4. The processing method according to claim 1, characterized in that: In step (2), the inhibitor A is acetaminophen; the trace elements are composed of: MgSO4·7H2O 1000-1200 mg / L, NaCl 100-110 mg / L, Na2MO4·2H2O 100-105 mg / L and MnSO4·7H2O 150-155 mg / L.

5. The processing method according to claim 1, characterized in that: In step (3), the filling amount of the modified bioactive filler is 30-40% of the volume of the filler area.

6. The processing method according to claim 5, characterized in that: The modified bioactive filler is prepared by the following method, and the specific steps are as follows: (3.1) Modification of polyurethane sponge filler: The polyurethane sponge filler is modified by using a strong oxidizing substance to obtain a modified polyurethane sponge filler capable of adsorbing macromolecular substances; (3.2) The modified polyurethane sponge filler is immersed in the mixed solution, taken out after immersion, and solidified at room temperature to obtain a modified biologically active filler; wherein the mixed solution is composed of a PVA solution and an activated sludge dispersion; the mixed volume ratio of the two is 1:3.5-4; and the MLSS of the activated sludge is 2000-5000 mg / L.

7. The processing method according to claim 6, characterized in that: The activated sludge dispersion is prepared by the following method: the residual sludge in the reactor II is over-aerated at DO 7-8 mg / L for 2-3 hours, and then settled for 4 hours after the aeration is completed; the lower layer of activated sludge is taken and mixed with the PVA solution; wherein the solid content of the residual sludge is not higher than 1%.

8. The processing method according to claim 6, characterized in that: The PVA solution is prepared by the following method: PVA and deionized water are mixed in a mass ratio of 1:9-10, and a cross-linking agent of 20-25% of the mass of PVA is added thereto, and the mixture is stirred at 80-90° C. for 4-5 hours to completely dissolve the PVA, thereby obtaining a PVA solution.

9. The processing method according to claim 1, characterized in that: In step (4), water enters and is aerated at the bottom of the reactor II, and water is discharged from the top. A stirrer is provided in the reactor II, and the hydraulic shear strength in the reactor II is 1200 to 1400 N / m2.

10. The processing method according to claim 1, characterized in that: In steps (3) and (4), the internal temperature of reactor I and reactor II is 30-32°C.

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