Resourceful treatment method for high-carbon-alcohol waste alkali liquor

Abstract

The invention discloses a resourceful treatment method for high-alcohol waste lye, and belongs to the technical field of waste lye treatment. The method comprises the following steps: homogenizing the water quality of the waste alkali liquid; a waste acid solution is added into the homogenized waste alkali solution for acidification treatment; the waste liquid is sent to a chromatography device for organic phase and water phase separation; performing ultraviolet light catalytic oxidation treatment on the organic phase; and sending the treated organic phase as an external carbon source to a sewage treatment system. The biodegradability of the waste lye treated by the method disclosed by the invention is obviously enhanced; meanwhile, a novel carbon source is obtained and can be used for an AO process of a sewage treatment system, compared with traditional additional carbon sources such as acetic acid and sodium acetate, the denitrification effect of microorganisms can be more effectively promoted, the effluent quality is better, the denitrification effect is stronger, meanwhile, the three-agent cost of a sewage field is reduced, resource utilization of waste alkali liquor is achieved, and certain economic benefits are achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of waste alkali liquor treatment, and specifically relates to a method for resource treatment of waste alkali liquor of high-carbon alcohol. Background Art

[0002] High-carbon alcohols are also known as higher fatty alcohols, which refer to mixtures of monohydric alcohols with more than six carbon atoms. High-carbon alcohols are often used in the synthesis of fine chemical products such as surfactants, plasticizers and detergents, and are widely used in petrochemicals, mechanical mining, construction metallurgy, papermaking and food. Among them, octanol and 2-propylheptanol (2-PH) are the products with the largest amount of high-carbon alcohols. The waste alkali liquor produced in the current production of high-carbon alcohols has the following characteristics: strong alkalinity, pH value of about 13; chemical oxygen demand COD as high as 40000mg / L-100000mg / L; many toxic and harmful substances, complex composition and high concentration, mainly aldehydes and ketones, including biotoxic substances such as valeraldehyde and carbon decadecene aldehyde, poor biodegradability, direct discharge to sewage fields will affect the smooth operation of biochemical equipment, and it is difficult to pre-treat alone.

[0003] At present, there are three main methods for treating waste alkali liquid: air oxidation, neutralization and incineration. The advantage of air oxidation is its high conversion efficiency, but its disadvantages are high requirements for equipment materials, large investment, high operating energy consumption, and low removal rate of some organic matter and COD. The advantage of neutralization is its simple treatment process, but its disadvantage is that the waste alkali liquid after neutralization has a high salt content, which has a greater impact on downstream sewage treatment plants. The advantage of incineration is its simple operation, short process, and ability to meet emission standards, but its disadvantages are high energy consumption and large investment.

[0004] Patent CN1124230C first uses inorganic acid to acidify the waste alkali liquid of the butyl octanol device, and then adds an organic extractant for extraction. However, after the treatment by this method, the COD removal rate is only 50%, and the removal efficiency is low. Patent CN104071940B first uses inorganic acid to acidify the waste alkali liquid, and then performs pervaporation membrane evaporation and concentration treatment on the acidified liquid, cools and crystallizes after oil-water separation to recover the inorganic acid sodium salt, returns the crystallization kettle liquid to the acidification reaction tube for circulation treatment, evaporates the condensate for adsorption treatment, and the adsorbed water part returns to the condensation device for preparing alkali liquid, and the remaining water is discharged into the sewage treatment plant for biological treatment. Although this method realizes the resource recovery of organic matter in the waste alkali liquid, it has large equipment investment, complex treatment process, high energy consumption, and the crystallization kettle liquid accumulated in the system cannot be completely treated. Patent CN101277907A discloses a method for treating wastewater from an acetal reaction process, wherein the wastewater from the acetal reaction process whose pH value has been adjusted to 0-6 is treated by single-stage or multi-stage extraction, the wastewater is subjected to steam stripping and condensation, and wastewater with a low organic impurity content is stripped out. The organic liquid obtained by phase separation of the condensate is used as an extractant for single-stage or multi-stage extraction. The steam stripping method of this method still increases the operating cost, and the water quality of the stripped water and subsequent treatment are not clearly explained.

[0005] On the other hand, biological nitrification and denitrification processes are widely used in sewage denitrification treatment due to their low cost and high efficiency. The anoxic-aerobic activated sludge process (AO process) is a commonly used biological treatment method in wastewater treatment, also known as the pre-denitrification biological treatment system, which is mainly divided into nitrification process and denitrification process. Among them, denitrification refers to the process in which heterotrophic denitrifying bacteria use organic carbon sources as electron donors to reduce nitrite nitrogen and nitrate nitrogen produced during nitrification into gaseous nitrogen in an anaerobic environment. Adding an external carbon source to low carbon-nitrogen ratio (BOD5 / TN<3) sewage can ensure denitrification. However, in recent years, the procurement cost of bulk chemicals such as acetic acid as a traditional carbon source has increased year by year, and finding an alternative new carbon source has become a top priority. Summary of the invention

[0006] In view of the deficiencies in the prior art, the purpose of the present invention is to provide an economical, efficient and easy-to-operate method for resource-based treatment of waste alkali liquor of high-carbon alcohols, wherein the biodegradability of the treated waste alkali liquor is significantly enhanced; at the same time, a new type of carbon source is obtained, which can be used in the AO process of a sewage treatment system to promote the denitrification of microorganisms, thereby achieving good effluent quality and a strong denitrification effect; on the one hand, as a carbon source, it ensures efficient denitrification of a biochemical device, and on the other hand, it realizes harmless resource utilization of waste alkali liquor.

[0007] In order to achieve the above object, according to one aspect of the present invention, a method for recycling waste alkali liquor of high-carbon alcohol is provided, characterized in that it comprises the following steps: (1) Waste alkali liquor is homogenized; (2) adding waste acid solution to the homogenized waste alkali solution for acidification treatment; (3) The waste liquid after acidification treatment is sent to a chromatography device for phase separation, the aqueous phase is sent to a sewage treatment system, and the organic phase is sent to an ultraviolet treatment system for ultraviolet photocatalytic oxidation treatment; (4) The organic phase after the ultraviolet catalytic oxidation treatment in step (3) is sent to the anoxic tank of the sewage treatment system as an external carbon source and mixed with other wastewater introduced. The wastewater treated in the anoxic tank enters the aerobic tank for nitrification treatment, part of the nitrified effluent is returned to the anoxic tank, the remaining effluent enters the sedimentation tank for sedimentation separation, part of the sludge is returned to the anoxic tank, and the supernatant is discharged as effluent.

[0008] In some embodiments, in step (1), the water homogenization time is 1h-10h.

[0009] In some embodiments, in step (2), the pH value of the waste liquid after the acidification treatment is 3-5, and the temperature of the acidification treatment is ≤65°C.

[0010] In some embodiments, in step (3), the operating pressure of the chromatograph is normal pressure, and the operating temperature is 15°C-65°C.

[0011] In some embodiments, in step (3), the ultraviolet treatment system includes a power supply, an ultraviolet lamp and a reaction tube, a quartz sleeve is provided inside the reaction tube, the ultraviolet lamp is installed inside the quartz sleeve, and the outside of the quartz sleeve is a sewage area; calculated based on the influent, the effective volume of the reaction tube satisfies a hydraulic retention time of 50s-100s.

[0012] In some embodiments, in step (3), the operating conditions of the ultraviolet treatment system are: the ultraviolet reaction temperature is 55°C-60°C, and the ultraviolet light wavelength is 170nm-300nm.

[0013] In some embodiments, in step (4), the BOD5 / TN value of the other wastewater is less than 3.

[0014] In some embodiments, in step (4), the pH of the sewage treatment system is 6-9, and the sludge age is 15-18 days.

[0015] In some embodiments, in step (4), the reflow ratio of the nitrification effluent is 3-5, and the reflow ratio of the sedimentation tank sludge is 0.3-0.5.

[0016] In some embodiments, in step (4), the hydraulic retention time of the anoxic tank is 0.5h-2h.

[0017] In some embodiments, in step (4), the hydraulic retention time of the aerobic tank is 4h-6h.

[0018] In some embodiments, in step (4), the hydraulic retention time of the sedimentation tank is 2h-4h.

[0019] In some embodiments, in step (4), the dissolved oxygen concentration in the anoxic tank is 0.1 mg / L-0.3 mg / L.

[0020] In some embodiments, in step (4), the dissolved oxygen concentration in the aerobic tank is 4 mg / L-6 mg / L.

[0021] In some embodiments, optionally, the method for resource recovery of waste alkali liquor from high-carbon alcohols further comprises the step of: directly sending part of the waste alkali liquor that has not been homogenized to the aerobic tank of the sewage treatment system as added alkalinity.

[0022] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention treats waste with waste, mixes waste acid liquid into waste alkali liquid to achieve acid-base neutralization, reduces the amount of acid and alkali used in the sewage treatment plant to neutralize and treat two streams of sewage separately, and saves operating costs; at the same time, it avoids the use of dilution water, so that the organic matter in the waste acid is dissolved into the waste alkali liquid, and the effective separation of biochemical and non-biochemical components can be achieved only through acidification, which provides conditions for ultraviolet light catalytic oxidation, reduces energy consumption and subsequent processing load, is suitable for large-scale processing, realizes atomic economy, saves water resources, and the slightly acidic condition can effectively prevent scaling.

[0023] (2) The waste alkali liquid homogenization-acidification treatment-chromatographic separation-ultraviolet oxidation process of the present invention does not add any reagents, thus avoiding secondary pollution and saving operating costs. The selection of a chromatograph reduces the downstream load, improves the efficiency of ultraviolet light, and has the effect of energy saving and consumption reduction. At the same time, the biodegradability of the ultraviolet effluent is enhanced, and it can be directly used in the AO process.

[0024] (3) The present invention can reserve a small portion of untreated waste alkali liquid as external alkalinity to be directly added to the AO process, thereby increasing the alkalinity of the raw water and strengthening the nitrification effect. It can also be started or stopped according to the effluent quality and operating conditions of the sewage treatment system, thereby increasing the operational flexibility of the process.

[0025] (4) The present invention uses high-carbon alcohol waste alkali liquor to obtain a new type of carbon source, which can be used in the AO process of the sewage treatment system. Compared with traditional external carbon sources such as acetic acid and sodium acetate, the organic matter in the high-carbon alcohol waste alkali liquor is more complex and has uneven molecular weight. For microorganisms, it is a nutrient with a more balanced gradation and can more effectively promote the denitrification of microorganisms. The microbial colony population cultivated by it is relatively rich. For wastewater rich in high-concentration difficult-to-degrade organic matter, this carbon source is conducive to the continuous degradation of microorganisms through gradual utilization, and the wastewater treatment is more thorough and the denitrification effect is stronger. However, acetic acid and sodium acetate are single nutrient sources and have poor endurance. At the same time, the present invention reduces the three-dose cost of the sewage field, realizes the resource utilization of waste alkali liquor, and has certain economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to make the content of the present invention more clearly understood, the present invention is further described in detail below according to specific embodiments of the present invention in conjunction with the accompanying drawings, wherein: Figure 1 The present invention is a process flow chart of a method for resource recovery of waste alkali liquor from high-carbon alcohols.

[0027] The reference numerals in the figure are as follows: 1-homogenization tank, 2-pH adjustment tank, 3-chromatograph, 4-ultraviolet treatment system, 5-anoxic tank, 6-aerobic tank, 7-sedimentation tank. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following general description and definition of the terms and expressions mentioned in the specification and claims are provided. Unless otherwise specified, all technical and scientific terms used herein have the common meanings understood by those skilled in the art for the present invention. In case of conflict, the definitions in this specification shall prevail.

[0029] In the present invention, the gradation refers to the distribution of nutrients in the carbon source.

[0030] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0031] Herein, when describing embodiments or examples, it should be understood that they are not used to limit the present invention to these embodiments or examples. On the contrary, all substitutes, improvements and equivalents of the methods and materials described in the present invention can be included in the scope limited by the claims.

[0032] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0033] The present invention provides a method for resource treatment of waste alkali liquor of high-carbon alcohols, characterized in that it comprises the following steps: (1) Waste alkali liquor is homogenized; (2) adding waste acid solution to the homogenized waste alkali solution for acidification treatment; (3) The waste liquid after acidification treatment is sent to a chromatography device for phase separation, the aqueous phase is sent to a sewage treatment system, and the organic phase is sent to an ultraviolet treatment system for ultraviolet photocatalytic oxidation treatment; (4) The organic phase after the ultraviolet catalytic oxidation treatment in step (3) is sent to the anoxic tank of the sewage treatment system as an external carbon source and mixed with other wastewater introduced. The wastewater treated in the anoxic tank enters the aerobic tank for nitrification treatment, part of the nitrification effluent is returned to the anoxic tank, and the remaining effluent enters the sedimentation tank for sedimentation separation. Part of the sludge is returned to the anoxic tank, and the supernatant is discharged as treated water.

[0034] According to the treatment method of the present invention, in some embodiments, in step (1), the time for water homogenization is 1h-10h. It can be understood that the water homogenization time can be any specific value of 1h, 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h, 10h or any value within the range of 1h-10h. Water homogenization is a mixing process, the purpose of which is to balance the changes in the water quality, water volume, etc. of the waste alkali liquid in view of the uneven distribution of the waste alkali liquid discharge, so that the intake of the waste alkali liquid is evenly distributed. In the present invention, the water homogenization can be carried out in a homogenization tank. The present invention has no special restrictions on the homogenization tank, which can be a conventional homogenization tank in the art.

[0035] According to the treatment method of the present invention, in some embodiments, in step (2), the pH value of the waste liquid after the acidification treatment is 3-5. It can be understood that the pH value of the waste liquid after the acidification treatment can be any specific value of 3, 4, 5 or any value within the range of 3-5; the temperature of the acidification treatment does not exceed 65°C, and further, the temperature of the acidification treatment is 5°C-45°C. In the present application, the acidification treatment can be carried out in a pH adjustment tank, and the material of the pH adjustment tank includes but is not limited to polytetrafluoroethylene, polyethylene, and an acid-resistant and alkali-resistant material lining; the present application achieves pH control by controlling the inflow of the waste acid liquid. If the pH is too high, the equipment and pipelines are prone to scaling. Too high a pH will also hinder the metabolic rate of microorganisms, which is not conducive to their growth, resulting in a significant reduction in the denitrification rate; if the pH is too low, it will cause acid corrosion of equipment and pipelines, increase investment costs, and if the pH is too low, fungi will completely dominate in the biochemical pool, and the nitrification reaction will almost stop. The present application controls the acidification treatment temperature to not exceed 65°C by introducing circulating water for cooling. Too high a temperature is not conducive to the operation of the subsequent chromatography, resulting in difficulty in separating the aqueous phase and the organic phase, thus affecting the separation effect.

[0036] According to the treatment method of the present invention, in some embodiments, in step (3), the operating pressure of the chromatograph is normal pressure, and the operating temperature is 15°C-65°C. It can be understood that the operating temperature can be any specific value of 15°C, 20°C, 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C or any value within the range of 15°C-65°C.

[0037] In the present invention, the chromatograph is composed of two phases: a stationary phase and a mobile phase. Among them, the stationary phase is mostly a solid substance or a component fixed on a solid, and its function is to adsorb or react the compounds in the mixture to be separated according to the affinity between them and the stationary phase. The present invention can use conventional stationary phases in the art, including but not limited to silica gel, dextran, polyvinyl alcohol, etc. The mobile phase refers to a solvent or solution, and its function is to contact the stationary phase and continuously move downward, so as to gradually bring out the mixture adsorbed or reacted on the stationary phase, and separate them according to the affinity between them and the mobile phase. The present invention can use conventional mobile phases in the art, including but not limited to water, chloroform, methanol, etc. The present application can separate the biodegradable and non-biodegradable components of the mixed waste liquid by controlling the operating temperature and pressure of the chromatograph. If the temperature is too high, the solubility of the medium becomes larger, the required stratification area increases, and the separation efficiency of the equipment is reduced; if the temperature is too low, it causes a waste of circulating cooling water, and the false indication of instruments such as liquid level caused by low temperature is not conducive to the stable operation of the chromatograph. The present application realizes the rapid separation of the organic phase and the aqueous phase by using a chromatograph, reduces the downstream load, and improves the efficiency of ultraviolet light.

[0038] According to the treatment method of the present invention, in some embodiments, in step (3), the ultraviolet treatment system includes a power supply, an ultraviolet lamp and a reaction tube, a quartz sleeve is provided inside the reaction tube, the ultraviolet lamp is installed inside the quartz sleeve, and the outside of the quartz sleeve is a sewage area; calculated based on the influent, the effective volume of the reaction tube satisfies the hydraulic retention time of 50s-100s, and it can be understood that the hydraulic retention time can be any specific value of 50s, 60s, 70s, 80s, 90s, 100s or any value within the range of 50s-100s. In the present application, the material of the quartz sleeve is preferably quartz to isolate the ultraviolet lamp and the sewage medium; the material of the reaction tube includes but is not limited to quartz, polytetrafluoroethylene and polyethylene.

[0039] According to the treatment method of the present invention, in some embodiments, in step (3), the operating conditions of the ultraviolet treatment system are: the ultraviolet reaction temperature is 55°C-60°C, and it can be understood that the ultraviolet reaction temperature can be any specific value among 55°C, 56°C, 57°C, 58°C, 59°C, and 60°C, or any value within the range of 55°C-60°C; the ultraviolet light wavelength is 170nm-300nm, and it can be understood that the ultraviolet light wavelength can be any specific value among 170nm, 180nm, 190nm, 200nm, 210nm, 220nm, 230nm, 240nm, 250nm, 260nm, 270nm, 280nm, 290nm, and 300nm, or any value within the range of 170nm-300nm.

[0040] In the present application, the control method of the ultraviolet reaction temperature includes but is not limited to the ultraviolet lamp power adjustment. Preferably, the power of the ultraviolet lamp is 500W / m 3 -2000W / m 3 It is understood that the power can be 500W / m 3 、600W / m 3 , 700W / m 3 、800W / m 3 , 900W / m 3 , 1000W / m 3 、1100W / m 3 , 1200W / m 3 、1300W / m 3 , 1400W / m 3 、1500W / m 3 、1600W / m 3 、1700W / m 3 、1800W / m 3 、1900W / m 3 , 2000W / m3 Any specific value in or 500W / m 3 -2000W / m 3 Any value in the range.

[0041] The present application controls the ultraviolet reaction temperature and the ultraviolet wavelength within the range, so as to ensure that the organic matter in the waste liquid is in an oxidized excited state after being irradiated with high-intensity ultraviolet light, especially most of the organic matter such as amyl alcohol and valeraldehyde is oxidized and degraded, part of the COD is reduced, and the biodegradability is significantly enhanced. If the ultraviolet reaction temperature is too low, the reaction is not thorough; if the ultraviolet reaction temperature is too high, the energy consumption increases and the life of the ultraviolet lamp tube is shortened; if the ultraviolet wavelength is lower than 170nm, the ultraviolet light penetration ability is weakened, and the axial area of ​​the pipeline becomes a reaction dead zone; if the ultraviolet wavelength is higher than 300nm, the ultraviolet light wave energy is reduced, and the purpose of chain breaking cannot be achieved for the difficult-to-degrade organic matter, and the ability to improve the biodegradability is limited.

[0042] According to the treatment method of the present invention, in some embodiments, in step (4), other wastewater refers to wastewater with a BOD5 / TN value of less than 3 and requiring an external carbon source. BOD5 (Biochemical Oxygen Demand) is an important indicator that uses the amount of dissolved oxygen consumed by microbial metabolism to indirectly indicate the degree of organic pollution in a water body. Generally, 5 days is used as the standard time for determining BOD, so it is called the five-day biochemical oxygen demand, expressed as BOD5. TN is the total amount of various forms of inorganic and organic nitrogen in water, that is, the total nitrogen content. The BOD5 / TN (i.e. C / N) ratio is the main indicator for identifying whether biological denitrification can be used. When BOD5 / TN is less than 3, denitrification cannot be carried out without adding an external carbon source.

[0043] In the present invention, the organic phase after the ultraviolet catalytic oxidation treatment is sent to the anoxic tank of the sewage treatment system as an external carbon source. The present invention can adopt the conventional external carbon source dosage in the art, for example, the treatment scale Q=10000m 3 / d, the total nitrogen in the influent is 100mg / L. If the emission is to meet the standard, the carbon source dosage can be 3000kgCOD / d.

[0044] Furthermore, in some specific embodiments, in step (4), the organic phase after the ultraviolet catalytic oxidation treatment is sent to the anoxic tank of the sewage treatment system as an external carbon source, and is mixed with other wastewater introduced at a volume ratio of 1:150-1:350.

[0045] According to the treatment method of the present invention, in some embodiments, in step (4), the pH of the sewage treatment system is 6-9, and it is understandable that the pH can be any specific value among 6, 7, 8, and 9, or any value within the range of 6-9; the sludge age of the sewage treatment system is 15-18 days, and it is understandable that the sludge age can be any specific value among 15, 16, 17, and 18, or any value within the range of 15-18.

[0046] In the present invention, the organic phase after ultraviolet catalytic oxidation treatment is sent to the anoxic tank of the sewage treatment system as an external carbon source, and mixed with other wastewater introduced to form mixed influent. The BOD5 / COD ratio of the mixed influent needs to be greater than or equal to 0.3. The BOD5 / COD ratio can be used to judge the biodegradability of the influent. If it is lower than this value, it means that the biodegradability is extremely poor and cannot be treated by biochemical method.

[0047] According to the treatment method of the present invention, in some embodiments, in step (4), the reflux ratio of the nitrification effluent is 3-5. It can be understood that the reflux ratio of the nitrification effluent can be any specific value among 3, 4, and 5, or any value within the range of 3-5; the reflux ratio of the sedimentation tank sludge is 0.3-0.5. It can be understood that the reflux ratio of the sludge can be any specific value among 0.3, 0.4, and 0.5, or any value within the range of 0.3-0.5.

[0048] According to the treatment method of the present invention, in some embodiments, in step (4), the hydraulic retention time of the anoxic tank is 0.5h-2h. It is understood that the hydraulic retention time of the anoxic tank can be any specific value of 0.5h, 1h, 1.5h, 2h or any value within the range of 0.5h-2h; the hydraulic retention time of the aerobic tank is 4h-6h. It is understood that the hydraulic retention time of the aerobic tank can be any specific value of 4h, 4.5h, 5h, 5.5h, 6h or any value within the range of 4h-6h; the hydraulic retention time of the sedimentation tank is 2h-4h. It is understood that the hydraulic retention time of the sedimentation tank can be any specific value of 2h, 2.5h, 3h, 3.5h, 4h or any value within the range of 2h-4h. The present invention can better control the degree of denitrification reaction, nitrification reaction and precipitation separation by respectively controlling the hydraulic retention time of the anoxic tank, the aerobic tank and the sedimentation tank, thereby ensuring better denitrification and carbon removal effects.

[0049] According to the treatment method of the present invention, in some embodiments, in step (4), the dissolved oxygen concentration of the anoxic tank is 0.1 mg / L-0.3 mg / L. It is understandable that the dissolved oxygen concentration of the anoxic tank can be any specific value among 0.1 mg / L, 0.15 mg / L, 0.2 mg / L, 0.25 mg / L, 0.3 mg / L, or any value within the range of 0.1 mg / L-0.3 mg / L; the dissolved oxygen concentration of the aerobic tank is 4 mg / L-6 mg / L. It is understandable that the dissolved oxygen concentration of the aerobic tank can be any specific value among 4 mg / L, 4.5 mg / L, 5 mg / L, 5.5 mg / L, 6 mg / L, or any value within the range of 4 mg / L-6 mg / L. By controlling the dissolved oxygen concentration in the anoxic pool and the aerobic pool, the present application can screen out the corresponding anoxic bacteria (such as anaerobic denitrifying bacteria) or aerobic bacteria (such as nitrifying bacteria) and inhibit the reproduction of other bacterial species. With the help of their life activities, certain specific pollutants in the water body can be removed in a targeted manner, thereby achieving efficient purification of the water body.

[0050] In the present invention, in the anoxic tank, microorganisms such as anaerobic denitrifying bacteria can oxidize most of the organic matter in the wastewater to release ammonia nitrogen; in the aerobic tank, microorganisms such as aerobic nitrifying bacteria can oxidize ammonia nitrogen into nitrate nitrogen, which is returned to the anoxic tank through reflux control. Under anaerobic conditions, the denitrification action of the anaerobic denitrifying bacteria reduces the nitrate nitrogen to molecular nitrogen, completing the cycle of C, N, and O in the ecology and realizing the denitrification treatment of the wastewater.

[0051] According to the treatment method of the present invention, in some embodiments, optionally, the resource treatment method of the high-carbon alcohol waste alkali liquor also includes the step of: sending a small portion of the untreated waste alkali liquor directly to the aerobic tank of the sewage treatment system for added alkalinity. Furthermore, the volume ratio of the untreated waste alkali liquor to the total water inlet of the sewage treatment system is ≤1 / 300. In the present invention, this step can be selected at any time according to the working conditions and the effluent water quality of the sewage treatment process; when the alkalinity is insufficient, this step can be used to enhance nitrification; when the alkalinity is sufficient, this step is disabled to further optimize the carbon source dosage.

[0052] The present invention obtains a new type of carbon source by specially treating the waste alkali liquor of high-carbon alcohols, which can be put into the sewage treatment system as an additional carbon source. Compared with traditional additional carbon sources such as acetic acid and sodium acetate, the components in the organic phase obtained after the special treatment are more complex, and the molecular weight is uneven. For microorganisms, it belongs to a nutrient with a more balanced gradation, which can more effectively promote the denitrification of microorganisms. The microbial colony population cultivated by it is relatively rich. For wastewater rich in high-concentration difficult-to-degrade organic matter, the carbon source is conducive to the continuous degradation of microorganisms through gradual utilization, and the wastewater treatment is more thorough, the effluent water quality is better, and the denitrification effect is stronger, while the nutrient sources of acetic acid and sodium acetate are single and the endurance is poor. At the same time, the present invention reduces the three-dose cost of the sewage field, realizes the resource utilization of the waste alkali liquor, and has certain economic benefits.

[0053] The present invention will be described in detail below by way of examples. It should be understood that the following examples are only used to further explain and illustrate the content of the present invention by way of example, and are not intended to limit the present invention.

[0054] In the present invention, the testing methods of various performance parameters in the embodiments and comparative examples are as follows: Chemical oxygen demand COD: tested according to HJ828-2017 standard; Five-day biochemical oxygen demand BOD5: tested according to HJ505-2009 standard; Total nitrogen content TN: tested according to BSEN12260-2003 standard; Ammonia nitrogen content: tested according to HJ / T195-2005 standard.

[0055] Example 1 The method for recycling waste alkali liquor of high carbon alcohol described in this embodiment is as follows: Figure 1 As shown, the process includes the following steps: 1000 kg / h of 2-PH waste alkali solution (BOD5 / COD=0.24, COD is 60000 mg / L, conductivity is 135500 μS·cm -1, pH=13.3), of which 50kg / h is directly discharged into the sewage treatment system as external alkalinity, 950kg / h enters the homogenization tank, the hydraulic retention time is preferably 10h, the effluent of the homogenization tank enters the pH adjustment tank, mixed with waste acid, and the pH value is controlled at about 3-5. Circulating water is introduced into the adjustment tank side for cooling, and the temperature in the tank is controlled not to exceed 65°C. The acidified waste liquid enters the chromatograph, the operating pressure of the chromatograph is normal pressure, and the operating temperature is 65°C. The aqueous phase at the bottom of the chromatograph is discharged into the sewage treatment system, and the organic phase at the top is pressurized by the lifting pump and sent to the ultraviolet treatment system for ultraviolet photocatalytic oxidation treatment. The ultraviolet treatment system includes a power supply, an ultraviolet lamp and a reaction tube. A quartz sleeve is arranged inside the reaction tube, and the ultraviolet lamp is installed inside the quartz sleeve. The outside of the quartz sleeve is a sewage area. The wavelength of ultraviolet light is 170-300nm, and the ultraviolet power is 2000W / m 3 , the UV reaction temperature is 60°C, and the hydraulic retention time of the sewage area in the reaction tube is 70s.

[0056] The organic phase after ultraviolet photocatalytic oxidation treatment is sent to the anoxic tank of the sewage treatment system as an external carbon source, and mixed with other wastewater introduced into the water inlet (BOD5 / TN value is less than 3, COD is 480mg / L, total nitrogen is 105mg / L, and ammonia nitrogen content is 78mg / L) at a volume ratio of 1:165. The hydraulic retention time of the anoxic tank is 0.5h, and the dissolved oxygen concentration of the anoxic tank is 0.3mg / L. The wastewater treated by denitrification in the anoxic tank enters the aerobic tank for nitrification treatment. The hydraulic retention time of the aerobic tank is 4h, and the dissolved oxygen concentration of the aerobic tank is 4mg / L. Part of the nitrified effluent is returned to the anoxic tank with a return ratio of 3-5, and the remaining effluent enters the sedimentation tank for sedimentation separation. The hydraulic retention time of the sedimentation tank is 2h. Part of the sludge is returned to the anoxic tank with a return ratio of 0.3-0.5, and the supernatant is discharged as effluent.

[0057] After testing, the BOD5 / COD of the organic phase after ultraviolet catalytic oxidation treatment was 0.73, the COD was 48000 mg / L, and the COD of the mixed influent after adding it in the form of carbon source was 555 mg / L; the COD of the effluent was 15 mg / L, the COD removal rate was 97.3%, the total nitrogen content was 8 mg / L, and the ammonia nitrogen content was 5 mg / L.

[0058] Example 2 The method for recycling waste alkali liquor of high carbon alcohol described in this embodiment is as follows: Figure 1 As shown, the method comprises the following steps: a 1000kg / h2-PH waste alkali solution (BOD5 / COD=0.29, COD is 100000mg / L, conductivity is 150000μS·cm -1, pH=13.5) enters the homogenization tank, the hydraulic retention time is preferably 5h, the effluent from the homogenization tank enters the pH adjustment tank, mixed with waste acid, and the pH value is controlled at about 3-5. Circulating water is introduced into the adjustment tank for cooling, and the temperature in the tank is controlled not to exceed 65°C. The acidified waste liquid enters the chromatograph, the operating pressure of the chromatograph is normal pressure, and the operating temperature is 25°C. The water phase at the bottom of the chromatograph is discharged into the sewage treatment system, and the organic phase at the top is pressurized by the lifting pump and sent to the ultraviolet treatment system for ultraviolet photocatalytic oxidation treatment. The ultraviolet treatment system includes a power supply, an ultraviolet lamp and a reaction tube. The reaction tube includes a quartz sleeve area and a sewage area. The ultraviolet wavelength of the ultraviolet treatment system is 170-300nm, and the ultraviolet power is 2000W / m 3 The ultraviolet reaction temperature is 55°C, and the hydraulic retention time of the sewage area in the reaction tube is 90s.

[0059] The organic phase after ultraviolet photocatalytic oxidation treatment is sent to the anoxic tank of the sewage treatment system as an external carbon source, and mixed with other wastewater introduced into the water inlet (BOD5 / TN value is less than 3, COD is 450mg / L, total nitrogen is 75mg / L, and ammonia nitrogen content is 65mg / L) at a volume ratio of 1:330. The hydraulic retention time of the anoxic tank is 1h, and the dissolved oxygen concentration of the anoxic tank is 0.2mg / L. The wastewater treated in the anoxic tank enters the aerobic tank for nitrification treatment. The hydraulic retention time of the aerobic tank is 6h, and the dissolved oxygen concentration of the aerobic tank is 6mg / L. Part of the nitrified effluent is returned to the anoxic tank with a return ratio of 3-5, and the remaining effluent enters the sedimentation tank for sedimentation separation. The hydraulic retention time of the sedimentation tank is 3h, and part of the sludge is returned to the anoxic tank with a return ratio of 0.3-0.5. The supernatant is discharged as effluent.

[0060] After testing, the BOD5 / COD of the organic phase after ultraviolet catalytic oxidation treatment was 0.65, the COD was 70000 mg / L, and the COD of the mixed influent after adding it in the form of carbon source was 558 mg / L; the COD of the effluent was 12 mg / L, the COD removal rate was 97.8%, the total nitrogen content was 5 mg / L, and the ammonia nitrogen content was 2 mg / L.

[0061] Example 3 The method for recycling waste alkali liquor of high carbon alcohol described in this embodiment is as follows: Figure 1 As shown, the method comprises the following steps: 1000 kg / h butyl octanol waste alkali liquid (BOD5 / COD=0.25, COD is 43350 mg / L, conductivity is 90900 μS·cm -1, pH=13.1), of which 50kg / h is directly discharged into the biochemical device of the sewage field as external alkalinity, 950kg / h enters the homogenization tank, the hydraulic retention time is preferably 10h, the effluent of the homogenization tank enters the pH adjustment tank, mixed with waste acid, and the pH value is controlled at about 3-5. Circulating water is introduced into the adjustment tank side for cooling, and the temperature in the tank is controlled not to exceed 65°C. The acidified waste liquid enters the chromatograph, the operating pressure of the chromatograph is normal pressure, and the operating temperature is 45°C. The aqueous phase at the bottom of the chromatograph is discharged into the sewage field, and the organic phase at the top is pressurized by the lifting pump and sent to the ultraviolet treatment system for ultraviolet photocatalytic oxidation treatment. The ultraviolet treatment system includes a power supply, an ultraviolet lamp and a reaction tube. The reaction tube includes a quartz sleeve area and a sewage area. The ultraviolet wavelength of the ultraviolet treatment system is 170-300nm, and the power is 1500W / m 3 The UV reaction temperature is 60°C and the hydraulic retention time of the sewage area in the reaction tube is 50s.

[0062] The organic phase after ultraviolet photocatalytic oxidation treatment is sent to the anoxic tank of the sewage treatment system as an external carbon source, and mixed with other wastewater introduced into the water inlet (BOD5 / TN value is less than 3, COD is 395 mg / L, total nitrogen is 70 mg / L, and ammonia nitrogen content is 60 mg / L) at a volume ratio of 1:170. The hydraulic retention time of the anoxic tank is 2 hours, and the dissolved oxygen concentration of the anoxic tank is 0.1 mg / L. The wastewater treated in the anoxic tank enters the aerobic tank for nitrification treatment. The hydraulic retention time of the aerobic tank is 5 hours, and the dissolved oxygen concentration of the aerobic tank is 5 mg / L. Part of the nitrified effluent is returned to the anoxic tank with a return ratio of 3-5, and the remaining effluent enters the sedimentation tank for sedimentation separation. The hydraulic retention time of the sedimentation tank is 4 hours. Part of the sludge is returned to the anoxic tank with a return ratio of 0.3-0.5, and the supernatant is discharged as effluent.

[0063] After testing, the BOD5 / COD of the organic phase after ultraviolet catalytic oxidation treatment was 0.82, the COD was 33000 mg / L, and the COD of the mixed influent after adding it in the form of carbon source was 446 mg / L; the COD of the effluent was 6.7 mg / L, the COD removal rate was 98.5%, the total nitrogen content was 5 mg / L, and the ammonia nitrogen content was 3 mg / L.

[0064] Comparative Example 1 The sewage treatment process is the same as that in Example 1, except that acetic acid is used as an external carbon source. The details are as follows: Acetic acid is sent to the anoxic tank of the sewage treatment system as an external carbon source and mixed with the wastewater introduced into the water inlet (BOD5 / TN value is less than 3, COD is 480 mg / L, total nitrogen is 105 mg / L, and ammonia nitrogen content is 78 mg / L) at a volume ratio of 1:165. The hydraulic retention time of the anoxic tank is 0.5h, and the dissolved oxygen concentration of the anoxic tank is 0.3mg / L. The wastewater treated by denitrification in the anoxic tank enters the aerobic tank for nitrification. The hydraulic retention time of the aerobic tank is 4h, and the dissolved oxygen concentration of the aerobic tank is 4mg / L. Part of the nitrified effluent is returned to the anoxic tank with a return ratio of 3-5. The remaining effluent enters the sedimentation tank for sedimentation separation. The hydraulic retention time of the sedimentation tank is 2h. Part of the sludge is returned to the anoxic tank with a return ratio of 0.3-0.5, and the supernatant is discharged as effluent.

[0065] After testing, the COD of the effluent was 42 mg / L, the COD removal rate was 91.3%, the total nitrogen content was 15 mg / L, and the ammonia nitrogen content was 10 mg / L.

[0066] Comparative Example 2 The sewage treatment process is the same as that in Example 2, except that acetic acid is used as an external carbon source. The details are as follows: Acetic acid is sent to the anoxic tank of the sewage treatment system as an external carbon source and mixed with the wastewater introduced into the water inlet (BOD5 / TN value is less than 3, COD is 450mg / L, total nitrogen is 75mg / L, and ammonia nitrogen content is 65mg / L) at a volume ratio of 1:330. The hydraulic retention time of the anoxic tank is 1h, and the dissolved oxygen concentration of the anoxic tank is 0.2mg / L. The wastewater treated in the anoxic tank enters the aerobic tank for nitrification treatment. The hydraulic retention time of the aerobic tank is 6h, and the dissolved oxygen concentration of the aerobic tank is 6mg / L. Part of the nitrified effluent is returned to the anoxic tank with a return ratio of 3-5. The remaining effluent enters the sedimentation tank for sedimentation separation. The hydraulic retention time of the sedimentation tank is 3h. Part of the sludge is returned to the anoxic tank with a return ratio of 0.3-0.5, and the supernatant is discharged as effluent.

[0067] After testing, the COD of the effluent was 55 mg / L, the COD removal rate was 87.8%, the total nitrogen was 11 mg / L, and the ammonia nitrogen content was 6 mg / L.

[0068] Comparative Example 3 The sewage treatment process is the same as that in Example 3, except that sodium acetate is used as an external carbon source. The details are as follows: Sodium acetate is sent to the anoxic tank of the sewage treatment system as an external carbon source, and mixed with the wastewater introduced into the water inlet (BOD5 / TN value is less than 3, COD is 395 mg / L, total nitrogen is 70 mg / L, and ammonia nitrogen content is 60 mg / L) at a volume ratio of 1:170. The hydraulic retention time of the anoxic tank is 2 hours, and the dissolved oxygen concentration of the anoxic tank is 0.1 mg / L. The wastewater treated in the anoxic tank enters the aerobic tank for nitrification treatment. The hydraulic retention time of the aerobic tank is 5 hours, and the dissolved oxygen concentration of the aerobic tank is 5 mg / L. Part of the nitrified effluent is returned to the anoxic tank with a return ratio of 3-5, and the remaining effluent enters the sedimentation tank for sedimentation separation. The hydraulic retention time of the sedimentation tank is 4 hours. Part of the sludge is returned to the anoxic tank with a return ratio of 0.3-0.5, and the supernatant is discharged as effluent.

[0069] After testing, the COD of the effluent was 45 mg / L, the COD removal rate was 88.6%, the total nitrogen content was 10 mg / L, and the ammonia nitrogen content was 7 mg / L.

[0070] Comparative Example 4 This comparative example uses conventional treatment process to treat waste alkali liquor, and puts the treated waste alkali liquor into sewage treatment system, which specifically includes the following steps: a 1000kg / h2-PH waste alkali liquor (BOD5 / COD=0.24, COD is 60000mg / L, conductivity is 135500μS·cm -1 , pH=13.3), diluted 500 times with a large amount of water, industrial sulfuric acid was added to the diluted waste alkali solution for neutralization, the pH value was controlled at about 3-5, and it was sent to the anoxic tank of the AO process of the sewage treatment system, and mixed with other wastewater introduced into the water inlet (BOD5 / TN value is less than 3, COD is 450mg / L, total nitrogen is 70mg / L, and ammonia nitrogen content is 60mg / L). Acetic acid is used as an external carbon source, and the hydraulic retention time of the anoxic tank is 2 h, the dissolved oxygen concentration in the anoxic tank is 0.1 mg / L, the wastewater treated in the anoxic tank enters the aerobic tank for nitrification treatment, the hydraulic retention time of the aerobic tank is 5h, the dissolved oxygen concentration in the aerobic tank is 5mg / L, part of the nitrification effluent is returned to the anoxic tank with a return ratio of 3-5, and the remaining effluent enters the sedimentation tank for sedimentation separation, the hydraulic retention time of the sedimentation tank is 4h, part of the sludge is returned to the anoxic tank with a return ratio of 0.3-0.5, and the supernatant is discharged as effluent.

[0071] After testing, the BOD5 / COD of the waste alkali liquid after dilution and neutralization with industrial sulfuric acid was 0.52; the COD of the effluent was 80 mg / L, the total nitrogen was 55 mg / L, and the ammonia nitrogen was 35 mg / L, which was far below the GB31571 direct discharge standard. The effluent COD and total nitrogen showed an obvious upward trend over time. After 7 days, the COD reached 118 mg / L and the total nitrogen was 67 mg / L, which were equivalent to the COD and total nitrogen of the influent after dilution.

[0072] By comparing Examples 1-3 and Comparative Examples 1-3, it can be seen that compared with traditional carbon sources such as acetic acid and sodium acetate, the new carbon source obtained in the examples has a stronger promoting effect on the denitrification of microorganisms. After adding the AO biochemical device, the effluent water quality is better and the denitrification effect is stronger. Comparative Example 4 uses a conventional treatment process to treat the waste alkali liquor, and it is found that the effluent water quality does not meet the direct discharge standard. It can be seen that the BOD5 / COD ratio of the waste liquid obtained after the high-carbon alcohol waste alkali liquor of the present invention is treated by special water homogenization-acidification-ultraviolet oxidation reaches 0.65-0.82, and the biodegradability is significantly enhanced, which can be used as a new carbon source.

[0073] Obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made on the basis of the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the protection scope of the present invention.

Claims

1. A method for recycling waste alkali liquor of high-carbon alcohols, characterized in that: The steps include: (1) Waste alkali liquid is homogenized; (2) adding waste acid solution to the homogenized waste alkali solution for acidification treatment; (3) The waste liquid after acidification treatment is sent to a chromatography device for phase separation, the aqueous phase is sent to a sewage treatment system, and the organic phase is sent to an ultraviolet treatment system for ultraviolet photocatalytic oxidation treatment; (4) The organic phase after the ultraviolet catalytic oxidation treatment in step (3) is sent to the anoxic tank of the sewage treatment system as an external carbon source and mixed with other wastewater introduced. The wastewater treated in the anoxic tank enters the aerobic tank for nitrification treatment, part of the nitrified effluent is returned to the anoxic tank, the remaining effluent enters the sedimentation tank for sedimentation separation, part of the sludge is returned to the anoxic tank, and the supernatant is discharged as effluent.

2. The method for recycling waste alkali liquor of high-carbon alcohols according to claim 1, characterized in that: In step (1), the water homogenization time is 1h-10h.

3. The method for recycling waste alkali liquor of high carbon alcohols according to claim 1, characterized in that: In step (2), the pH value of the waste liquid after the acidification treatment is 3-5, and the temperature of the acidification treatment is ≤65°C.

4. The method for recycling waste alkali liquor of high-carbon alcohols according to claim 1, characterized in that: In step (3), the operating pressure of the chromatograph is normal pressure, and the operating temperature is 15°C-65°C.

5. The method for recycling waste alkali liquor of high carbon alcohol according to claim 1, characterized in that: In step (3), the ultraviolet treatment system includes a power supply, an ultraviolet lamp and a reaction tube. A quartz sleeve is arranged inside the reaction tube, and the ultraviolet lamp is installed inside the quartz sleeve. The outside of the quartz sleeve is a sewage area. Calculated based on the influent, the effective volume of the reaction tube satisfies a hydraulic retention time of 50s-100s.

6. The method for recycling waste alkali liquor of high-carbon alcohols according to claim 1, characterized in that: In step (3), the operating conditions of the ultraviolet treatment system are: ultraviolet reaction temperature is 55°C-60°C, and the ultraviolet light wavelength is 170nm-300nm.

7. The method for recycling waste alkali liquor of high-carbon alcohols according to claim 1, characterized in that: In step (4), the BOD5 / TN value of other wastewater is less than 3.

8. The method for recycling waste alkali liquor of high-carbon alcohols according to claim 1, characterized in that: In step (4), the pH of the sewage treatment system is 6-9, and the sludge age is 15-18 days; the return ratio of the nitrification effluent is 3-5, and the return ratio of the sedimentation tank sludge is 0.3-0.

5.

9. The method for recycling waste alkali liquor of high-carbon alcohols according to claim 1, characterized in that: The method meets one or more of the following characteristics: In step (4), the hydraulic retention time of the anoxic tank is 0.5h-2h; In step (4), the hydraulic retention time of the aerobic pool is 4h-6h; In step (4), the hydraulic retention time of the sedimentation tank is 2h-4h; In step (4), the dissolved oxygen concentration in the anoxic tank is 0.1 mg / L-0.3 mg / L; In step (4), the dissolved oxygen concentration in the aerobic pool is 4 mg / L-6 mg / L.

10. The method for recycling waste alkali liquor of high-carbon alcohols according to claim 1, characterized in that: The step also includes sending part of the un-homogenized waste alkali liquor directly to the aerobic tank of the sewage treatment system as added alkalinity.

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