Ammonia distillation wastewater purifying agent and treatment method

Abstract

This invention relates to a purification agent and treatment method for ammonia-containing wastewater. The purification agent aims to address the problems of high dosage, high cost, and poor purification effect of existing chemical purification agents. The treatment method aims to solve the technical problems of poor treatment effect, long treatment time, high energy consumption, complex process, and high investment cost of existing ammonia-containing wastewater treatment methods. The purification agent consists of 30%-60% cyclohexanehexaphosphate, 1%-5% hexuronic acid, 1%-10% citric acid, and the balance being distilled water and / or demineralized water. The treatment method organically combines reagent reactions (neutralization, complexation, adsorption), precipitation separation, and fiber ball filtration to achieve wastewater purification. This purification method offers good purification effect, simple operation, low investment cost, and is less likely to generate hazardous waste.

Description

Technical Field

[0001] This invention application relates to the field of coking wastewater treatment, specifically to ammonia-containing wastewater purification agents and treatment methods. Background Technology

[0002] Coking wastewater is industrial wastewater generated in the coking industry through the high-temperature dry distillation of coal and subsequent processes such as coal gas purification and chemical product recovery. It contains high concentrations of pollutants such as organic matter, phenols, ammonia nitrogen, cyanide, and polycyclic aromatic hydrocarbons. These pollutants are characterized by their reluctance to degrade, high toxicity, and high corrosiveness, making coking wastewater a toxic and harmful industrial wastewater that is difficult to treat and poses a serious threat to the environment and human health.

[0003] Ammonia stripping wastewater is a type of wastewater generated during coking wastewater treatment, primarily containing ammonia nitrogen and other organic pollutants. It originates from moisture added during coal blending and bound water in the coal. Currently, there are various methods for treating ammonia stripping wastewater, mainly falling into two categories: physicochemical and biological methods. Physicochemical methods include stripping, dynamic molecular weight extraction (MAP), breakpoint chlorination, membrane absorption, and ammonia stripping, which remove ammonia nitrogen through physical or chemical reactions. Biological methods include anaerobic ammonia oxidation, AO (anaerobic-aerobic) or AAO (anaerobic-anoxic-aerobic) processes, and membrane bioreactors, which remove ammonia nitrogen through microbial metabolic activity. Although these methods are relatively mature in removing ammonia nitrogen, they are typically time-consuming, energy-intensive, and have high operation and maintenance costs. Furthermore, the recalcitrant organic matter and highly toxic substances in ammonia stripping wastewater, such as phenols and cyanides, inhibit microbial growth, resulting in low biochemical treatment efficiency. The treated effluent may still contain a certain amount of harmful substances, making it difficult to fully meet environmental emission standards.

[0004] The information disclosed in this background section is intended only to enhance the understanding of the background technology of this disclosure and should not be construed as an admission or in any way implying that the information constitutes prior art known to those skilled in the art. Summary of the Invention

[0005] In view of the shortcomings of the existing technology, the first objective of this application is to provide an ammonia-containing wastewater purification agent, which aims to solve the problems of high dosage, high cost and poor purification effect of existing chemical purification agents; the second objective of this application is to provide an ammonia-containing wastewater purification treatment method, which aims to solve the technical problems of poor treatment effect, long time consumption, high energy consumption, complex process and high investment cost of existing ammonia-containing wastewater treatment.

[0006] According to the first aspect disclosed in this application, an ammonia-removing wastewater purification agent is provided, which, by weight percentage, is composed of the following raw materials:

[0007] Cyclohexanehexyl hexaphosphate 30%–60%, hexuronic acid 1%–5%, citric acid 1%–10%, distilled water and / or desalinated water 25%–68%.

[0008] According to another aspect of this application, a method for purifying and treating ammonia-containing wastewater is provided, comprising the following steps:

[0009] S1. The wastewater discharged from the coking ammonia stripping process is conditioned to 30-40℃ and then directed to the reaction tank;

[0010] S2, at 40-50 ml / m 3 The amount of wastewater used is to add the ammonia-containing wastewater purification agent into the reaction tank, and under stirring conditions, it reacts with the ammonia-containing wastewater to carry out chemical adsorption, and the wastewater after the reaction is led to the corresponding sedimentation tank for sedimentation;

[0011] S3. After sedimentation, the clarified liquid is sent to the corresponding mechanical filter. After at least one stage of mechanical filtration, it is sent to the circulating water tank. The settled sludge is discharged from the sedimentation tank.

[0012] In some embodiments of this disclosure, the neutralization reaction time in step S2 is ≥3h.

[0013] In some embodiments of this disclosure, the sedimentation tank in step S2 is a radial flow sedimentation tank.

[0014] In some embodiments of this disclosure, the mechanical filter in step S3 is a non-compressed fiber ball filter, and the filter media it is filled with is made by impregnating and drying fiber balls with the ammonia-removing wastewater purifying agent.

[0015] In some embodiments of this disclosure, the mechanical filter is backwashed when the inlet pressure of the mechanical filter is ≤0.15MPa.

[0016] One or more technical solutions provided in the embodiments of this application have at least one of the following technical effects or advantages:

[0017] 1. The purification agent components (cyclohexanehexyl hexaphosphate, hexuronic acid, and citric acid working together) of the ammonia-containing wastewater purifier in this application neutralize, complex, and adsorb and precipitate ammonia nitrogen, organic matter, cyanide, phenols, and other pollutants in the wastewater, thereby eliminating, passivating, or precipitating and separating these pollutants, and thus achieving the effect of rapid water purification.

[0018] 2. The ammonia-containing wastewater purification method in this application organically combines reagent reactions (neutralization, complexation, adsorption), precipitation separation, and fiber ball filtration, among other comprehensive measures. This allows for the direct treatment, purification, and recycling of ammonia-containing wastewater, enhancing purification efficiency, shortening treatment time and process time, saving treatment costs, and generating no hazardous waste. It can replace wastewater biological treatment processes, requires simple equipment, occupies a small area, is easy to operate and maintain, and has strong environmental adaptability. Attached Figure Description

[0019] Figure 1 This is a simplified process flow diagram of a single-stage treatment and purification process for ammonia-containing wastewater in one embodiment of this application.

[0020] Figure 2 This is a simplified flow chart of a multi-stage treatment and purification process for ammonia-containing wastewater in one embodiment of this application. Detailed Implementation

[0021] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0022] Unless otherwise specified, the instruments and equipment involved in the following embodiments are all conventional instruments and equipment; unless otherwise specified, the test materials and reagents involved are all commercially available; unless otherwise specified, the test and detection methods involved are all conventional methods. Example

[0023] This example discloses a method for purifying and treating ammonia-containing wastewater. (See also...) Figure 1 , Figure 2 This includes the following steps:

[0024] S1. Open the main valve for ammonia stripping wastewater, and inject the wastewater discharged from the coking ammonia stripping process into the reaction tank after the temperature drops to 30-40℃ through the cooler. The liquid level should be just before the overflow position.

[0025] S2. Turn on the stirring pump and the dosing pump, and set the dosing pump to drip at 5 ml / min. Dilute the purification agent (by weight percentage: 50% cyclohexanehexaphosphate, 5% hexuronic acid, 8% citric acid, with the remainder being demineralized water) in the agent dilution tank (the raw ammonia wastewater purifier is diluted at a ratio of 1:10) and introduce it into the reaction tank via the wastewater pipeline (45 ml of purification agent is added per cubic meter of water per hour). Under the action of the agitator, the agent reacts chemically with the ammonia wastewater for ≥3 hours. The cyclohexanehexaphosphate, hexuronic acid, and citric acid in the ammonia wastewater purifier work together to neutralize, complex, and adsorb / precipitate ammonia nitrogen, organic matter, cyanide, phenols, and other pollutants in the wastewater, thereby eliminating, passivating, or precipitating these pollutants, achieving rapid water purification. After the ammonia-containing wastewater reacts fully with the purification agent, the clarified liquid overflows into the corresponding radial flow sedimentation tank through the overflow port between the reaction tank and the radial flow sedimentation tank for sedimentation.

[0026] S3. When the wastewater level in the radial flow sedimentation tank reaches 1.6 m, open the inlet and outlet valves of the booster pump, open the vent valve of the non-compressed fiber ball filter to vent and fill the pump, then open the inlet and outlet valves of the non-compressed fiber ball filter, start the booster pump to pressurize to 0.5 MPa, and pressurize the clarified liquid after sedimentation to send it to the non-compressed fiber ball filter for at least one stage of mechanical filtration. The sludge after sedimentation is periodically transported to the bottom of the continuous sludge thickening tank in the sedimentation tank through bottom scraping and surface interception, and then discharged through a plate and frame filter press for harmless treatment. After the non-compressed fiber ball filter is filled with liquid, turn off the booster pump and send the purified wastewater to the circulating water tank. During the ammonia stripping wastewater treatment process, if the inlet pressure of the non-compressed fiber ball filter is ≤0.15 MPa, open the flushing water valve to backwash the non-compressed fiber ball filter.

[0027] The packing material in the above-mentioned non-compressed fiber ball filter is treated as follows: the fiber balls are fully immersed in the above-mentioned purifying agent for 24 hours and then dried. Example

[0028] A coking plant in Anyang constructed a phase I and a phase II ammonia-containing wastewater purification and treatment system in 2022 and 2023, respectively, and adopted the ammonia-containing wastewater purification and treatment method described in Example 1. The treatment effect on ammonia-containing wastewater was good during the commissioning and operation period.

[0029] The first sample was taken 1.5 hours after the first phase of the system was put into operation, and then samples were taken every 4 hours thereafter. Samples were taken from the main ammonia wastewater pipe, the sedimentation tank drain, and the filter drain. The sampling method was to collect samples from the drain discharge for monitoring. The test results after stable operation are shown in Table 1. As can be seen from Table 1, compared with the ammonia wastewater before purification, although the pH value and turbidity of the ammonia wastewater increased after adding the purification agent, the conductivity, chloride ion content, ammonia nitrogen content, and COD content all decreased. After adding the agent and then filtering through the non-compressed fiber ball filter, the pH value, turbidity, conductivity, chloride ion content, ammonia nitrogen content, and COD content of the ammonia wastewater all decreased significantly. This indicates that the purification agent and the fiber ball filter in the ammonia wastewater purification treatment method have a good purification effect on the wastewater quality.

[0030] Table 1. Treatment effects at different stages of ammonia-containing wastewater purification process.

[0031] .

[0032] After the first and second phases of operation were put into operation, the purification effect was stable. Random sampling was carried out on March 20, 2024. The sampling method was to collect samples from the main ammonia wastewater discharge. The test indicators and results are shown in Table 2. As can be seen from the table, compared with the ammonia wastewater before purification, the water quality of the purified water treated by the ammonia wastewater purification method described in Example 1 was significantly improved. Its COD content, NH3-N content, pH value and conductivity all decreased significantly, indicating that the ammonia wastewater purification method has a good purification effect on ammonia wastewater. The purified wastewater can be directly discharged into the circulating water tank for recycling as reclaimed water.

[0033] Table 2. Effects of ammonia-containing wastewater purification methods on ammonia-containing wastewater treatment

[0034] .

[0035] Although some preferred embodiments of this application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this application.

[0036] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of its inventive concept. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A purification agent for ammonia-containing wastewater, characterized in that, It is composed of the following raw materials by weight percentage: Cyclohexanehexyl hexaphosphate 30%–60%, hexuronic acid 1%–5%, citric acid 1%–10%, distilled water and / or desalinated water 25%–68%.

2. A method for purifying and treating ammonia-containing wastewater, characterized in that, Includes the following steps: S1. The wastewater discharged from the coking ammonia stripping process is heated to 30-40℃ and then introduced into the reaction tank; S2, at 40-50 mL / m 3 The wastewater is treated by adding the ammonia-steaming wastewater purifier described in claim 1 into the reaction tank, where it undergoes a chemical reaction and adsorption with the harmful components of the ammonia-steaming wastewater under stirring conditions, and the wastewater after the reaction is directed to the corresponding sedimentation tank for sedimentation. S3. The clarified liquid after sedimentation is led to the corresponding mechanical filter, and after at least one stage of mechanical filtration, it is sent to the circulating water tank. The sludge after sedimentation is discharged from the sedimentation tank. in In step S2, the sedimentation tank is a radial flow sedimentation tank; In step S3, the mechanical filter is a non-compressed fiber ball filter, wherein the filter media is made by impregnating and drying fiber balls with the ammonia-removing wastewater purifying agent described in claim 1.

3. The method for purifying and treating ammonia-containing wastewater according to claim 2, characterized in that, In step S3, when the inlet pressure of the mechanical filter is ≤0.15MPa, the mechanical filter is backwashed.

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