Ammonia-nitrogen wastewater treatment process and system

Abstract

The embodiment of the invention discloses an ammonia-nitrogen wastewater treatment process and system, and in the process, the ammonia-nitrogen wastewater is firstly subjected to water quality analysis to obtain the water quality state and the ammonia-nitrogen concentration of the ammonia-nitrogen wastewater, then the ammonia-nitrogen wastewater is subjected to pH adjustment to prepare for a subsequent precipitation reaction, and an agent containing magnesium ions and phosphate ions is added to obtain the ammonia-nitrogen wastewater. Ammonia nitrogen in the ammonia nitrogen wastewater is removed through a precipitation reaction, the process has a remarkable treatment effect on the high-concentration ammonia nitrogen wastewater, the ammonia nitrogen can be quickly converted into precipitates, the removal rate can reach 95% or above, the process is particularly suitable for wastewater with the ammonia nitrogen concentration of 500-5000mg / L, the precipitates generated by wastewater treatment in some specific industries can be recycled as fertilizers or other resources, and the method is suitable for industrial production. The method realizes effective utilization of resources, has good adaptability to high-concentration ammonia-nitrogen wastewater generated in different industries, and can treat the wastewater by adjusting process parameters as long as the water quality meets certain conditions. Chemical agents needed in the treatment process are conventional standard products, low in price and easy to obtain.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of wastewater treatment, and in particular to an ammonia nitrogen wastewater treatment process and system. Background Art

[0002] High-concentration ammonia nitrogen wastewater mainly comes from industries such as chemical engineering, chemical fertilizers, coking, pharmaceuticals, food processing, and landfill leachate. The wastewater from these industries has complex components, such as high salt content and high suspended solid content, resulting in poor biodegradability, high treatment difficulty, and great harm to the ecological environment.

[0003] There are two main categories of common treatment process methods for high-concentration ammonia nitrogen wastewater: ① Physicochemical methods: stripping method, gas method, adsorption method, breakpoint chlorination method, ion exchange method, etc.; ② Biological methods: traditional biological denitrification method, shortcut nitrification-denitrification method, anaerobic ammonium oxidation method, etc. For high-concentration ammonia nitrogen wastewater, the traditional physical stripping method will generate a large amount of irritating ammonia gas, and the chemical breakpoint chlorination method will consume a large amount of chemical reagents. Physicochemical methods generally have disadvantages such as harsh reaction conditions, large floor area, high energy consumption, and high operating costs; in biological methods, due to the serious inhibition and poisoning effects of high-concentration ammonia nitrogen on the microbial community, the treatment effect of high-concentration ammonia nitrogen wastewater is poor.

[0004] Although a large number of traditional ammonia nitrogen denitrification technologies have been applied, they all have technical shortcomings. Therefore, it is of great significance to develop a process for treating high-concentration ammonia nitrogen wastewater by an efficient physicochemical precipitation method. The physicochemical precipitation method for treating high-concentration ammonia nitrogen wastewater has advantages such as high treatment efficiency and resource recoverability, and can be used as the pretreatment of the overall sewage treatment process to reduce the load of the subsequent process section. This treatment process will realize the industrial application of the physicochemical precipitation method for treating high-concentration ammonia nitrogen wastewater, and improve the treatment efficiency through the automatic control of the process flow, innovating the treatment process of high-concentration ammonia nitrogen wastewater. Summary of the Invention

[0005] A series of simplified concepts are introduced in the Summary of the Invention section, which will be further elaborated in the Detailed Description section. This part of the present invention does not mean to attempt to define the key features and essential technical features of the claimed technical solution, nor does it mean to attempt to determine the protection scope of the claimed technical solution.

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art or related technologies.

[0007] To this end, the first aspect of the present invention provides an ammonia nitrogen wastewater treatment process.

[0008] The second aspect of the present invention provides an ammonia nitrogen wastewater treatment system.

[0009] In view of this, according to the first aspect of the embodiments of the present application, an ammonia nitrogen wastewater treatment process is proposed, including: Conduct a water quality analysis on the ammonia nitrogen wastewater to obtain the ammonia nitrogen concentration and pH value of the wastewater; Adjust the pH value of the ammonia nitrogen wastewater based on the pH value; Determine the dosage of the medicament based on the ammonia nitrogen concentration of the wastewater, add the medicament to the ammonia nitrogen wastewater, and use the precipitation reaction to remove the ammonia nitrogen in the ammonia nitrogen wastewater; Among them, the medicament includes magnesium ions and phosphate ions.

[0010] In a feasible implementation manner, the medicament also includes polymeric ferric sulfate and polyacrylamide.

[0011] In a feasible implementation manner, the step of using the precipitation reaction to remove the ammonia nitrogen in the ammonia nitrogen wastewater includes: removing the ammonia nitrogen in the ammonia nitrogen wastewater through the following chemical reaction: The ammonia nitrogen wastewater treatment process further includes: Removing the precipitate in the liquid.

[0012] In a feasible implementation manner, the step of adjusting the pH value of the ammonia nitrogen wastewater based on the pH value includes: Adjust the pH value of the wastewater to 9 to 10 using hydrochloric acid or sodium hydroxide; During the pH value adjustment process, the stirring speed is 90 revolutions per minute to 110 revolutions per minute. In a feasible implementation manner, the preparation of the medicament solution includes: Phosphate solution, magnesium chloride solution, polymeric ferric sulfate, hydrochloric acid and sodium hydroxide; Among them, the raw material of the phosphate solution can include phosphoric acid waste acid.

[0013] In a feasible implementation manner, the step of determining the dosage of the medicament based on the ammonia nitrogen concentration of the wastewater includes adding the medicament according to the following medicament ratio: Mg:N:P = 1.2:1:1.1; Among them, the ratio of the actual dosage of the medicament to the theoretical dosage is 105% to 110%.

[0014] In a feasible implementation manner, the step of adding the medicament to the ammonia nitrogen wastewater and using the precipitation reaction to remove the ammonia nitrogen in the ammonia nitrogen wastewater includes: At a temperature between 10 - 40 °C and a pH value between 9 - 11, react for 10 minutes to 20 minutes to precipitate the ammonia nitrogen in the ammonia nitrogen wastewater.

[0015] According to a second aspect of the embodiments of the present application, an ammonia nitrogen wastewater treatment system is proposed, which is applied to the ammonia nitrogen wastewater treatment process of any of the above technical solutions. The ammonia nitrogen wastewater treatment system includes: An adjustment tank, a primary sedimentation tank, an acid-base adjustment tank, a comprehensive treatment tank, and an acid adjustment tank that are connected in sequence; A sedimentation tank, which is connected to the comprehensive treatment tank and the acid adjustment tank; A sludge tank, which is connected to the sedimentation tank; Wherein, the comprehensive treatment tank is used for mixing reaction and sedimentation.

[0016] In a feasible implementation manner, the comprehensive treatment tank includes: A first reaction tank, a second reaction tank, and a sedimentation tank that are connected in sequence; Wherein, stirrers are arranged in the first reaction tank and the second reaction tank; Wherein, an inclined tube sedimentation area is formed in the sedimentation tank.

[0017] In a feasible implementation manner, the comprehensive treatment tank includes: A coagulant aid dosing device, which is connected to the first reaction tank and the second reaction tank.

[0018] Compared with the prior art, the present invention at least includes the following beneficial effects: The ammonia nitrogen wastewater treatment process provided by the embodiments of the present application first analyzes the water quality of the ammonia nitrogen wastewater to obtain the water quality state and ammonia nitrogen concentration of the ammonia nitrogen wastewater, then adjusts the pH of the ammonia nitrogen wastewater to prepare for the subsequent precipitation reaction, and then adds a reagent including magnesium ions and phosphate ions. Through the precipitation reaction, the ammonia nitrogen in the ammonia nitrogen wastewater is removed. This process has a significant treatment effect on high-concentration ammonia nitrogen wastewater, can quickly convert ammonia nitrogen into precipitation, and the removal rate can reach more than 95%. It is especially suitable for wastewater with an ammonia nitrogen concentration of 500-5000 mg / L. The precipitation generated by treating wastewater from certain specific industries (industries without heavy metals or toxic substances) can be recycled as fertilizers or other resources, realizing the effective utilization of resources, having certain economic value, and having good adaptability to high-concentration ammonia nitrogen wastewater generated by different industries. As long as the water quality meets certain conditions, it can be treated by adjusting process parameters. The chemical reagents required during the treatment process are all conventional standard products, with low prices and easy access.

[0019] The above description is only an overview of the technical solution of the present invention. In order to be able to understand the technical means of the present invention more clearly, it can be implemented according to the content of the specification. And in order to make the above and other purposes, features, and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are specifically exemplified below. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] By reading the following detailed description of the preferred embodiments, various other advantages and benefits will become clear to those of ordinary skill in the art. The drawings are only for the purpose of showing the preferred embodiments and are not considered to be a limitation of the present application. Moreover, throughout the drawings, the same reference numerals are used to represent the same components. In the drawings: Figure 1 It is a schematic step flow chart of an ammonia nitrogen wastewater treatment process according to an embodiment provided by the present application; Figure 2 It is a schematic flow chart of an ammonia nitrogen wastewater treatment system according to an embodiment provided by the present application; Figure 3 It is a schematic structural diagram of an ammonia nitrogen wastewater treatment system according to an embodiment provided by the present application; Figure 4 It is a schematic structural diagram of a comprehensive treatment tank of an ammonia nitrogen wastewater treatment system according to an embodiment provided by the present application.

[0021] Among them, Figures 1 to 4 The corresponding relationship between the reference numerals and the component names in the figure is as follows: 110 regulating tank, 120 primary sedimentation tank, 130 acid-base regulating tank, 140 comprehensive treatment tank, 150 acid-adjusting tank, 160 sedimentation tank; 1 ultrasonic level gauge, 2 lift pump, 3 process pipeline, 4 electromagnetic flowmeter, 5 PAC dosing device, 6 first PAM dosing device, 7 alkali (acid) dosing device, 8 first pH meter, 9 ammonia nitrogen on-line analyzer, 10 magnesium chloride dosing device, 11 phosphate dosing device, 12 polyferric sulfate dosing device, 13 second PAM dosing device, 14 first reaction tank, 15 second reaction tank, 16 coagulation tank, 17 flocculation tank, 18 inclined tube sedimentation area, 19 total phosphorus on-line analyzer, 20 acid dosing device, 21 second pH meter, 22 sludge discharge electric valve, 23 mixer. Specific embodiments

[0022] In the following description, a large number of specific details are given in order to provide a more thorough understanding of the technical solutions provided by the present invention. However, it is obvious to those skilled in the art that the technical solutions provided by the present invention can be implemented without one or more of these details.

[0023] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present invention. As used herein, unless the context clearly indicates otherwise, the singular forms are also intended to include the plural forms. In addition, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they specify the presence of the described features, wholes, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, wholes, steps, operations, elements, components, and / or combinations thereof.

[0024] Now, exemplary embodiments according to the present invention will be described in more detail with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many different forms and should not be construed as being limited only to the embodiments set forth herein. It should be understood that these embodiments are provided so that the disclosure of the present invention is thorough and complete, and the concept of these exemplary embodiments is fully conveyed to those of ordinary skill in the art.

[0025] As Figure 1 shown, a process for treating ammonia nitrogen wastewater is proposed according to the first aspect of the embodiments of the present application, including: Step 101: Analyze the water quality of the ammonia nitrogen wastewater to obtain the ammonia nitrogen concentration and pH value of the wastewater. It can be understood that in addition to analyzing the ammonia nitrogen concentration and pH value of the wastewater, the suspended solids and other ionic components can also be analyzed to make the subsequent treatment more targeted.

[0026] Step 102: Adjust the pH value of the ammonia nitrogen wastewater based on the pH value. It can be understood that an acid-base adjustment tank can be set up, and according to the water quality analysis results, hydrochloric acid or sodium hydroxide is used to adjust the pH value of the wastewater to an appropriate range. During the adjustment process, a stirring device is required to evenly distribute the acid or base in the wastewater, and the stirring speed is generally controlled at 100 revolutions per minute. The pH adjustment process uses PID automatic adjustment to control the amount of acid or base added to avoid excessive fluctuations in the pH value and make the pH adjustment more accurate.

[0027] Step 103: Determine the dosage of the reagent based on the ammonia nitrogen concentration of the wastewater, add the reagent to the ammonia nitrogen wastewater, and use the precipitation reaction to remove the ammonia nitrogen in the ammonia nitrogen wastewater; wherein, the reagent includes magnesium ions and phosphate ions.

[0028] The ammonia nitrogen wastewater treatment process provided by the embodiments of the present application first analyzes the water quality of the ammonia nitrogen wastewater to obtain the water quality status and ammonia nitrogen concentration of the ammonia nitrogen wastewater. Then, the pH of the ammonia nitrogen wastewater is adjusted to prepare for the subsequent precipitation reaction. After that, a reagent including magnesium ions and phosphate ions is added, and through the precipitation reaction, the ammonia nitrogen in the ammonia nitrogen wastewater is removed. This process has a remarkable treatment effect on high-concentration ammonia nitrogen wastewater, can quickly convert ammonia nitrogen into precipitation, and the removal rate can reach more than 95%. It is especially suitable for wastewater with an ammonia nitrogen concentration of 500-5000 mg / L. The precipitation generated by treating the wastewater of certain specific industries (industries without heavy metals or toxic substances) can be recycled as fertilizers or other resources, realizing the effective utilization of resources, having certain economic value, and having good adaptability to high-concentration ammonia nitrogen wastewater generated by different industries. As long as the water quality meets certain conditions, it can be treated by adjusting the process parameters. The chemical reagents required in the treatment process are all conventional standard products, with low prices and easy access.

[0029] In some examples, before the precipitation reaction, an initial sedimentation tank can be set up. Excessive suspended solids and impurities will affect the progress and treatment effect of the chemical reaction. The initial sedimentation tank can be used to remove the suspended solids and impurities in the wastewater to prevent them from interfering with the subsequent precipitation reaction or making the precipitate contain impurities and affecting the comprehensive utilization of the precipitate.

[0030] In a feasible implementation manner, the reagent also includes ferric sulfate and polyacrylamide.

[0031] In this technical solution, considering that phosphorus is introduced in the wastewater treatment, in order to reduce the difficulty of phosphorus removal in the subsequent process, ferric sulfate and polyacrylamide are added to the sedimentation tank of this process. While removing phosphorus with iron salts, precipitation is promoted. The process provided by the embodiments of the present application is used as a pretreatment process for high-concentration ammonia nitrogen wastewater to remove both ammonia nitrogen and phosphorus at the same time, reducing the load for the subsequent process.

[0032] In a feasible implementation manner, the step of removing the ammonia nitrogen in the ammonia nitrogen wastewater by using the precipitation reaction includes: removing the ammonia nitrogen in the ammonia nitrogen wastewater through the following chemical reaction: The ammonia nitrogen wastewater treatment process also includes: Removing the precipitate in the liquid.

[0033] In this technical solution, a specific way of chemical reaction is further provided. This process uses specific reagents to react with ammonia nitrogen in wastewater to form a precipitate, transferring ammonia nitrogen from the liquid phase to the solid phase, and then achieving the purpose of removing ammonia nitrogen through precipitation separation. It replaces the ammonia nitrogen treatment process in traditional technologies, has a remarkable treatment effect on high-concentration ammonia nitrogen wastewater, can quickly convert ammonia nitrogen into a precipitate, and the removal rate can reach over 95%. It is especially suitable for wastewater with an ammonia nitrogen concentration of 500 - 5000 mg / L. The precipitate generated from wastewater treatment can be recycled as fertilizer or other resources, realizing the effective utilization of resources and having certain economic value. It has good adaptability to high-concentration ammonia nitrogen wastewater generated from different industries. As long as the water quality meets certain conditions, it can be treated by adjusting process parameters.

[0034] In this technical solution, after the precipitation reaction is completed, the precipitate in the liquid can also be removed to achieve solid-liquid separation. Both the liquid and the precipitate can be recycled. Specifically, the precipitation method uses an inclined tube sedimentation tank, and the water inlet method is from bottom to top. Let the wastewater after the reaction precipitate in the sedimentation tank. The precipitation time depends on the actual situation, generally 1.5 hours, so that the generated precipitate fully settles to the bottom of the inclined tube sedimentation tank. The precipitate is regularly discharged to a concentration tank, and the supernatant enters the subsequent process for in-depth treatment. After the separated precipitate is mechanically dewatered, it is washed, dried, etc., and can be recycled as fertilizer or other resources.

[0035] It can be understood that the generated magnesium ammonium phosphate precipitate has certain value and can be used as a raw material for slow-release compound fertilizer; or after heating, it generates magnesium oxide, ammonia gas and phosphoric acid, realizing waste resource utilization.

[0036] In a feasible implementation manner, the steps of adjusting the pH value of ammonia nitrogen wastewater based on acidity and alkalinity include: using hydrochloric acid or sodium hydroxide to adjust the pH value of the wastewater to 9 - 10; during the process of adjusting the pH value, the stirring speed is 90 - 110 revolutions per minute. With such settings, it is more conducive to the precipitation reaction. In some examples, more preferably, using hydrochloric acid or sodium hydroxide to adjust the pH value of the wastewater to 9.5 can make the precipitation reaction more efficient. More preferably, the stirring speed is 100 revolutions per minute, which can improve the pH adjustment efficiency.

[0037] In a feasible implementation manner, the solution for preparing the reagent includes: phosphate solution, magnesium chloride solution, polyferric sulfate, hydrochloric acid and sodium hydroxide; among them, the raw material of the phosphate solution can include phosphoric acid waste acid.

[0038] In this technical solution, the specific component composition of the reagent is further provided. The reagent can include the following components: Phosphate solution: Phosphoric acid waste acid is preferred, with an effective content of over 30%; secondly, sodium hydrogen phosphate is selected, with a configured concentration of 10%. The recycled phosphoric acid waste liquid (such as industrial by-products) is used to replace the traditional phosphate as the phosphorus source, and inexpensive magnesium chloride is used as the magnesium source, significantly reducing the treatment cost; Magnesium chloride solution: The configured concentration is 10%; Polyferric sulfate: A liquid with an effective content of 10%; Hydrochloric acid: 31% industrial hydrochloric acid; Sodium hydroxide: 30% liquid. Based on this, the precipitation reaction can be carried out between the reagent and the ammonia nitrogen wastewater to remove the ammonia nitrogen in the waste liquid.

[0039] In a feasible implementation manner, the step of determining the reagent addition amount based on the ammonia nitrogen concentration in the wastewater includes adding the reagents according to the following reagent ratio: Mg:N:P = 1.2:1:1.1; Among them, the ratio of the actual reagent addition amount to the theoretical addition amount is 105% to 10%.

[0040] In this technical solution, by optimizing the dosing ratio of the phosphoric acid waste liquid and magnesium chloride, the ammonia nitrogen removal rate ≥ 95% is achieved, while reducing reagent waste. In a feasible implementation manner, the steps of adding reagents to the ammonia nitrogen wastewater and using the precipitation reaction to remove the ammonia nitrogen in the ammonia nitrogen wastewater include: At a temperature between 10 - 40 °C and a pH value between 9 and 19, react for 10 to 20 minutes to precipitate the ammonia nitrogen in the ammonia nitrogen wastewater.

[0041] In this technical solution, according to the ammonia nitrogen concentration and water volume in the wastewater, the dosing amount of the required reagent is calculated. It can be dosed according to the stoichiometric ratio. According to the ammonia nitrogen concentration, the dosing ratio is Mg:N:P = 1.2:1:1.1. Considering the actual situation, a certain proportion (5% - 10%) can be appropriately overdosed to ensure the full removal of ammonia nitrogen. The reagent is prepared into a solution with a certain concentration and slowly added to the wastewater with the pH value adjusted through a metering pump. At the same time, a stirring device is used for stirring, and the stirring speed is 100 revolutions per minute to ensure the full mixing of the reagent and the wastewater. The reaction time is about 15 minutes. This can further improve the efficiency of the precipitation reaction.

[0042] In this technical solution, the pH value (9.5), reaction time (15 minutes), and temperature (10 - 40 °C) are precisely regulated to ensure the efficient precipitation of magnesium ammonium phosphate and simultaneously inhibit side reactions.

[0043] It can be understood that during the precipitation reaction process, reaction condition control is required: during the precipitation reaction process, it is necessary to ensure that the temperature of the wastewater is between 10 - 40 °C. Too high or too low temperature may affect the rate and effect of the precipitation reaction. The pH should be controlled at 9.5, and corresponding beaker experiments should be carried out for different water qualities to promote the reaction.

[0044] The process provided by the embodiments of the present application uses phosphoric acid waste liquid + magnesium chloride as a precipitant and a specific combination of treatment processes, including a unique combination of specific precipitant types and combinations, pH control ranges, chemical dosages, reaction times, stirring speeds, etc., to achieve efficient ammonia nitrogen removal and precipitate generation, highlighting low cost and waste recycling. A unique and cost - effective source of precipitant is used, such as using industrial by - products or waste as a magnesium source or a phosphorus source, as well as corresponding usage methods and treatment steps.

[0045] As Figures 2 to 4 As shown, according to the second aspect of the embodiments of the present application, an ammonia nitrogen wastewater treatment system is proposed, which is applied to the ammonia nitrogen wastewater treatment process of any of the above - mentioned technical solutions. The ammonia nitrogen wastewater treatment system includes: an adjustment tank 110, a primary sedimentation tank 120, an acid - base adjustment tank 130110, a comprehensive treatment tank 140, and an acid - adjustment tank 150 that are connected in sequence; a sedimentation tank 160, where the sedimentation tank 160 is connected to the comprehensive treatment tank 140 and the acid - adjustment tank 150; a sludge tank, where the sludge tank is connected to the sedimentation tank 160; a solid - liquid separation device, where the solid - liquid separation device is connected to the sedimentation tank 160, and the moisture content of the precipitate is dehydrated to less than 60% through a plate - and - frame filter press, facilitating the comprehensive utilization of the precipitate; among them, the comprehensive treatment tank 140 is used for mixing reaction and sedimentation.

[0046] Since the ammonia nitrogen wastewater treatment system provided by the embodiments of the present application is applied to the ammonia nitrogen wastewater treatment process of any of the above - mentioned technical solutions, the ammonia nitrogen wastewater treatment system has all the beneficial effects of the ammonia nitrogen wastewater treatment process of the above - mentioned technical solutions.

[0047] The regulating tank 110 of the ammonia nitrogen wastewater treatment system provided by the embodiments of the present application is used to receive the supernatant output via other supplies. The water volume can be regulated and the water quality can be balanced through the regulating tank 110. Primary sedimentation tank 120: According to the water quality situation, if the suspended solid content in the wastewater is relatively high, the primary sedimentation tank 120 should be set up. It can remove the suspended solids and impurities in the wastewater to prevent them from interfering with the subsequent precipitation reaction. It is equipped with an automatic coagulant and flocculant dosing system, a stirring device, etc. The acid-base regulating tank 130 is used to adjust the pH value of the wastewater. It is equipped with a stirring device, an automatic dosing system (including an acid tank or an alkali tank), a pH meter, etc., to automatically and accurately adjust the pH value of the wastewater to meet the process requirements. The comprehensive treatment tank 140 is used for mixing reaction and precipitation. The reaction section is equipped with a stirring device and an automatic dosing system to ensure full mixing and reaction of the reagent and the wastewater. An online ammonia nitrogen analyzer is set at the inlet of the reaction tank, and the automatic dosing system is accurately adjusted according to the ammonia nitrogen concentration in the influent water. The precipitation section is designed based on the inclined tube sedimentation tank 160 for precipitation separation to improve the precipitation efficiency. A sludge discharge port is provided at the bottom and an electric valve is installed to facilitate the collection of precipitation. Polyacrylamide (PAM) and polyferric sulfate (PFS) are added into the inclined tube sedimentation tank 160 for phosphorus removal and promoting precipitation, reducing the total phosphorus content in the wastewater entering the subsequent process. The acid adjustment tank 150 is used to adjust the pH to meet the requirements of the subsequent process. The sludge tank is used to concentrate the precipitation discharged from the inclined tube sedimentation tank 160, reduce the moisture content, and facilitate solid-liquid separation. The solid-liquid separation equipment is used to set up a plate and frame filter press to control the moisture content of the dehydrated precipitation below 60% and then carry out comprehensive utilization.

[0048] Based on this, through the ammonia nitrogen wastewater treatment system provided by the embodiments of the present application combined with the ammonia nitrogen wastewater treatment process, the treatment effect on high-concentration ammonia nitrogen wastewater is remarkable. The ammonia nitrogen can be quickly converted into precipitation, and the removal rate can reach more than 95%. It is especially suitable for wastewater with an ammonia nitrogen concentration of 500 - 5000 mg / L. The precipitation generated from the wastewater treatment in certain specific industries (industries without heavy metals or toxic substances) can be recycled as fertilizers or other resources, realizing the effective utilization of resources, having certain economic value, and having good adaptability to high-concentration ammonia nitrogen wastewater generated by different industries. As long as the water quality meets certain conditions, it can be treated by adjusting the process parameters. The chemical reagents required during the treatment process are all conventional standard products, with low prices and easy access. This system can improve the reaction efficiency, reduce the floor area, and lower the energy consumption.

[0049] In some examples, the ammonia nitrogen wastewater treatment system may further include an automatic control system: This process flow is integrated on a programmable logic controller, integrating instrument devices such as a pH meter, an ammonia nitrogen online analyzer 9, a total phosphorus online analyzer 19, a variable-frequency metering pump, and an ultrasonic level gauge 1. It can automatically add the drug dosage according to the monitored parameters, realizing the full-automatic visual operation of the process system.

[0050] In a feasible implementation, the comprehensive treatment tank 140 includes: a first reaction tank 14, a second reaction tank 15, and a sedimentation tank 160 that are connected in sequence; wherein, stirrers 23 are arranged in the first reaction tank 14 and the second reaction tank 15; wherein, an inclined tube sedimentation area 18 is formed in the sedimentation tank 160. With such a setting, the efficiency of the sedimentation reaction can be improved, and at the same time, it is convenient for the sedimentation of sediments.

[0051] In a feasible implementation, the comprehensive treatment tank 140 includes: a coagulant aid dosing device that is connected to the first reaction tank 14 and the second reaction tank 15. With such a setting, the sedimentation efficiency of the sediment can be further improved.

[0052] In some examples, the ammonia nitrogen wastewater treatment system may further include an ultrasonic level gauge 1, a lift pump 2, a process pipeline 3, and an electromagnetic flowmeter 4 arranged within the regulation tank 110 to better control the liquid level, output the liquid, and count the output flow rate. The primary sedimentation tank 120 may also be connected to a PAC dosing device 5 and a first PAM dosing device 6 to facilitate the addition of chemicals. The acid-base regulation tank 130110 may be connected to an alkali (acid) addition device 7, a first pH meter 8, and an ammonia nitrogen on-line analyzer 9 to facilitate the adjustment of the pH value of the waste liquid and the analysis of ammonia nitrogen. The comprehensive treatment tank 140 may also be connected to a magnesium chloride dosing device 10, a phosphate dosing device 11, a polyferric sulfate dosing device 12, and a second PAM dosing device 13 to facilitate the addition of chemicals. The comprehensive treatment tank 140 may also form a coagulation tank 16 and a coagulant aid tank 17 to improve the efficiency of the sedimentation reaction. The comprehensive treatment tank 140 may also be connected to a total phosphorus on-line analyzer 19 to facilitate the monitoring of the total phosphorus content of the liquid output via the comprehensive treatment tank 140. The acid adjustment tank 150 may also be connected to an acid addition device 20 and a second pH meter 21 to facilitate the control of the acidity of the output liquid. A sludge discharge electric valve 22 may also be provided between the sludge tank and the comprehensive treatment tank 140.

[0053] Example 1: Take the wastewater containing high-concentration ammonia nitrogen from a pharmaceutical factory. After testing: the suspended solid content is 318 mg / L, the ammonia nitrogen content is 3715 mg / L, and the pH is 5.3. Add the prepared 10% PAC solution and 0.1% PAM solution to the primary sedimentation tank 120 at the dosing rates of 5 ml / L and 2 ml / L respectively to remove the suspended solids in the wastewater. After testing, the suspended solid content of the effluent from the primary sedimentation tank 120 is 52 mg / L, and the removal rate is 83.65%. The effluent from the primary sedimentation tank 120 enters the acid-base adjustment tank 130110, and 30% liquid caustic soda is added. The dosing amount of the liquid caustic soda is automatically controlled by the pH meter at the outlet of the primary sedimentation tank 120 to make the effluent pH stable at 9.5. The effluent from the acid-base adjustment tank 130110 enters the comprehensive reaction tank. At this time, the ammonia nitrogen online analyzer 9 is required to analyze the ammonia nitrogen concentration. According to the ratio of Mg:N:P = 1.2:1:1.1, the dosing amount is calculated by the control system and the reagent is automatically added. Among them, 10% magnesium chloride solution is added to the first reaction tank 14 and stirred at a stirring speed of 100 revolutions per minute for 15 minutes. Then the wastewater flows by gravity into the second reaction tank 15, and 30% phosphoric acid waste acid with a certain concentration is added and stirred at a stirring speed of 100 revolutions per minute for 15 minutes. Then the wastewater flows by gravity into the coagulation tank 16, and 10% polyferric sulfate solution is added and stirred at a stirring speed of 100 revolutions per minute for 15 minutes. The dosing amount of the polyferric sulfate solution is automatically adjusted by the total phosphorus online analyzer 19 in the inclined tube sedimentation area 18, and the total phosphorus is controlled at 5 mg / L. Then the wastewater flows by gravity into the coagulant aid tank 17, and 0.1% PAM solution is added and continues to be stirred at a stirring speed of 100 revolutions per minute for 15 minutes. Then it flows by gravity into the inclined tube sedimentation area 18 for solid-liquid separation. The ammonia nitrogen measured at the end of the inclined tube sedimentation area 18 is 146.64 mg / L. Then it flows by gravity into the acid adjustment tank 150, and 31% industrial hydrochloric acid is added. The dosing amount of the hydrochloric acid is automatically controlled by the pH meter at the outlet of the acid adjustment tank 150 to make the effluent pH stable at 8. Then the wastewater enters the subsequent treatment process. The sludge in the primary sedimentation tank 120 enters the sludge tank of the subsequent process for combined treatment, and the supernatant is refluxed to the adjustment tank 110. The sludge in the inclined tube sedimentation area 18 of the comprehensive treatment tank 140 enters the sludge tank separately. After precipitation and dehydration, it is further comprehensively utilized. The supernatant and the press filtrate of the sludge tank enter the acid adjustment tank 150. After analysis, the suspended solid content of the effluent from the primary sedimentation tank 120 is reduced from 318 mg / L to 52 mg / L, and the removal rate is 83.65%, meeting the requirements of the subsequent process treatment. The ammonia nitrogen is reduced from 3715 mg / L to 146.64 mg / L, and the removal rate is 96.05%. The total phosphorus is 5 mg / L, and the pH is 8. This process reduces the load for the subsequent biochemical process.

[0054] Example 2: Take the leachate from a domestic waste landfill. After testing, the suspended solid content is 167.2 mg / L, the ammonia nitrogen content is 1255.7 mg / L, and the pH is 7.6. Add the prepared 10% PAC solution and 0.1% PAM solution to the primary sedimentation tank 120 at the dosing rates of 5 ml / L and 2 ml / L respectively to remove the suspended solids in the wastewater. After testing, the suspended solid content of the effluent from the primary sedimentation tank 120 is 38.4 mg / L, and the removal rate is 77.03%. The effluent from the primary sedimentation tank 120 enters the acid-base adjustment tank 130110, and 30% liquid caustic soda is added. The dosing amount of the liquid caustic soda is automatically controlled by the pH meter at the outlet of the primary sedimentation tank 120 to keep the effluent pH stable at 9.5. The effluent from the acid-base adjustment tank 130110 enters the comprehensive reaction tank. At this time, the ammonia nitrogen concentration needs to be analyzed by the ammonia nitrogen on-line analyzer 9. After calculating the dosing amount by the control system according to the ratio of Mg:N:P = 1.2:1:1.1, the reagent is automatically added. Among them, 10% magnesium chloride solution is added to the first reaction tank 14 and stirred at a stirring speed of 100 revolutions per minute for 15 minutes. Then the wastewater flows by gravity into the second reaction tank 15, and 30% phosphoric acid waste acid with a certain concentration is added and stirred at a stirring speed of 100 revolutions per minute for 15 minutes. Then the wastewater flows by gravity into the coagulation tank 16, and 10% polyferric sulfate solution is added and stirred at a stirring speed of 100 revolutions per minute for 15 minutes. The dosing amount of the polyferric sulfate solution is automatically adjusted by the total phosphorus on-line analyzer 19 in the inclined tube sedimentation area 18 to control the total phosphorus at 5 mg / L. Then the wastewater flows by gravity into the coagulant aid tank 17, and 0.1% PAM solution is added and continues to be stirred at a stirring speed of 100 revolutions per minute for 15 minutes. Then it flows by gravity into the inclined tube sedimentation area 18 for solid-liquid separation. The ammonia nitrogen measured at the end of the inclined tube sedimentation area 18 is 44.33 mg / L. Then it flows by gravity into the acid adjustment tank 150, and 31% industrial hydrochloric acid is added. The dosing amount of the hydrochloric acid is automatically controlled by the pH meter at the outlet of the acid adjustment tank 150 to keep the effluent pH stable at 8. Then the wastewater enters the subsequent treatment process. The sludge from the primary sedimentation tank 120 enters the sludge tank of the subsequent process for combined treatment, and the supernatant is refluxed to the adjustment tank 110; the sludge in the inclined tube sedimentation area 18 of the comprehensive treatment tank 140 enters the sludge tank separately. After precipitation and dehydration, it is further comprehensively utilized, and the supernatant and the pressure filtrate of the sludge tank enter the acid adjustment tank 150. After analysis, the suspended solid content of the effluent from the primary sedimentation tank 120 is reduced from 167.2 mg / L to 38.4 mg / L, and the removal rate is 77.03%, meeting the requirements of the subsequent process treatment; the ammonia nitrogen is reduced from 1255.7 mg / L to 44.35 mg / L, and the removal rate is 96.47%; the total phosphorus is 5 mg / L, and the pH is 8. This process reduces the load for the subsequent biochemical process.

[0055] In the present invention, the terms "first", "second", "third" are for descriptive purposes only and should not be construed as indicating or implying relative importance; the term "plural" means two or more, unless otherwise clearly defined. Terms such as "installed", "connected", "joined", "fixed" and the like should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "joined" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0056] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation to the present invention.

[0057] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "specific embodiments", 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 representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0058] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A process for treating ammonia nitrogen wastewater, characterized in that: include: Conduct water quality analysis on ammonia nitrogen wastewater to obtain the ammonia nitrogen concentration and pH value of the wastewater; Adjusting the pH value of the ammonia nitrogen wastewater based on the pH value; Determine the amount of reagent to be added based on the ammonia nitrogen concentration of the wastewater, add the reagent to the ammonia nitrogen wastewater, and use precipitation reaction to remove ammonia nitrogen in the ammonia nitrogen wastewater; Wherein, the medicine includes magnesium ions and phosphate ions.

2. The ammonia nitrogen wastewater treatment process according to claim 1, characterized in that: The medicament also includes ferric sulfate and polyacrylamide.

3. The ammonia nitrogen wastewater treatment process according to claim 1, characterized in that: The steps of removing ammonia nitrogen from ammonia nitrogen wastewater by precipitation reaction include: removing ammonia nitrogen from ammonia nitrogen wastewater by the following chemical reaction: The ammonia nitrogen wastewater treatment process also includes: Remove sediment from liquids.

4. The ammonia nitrogen wastewater treatment process according to claim 1, characterized in that: The step of adjusting the pH value of the ammonia nitrogen wastewater based on the pH value comprises: Use hydrochloric acid or sodium hydroxide to adjust the pH value of the wastewater to 9-10; During the pH adjustment process, the stirring speed is 90 to 110 rpm.

5. The ammonia nitrogen wastewater treatment process according to claim 1, characterized in that: The solution for preparing the medicament comprises: Phosphate solution, magnesium chloride solution, polyferric sulfate, hydrochloric acid and sodium hydroxide; The raw material of the phosphate solution may include waste phosphoric acid.

6. The ammonia nitrogen wastewater treatment process according to claim 1, characterized in that: The step of determining the amount of reagent to be added based on the ammonia nitrogen concentration of the wastewater includes adding the reagent using the following reagent ratio: Mg:N:P=1.2:1:1.1; Among them, the ratio of the actual amount of agent added to the theoretical amount of agent added is 105% to 10%.

7. The ammonia nitrogen wastewater treatment process according to claim 1, characterized in that: The steps of adding a reagent to the ammonia nitrogen wastewater and removing ammonia nitrogen from the ammonia nitrogen wastewater by precipitation reaction include: At a temperature between 10-40°C and a pH between 9 and 19, the reaction is carried out for 10 to 20 minutes to precipitate the ammonia nitrogen in the ammonia nitrogen wastewater.

8. An ammonia nitrogen wastewater treatment system, characterized in that: Applied to the ammonia nitrogen wastewater treatment process according to any one of claims 1 to 7, the ammonia nitrogen wastewater treatment system comprises: The regulating tank, primary sedimentation tank, acid-base regulating tank, comprehensive treatment tank and acid regulating tank are connected in sequence; A sedimentation tank, the sedimentation tank is connected to the comprehensive treatment tank and the acid adjustment tank; A sludge tank, wherein the sludge tank is connected to the sedimentation tank; Wherein, the comprehensive treatment pool is used for mixing reaction and precipitation.

9. The ammonia nitrogen wastewater treatment system according to claim 8, characterized in that: The comprehensive treatment pool comprises: A first reaction tank, a second reaction tank and a sedimentation tank connected in sequence; Wherein, a stirrer is provided in the first reaction tank and the second reaction tank; Wherein, an inclined tube sedimentation area is formed in the sedimentation tank.

10. The ammonia nitrogen wastewater treatment system according to claim 9, characterized in that: The comprehensive treatment pool comprises: A coagulant-aiding and dosing device is connected to the first reaction tank and the second reaction tank.

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