Diacetylmonoxime sewage pretreatment method

Abstract

The invention belongs to the technical field of sewage treatment, and particularly relates to a diacetylmonoxime sewage pretreatment method. The diacetylmonoxime sewage pretreatment method comprises the following steps: (1) adjusting diacetylmonoxime sewage to be acidic, and carrying out distillation treatment under a vacuum condition; (2) adding an oxidizing agent into the distillation raffinate, and carrying out an oxidation reaction; and (3) adjusting the reaction liquid obtained in the step (2) to be alkaline, and adding an oxidation phosphorus removal agent to carry out nitrogen and phosphorus removal treatment. The diacetylmonoxime sewage pretreatment method has the beneficial effects that the adopted chemicals are simple and easy to obtain, the cost is low, the follow-up treatment difficulty is small, no sludge is generated, and secondary pollution to the environment is avoided; according to the diacetylmonoxime sewage pretreatment method, butanone and diacetylmonoxime in sewage can be fully recycled, automatic control can be achieved in the whole process, resource waste is avoided, the operation difficulty is reduced, the adding amount of raw materials can be adjusted in real time according to indexes, and the fluctuation resistance is high.

Description

Technical Field

[0001] The present invention belongs to the technical field of sewage treatment, and particularly relates to a method for pretreatment of butanone oxime sewage. Background Art

[0002] Butanone oxime sewage has various harms to the environment and organisms. Butanone oxime sewage is difficult to degrade in the environment, will cause long-term pollution to water bodies, and this kind of sewage may have toxic effects on aquatic organisms, resulting in the death or growth inhibition of aquatic organisms. In addition, butanone oxime sewage may also accumulate through the food chain and ultimately affect human health.

[0003] At present, the pretreatment method of butanone oxime sewage is mainly improved on the basis of Fenton reaction plus biochemical reaction, and a large amount of chemical reagents (such as sulfuric acid, ferrous sulfate, iron-carbon, activated carbon, etc.) need to be added. The addition of a large amount of chemical reagents will result in high sewage treatment costs, complex operations, and weak anti-fluctuation ability; at the same time, due to the large amount of chemical reagents contained in the sewage, there is more sludge after sewage treatment, and the subsequent sludge treatment is difficult.

[0004] The present invention discloses a simple and low-cost pretreatment technology for butanone oxime sewage. After adjusting the pH of the sewage to 2-4 with hydrochloric acid, hydrolysis distillation is carried out to recover butanone and butanone oxime in the wastewater, and then sodium hypochlorite is added to oxidize hydroxylamine in the sewage; finally, by adding liquid alkali, sodium hypochlorite and phosphorus remover, neutralization, phosphorus removal and oxidation are carried out to remove total phosphorus, ammonia nitrogen and cyanide in the sewage. After novelty search, no patent application for a similar pretreatment method of butanone oxime sewage has been found. Summary of the Invention

[0005] The present application provides a method for treating butanone oxime sewage, aiming to solve the problems of difficult treatment and high cost of butanone oxime sewage treatment in the prior art.

[0006] The present application provides a method for pretreatment of butanone oxime sewage, including the following steps:

[0007] (1) Adjust the butanone oxime sewage to acidic and carry out distillation treatment under vacuum conditions;

[0008] (2) Add an oxidant to the distillation residue and carry out an oxidation reaction;

[0009] (3) Adjust the reaction solution obtained in step (2) to alkaline and add an oxidation phosphorus remover for denitrification and phosphorus removal treatment.

[0010] According to some embodiments of the butanone oxime sewage treatment method described in the present application, in step (1), the acidic adjustment reagent for adjusting the butanone oxime sewage includes one or more of sulfuric acid, hydrochloric acid, phosphoric acid and oxalic acid.

[0011] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, the acidic adjusting reagent for adjusting the methyl ethyl ketoxime sewage is hydrochloric acid; more preferably, the mass concentration of the hydrochloric acid is 10%-20%.

[0012] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, the pH value of the methyl ethyl ketoxime sewage is adjusted to 2-4.

[0013] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, in step (1), the temperature of the distillation is 75-85°C, and the time of the distillation is 15-30 min.

[0014] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, the vacuum degree of the distillation is -10 Kpa to -20 Kpa.

[0015] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, in step (2), the oxidant includes hydrogen peroxide and / or sodium hypochlorite.

[0016] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, the addition amount of the oxidant in each liter of the distillation residue is 0.5-2 g.

[0017] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, the oxidant includes an aqueous solution of sodium hypochlorite with a mass fraction of 10%-15% or hydrogen peroxide with a mass fraction of 27%-40%.

[0018] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, in step (2), the temperature of the oxidation reaction is 60-70°C, and the time of the oxidation reaction is 100-150 min.

[0019] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, the adjusting reagents for adjusting the reaction solution to be alkaline include sodium hydroxide and / or potassium hydroxide.

[0020] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, the adjusting reagents for adjusting the reaction solution to be alkaline include a sodium hydroxide solution with a mass concentration of 10%-40%.

[0021] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, the pH of the reaction solution is adjusted to 8-10.

[0022] According to some embodiments of the method for treating methyl ethyl ketoxime sewage of the present application, the oxidation dephosphorization agent includes sodium hypochlorite and a calcium ion salt.

[0023] According to some embodiments of the method for treating methyl ethyl ketoxime sewage described in the present application, the calcium ion-containing salt includes calcium chloride and / or calcium hydroxide.

[0024] According to some embodiments of the method for treating methyl ethyl ketoxime sewage described in the present application, the mass ratio of sodium hypochlorite to calcium ion-containing salt in the phosphorus removal oxidant is (0.1 - 1):(0.1 - 1).

[0025] According to some embodiments of the method for treating methyl ethyl ketoxime sewage described in the present application, the addition amount of the phosphorus removal oxidant in each liter of the reaction solution is 0.8 - 3 g.

[0026] According to some embodiments of the method for treating methyl ethyl ketoxime sewage described in the present application, the pretreatment method of methyl ethyl ketoxime sewage further includes passing the reaction solution containing the phosphorus removal oxidant into an iron-carbon bed for decarbonization and phosphorus removal treatment.

[0027] According to some embodiments of the method for treating methyl ethyl ketoxime sewage described in the present application, in step (3), the temperature of the denitrification and phosphorus removal treatment is 20 - 30 °C, and the time of the denitrification and phosphorus removal treatment is 30 - 60 min.

[0028] The beneficial effects of the present application include: The medicaments used in the pretreatment method of methyl ethyl ketoxime sewage described in the present application are simple to obtain, low in cost, easy to treat in the subsequent process, without sludge generation, and will not cause secondary pollution to the environment.

[0029] The pretreatment method of methyl ethyl ketoxime sewage described in the present application can fully recover methyl ethyl ketone and methyl ethyl ketoxime in the sewage, and can realize automatic control throughout the process, avoiding waste of resources, reducing the operation difficulty, and can adjust the addition amount of raw materials in real time according to the indicators, with strong anti-fluctuation ability.

[0030] The pretreatment method of methyl ethyl ketoxime sewage described in the present application can simultaneously remove cyanide while removing total nitrogen, total phosphorus and COD. Specific Embodiments

[0031] The embodiments of the present invention are described in detail below. The examples of the embodiments are exemplary and are intended to explain the present invention, but should not be construed as limiting the present invention.

[0032] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples", etc., mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic descriptions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0033] An embodiment of the present application provides a method for pretreating methyl ethyl ketoxime sewage, comprising the following steps:

[0034] (1) Adjust the methyl ethyl ketoxime sewage to acidic and perform distillation treatment under vacuum conditions;

[0035] (2) Add an oxidant to the distillation residue and perform an oxidation reaction;

[0036] (3) Adjust the reaction solution obtained in step (2) to alkaline and add an oxidation phosphorus removal agent for denitrification and phosphorus removal treatment.

[0037] The method described in the present application adopts the method of hydrolysis distillation to recover methyl ethyl ketone and methyl ethyl ketoxime in methyl ethyl ketoxime sewage. The methyl ethyl ketoxime molecule undergoes a hydrolysis reaction with water in an acidic environment. During the hydrolysis process, the methyl ethyl ketoxime molecule is first protonated, and the protonated methyl ethyl ketoxime will undergo a nucleophilic substitution reaction with water molecules. After hydrolysis, methyl ethyl ketone and methyl ethyl ketoxime are distilled out and recovered by condensation for reuse, and at the same time, the purpose of reducing the COD in the sewage is achieved.

[0038] In some embodiments of the present application, in step (1), the acidic adjustment reagent for adjusting the methyl ethyl ketoxime sewage includes one or more of sulfuric acid, hydrochloric acid, phosphoric acid, and oxalic acid.

[0039] In some embodiments of the present application, the acidic adjustment reagent for adjusting the methyl ethyl ketoxime sewage is hydrochloric acid. Hydrochloric acid is cheap, easy to obtain, and the amount of sludge generated subsequently is small.

[0040] In some embodiments of the present application, the mass concentration of the hydrochloric acid is 10% - 20%, such as 10%, 12%, 16%, 18%, 20%, etc.

[0041] In some embodiments of the present application, the pH value of the methyl ethyl ketoxime sewage is adjusted to 2 - 4, such as pH = 2, pH = 3, pH = 4, etc.

[0042] In some embodiments of the present application, in step (1), the temperature of the distillation is 75 - 85 °C, such as 75 °C, 80 °C, 82 °C, 85 °C, etc., and the time of the distillation is 15 - 30 min, such as 15 min, 18 min, 20 min, 30 min, etc.

[0043] In some embodiments of the present application, the vacuum degree of the distillation is -10 Kpa to -20 Kpa, such as -10 Kpa, -12 Kpa, -15 Kpa, -18 Kpa, -20 Kpa, etc.

[0044] In some embodiments of the present application, in step (2), the oxidant includes hydrogen peroxide and / or sodium hypochlorite.

[0045] In some embodiments of the present application, the addition amount of the oxidant in each liter of the distillation residue liquid is 0.5 - 2 g, such as 0.5 g, 0.8 g, 1.2 g, 1.5 g, 1.8 g, 2 g, etc.

[0046] In some embodiments of the present application, the oxidant includes an aqueous solution of sodium hypochlorite with a mass fraction of 10% - 15% or hydrogen peroxide with a mass fraction of 27% - 40%. Sodium hypochlorite decomposes to generate hypochlorite ions, which can break the organic matter chains such as long-chain macromolecules or benzene rings in water to form small molecule substances. Then, under the action of iron-carbon microelectrolysis, the wastewater is electrolyzed. This oxidation treatment method can improve the B / C ratio of the sewage and is more conducive to the subsequent biochemical treatment of the sewage.

[0047] In some embodiments of the present application, in step (2), the temperature of the oxidation reaction is 60 - 70 °C, such as 60 °C, 65 °C, 70 °C, etc., and the time of the oxidation reaction is 100 - 150 min, such as 100 min, 120 min, 130 min, 140 min, 150 min, etc.

[0048] In some embodiments of the present application, the adjusting reagent for adjusting the reaction solution to be alkaline includes sodium hydroxide and / or potassium hydroxide.

[0049] In some embodiments of the present application, the adjusting reagent for adjusting the reaction solution to be alkaline includes a sodium hydroxide solution with a mass concentration of 10% - 40%.

[0050] In some embodiments of the present application, the pH of the reaction solution is adjusted to 8 - 10, such as pH = 8, pH = 9, pH = 10, etc.

[0051] In some embodiments of the present application, the phosphorus removal oxidant includes sodium hypochlorite and a calcium ion salt.

[0052] In some embodiments of the present application, the calcium ion salt includes calcium chloride and / or calcium hydroxide.

[0053] In some embodiments of the present application, the mass ratio of sodium hypochlorite to calcium ion salt in the phosphorus removal oxidant is (0.1 - 1):(0.1 - 1). Sodium hypochlorite is a strong oxidant that can undergo an oxidation reaction with the organic matter in sewage, decomposing it into small molecule substances or inorganic substances, thereby reducing the chemical oxygen demand (COD) in sewage. The dosing ratio of sodium hypochlorite to sewage is calculated based on the reaction of hypochlorite ion (ClO-) with macromolecular organic matter in a ratio of 1:1 and maintaining an appropriate excess of hypochlorite ion.

[0054] In some embodiments of the present application, the dosage of the phosphorus removal oxidant added to each liter of the reaction solution is 0.8 - 3 g, such as 0.8 g, 1.2 g, 1.5 g, 2.6 g, 3 g, etc.

[0055] In some embodiments of the present application, the method for pre - treating methyl ethyl ketoxime sewage further includes passing the reaction solution containing the phosphorus removal oxidant through an iron - carbon bed for decarbonization and phosphorus removal treatment. The iron - carbon micro - electrolysis technology is an ideal process for treating high - concentration organic wastewater at present, also known as the internal electrolysis method. Without power supply, it uses the potential difference between "iron + carbon + catalytic element + coupling element" in the micro - electrolysis materials filled in the wastewater to electrolyze the wastewater to degrade organic pollutants. When the system is filled with water, numerous micro - battery systems will be formed inside the equipment, constituting an electric field in its working space. The newly generated [H], Fe 2+ etc. in the treatment process can undergo oxidation - reduction reactions with many components in the wastewater. For example, they can destroy the chromophore or auxochrome group of the colored substances in the colored wastewater, essentially breaking the chain to achieve the effect of degradation and decolorization; the generated Fe 2+ is further oxidized to Fe 3+ , and their hydrates have strong adsorption - flocculation activity. Especially after adding alkali to adjust the pH value, ferrous hydroxide and ferric hydroxide colloid flocculants are formed. Their adsorption capacity is much higher than that of the ferric hydroxide colloid obtained by the hydrolysis of general agents, and they can adsorb a large number of tiny particles, metal particles, and organic macromolecules dispersed in water. Its working principle is based on the combined action of electrochemistry, oxidation - reduction, physical adsorption, and flocculation precipitation to treat wastewater. This process can greatly reduce the COD and chromaticity when used to treat refractory high - concentration wastewater, improve the biodegradability of the wastewater, and at the same time has a good effect on the removal of ammonia nitrogen.

[0056] In some embodiments of the present application, in step (3), the temperature of the denitrification and phosphorus removal treatment is 20 - 30 °C, and the time of the denitrification and phosphorus removal treatment is 30 - 60 min, such as 30 min, 35 min, 40 min, 46 min, 50 min, 55 min, 60 min, etc.

[0057] The technical solution of the present application will be further described below with specific embodiments.

[0058] In the examples of the present application, the 10% sodium hypochlorite aqueous solution, the 20% hydrochloric acid and the 32% sodium hydroxide were purchased from the electrochemical plant of Juhua Group Co., Ltd.; the phosphorus removal agent was purchased from the patented product of Quzhou Juhua Nylon Co., Ltd.

[0059] Example 1

[0060] A method for pretreating butanone oxime wastewater comprises the following steps:

[0061] (1) Take 1000 ml of butanone oxime wastewater and analyze the butanone oxime, butanone, COD, ammonia nitrogen, TN, CN in the butanone oxime wastewater. - and TP content (the results are shown in Table 1). The pH of the butanone oxime wastewater was adjusted to 2 with 20% hydrochloric acid by mass, and then the butanone oxime wastewater was vacuum distilled for 30 minutes at a temperature of 85°C and a vacuum degree of -10Kpa to recover the fractions of butanone and butanone oxime;

[0062] (2) adding a 10% sodium hypochlorite aqueous solution to the distillation residue in an amount of 1.2 g of sodium hypochlorite per liter of distillation residue, and performing an oxidation reaction at a temperature of 60° C. for 100 min;

[0063] (3) Adding a 32% sodium hydroxide solution to the reaction solution obtained in step (2) to adjust the pH to 8, then adding a 10% sodium hypochlorite aqueous solution and a dephosphorizing agent calcium chloride, wherein the amount of sodium hypochlorite added is 1 g per liter of the reaction solution, and the amount of the dephosphorizing agent added is 1 g per liter of the reaction solution, and then passing the reaction solution containing the oxidizing dephosphorizing agent into an iron-carbon bed for precipitation at a temperature of 25° C. for 30 minutes, and analyzing the butanone oxime, butanone, COD, ammonia nitrogen, TN, CN in the wastewater. - and TP content (the results are shown in Table 1), and transported to the sewage treatment plant for deep treatment.

[0064] Example 2

[0065] The butanone oxime wastewater pretreatment method described in Example 2 is different from that in Example 1 only in that the butanone oxime wastewater pretreatment method described in Example 2 uses the oxidant hydrogen peroxide instead of sodium hypochlorite.

[0066] The specific steps include:

[0067] (1) Take 1000 ml of butanone oxime wastewater and analyze the butanone oxime, butanone, COD, ammonia nitrogen, TN, CN in the butanone oxime wastewater. -The content of butanone oxime, butanone, COD, ammonia nitrogen, TN, CN⁻ and TP (the results are shown in Table 1). Adjust the pH of the butanone oxime sewage to 2 with 20% hydrochloric acid by mass fraction, and then vacuum distill the butanone oxime sewage for 30 min under the conditions of a temperature of 85 °C and a vacuum degree of -10 KPa to recover the distillate fractions of butanone and butanone oxime;

[0068] (2) Add an aqueous hydrogen peroxide solution with a mass fraction of 35% to the distillation residue, and add it in an amount of 3.43 hydrogen peroxide per liter of the distillation residue. Under the condition of a temperature of 60 °C, carry out an oxidation reaction for 100 min;

[0069] (3) Add a sodium hydroxide solution with a mass fraction of 32% to the reaction solution obtained in step (2) to adjust its pH to 8, and then add an aqueous sodium hypochlorite solution with a mass fraction of 10% and a phosphorus removal agent calcium chloride. Add them according to the addition amount of 1 g of sodium hypochlorite per liter of the reaction solution and the addition amount of 1 g of the phosphorus removal agent per liter of the reaction solution. Then, pass the reaction solution containing the oxidation and phosphorus removal agent through an iron-carbon bed and precipitate for 30 min at a temperature of 25 °C, and analyze the content of butanone oxime, butanone, COD, ammonia nitrogen, TN, CN⁻ - and TP (the results are shown in Table 1), and transport it to a sewage treatment plant for advanced treatment.

[0070] Example 3

[0071] The difference between the butanone oxime sewage pretreatment method described in Example 3 and that in Example 1 is only that: the pH of the butanone oxime sewage is adjusted to 4 in the butanone oxime sewage pretreatment method described in Example 3.

[0072] The specific operation steps include:

[0073] (1) Take 1000 ml of butanone oxime sewage, analyze the content of butanone oxime, butanone, COD, ammonia nitrogen, TN, CN⁻ and TP in the above butanone oxime sewage (the results are shown in Table 1). Adjust the pH of the butanone oxime sewage to 4 with 20% hydrochloric acid by mass fraction, and then vacuum distill the butanone oxime sewage for 30 min under the conditions of a temperature of 85 °C and a vacuum degree of -10 KPa to recover the distillate fractions of butanone and butanone oxime;

[0074] (2) Add an aqueous sodium hypochlorite solution with a mass fraction of 10% to the distillation residue, and add it in an amount of 1.2 g of sodium hypochlorite per liter of the distillation residue. Under the condition of a temperature of 60 °C, carry out an oxidation reaction for 100 min;

[0075] (3) Add a sodium hydroxide solution with a mass fraction of 32% to the reaction solution obtained in step (2) to adjust its pH to 8, then add a sodium hypochlorite aqueous solution with a mass fraction of 10% and a phosphorus removal agent calcium chloride. Add them according to the addition amount of 1 g of sodium hypochlorite per liter of the reaction solution and the addition amount of 1 g of the phosphorus removal agent per liter of the reaction solution. Then, pass the reaction solution containing the oxidation phosphorus removal agent through an iron-carbon bed and precipitate for 30 min at a temperature of 25°C. Analyze the contents of butanone oxime, butanone, COD, ammonia nitrogen, TN, CN⁻, and TP in the sewage (the results are shown in Table 1), and transport it to a sewage treatment plant for advanced treatment.

[0076] Example 4

[0077] The difference between the butanone oxime sewage pretreatment method described in Example 4 and that in Example 1 is only that: the butanone oxime sewage pretreatment method described in Example 4 adjusts the pH of the butanone oxime sewage to 5.

[0078] The specific operation steps include:

[0079] (1) Take 1000 ml of butanone oxime sewage, analyze the contents of butanone oxime, butanone, COD, ammonia nitrogen, TN, CN⁻, and TP in the above butanone oxime sewage (the results are shown in Table 1). Adjust the pH of the butanone oxime sewage to 5 with a hydrochloric acid solution with a mass fraction of 20%. Then, vacuum distill the butanone oxime sewage for 30 min at a temperature of 85°C and a vacuum degree of -10 Kpa to recover the distillate butanone and butanone oxime;

[0080] (2) Add a sodium hypochlorite aqueous solution with a mass fraction of 10% to the distillation residue, and add it according to the amount of 1.2 g of sodium hypochlorite per liter of the distillation residue. Under the condition of a temperature of 60°C, carry out an oxidation reaction for 100 min;

[0081] (3) Add a sodium hydroxide solution with a mass fraction of 32% to the reaction solution obtained in step (2) to adjust its pH to 8, then add a sodium hypochlorite aqueous solution with a mass fraction of 10% and a phosphorus removal agent calcium chloride. Add them according to the addition amount of 1 g of sodium hypochlorite per liter of the reaction solution and the addition amount of 1 g of the phosphorus removal agent per liter of the reaction solution. Then, pass the reaction solution containing the oxidation phosphorus removal agent through an iron-carbon bed and precipitate for 30 min at a temperature of 25°C. Analyze the contents of butanone oxime, butanone, COD, ammonia nitrogen, TN, CN⁻, and TP in the sewage (the results are shown in Table 1), and transport it to a sewage treatment plant for advanced treatment.

[0082] Example 5

[0083] The difference between the butanone oxime sewage pretreatment method described in Example 5 and that in Example 1 is only that: the butanone oxime sewage pretreatment method described in Example 5 adjusts the pH of the butanone oxime sewage to 7.

[0084] The specific operation steps include:

[0085] (1) Take 1000 ml of methyl ethyl ketoxime sewage, analyze the contents of methyl ethyl ketoxime, methyl ethyl ketone, COD, ammonia nitrogen, TN, CN−, and TP in the above-mentioned methyl ethyl ketoxime sewage (the results are shown in Table 1). Adjust the pH of the methyl ethyl ketoxime sewage to 7 with 20% hydrochloric acid by mass fraction, and then vacuum distill the methyl ethyl ketoxime sewage for 30 min under the conditions of a temperature of 85 °C and a vacuum degree of -10 KPa to recover the distillate fractions of methyl ethyl ketone and methyl ethyl ketoxime;

[0086] (2) Add an aqueous solution of sodium hypochlorite with a mass fraction of 10% to the distillation residue, and add it in an amount of 1.2 g of sodium hypochlorite per liter of the distillation residue. Under the condition of a temperature of 60 °C, carry out an oxidation reaction for 100 min;

[0087] (3) Add a sodium hydroxide solution with a mass fraction of 32% to the reaction solution obtained in step (2) to adjust its pH to 8, and then add an aqueous solution of sodium hypochlorite with a mass fraction of 10% and a phosphorus removal agent calcium chloride. Add them according to the addition amount of 1 g of sodium hypochlorite per liter of the reaction solution and the addition amount of 1 g of the phosphorus removal agent per liter of the reaction solution. Then, pass the reaction solution containing the oxidation and phosphorus removal agent through an iron-carbon bed and precipitate for 30 min under the condition of a temperature of 25 °C. Analyze the contents of methyl ethyl ketoxime, methyl ethyl ketone, COD, ammonia nitrogen, TN, CN−, and TP in the sewage (the results are shown in Table 1), and transport it to a sewage treatment plant for advanced treatment.

[0088] Example 6

[0089] The difference between the pretreatment method of methyl ethyl ketoxime sewage described in Example 6 and that in Example 1 is only that: the pH of the reaction solution is adjusted to 9 in the pretreatment method of methyl ethyl ketoxime sewage described in Example 6.

[0090] The specific operation steps include:

[0091] (1) Take 1000 ml of methyl ethyl ketoxime sewage, analyze the contents of methyl ethyl ketoxime, methyl ethyl ketone, COD, ammonia nitrogen, TN, CN−, and TP in the above-mentioned methyl ethyl ketoxime sewage (the results are shown in Table 1). Adjust the pH of the methyl ethyl ketoxime sewage to 2 with 20% hydrochloric acid by mass fraction, and then vacuum distill the methyl ethyl ketoxime sewage for 30 min under the conditions of a temperature of 85 °C and a vacuum degree of -10 KPa to recover the distillate fractions of methyl ethyl ketone and methyl ethyl ketoxime;

[0092] (2) Add an aqueous solution of sodium hypochlorite with a mass fraction of 10% to the distillation residue, and add it in an amount of 1.2 g of sodium hypochlorite per liter of the distillation residue. Under the condition of a temperature of 60 °C, carry out an oxidation reaction for 100 min;

[0093] (3) Add sodium hydroxide solution with a mass fraction of 32% to the reaction solution obtained in step (2) to adjust its pH to 7, then add sodium hypochlorite aqueous solution with a mass fraction of 10% and calcium chloride as a phosphorus remover. Add them according to the addition amount of 1 g of sodium hypochlorite per liter of the reaction solution and 1 g of the phosphorus remover per liter of the reaction solution. Then, pass the reaction solution containing the oxidation phosphorus remover through an iron-carbon bed and precipitate for 30 min at a temperature of 25 °C. Analyze the contents of butanone oxime, butanone, COD, ammonia nitrogen, TN, CN⁻, and TP in the sewage (the results are shown in Table 1), and transport it to a sewage treatment plant for advanced treatment.

[0094] Example 7

[0095] The difference between the butanone oxime sewage pretreatment method described in Example 7 and that in Example 1 is only that: the pH of the reaction solution is adjusted to 10 in the butanone oxime sewage pretreatment method described in Example 7.

[0096] The specific operation steps include:

[0097] (1) Take 1000 ml of butanone oxime sewage, analyze the contents of butanone oxime, butanone, COD, ammonia nitrogen, TN, CN⁻, and TP in the above butanone oxime sewage (the results are shown in Table 1). Adjust the pH of the butanone oxime sewage to 2 with hydrochloric acid with a mass fraction of 20%, and then vacuum distill the butanone oxime sewage for 30 min at a temperature of 85 °C and a vacuum degree of -10 KPa to recover the distillate butanone and butanone oxime;

[0098] (2) Add sodium hypochlorite aqueous solution with a mass fraction of 10% to the distillation residue, and add it according to the amount of 1.2 g of sodium hypochlorite per liter of the distillation residue. Under the condition of a temperature of 60 °C, carry out an oxidation reaction for 100 min;

[0099] (3) Add sodium hydroxide solution with a mass fraction of 32% to the reaction solution obtained in step (2) to adjust its pH to 10, then add sodium hypochlorite aqueous solution with a mass fraction of 10% and calcium chloride as a phosphorus remover. Add them according to the addition amount of 1 g of sodium hypochlorite per liter of the reaction solution and 1 g of the phosphorus remover per liter of the reaction solution. Then, pass the reaction solution containing the oxidation phosphorus remover through an iron-carbon bed and precipitate for 30 min at a temperature of 25 °C. Analyze the contents of butanone oxime, butanone, COD, ammonia nitrogen, TN, CN⁻, and TP in the sewage (the results are shown in Table 1), and transport it to a sewage treatment plant for advanced treatment.

[0100] Example 8

[0101] The difference between the butanone oxime sewage pretreatment method described in Example 8 and that in Example 1 is only that: the pH of the reaction solution is adjusted to 10.5 in the butanone oxime sewage pretreatment method described in Example 8.

[0102] The specific operation steps include:

[0103] (1) Take 1000 ml of methyl ethyl ketoxime sewage, analyze the contents of methyl ethyl ketoxime, methyl ethyl ketone, COD, ammonia nitrogen, TN, CN−, and TP in the above-mentioned methyl ethyl ketoxime sewage (the results are shown in Table 1). Adjust the pH of the methyl ethyl ketoxime sewage to 2 with 20% hydrochloric acid by mass fraction, and then vacuum distill the methyl ethyl ketoxime sewage for 30 min under the conditions of a temperature of 85 °C and a vacuum degree of -10 KPa to recover the distillate fractions of methyl ethyl ketone and methyl ethyl ketoxime;

[0104] (2) Add an aqueous solution of sodium hypochlorite with a mass fraction of 10% to the distillation residue, and add it in an amount of 1.2 g of sodium hypochlorite per liter of the distillation residue. Under the condition of a temperature of 60 °C, carry out an oxidation reaction for 100 min;

[0105] (3) Add a sodium hydroxide solution with a mass fraction of 32% to the reaction solution obtained in step (2) to adjust its pH to 10.5, and then add an aqueous solution of sodium hypochlorite with a mass fraction of 10% and a phosphorus removal agent calcium chloride. Add them according to the addition amount of 1 g of sodium hypochlorite per liter of the reaction solution and the addition amount of 1 g of the phosphorus removal agent per liter of the reaction solution. Then, pass the reaction solution containing the oxidation and phosphorus removal agent through an iron-carbon bed and precipitate for 30 min under the condition of a temperature of 25 °C. Analyze the contents of methyl ethyl ketoxime, methyl ethyl ketone, COD, ammonia nitrogen, TN, CN−, and TP in the sewage (the results are shown in Table 1), and transport it to a sewage treatment plant for advanced treatment.

[0106] Example 9

[0107] The difference between the pretreatment method of methyl ethyl ketoxime sewage described in Example 9 and that in Example 1 is only that: the pH of the reaction solution is adjusted to 11 in the pretreatment method of methyl ethyl ketoxime sewage described in Example 9.

[0108] The specific operation steps include:

[0109] (1) Take 1000 ml of methyl ethyl ketoxime sewage, analyze the contents of methyl ethyl ketoxime, methyl ethyl ketone, COD, ammonia nitrogen, TN, CN−, and TP in the above-mentioned methyl ethyl ketoxime sewage (the results are shown in Table 1). Adjust the pH of the methyl ethyl ketoxime sewage to 2 with 20% hydrochloric acid by mass fraction, and then vacuum distill the methyl ethyl ketoxime sewage for 30 min under the conditions of a temperature of 85 °C and a vacuum degree of -10 KPa to recover the distillate fractions of methyl ethyl ketone and methyl ethyl ketoxime;

[0110] (2) Add an aqueous solution of sodium hypochlorite with a mass fraction of 10% to the distillation residue, and add it in an amount of 1.2 g of sodium hypochlorite per liter of the distillation residue. Under the condition of a temperature of 60 °C, carry out an oxidation reaction for 100 min;

[0111] (3) Add sodium hydroxide solution with a mass fraction of 32% to the reaction solution obtained in step (2) to adjust its pH to 11, then add sodium hypochlorite aqueous solution with a mass fraction of 10% and calcium chloride as a phosphorus remover. Add them according to the dosage of 1 g of sodium hypochlorite per liter of the reaction solution and 1 g of the phosphorus remover per liter of the reaction solution. Then, pass the reaction solution containing the oxidation phosphorus remover through an iron-carbon bed and precipitate for 30 min at a temperature of 25°C. Analyze the contents of butanone oxime, butanone, COD, ammonia nitrogen, TN, CN⁻, and TP in the sewage (the results are shown in Table 1), and transport it to a sewage treatment plant for advanced treatment.

[0112] Effect study of the pretreatment method for butanone oxime sewage described in this application:

[0113] Note: The COD content in the sewage of this application is determined by the dichromate method HJ828 - 2017;

[0114] The ammonia nitrogen content in the sewage is determined by the Nessler reagent method HT535 - 2009;

[0115] The total nitrogen content in the sewage is determined by the gas-phase molecular absorption spectrometry method GB199 - 2005;

[0116] The total phosphorus content in the sewage is determined by the ammonium molybdate spectrophotometry method GB 11893 - 89;

[0117] CN in the sewage - content is determined by the silver nitrate titration method GB7486 - 87;

[0118] Butanone and butanone oxime in the sewage are determined by gas chromatography, and the instrument selected is Shimadzu.

[0119] Table 1

[0120]

[0121]

[0122] It can be seen from Table 1 that hydrolysis distillation under acidic conditions is crucial for the removal of COD and TN. The treatment effects of COD and TN are better when the pH is less than 5. When the pH is greater than 7, the treatment effect deteriorates sharply; adding the same mass of hydrogen peroxide has slightly better effect than sodium hypochlorite, but sodium hypochlorite has an obvious cost advantage over hydrogen peroxide; on the basis of the same dosage of sodium hypochlorite, between pH 8 - 10 for NH 3- N, CN -, the removal effect of TP is the best, which can reach more than 90%. When PH>10, side reactions occur between the dephosphorization agent calcium ions to form calcium hydroxide precipitation, resulting in a poor dephosphorization effect; under the same hydrolysis and distillation conditions, due to the increase in the pH of the oxidative dephosphorization reaction solution, more precipitates are formed, and part of the organic matter is wrapped in, which also promotes the removal of COD.

[0123] Table 2

[0124]

[0125] It can be seen from Table 2 that the hydrolysis and distillation should be carried out under acidic conditions, and the effect is better when PH is less than 4, and more than 99.9% of butanone oxime can be removed. When PH>4, the removal effect of butanone oxime drops sharply. Combining the analysis with Table 1, it can be seen that COD and TN in the sewage mainly come from butanone oxime, butanone and their by-products. As long as the hydrolysis and distillation are carried out under acidic conditions, most of the COD and TN in the sewage can be removed.

[0126] Although the above embodiments have been shown and described, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions, and variations made by those of ordinary skill in the art to the above embodiments are within the protection scope of the present invention.

Claims

1. A method for pretreating butanone oxime wastewater, characterized in that: The following steps are involved: (1) adjusting butanone oxime wastewater to acidity and performing distillation treatment under vacuum conditions; (2) adding an oxidant to the distillation residue to carry out an oxidation reaction; (3) The reaction solution obtained in step (2) is adjusted to be alkaline, and an oxidizing dephosphorization agent is added to carry out denitrification and dephosphorization treatment.

2. The butanone oxime wastewater pretreatment method according to claim 1, characterized in that: In step (1), the acidity regulating reagent for regulating the butanone oxime wastewater includes one or more of sulfuric acid, hydrochloric acid, phosphoric acid and oxalic acid; Preferably, the acidity regulating agent for regulating butanone oxime wastewater is hydrochloric acid; more preferably, the mass concentration of the hydrochloric acid is 10%-20%; And / or, the pH value of the butanone oxime wastewater is adjusted to 2-4.

3. The butanone oxime wastewater pretreatment method according to claim 1, characterized in that: In step (1), the distillation temperature is 75-85° C. and the distillation time is 15-30 min; And / or, the vacuum degree of the distillation is -10Kpa to -20Kpa.

4. The method for pretreating butanone oxime wastewater according to claim 1, wherein: In step (2), the oxidant includes hydrogen peroxide and / or sodium hypochlorite; and / or, the amount of oxidant added per liter of distillation residue is 0.5-2 g; Preferably, the oxidant comprises a sodium hypochlorite aqueous solution with a mass fraction of 10%-15% or a hydrogen peroxide solution with a mass fraction of 27%-40%.

5. The method for pretreating butanone oxime wastewater according to claim 1, characterized in that: In step (2), the temperature of the oxidation reaction is 60-70° C., and the time of the oxidation reaction is 100-150 min.

6. The method for pretreating butanone oxime wastewater according to claim 1, characterized in that: The regulating reagent for regulating the reaction solution to alkalinity includes sodium hydroxide and / or potassium hydroxide; Preferably, the regulating agent for adjusting the reaction solution to alkalinity comprises a sodium hydroxide solution with a mass concentration of 10%-40%.

7. The method for pretreating butanone oxime wastewater according to claim 1, characterized in that: The pH of the reaction solution was adjusted to 8-10.

8. The method for pretreating butanone oxime wastewater according to claim 1, characterized in that: The oxidative phosphorus removal agent includes sodium hypochlorite and a calcium ion-containing salt; Preferably, the calcium ion-containing salt comprises calcium chloride and / or calcium hydroxide; Preferably, the mass ratio of sodium hypochlorite to calcium ion-containing salt in the oxidative phosphorus removal agent is (0.1-1): (0.1-1).

9. The method for pretreating butanone oxime wastewater according to claim 1, characterized in that: The amount of the oxidative phosphorus removal agent added to each liter of the reaction solution is 0.8-3 g.

10. The method for pretreating butanone oxime wastewater according to claim 1, characterized in that: The butanone oxime wastewater pretreatment method further comprises passing the reaction solution containing the oxidative dephosphorization agent into an iron-carbon bed for decarbonization and dephosphorization treatment; And / or, in step (3), the temperature of the denitrification and dephosphorization treatment is 20-30°C, and the time of the denitrification and dephosphorization treatment is 30-60 minutes.

Images