A recycling and treatment process for high-salinity wastewater

Abstract

This invention provides a process for the recycling and treatment of high-salinity wastewater, relating to the field of wastewater treatment technology. The process includes: Step 1: Analyzing the organic composition of various high-salinity wastewaters to determine the composition and content of materials; Step 2: Developing corresponding treatment plans for the specific components of each high-salinity wastewater; Step 3: Treating the high-salinity wastewater according to the treatment plan, and adjusting and optimizing the plan to remove organic matter and reduce the color of the high-salinity wastewater; Step 4: Evaporating the treated wastewater to precipitate salt, preparing qualified by-product salt or by-product sodium sulfite. Compared to traditional methods of removing organic matter from wastewater such as Fenton oxidation and biochemical processes, this invention is cleaner, more environmentally friendly, and more effective, significantly reducing the treatment cost of high-salinity wastewater.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically a process for the recovery and treatment of high-salinity wastewater. Background Technology

[0002] High-salinity wastewater treatment involves reducing the COD and ammonia nitrogen content in the wastewater and separating the salt content to achieve the recovery and utilization of industrial salt and freshwater. Currently, there are more than ten methods for treating high-salinity wastewater, including electrodialysis, evaporation crystallization, membrane separation, ion exchange, incineration, biological methods, oxidation-reduction methods, and coagulation sedimentation.

[0003] The integration of distillation and biochemical methods is used for high-salinity, biodegradable wastewater. First, a multi-effect evaporation, concentration, and crystallization process is employed for pretreatment to reduce the concentration of soluble inorganic salt ions, followed by COD removal using a suitable activated sludge method. Similarly, the integration of distillation and incineration methods is used for high-COD, high-calorific-value wastewater. Pretreatment is followed by incineration to ensure the wastewater meets discharge standards. In addition to treating high-salinity wastewater, increasing emphasis is placed on resource recovery and utilization. For example, specific processes and technologies are used to convert the salts in the wastewater into usable products.

[0004] Currently, high-salinity wastewater treatment methods, such as Fenton oxidation and biochemical methods for removing organic matter from wastewater, have the following problems: they cannot completely remove organic matter from the wastewater, resulting in waste salt containing a large amount of organic matter, which cannot be used as a by-product for resource utilization; they are not clean enough and are costly. Summary of the Invention

[0005] This invention provides a process for the recycling and treatment of high-salinity wastewater, which solves at least one of the technical problems mentioned in the background art.

[0006] To address the aforementioned technical problems, this invention discloses a high-salinity wastewater recycling and treatment process, comprising:

[0007] Step 1: Analyze the organic composition of each high-salinity wastewater to determine the composition and content of materials in the wastewater;

[0008] Step 2: Develop corresponding treatment plans for the specific components of each high-salinity wastewater;

[0009] Step 3: Treat the high-salinity wastewater according to the treatment plan, and adjust and optimize the plan to remove organic matter and reduce the color of the high-salinity wastewater;

[0010] Step 4: Evaporate the treated wastewater to obtain qualified by-product salt or by-product sodium sulfite.

[0011] Preferably, the high-salinity wastewater is quizalofop-P-ethyl cyclized acidified wastewater, and the treatment process of the quizalofop-P-ethyl cyclized acidified wastewater includes the following steps:

[0012] Step 3001: Add liquid alkali to the acidified wastewater containing quizalofop-P-ethyl cyclamate to adjust it to a certain pH value;

[0013] Step 3002: Add hydrogen peroxide and heat to a certain temperature, then maintain the temperature for the reaction;

[0014] Step 3003: After the reaction is complete, add liquid alkali to neutralize and filter to remove residue;

[0015] Step 3004: Add activated carbon to the filtrate for decolorization and filtration;

[0016] The filtrate obtained in step 4 and step 3004 above is evaporated and salt is precipitated by MVR. The crude wet salt is then added to saturated brine, pulped at room temperature, and centrifuged to obtain the final by-product wet salt.

[0017] The filtered waste residue is sent to qualified units for treatment, the mother liquor from evaporation and concentration is sent to the "three wastes" biochemical treatment, and the mother liquor from pulping and centrifugation is reused for evaporation and salt precipitation.

[0018] Preferably, the high-salinity wastewater is DHPPA secondary acidification wastewater, and the treatment process of the DHPPA secondary acidification wastewater includes the following steps:

[0019] Step 311: After the DHPPA secondary acidification wastewater is adsorbed by the resin, liquid alkali is added for neutralization;

[0020] Step 312: After the resin regeneration is completed, the wastewater obtained in step 311 is transferred back into the resin for secondary adsorption and decolorization. The resin after decolorization and adsorption does not need to be regenerated and can be directly used for the next batch of wastewater adsorption.

[0021] In step 4, the decolorized effluent obtained in step 3 is evaporated at the MVR to precipitate salt, yielding wet salt as a byproduct.

[0022] The concentrated mother liquor from evaporation is combined with the secondary acidification wastewater from DHPPA and then subjected to resin adsorption treatment.

[0023] The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined, liquid alkali is added for neutralization and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue from the distillation kettle is sent to a qualified unit for treatment.

[0024] Preferably, the high-salinity wastewater is nicotinic acid wastewater;

[0025] When the nicotinic wastewater is a monoamined wastewater of nicotinic acid, the treatment process of the monoamined wastewater of nicotinic acid includes the following steps:

[0026] Step 321: Add liquid alkali to the monoamined wastewater of nicotinamide, heat to reflux, and the dimethylamine tail gas generated by reflux is converted into dimethylamine aqueous solution through secondary water absorption;

[0027] Step 322: After ammonia removal, the wastewater is neutralized and then distilled to remove light components. The light components serve as a biochemical carbon source. The wastewater after light component removal is filtered and then subjected to resin adsorption.

[0028] In step 4, the adsorbed water obtained in step 3 is evaporated at the MVR to precipitate salt and obtain by-product salt.

[0029] The concentrated mother liquor is then reused for resin adsorption.

[0030] The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue in the distillation kettle is sent to a qualified unit for treatment.

[0031] When the nicotinamide wastewater is diaminedated nicotinamide wastewater, the treatment process for the diaminedated nicotinamide wastewater includes the following steps:

[0032] Step 331: Add liquid alkali to the diaminedation wastewater of nicotinamide, heat to reflux, and the ammonia gas generated by reflux is absorbed by secondary water to produce ammonia water;

[0033] Step 332: The wastewater after ammonia removal is acidified, filtered, and then subjected to resin adsorption;

[0034] Step 333: The adsorbed water is first neutralized with liquid alkali. After the resin regeneration is completed, the resin adsorption and decolorization are carried out again. The decolorized resin does not need to be regenerated and can be directly used for the next batch of wastewater adsorption.

[0035] In step 4, the decolorized wastewater obtained in step 3 is evaporated to precipitate salt and produce by-product salt.

[0036] The concentrated mother liquor is then reused for resin adsorption.

[0037] The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined, liquid alkali is added for neutralization and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue in the distillation kettle is sent to a qualified unit for treatment.

[0038] When the nicotinic wastewater is triacetone wastewater from nicotinic acid, the treatment process for the triacetone wastewater from nicotinic acid includes the following steps:

[0039] Step 341: Remove the light components from the triacetone wastewater in nicotinamide and use the light components as a biochemical carbon source;

[0040] Step 342: The wastewater after the removal of light components is filtered and then subjected to resin adsorption;

[0041] In step 4, the adsorbed water obtained in step 3 is evaporated to precipitate salt and produce by-product salt.

[0042] The concentrated mother liquor is then reused for resin adsorption.

[0043] The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue from the distillation kettle is sent to a qualified unit for treatment.

[0044] Preferably, when the high-salinity wastewater is sodium sulfite wastewater, the treatment process for the sodium sulfite wastewater includes:

[0045] Step 351: Add liquid alkali to the sodium sulfite wastewater to adjust it to a certain pH value, then filter;

[0046] Step 352: The filtrate is heated and distilled under negative pressure. After being concentrated to a certain multiple, it is discharged and centrifuged at a certain temperature to obtain wet sodium sulfite as a byproduct.

[0047] The filter residue is sent to a qualified unit for processing; the concentrated mother liquor is reused for salt precipitation during evaporation.

[0048] Preferably, the treatment scheme includes resin adsorption, which is carried out based on a resin separation device;

[0049] A periodic resin separation status assessment process is performed during the resin adsorption process.

[0050] During each resin separation status assessment process, the wastewater flow rate at the wastewater inlet of the resin separation device, the wastewater flow velocity at the resin inlet side of the resin separation device, and the wastewater flow velocity at the resin outlet side of the resin separation device are detected, as well as the flow velocity at the outlet of the wastewater valve of the resin separation device at the current valve opening.

[0051] And determine the first ratio of the average wastewater flow rate on the resin outlet side to the average wastewater flow rate on the resin inlet side for each resin separation status assessment process.

[0052] Based on each resin separation state assessment process, the average flow rate at the outlet of the corresponding wastewater outlet valve at the current valve opening and the average wastewater flow rate at the wastewater inlet are used to determine the wastewater retention coefficient; and when the first ratio is greater than the first preset value, the valve flow rate loss coefficient is determined.

[0053] When either the first ratio is less than or equal to the first preset value or the valve flow rate loss coefficient is greater than the preset loss coefficient, the control alarm will issue a warning.

[0054] Preferably, the resin adsorption process for the current wastewater to be adsorbed includes:

[0055] Step 301: When the alarm is not triggered, obtain the valve flow rate loss coefficients obtained from the latest resin separation status assessment process, construct the time-valve loss coefficient change curve, obtain the required flow rate range of the current wastewater to be adsorbed through the valve outlet of the resin separation device, and obtain the valve opening-standard flow rate change curve corresponding to the current wastewater to be adsorbed; the valve was not cleaned during the time period corresponding to each time-valve loss coefficient change curve.

[0056] Step 302: Based on the selected flow rate within the required flow rate range according to a predetermined rule, and the time-valve loss coefficient change curve obtained in step 301, determine the current predicted retention coefficient corresponding to each selected flow rate.

[0057] Step 303: Obtain the standard flow rate range of the wastewater to be adsorbed and the resin adsorption effect evaluation value curve under the corresponding standard conditions.

[0058] Step 304: Based on the current predicted retention coefficient corresponding to each selected flow rate determined in Step 302, the first ratio determined in the latest resin separation state assessment process, and the standard flow rate range of wastewater - resin adsorption effect evaluation value curve, determine the comprehensive evaluation value of each selected flow rate.

[0059] Step 305: Determine the average of the N selected flow velocities with the largest comprehensive evaluation value that are greater than the preset evaluation value as the first flow velocity, and determine the target valve opening corresponding to the valve opening-standard flow velocity change curve corresponding to the current wastewater to be adsorbed.

[0060] Step 306: Adjust the actual valve opening of the valve to the target valve opening, and set the actual influent flow rate to the current wastewater to be adsorbed as the corresponding rated influent flow rate. Perform resin adsorption on the current wastewater to be adsorbed until the valve opening adjustment conditions are met.

[0061] Preferably, the conditions for adjusting the valve opening are: the difference between the first ratio determined in step 304 and the first ratio determined in the subsequent resin separation state evaluation process is greater than a first preset difference; the difference between the valve loss coefficient determined in the subsequent resin separation state evaluation process and the valve loss coefficient determined in step 301 is greater than a second preset difference; or any of the following occurs:

[0062] Preferably, step 4 includes:

[0063] Step 41: Pre-treat the treated wastewater by heating;

[0064] Step 42: Input the pre-treated wastewater into the evaporation device for evaporation;

[0065] Step 41 is performed based on a heat exchange device, which includes: a main heat exchanger and several auxiliary heat exchangers arranged in sequence. The wastewater outlet of the preceding heat exchanger and the wastewater inlet of the following heat exchanger are connected by a pipe. A branch pipe is fixedly connected in the middle of the pipe. A valve is installed on the branch pipe. A valve is installed on the pipe near the wastewater inlet of the following heat exchanger. The branch pipe is connected to a pipe, and the pipe is connected to the wastewater inlet of the evaporation device. The main heat exchanger and several auxiliary heat exchangers are all connected to a steam inlet pipe. When each valve is working, it operates at its corresponding rated opening.

[0066] During operation, each heat exchanger undergoes a second heat exchange status assessment every first time interval. The current heat exchange status assessment process includes:

[0067] Based on the detection, the actual heat exchange efficiency and actual wastewater flow rate efficiency of the operating heat exchanger and the wastewater flow rate efficiency of the wastewater inlet of the operating auxiliary heat exchanger compared with the wastewater outlet of the previous operating heat exchanger are determined.

[0068] If any of the following is not within the corresponding preset range: the actual heat exchange efficiency of the operating heat exchanger, the actual wastewater flow rate efficiency, or the wastewater flow rate efficiency of the wastewater inlet of the operating auxiliary heat exchanger compared to the wastewater outlet of the previous operating heat exchanger, an alarm will be triggered by alarm device two.

[0069] Preferably, step 41 includes:

[0070] Step 411: Obtain the current steam parameters of the steam inlet pipe and the current temperature of the wastewater to be evaporated before entering the main heat exchanger, and obtain the latest determined operating status evaluation parameters; the heat exchange device was not cleaned, replaced, or repaired when the current and latest operating status evaluation parameters were determined.

[0071] Step 412: Obtain the target heat exchange parameters of the current wastewater to be evaporated, and determine the target inflow velocity of the current wastewater to be evaporated into the main heat exchanger based on the target heat exchange parameters and step 411. The target heat exchange parameters include: the target temperature entering the evaporation device and the target flow velocity range entering the evaporation device.

[0072] Step 413: Obtain the wastewater flow rate-theoretical heat exchange efficiency variation curve of the current type of wastewater to be evaporated in each heat exchanger;

[0073] Step 414: Based on steps 411, 412, and 413, first determine the heat exchange satisfaction value of the main heat exchanger. When the heat exchange satisfaction value of the main heat exchanger is greater than or equal to 1, control the actual flow rate of the wastewater inlet of the main heat exchanger to the target inlet flow rate, control valve one corresponding to the main heat exchanger to be closed and valve two to be opened, and control valve one and valve two corresponding to all auxiliary heat exchangers to be closed, so as to realize heat exchange on the current wastewater to be evaporated (belonging to the current type of wastewater to be evaporated);

[0074] Step 415: When the heat exchange satisfaction value of the main heat exchanger is less than 1, based on steps 411, 412, and 413, determine the number of auxiliary heat exchangers that need to be operated, and control the valve one of the last auxiliary heat exchanger that needs to be operated to be closed and the valve two to be opened, while the valve one of the other auxiliary heat exchangers that need to be operated is opened and the valve two is closed.

[0075] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0076] Compared with the prior art, the present invention has the following beneficial effects:

[0077] The present invention reduces the alkali dosage of quizalofop-P-ethyl cyclization acidification wastewater to 2.70-3.0 eq, which is significantly lower than the 4.0-6.0 eq of the existing process, effectively reducing environmental protection costs and making it suitable for industrial production.

[0078] High-salinity wastewater is pretreated, and the treatment scheme is adjusted and optimized to remove organic matter and reduce the color of the wastewater, thereby obtaining qualified by-product salts and by-product acids.

[0079] Compared to traditional methods of removing organic matter from wastewater, such as Fenton oxidation and biochemical processes, the technology in this project is cleaner, more environmentally friendly, and more effective, significantly reducing the treatment cost of high-salinity wastewater.

[0080] After treatment, the industrial salt separated from the high-salt chemical wastewater meets the first-class standard of sodium chloride industrial dry salt (GB / T5462-2015).

[0081] After treatment, the industrial high-salt wastewater was separated into sodium sulfite by-products that met the qualified product indicators of the industrial anhydrous sodium sulfite standard (HGT2967-2010). Attached Figure Description

[0082] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0083] Figure 1 This is a schematic diagram of the process of the present invention. Detailed Implementation

[0084] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0085] Furthermore, in this invention, the use of terms such as "first" and "second" is for descriptive purposes only and does not specifically refer to any order or sequence, nor is it intended to limit the invention. They are merely used to distinguish components or operations described using the same technical terms and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the technical solutions and features of the various embodiments can be combined with each other, but this must be based on the ability of those skilled in the art to implement them. If a combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0086] The present invention provides the following embodiments:

[0087] Example 1: This embodiment of the invention provides a process for the recycling and treatment of high-salinity wastewater, such as... Figure 1 As shown, it includes:

[0088] Step 1: Analyze the organic composition of each high-salinity wastewater to determine the composition and content of materials in the wastewater;

[0089] Step 2: Develop corresponding treatment plans for the specific components of each high-salinity wastewater;

[0090] Step 3: Treat the high-salinity wastewater according to the treatment plan, and adjust and optimize the plan to remove organic matter and reduce the color of the high-salinity wastewater;

[0091] Step 4: Evaporate the treated wastewater to obtain qualified by-product salt or by-product sodium sulfite.

[0092] When the high-salinity wastewater is quizalofop-P-ethyl cyclized acidified wastewater, the treatment process for the quizalofop-P-ethyl cyclized acidified wastewater includes the following steps:

[0093] Step 3001: Add liquid alkali to the acidified wastewater containing quizalofop-P-ethyl to adjust the pH value to a certain level (10-12).

[0094] Step 3002: Add hydrogen peroxide and heat to a certain temperature (60-80℃), maintain the temperature for reaction;

[0095] Step 3003: After the reaction is complete, add liquid alkali to neutralize and filter to remove residue;

[0096] Step 3004: Add activated carbon to the filtrate for decolorization and filtration;

[0097] In step 4 above, the filtrate obtained in step 3004 is evaporated and salt is precipitated by MVR. The crude wet salt is then added to saturated brine, pulped at room temperature, and centrifuged to obtain the final by-product wet salt.

[0098] The filtered waste residue is sent to qualified units for treatment, the mother liquor from evaporation and concentration is sent to the "three wastes" biochemical treatment, and the mother liquor from pulping and centrifugation is reused for evaporation and salt precipitation.

[0099] The high-salinity wastewater is DHPPA secondary acidification wastewater, and the treatment process of the DHPPA secondary acidification wastewater includes the following steps:

[0100] Step 311: After the DHPPA secondary acidification wastewater is adsorbed by the resin, liquid alkali is added for neutralization;

[0101] Step 312: After the resin regeneration is completed, the wastewater obtained in step 311 is transferred back into the resin for secondary adsorption and decolorization. The resin after decolorization and adsorption does not need to be regenerated and can be directly used for the next batch of wastewater adsorption.

[0102] In step 4, the decolorized effluent obtained in step 3 is evaporated at the MVR to precipitate salt, yielding wet salt as a byproduct.

[0103] The concentrated mother liquor from evaporation is combined with the secondary acidification wastewater from DHPPA and then subjected to resin adsorption treatment.

[0104] The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined, liquid alkali is added for neutralization and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue from the distillation kettle is sent to a qualified unit for treatment.

[0105] When the high-salt wastewater is nicotinic acid wastewater;

[0106] When the nicotinic wastewater is a monoamined wastewater of nicotinic acid, the treatment process of the monoamined wastewater of nicotinic acid includes the following steps:

[0107] Step 321: Add liquid alkali to the amination wastewater of nicotinamide, heat to reflux, and the dimethylamine tail gas generated by reflux is processed into dimethylamine aqueous solution through secondary water absorption (recycled to the nicotinamide section of nicotinamide).

[0108] Step 322: After ammonia removal, the wastewater is neutralized and then distilled to remove light components. The light components serve as a biochemical carbon source. The wastewater after light component removal is filtered and then subjected to resin adsorption.

[0109] In step 4, the adsorbed water obtained in step 3 is evaporated at the MVR to precipitate salt and obtain by-product salt.

[0110] The concentrated mother liquor is then reused for resin adsorption.

[0111] The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue in the distillation kettle is sent to a qualified unit for treatment.

[0112] When the nicotinamide wastewater is diaminedated nicotinamide wastewater, the treatment process for the diaminedated nicotinamide wastewater includes the following steps:

[0113] Step 331: Add liquid alkali to the diamine wastewater of nicotinamide and heat it to reflux. The ammonia gas generated by reflux is absorbed by secondary water to produce ammonia water (which is reused in the disulfonamide section of nicotinamide). Secondary water is the graded water used in the process to absorb tail gas.

[0114] Step 332: The wastewater after ammonia removal is acidified, filtered, and then subjected to resin adsorption;

[0115] Step 333: The adsorbed water is first neutralized with liquid alkali. After the resin regeneration is completed, the resin adsorption and decolorization are carried out again. The decolorized resin does not need to be regenerated and can be directly used for the next batch of wastewater adsorption.

[0116] In step 4, the decolorized wastewater obtained in step 3 is evaporated to precipitate salt and produce by-product salt.

[0117] The concentrated mother liquor is then reused for resin adsorption.

[0118] The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined, liquid alkali is added for neutralization and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue in the distillation kettle is sent to a qualified unit for treatment.

[0119] When the nicotinic wastewater is triacetone wastewater from nicotinic acid, the treatment process for the triacetone wastewater from nicotinic acid includes the following steps:

[0120] Step 341: Remove the light components from the triacetone wastewater in nicotinamide and use the light components as a biochemical carbon source;

[0121] Step 342: The wastewater after the removal of light components is filtered and then subjected to resin adsorption;

[0122] In step 4, the adsorbed water obtained in step 3 is evaporated to precipitate salt and produce by-product salt.

[0123] The concentrated mother liquor is then reused for resin adsorption.

[0124] The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue from the distillation kettle is sent to a qualified unit for treatment.

[0125] When the high-salinity wastewater is sodium sulfite wastewater, the treatment process for the sodium sulfite wastewater includes:

[0126] Step 351: Add liquid alkali to the sodium sulfite wastewater to adjust it to a certain pH value, then filter;

[0127] Step 352: The filtrate is heated and distilled under negative pressure. After being concentrated to a certain multiple, it is discharged and centrifuged at a certain temperature to obtain wet sodium sulfite as a byproduct.

[0128] The filter residue is sent to a qualified unit for processing; the concentrated mother liquor is reused for salt precipitation during evaporation.

[0129] (1) The quinine cyclization acidification wastewater mainly contains acetic acid, sulfides and some phenolic substances. The wastewater has a strong odor and a dark color. The wastewater is pretreated with oxidants such as hydrogen peroxide and hypochlorous acid to remove most of the sulfides and phenolic substances. Then, depending on the specific treatment situation, activated carbon decolorization or resin adsorption is carried out to obtain qualified treated wastewater. Finally, evaporation treatment is carried out to obtain qualified by-product salt.

[0130] (2) DHPPA secondary acidification wastewater

[0131] DHPPA secondary acidification wastewater contains about 1% phenolic substances, and its biochemical treatment effect is poor. The wastewater can be treated with resin adsorption to remove organic phenols, and then evaporated to obtain qualified by-product salt.

[0132] (3) Nicosulfuron wastewater

[0133] The monoamined wastewater from nicotinamide mainly contains dimethylamine and a small amount of organic matter. The wastewater is first treated to remove ammonia, and then the small amount of organic matter is removed by resin adsorption before being evaporated to precipitate salt.

[0134] The diaminedation wastewater of nicotinamide mainly contains ammonia and a small amount of organic matter. The wastewater is first treated to remove ammonia, and then the small amount of organic matter is removed by resin adsorption before being evaporated to precipitate salt.

[0135] The triacetone wastewater containing nicotinamide contains a small amount of acetone, ethanol and a small amount of organic matter. It can be directly treated by resin adsorption or the solvent can be removed by distillation before resin adsorption to remove the small amount of organic matter before evaporation to precipitate salt.

[0136] (4) Sodium sulfite wastewater

[0137] Sodium sulfite wastewater originates from the absorption of tail gas from the chlorination reaction using thionyl chloride. The chlorination tail gas produces hydrogen chloride and sulfur dioxide. After the hydrogen chloride in the tail gas is removed by a three-stage water absorption process, the sulfur dioxide is absorbed by liquid alkali to form sodium sulfite wastewater. During the absorption process, it is necessary to control the intake of oxygen in the system to prevent sulfurous acid from being oxidized to sulfuric acid. After the absorption is saturated, the salt can be evaporated to obtain sodium sulfite as a byproduct.

[0138] Traditional methods for removing organic matter from wastewater, such as Fenton oxidation and biochemical treatment, have the following drawbacks:

[0139] Fenton oxidation:

[0140] Chemical consumption and sludge generation: Large amounts of H2O2 and Fe²⁺ need to be added, resulting in high chemical costs and the generation of iron-containing sludge. If the sludge is not disposed of properly (such as by indiscriminate landfill), the iron ions and incompletely degraded organic matter may seep into the soil and water bodies, causing secondary pollution.

[0141] Acidic conditions and equipment corrosion: The reaction needs to be carried out in an acidic environment (around pH 2-4), which places high demands on the equipment materials. If the anti-corrosion measures are not in place, equipment corrosion will lead to the dissolution of metal ions, polluting wastewater, and may also shorten the equipment life and increase the generation of solid waste (scrapped equipment).

[0142] Biochemistry:

[0143] High requirements for wastewater quality: Microorganisms are sensitive to water quality (such as pH, temperature, and toxic substances). If the wastewater contains high concentrations of recalcitrant organic matter, heavy metals, or highly toxic substances (such as phenols and cyanides), it will inhibit or even kill microorganisms, leading to the collapse of the treatment system. If the wastewater is directly introduced into the biological treatment process without pretreatment, it is equivalent to "transferring the pollution risk" and undermining the environmental friendliness of biological treatment.

[0144] Sludge disposal issues: The biological process produces residual sludge. If the sludge has a high water content and is not properly treated (such as not undergoing anaerobic digestion to reduce volume, or failing to meet standards for landfill / incineration), the organic matter, pathogens, and heavy metals in the sludge will pollute the soil, water bodies, and atmosphere, becoming a new environmental hazard.

[0145] Degradation efficiency limitations: For some recalcitrant and structurally complex organic compounds (such as polycyclic aromatic hydrocarbons and long-chain alkyl compounds), simple biochemical methods degrade slowly and have low removal rates. They need to be combined with pretreatment / deep treatment processes such as Fenton oxidation. Otherwise, they cannot meet the strict environmental emission standards, which indirectly reduces the "cleanliness" of single biochemical methods.

[0146] The beneficial effects of the above technical solution are as follows:

[0147] The present invention reduces the alkali dosage of quizalofop-P-ethyl cyclization acidification wastewater to 2.70-3.0 eq, which is significantly lower than the 4.0-6.0 eq of the existing process, effectively reducing environmental protection costs and making it suitable for industrial production.

[0148] High-salinity wastewater is pretreated, and the treatment scheme is adjusted and optimized to remove organic matter and reduce the color of the wastewater, thereby obtaining qualified by-product salts and by-product acids.

[0149] Compared to traditional methods of removing organic matter from wastewater, such as Fenton oxidation and biochemical processes, the technology in this project is cleaner, more environmentally friendly, and more effective, significantly reducing the treatment cost of high-salinity wastewater.

[0150] After treatment, the industrial salt separated from the high-salt chemical wastewater meets the first-class standard of sodium chloride industrial dry salt (GB / T5462-2015).

[0151] After treatment, the industrial high-salt wastewater was separated into sodium sulfite by-products that met the qualified product indicators of the industrial anhydrous sodium sulfite standard (HGT2967-2010).

[0152] Example 2, based on Example 1, the treatment scheme includes resin adsorption, which is carried out using a resin separation device;

[0153] A periodic resin separation status assessment process is performed during the resin adsorption process.

[0154] During each resin separation status assessment process, the wastewater flow rate at the wastewater inlet of the resin separation device is measured (a corresponding rated inlet flow rate is set for each type of wastewater to be adsorbed), the wastewater flow velocity at the resin inlet side of the resin separation device, and the wastewater flow velocity at the resin outlet side of the resin separation device. The flow velocity at the outlet of the wastewater valve of the resin separation device at the current valve opening is also measured. All of the above parameters are measured simultaneously during each resin separation status assessment process. The rated flow rate mentioned above is the standard value that the wastewater inlet should maintain when the resin separation device can stably and efficiently treat a specific type of wastewater to be adsorbed (such as wastewater with fixed composition, concentration, and other parameters (or within the same range)) after process design and verification.

[0155] And determine the first ratio of the average wastewater flow rate on the resin outlet side to the average wastewater flow rate on the resin inlet side for each resin separation status assessment process.

[0156] Based on each resin separation state assessment process, the average flow rate at the outlet of the corresponding wastewater outlet valve at the current valve opening and the average wastewater flow rate at the wastewater inlet are used to determine the wastewater retention coefficient; and when the first ratio is greater than the first preset value, the valve flow rate loss coefficient is determined; the wastewater outlet pipe is connected to a valve.

[0157] When either the first ratio is less than or equal to the first preset value or the valve flow rate loss coefficient is greater than the preset loss coefficient, the control alarm will issue a warning.

[0158] Wherein, the first ratio = the average value of the wastewater flow velocity on the resin outlet side ÷ the average value of the wastewater flow velocity on the resin inlet side;

[0159] Among them, the valve flow rate loss coefficient in the resin separation state assessment process for: ,in, For the resin separation status assessment process, the average flow velocity at the outlet of the wastewater valve at the current valve opening is used. The theoretical flow rate at the outlet of the valve for wastewater discharge at the current valve opening (determined based on the initially used valve and wastewater outlet pipe).

[0160] The wastewater retention coefficient K in the resin separation status assessment process is calculated based on the following formula:

[0161] Where Q is the average wastewater flow rate at the wastewater inlet during the resin separation state assessment process; B is the internal diameter of the wastewater outlet pipe at the valve outlet. t is the internal diameter of the resin separation device; h is the height of the resin in the resin separation device; t is the unit time.

[0162] The beneficial effects of the above technical solution are as follows:

[0163] The system simultaneously monitors the wastewater inlet flow rate, the flow velocities on both sides of the resin, and the flow rate at the valve's rated opening, capturing changes in the entire process from "fluid input - resin adsorption - fluid output." For example, when the resin is clogged, the flow velocity at the resin outlet decreases, which can be accurately identified using the first ratio, avoiding misjudgment based on a single parameter.

[0164] Valve flow rate loss coefficient: By comparing the actual flow rate with the theoretical flow rate at the valve's rated opening, valve wear and blockage (such as insufficient opening due to scaling) can be identified, thus preventing system pressure fluctuations caused by valve failure.

[0165] Wastewater retention coefficient: Combining flow rate, pipe diameter, and resin height, it quantifies the residence time and flow pattern of wastewater in the resin separation device, ensuring sufficient adsorption reaction and indirectly monitoring resin adsorption efficiency (too short a residence time will result in insufficient adsorption, while too long a residence time may lead to secondary pollution).

[0166] Periodic condition assessments prevent "accumulated faults from causing equipment damage." By providing early warnings of resin blockage and valve wear, resin can be cleaned and valves maintained in a timely manner, reducing resin breakage and pipeline corrosion caused by long-term abnormal operation, and lowering equipment maintenance costs and replacement frequency.

[0167] The system triggers early warnings based on two conditions: "first ratio + valve flow rate loss coefficient," covering two core issues: "resin section blockage" and "valve section failure."

[0168] Long-term monitoring of the first ratio and valve flow rate loss coefficient can provide inverse guidance for resin selection (such as replacing with anti-fouling resin if frequent clogging occurs) and pipeline / valve design (such as optimizing valve flow channels to reduce wear), driving continuous process iteration and adapting to wastewater treatment needs in different water quality and quantity scenarios.

[0169] Example 3, based on Example 2, describes the resin adsorption process for the current wastewater requiring adsorption, which includes:

[0170] Step 301: When alarm 1 is not triggered, obtain the valve flow rate loss coefficients obtained from the latest resin separation state assessment processes, construct a time-valve loss coefficient variation curve (the horizontal axis of the time-valve loss coefficient variation curve is time (specifically the time of the last detection in each resin separation state assessment process), and the vertical axis is the valve loss coefficient determined by the corresponding resin separation state assessment process), obtain the required flow rate range of the valve outlet of the resin separation device for the current wastewater to be adsorbed (determined according to process efficiency requirements, etc.), and obtain the valve opening degree-standard flow rate variation curve corresponding to the current wastewater to be adsorbed; the valve was not cleaned during the time period corresponding to each time-valve loss coefficient variation curve.

[0171] The valve opening-standard flow rate variation curve for the current wastewater to be adsorbed is based on: the initial valves used, the resin separation device, and the same type of wastewater to be adsorbed (e.g., the same composition, concentration, and other parameters, or within the same range), the rated flow rate of the same type of wastewater to be adsorbed, and the initial resin used for the same type of wastewater to be adsorbed, determined through experiments. In the valve opening-standard flow rate variation curve, the horizontal axis represents the valve opening, and the vertical axis represents the experimentally obtained flow rate at the valve outlet.

[0172] Step 302: Based on the selected flow rate (which can be selected according to a preset flow rate interval) within the required flow rate range according to a predetermined rule, the time-valve loss coefficient change curve obtained in step 301 is used to determine the current predicted retention coefficient corresponding to each selected flow rate.

[0173] ;

[0174] Where D is the valve flow rate loss coefficient determined in the latest resin separation status assessment process; This is the rated flow rate corresponding to the current wastewater that needs to be adsorbed; Select the f-th flow rate; The height of the resin corresponding to the current wastewater to be adsorbed; The average value of the reduction in valve loss coefficient per unit time is obtained based on the time-valve loss coefficient change curve obtained in step 301. The ideal valve opening adjustment time interval for the current wastewater to be adsorbed (the "ideal" time interval determined in advance through experiments or simulations, used to standardize how often the valve opening should be evaluated and adjusted, so that the parameter adjustment of the entire adsorption process has a time rhythm, neither too frequent (avoiding frequent equipment operation wear and tear, data fluctuation interference) nor too long (preventing the cumulative impact of changes in valve status, water quality, etc. on the adsorption effect)).

[0175] Step 303: Obtain the standard flow rate range of the wastewater to be adsorbed under the corresponding standard conditions, and the resin adsorption effect evaluation value curve (determined by experiments, the horizontal axis is the flow rate at the valve outlet during the experiment, and the vertical axis is the resin adsorption effect evaluation value corresponding to the horizontal axis).

[0176] The standard conditions for the current wastewater to be adsorbed are: the valves and resin separation devices used initially, the wastewater to be adsorbed being the same type of wastewater (such as having the same composition, concentration, or other parameters or being within the same range), the rated flow rate of the wastewater to be adsorbed being the same type of wastewater, and the resin used initially for the wastewater to be adsorbed being the same type of wastewater.

[0177] The resin adsorption effect evaluation value is calculated based on the following formula: ;

[0178] T represents the number of resin adsorption performance evaluation indicators (including the removal rate of each target pollutant); The evaluation weight of the j-th resin adsorption effect evaluation index (the value is greater than 0 and less than 1); Let be the compliance degree of the j-th resin adsorption effect evaluation index. If the j-th resin adsorption effect evaluation index meets the requirements of the corresponding resin adsorption effect evaluation index, then... The value is 1, otherwise The value is 0;

[0179] Step 304: Based on the current predicted retention coefficient corresponding to each selected flow rate determined in Step 302, the first ratio determined in the latest resin separation state assessment process, and the standard flow rate range of wastewater - resin adsorption effect evaluation value curve, determine the comprehensive evaluation value of each selected flow rate.

[0180] ;

[0181] This is the comprehensive evaluation value for the f-th selected flow velocity; Select the f-th flow rate; For the current wastewater requiring adsorption under corresponding standard conditions, the standard flow rate range of the wastewater versus the resin adsorption effect evaluation value curve is shown in the figure. The corresponding resin adsorption effect evaluation value; , These are the evaluation weights for the first ratio and the evaluation weights for the retention coefficient (both are greater than 0 and less than 1, such as 0.6 and 0.4 respectively). Let f be the predicted retention coefficients corresponding to the selected flow velocities; This represents the ideal retention coefficient for the current wastewater requiring adsorption. The first ratio determined in the latest resin separation status assessment process; The ideal first ratio of the current wastewater to be adsorbed; the ideal retention coefficient and the ideal first ratio of the current wastewater to be adsorbed are the retention coefficient and the first ratio when the resin adsorption effect evaluation value is maximized, determined by adjusting the retention coefficient and the first ratio test under the corresponding standard conditions;

[0182] Step 305: Determine the N values ​​(N can be 5) with the largest comprehensive evaluation value that are greater than the preset evaluation value. Select the average flow velocity as the first flow velocity and determine the target valve opening corresponding to the valve opening-standard flow velocity change curve corresponding to the current wastewater to be adsorbed.

[0183] Step 306: Adjust the actual valve opening of the valve to the target valve opening, and set the actual influent flow rate to the current wastewater to be adsorbed as the corresponding rated influent flow rate. Perform resin adsorption on the current wastewater to be adsorbed until the valve opening adjustment conditions are met.

[0184] The conditions for adjusting the valve opening are as follows: the difference between the first ratio determined in step 304 (e.g., 0.9) and the first ratio determined in the subsequent resin separation state assessment process (e.g., 0.8) is greater than the first preset difference (e.g., 0.5); the difference between the valve loss coefficient determined in the subsequent resin separation state assessment process (e.g., 0.2) and the valve loss coefficient determined in step 301 (e.g., 0.1) is greater than the second preset difference (e.g., 0.7); or any of the following occurs: the type of wastewater to be adsorbed changes.

[0185] The beneficial effects of the above technical solution are as follows:

[0186] By using the "time-valve loss coefficient variation curve" and the "valve opening-standard flow rate variation curve" (step 301), the valve state decay pattern is tracked in real time. Combined with the process requirements of the wastewater to be adsorbed (required flow rate range), the valve opening is dynamically matched with the required flow rate of the wastewater. For example, the valve loss coefficient is different at different time periods, and the curve can accurately reflect its changes, avoiding flow rate runaway due to valve aging and ensuring the stability of the adsorption process.

[0187] By using the "predicted retention coefficient" (step 302) and "comprehensive evaluation value" (step 304) models, parameters such as valve status, flow rate, and resin adsorption effect are quantitatively correlated. This allows for the prediction of adsorption effects at different flow rates, upgrading process control from "experience-driven" to "data-driven," significantly improving adsorption accuracy.

[0188] Based on the "standard flow rate range of wastewater - resin adsorption effect evaluation value curve" (step 303), the flow rate with the "optimal comprehensive evaluation value" is selected (step 305). Under the premise of ensuring the pollutant removal rate (such as the target pollutant removal rate being constrained by the evaluation value), the wastewater treatment capacity is maximized. For example, the average of N optimal flow rates is taken to obtain the "first flow rate", which avoids insufficient adsorption due to excessively high flow rate, and also prevents capacity limitation due to excessively low flow rate, thus achieving a balance between "treatment efficiency" and "effect".

[0189] The parameter adjustment is dynamically triggered by the "valve opening adjustment condition" (step 306) to adapt to working conditions such as water quality fluctuations (changes in wastewater type) and equipment aging (changes in valve loss coefficient).

[0190] The opening-flow rate curve and effect evaluation value curve (steps 301 and 303) constructed based on "standard conditions" (initial valve, resin, and wastewater parameters) can be directly reused in similar wastewater treatment scenarios. New projects only need to replace the water quality parameters to quickly adapt to the process, shorten the technology development cycle, and reduce project implementation costs.

[0191] Example 4, based on Example 1, step 4 includes:

[0192] Step 41: Pre-treat the treated wastewater by heating;

[0193] Step 42: Input the pre-treated wastewater into the evaporation device for evaporation;

[0194] Step 41 is performed based on a heat exchange device, which includes: a main heat exchanger and several auxiliary heat exchangers arranged in sequence. The wastewater outlet of the preceding heat exchanger and the wastewater inlet of the following heat exchanger are connected by a pipe. A branch pipe is fixedly connected in the middle of the pipe. A valve is installed on the branch pipe. A valve is installed on the pipe near the wastewater inlet of the following heat exchanger. The branch pipe is connected to a pipe, and the pipe is connected to the wastewater inlet of the evaporation device. The main heat exchanger and several auxiliary heat exchangers are all connected to a steam inlet pipe. When each valve is working, it operates at its corresponding rated opening.

[0195] During operation, each heat exchanger undergoes a second heat exchange status assessment every first time interval. The current heat exchange status assessment process includes:

[0196] Based on the detection, the operating status evaluation parameters are determined within the current second time period. These parameters include: the actual heat exchange efficiency of the operating heat exchanger (determined based on the heat exchanger efficiency model) and the actual wastewater flow rate efficiency (average flow rate of the wastewater outlet of the heat exchanger during the current second time period ÷ average flow rate of the wastewater inlet of the heat exchanger during the current second time period) and the wastewater flow rate efficiency of the operating auxiliary heat exchanger wastewater inlet compared to the wastewater outlet of the previous operating heat exchanger (average flow rate of the auxiliary heat exchanger wastewater inlet during the current second time period ÷ average flow rate of the wastewater outlet of the previous operating heat exchanger).

[0197] If any of the operating status evaluation parameters is outside the corresponding preset range, an alarm will be triggered by alarm device two.

[0198] The beneficial effects of the above scheme are as follows:

[0199] A series heat exchanger network (main heat exchanger + auxiliary heat exchanger) achieves stepped utilization of heat through a series structure where the wastewater outlet of the preceding heat exchanger is connected to the wastewater inlet of the following heat exchanger. For example, the main heat exchanger preheats the wastewater to a certain temperature, and the auxiliary heat exchanger further heats it. Compared with single-stage heat exchange, this can reduce steam consumption (the steam heat is absorbed by multiple stages).

[0200] By adjusting the wastewater flow direction through valves one and two (such as bypassing some auxiliary heat exchangers), the system can maintain continuous operation when some heat exchangers fail or their efficiency decreases, while avoiding the interruption of the entire process due to the failure of a single heat exchanger.

[0201] Every first interval (e.g., 5-30 minutes, which can be adjusted according to the specific efficiency determined in the previous evaluation), a second interval (e.g., 30 seconds to 2 minutes) is performed to assess the heat exchange status, monitoring key parameters such as actual heat exchange efficiency and wastewater flow rate efficiency in real time. When parameters deviate from the preset range, alarm two is triggered, facilitating timely cleaning of scale and equipment maintenance, and preventing a decrease in evaporation efficiency due to heat exchanger performance degradation.

[0202] This invention sets up a main heat exchanger based on all wastewater that can be preheated by the heat exchange device, ensuring that all wastewater that can be preheated by the heat exchange device needs to use the main heat exchanger for heat exchange. However, the number of auxiliary heat exchangers that need to be turned on varies depending on the type of wastewater, which may be 0, to meet the heat exchange requirements of different types of wastewater and avoid the limited range of wastewater heat exchange requirements that can be met by a fixed heat exchanger. Furthermore, the number of auxiliary heat exchangers can be increased if the actual heat exchange efficiency of the heat exchange device, the wastewater flow rate efficiency, etc., deviate from the warning state but do not reach the warning state.

[0203] Example 4, based on Example 3, step 41 includes:

[0204] Step 411: Obtain the current steam parameters (including steam temperature and steam flow rate) of the steam inlet pipe and the current temperature of the wastewater to be evaporated before entering the main heat exchanger, and obtain the latest determined operating status evaluation parameters;

[0205] Step 412: Obtain the target heat transfer parameters of the current wastewater to be evaporated, and determine the target inflow velocity of the current wastewater to be evaporated into the main heat exchanger based on the target heat transfer parameters and step 411. The target heat exchange parameters include: the target temperature entering the evaporator and the target flow rate range entering the evaporator.

[0206] ;

[0207] This refers to the maximum value of the target flow velocity range entering the evaporation device from the target heat exchange parameters of the current type of wastewater to be evaporated; The product of the latest determined actual wastewater flow rate efficiency of all heat exchangers required for the initial evaporation of the current type of wastewater; For all heat exchangers initially required for the current type of wastewater to be evaporated, the product of the wastewater flow rate efficiency of the newly determined auxiliary heat exchanger inlet and the wastewater outlet of the previously operating heat exchanger.

[0208] The initial required heat exchangers are the minimum set of heat exchangers required, determined through heat balance calculations and experiments, based on the baseline wastewater temperature, the target heat exchange parameters of the current type of wastewater to be evaporated, and the baseline steam parameters, all under initial operating conditions (where all efficiencies are relatively high). The wastewater type is defined as having the same composition, concentration, or other parameters, or being within the same range.

[0209] Step 413: Obtain the wastewater flow rate-theoretical heat exchange efficiency variation curve of the current type of wastewater to be evaporated in each heat exchanger (the horizontal axis is the average wastewater flow rate of the heat exchanger, and the vertical axis is the theoretical heat exchange efficiency corresponding to the horizontal axis, which is determined by experiments based on the heat exchangers initially used for the current type of wastewater to be evaporated); the wastewater flow rate-theoretical heat exchange efficiency variation curve of each heat exchanger: each heat exchanger is determined by the heat exchange efficiency model or experiment based on the reference wastewater temperature and reference steam parameters under the initial use state;

[0210] Step 414: Based on steps 411, 412, and 413, first determine the heat exchange satisfaction value of the main heat exchanger. When the heat exchange satisfaction value of the main heat exchanger is greater than or equal to 1, control the actual flow velocity of the wastewater inlet of the main heat exchanger to the target inlet velocity, control valve one corresponding to the main heat exchanger to be closed and valve two to be opened, and control valves one and two corresponding to all auxiliary heat exchangers to be closed, thereby achieving heat exchange for the current wastewater to be evaporated. The actual flow velocity of the current wastewater to be evaporated entering the main heat exchanger is the target inlet velocity. ;

[0211] ;

[0212] in, The heat exchange satisfaction value of the main heat exchanger; This refers to the minimum target temperature entering the evaporation device among the target heat exchange parameters of the current type of wastewater to be evaporated; This refers to the steam temperature (the current steam temperature in the steam inlet pipe's steam parameters). The actual wastewater flow rate efficiency of the main heat exchanger in the latest determined operating status assessment parameters; The temperature of the wastewater to be evaporated before it enters the main heat exchanger; for The vertical axis corresponds to the wastewater flow velocity-theoretical heat exchange efficiency change curve of the main heat exchanger corresponding to the current type of wastewater to be evaporated. The actual heat exchange efficiency of the main heat exchanger in the latest determined operating status assessment parameters; The vertical axis of the average wastewater flow velocity of the main heat exchanger in the latest determined operating status assessment parameters is the curve of wastewater flow velocity versus theoretical heat exchange efficiency. , These are flow velocity weight one and flow velocity weight two, respectively (their values ​​are greater than 0 and less than 1, and can be 0.5 and 0.5, respectively). For heat transfer efficiency model and The temperature of the wastewater after heat exchange is determined; The average flow velocity of the wastewater in the heat exchanger; This represents the current steam flow rate at the steam inlet pipe.

[0213] The heat transfer efficiency model can be any existing heat transfer efficiency model, such as:

[0214] ;

[0215] Substitute the current heat exchange efficiency of the heat exchanger (the heat exchange efficiency of the main heat exchanger) into the above... (Other heat exchangers can be substituted accordingly). , These are the wastewater temperature at the current heat exchanger's wastewater outlet and wastewater temperature at the wastewater inlet (substitute into...). ); The specific heat capacity of the current wastewater; This represents the cross-sectional area of ​​the wastewater pipes in the current heat exchanger. The average flow velocity of the wastewater in the current heat exchanger (substitute the average flow velocity of the wastewater in the main heat exchanger) ); These are the current steam inlet flow rate, specific heat capacity of the steam, steam inlet temperature, and steam outlet temperature of the heat exchanger, respectively. , The radius of the wastewater pipe in the current heat exchanger;

[0216] Step 415: When the heat exchange satisfaction value of the main heat exchanger is less than 1, based on steps 411, 412, and 413, determine the number of auxiliary heat exchangers that need to be operated, and control the valve one of the last auxiliary heat exchanger that needs to be operated to be closed and the valve two to be opened. For the other auxiliary heat exchangers that need to be operated, valve one is open and valve two is closed. The actual flow rate of the wastewater to be evaporated entering the main heat exchanger is the target inflow velocity. ;

[0217] Based on the heat exchange efficiency model, the heat exchange satisfaction value of each auxiliary heat exchanger is calculated sequentially until the heat exchange satisfaction value is greater than or equal to 1. Then, the auxiliary heat exchanger with a heat exchange satisfaction value greater than or equal to 1, as well as the main heat exchanger and auxiliary heat exchanger calculated before it, all need to be put into operation.

[0218] The beneficial effects of the above technical solution are as follows:

[0219] The solution comprehensively correlates the state parameters of the hot fluid (steam) and the cold fluid (wastewater) by collecting steam parameters, initial wastewater temperature, actual heat exchange efficiency, and flow rate efficiency (step 411). For example, steam temperature and wastewater temperature before entering the heat exchanger are used as basic inputs, combined with the actual heat exchange efficiency of the heat exchanger (reflecting equipment degradation) and flow rate efficiency (reflecting the flow channel state), to achieve "full parameter perception" of the heat exchange process. This multi-dimensional collaboration upgrades the heat exchange effect from "experience-based judgment" to "data quantification," ensuring that the final wastewater temperature and flow rate entering the evaporator accurately match the target parameters (step 412).

[0220] Based on the wastewater flow rate versus theoretical heat exchange efficiency curve (step 413), the scheme can predict the theoretical heat exchange efficiency according to the actual flow rate. For example, when the wastewater flow rate changes, the theoretical efficiency can be quickly deduced from the curve, and the "heat exchange satisfaction value" can be calculated in combination with steam parameters to dynamically determine whether to activate the auxiliary heat exchanger. This dynamic adaptation allows the system to accurately respond to fluctuations in wastewater and steam temperatures, ensuring the stability of wastewater parameters after heat exchange.

[0221] The design follows the logic of "primary heat exchanger priority, auxiliary heat exchanger supplemented as needed" (steps 414 / 415): auxiliary heat exchangers are only gradually activated when the heat exchange efficiency of the primary heat exchanger is insufficient (satisfaction coefficient < 1). Compared to the traditional mode of "full activation of auxiliary heat exchangers," this reduces steam consumption (no additional steam is needed for auxiliary equipment when the primary heat exchanger is at full load). For example, under low-load conditions, the primary heat exchanger can meet the demand by operating independently, thus improving steam utilization.

[0222] The "target inflow velocity" is calculated (step 412), and the heat exchange efficiency model (step 414) is used to deeply couple the wastewater flow velocity with the heat exchange efficiency. For example, when the actual efficiency of the main heat exchanger decreases, the heat exchange capacity is compensated by increasing the wastewater flow velocity, and then the addition of an auxiliary heat exchanger is considered, rather than adjusting the steam parameters. This is especially suitable for the instability of the secondary steam in the MVR evaporation and salt precipitation unit (the secondary steam of the MVR evaporation and salt precipitation unit enters the heat exchange unit for heat exchange).

[0223] The solution introduces periodic updates to "actual heat exchange efficiency, actual wastewater flow rate efficiency, and wastewater flow rate efficiency at the inlet of the auxiliary heat exchanger and the outlet of the previous operating heat exchanger" (step 411), to capture in real time the performance degradation of heat exchangers and pipes caused by scaling and wear. For example, scaling during heat exchanger operation will reduce the actual heat exchange efficiency. The system automatically adjusts the flow rate or activates the auxiliary heat exchanger by satisfying the coefficient calculation to compensate for the decrease in heat exchange capacity caused by equipment degradation, ensuring long-term stable operation of the system (avoiding loss of control of evaporator feed parameters due to equipment aging).

[0224] Regardless of changes in wastewater type, wastewater temperature fluctuations, or steam parameter variations, the solution adapts and is compatible with multiple operating conditions through a closed loop of "dynamic calculation of target parameters - on-demand commissioning of heat exchangers - precise flow rate control".

[0225] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A process for recycling and treating high-salinity wastewater, characterized in that: include: Step 1: Analyze the organic composition of each high-salinity wastewater to determine the composition and content of materials in the wastewater; Step 2: Develop corresponding treatment plans for the specific components of each high-salinity wastewater; Step 3: Treat the high-salinity wastewater according to the treatment plan, and adjust and optimize the plan to remove organic matter and reduce the color of the high-salinity wastewater; Step 4: Evaporate the treated wastewater to obtain qualified by-product salt; The treatment scheme includes resin adsorption, which is carried out using a resin separation device. A periodic resin separation status assessment process is performed during the resin adsorption process. During each resin separation status assessment process, the wastewater flow rate at the wastewater inlet of the resin separation device, the wastewater flow velocity at the resin inlet side of the resin separation device, and the wastewater flow velocity at the resin outlet side of the resin separation device are detected, as well as the flow velocity at the outlet of the wastewater valve of the resin separation device at the current valve opening. And determine the first ratio of the average wastewater flow rate on the resin outlet side to the average wastewater flow rate on the resin inlet side for each resin separation status assessment process. Based on each resin separation status assessment process, the average flow rate at the outlet of the corresponding wastewater outlet valve at the current valve opening and the average wastewater flow rate at the wastewater inlet are used to determine the wastewater retention coefficient. And when the first ratio is greater than the first preset value, the valve flow rate loss coefficient is determined; When either the first ratio is less than or equal to the first preset value or the valve flow rate loss coefficient is greater than the preset loss coefficient, the control alarm will issue a warning. The resin adsorption process for the current wastewater requiring adsorption includes: Step 301: When the alarm is not triggered, obtain the valve flow rate loss coefficients obtained from the latest resin separation status assessment process, construct the time-valve loss coefficient change curve, obtain the required flow rate range of the current wastewater to be adsorbed through the valve outlet of the resin separation device, and obtain the valve opening-standard flow rate change curve corresponding to the current wastewater to be adsorbed; the valve was not cleaned during the time period corresponding to each time-valve loss coefficient change curve. Step 302: Based on the selected flow rate within the required flow rate range according to a predetermined rule, and the time-valve loss coefficient change curve obtained in step 301, determine the current predicted retention coefficient corresponding to each selected flow rate. Step 303: Obtain the standard flow rate range of the wastewater to be adsorbed and the resin adsorption effect evaluation value curve under the corresponding standard conditions. Step 304: Based on the current predicted retention coefficient corresponding to each selected flow rate determined in Step 302, the first ratio determined in the latest resin separation state assessment process, and the standard flow rate range of wastewater - resin adsorption effect evaluation value curve, determine the comprehensive evaluation value of each selected flow rate. Step 305: Determine the average of the N selected flow velocities with the largest comprehensive evaluation value that are greater than the preset evaluation value as the first flow velocity, and determine the target valve opening corresponding to the valve opening-standard flow velocity change curve corresponding to the current wastewater to be adsorbed. Step 306: Adjust the actual valve opening of the valve to the target valve opening, and set the actual influent flow rate to the current wastewater to be adsorbed as the corresponding rated influent flow rate. Perform resin adsorption on the current wastewater to be adsorbed until the valve opening adjustment conditions are met.

2. The high-salinity wastewater recycling and treatment process according to claim 1, characterized in that: The high-salinity wastewater is DHPPA secondary acidification wastewater, and the treatment process of the DHPPA secondary acidification wastewater includes the following steps: Step 311: After the DHPPA secondary acidification wastewater is adsorbed by the resin, liquid alkali is added for neutralization; Step 312: After the resin regeneration is completed, the wastewater obtained in step 311 is transferred back into the resin for secondary adsorption and decolorization. The resin after decolorization and adsorption does not need to be regenerated and can be directly used for the next batch of wastewater adsorption. In step 4, the decolorized effluent obtained in step 3 is evaporated at the MVR to precipitate salt, yielding wet salt as a byproduct. The concentrated mother liquor from evaporation is combined with the secondary acidification wastewater from DHPPA and then subjected to resin adsorption treatment. The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined, liquid alkali is added for neutralization and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue from the distillation kettle is sent to a qualified unit for treatment.

3. The high-salinity wastewater recycling and treatment process according to claim 1, characterized in that: The high-salt wastewater is nicotinic acid wastewater; When the nicotinic wastewater is a monoamined wastewater of nicotinic acid, the treatment process of the monoamined wastewater of nicotinic acid includes the following steps: Step 321: Add liquid alkali to the monoamined wastewater of nicotinamide, heat to reflux, and the dimethylamine tail gas generated by reflux is converted into dimethylamine aqueous solution through secondary water absorption; Step 322: After ammonia removal, the wastewater is neutralized and then distilled to remove light components. The light components serve as a biochemical carbon source. The wastewater after light component removal is filtered and then subjected to resin adsorption. In step 4, the adsorbed water obtained in step 3 is evaporated at the MVR to precipitate salt and obtain by-product salt. The concentrated mother liquor is then reused for resin adsorption. The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue in the distillation kettle is sent to a qualified unit for treatment. When the nicotinamide wastewater is diaminedated nicotinamide wastewater, the treatment process for the diaminedated nicotinamide wastewater includes the following steps: Step 331: Add liquid alkali to the diaminedation wastewater of nicotinamide, heat to reflux, and the ammonia gas generated by reflux is absorbed by secondary water to produce ammonia water; Step 332: The wastewater after ammonia removal is acidified, filtered, and then subjected to resin adsorption; Step 333: The adsorbed water is first neutralized with liquid alkali. After the resin regeneration is completed, the resin adsorption and decolorization are carried out again. The decolorized resin does not need to be regenerated and can be directly used for the next batch of wastewater adsorption. In step 4, the decolorized wastewater obtained in step 3 is evaporated to precipitate salt and produce by-product salt. The concentrated mother liquor is then reused for resin adsorption. The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined, liquid alkali is added for neutralization and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue in the distillation kettle is sent to a qualified unit for treatment. When the nicotinic wastewater is triacetone wastewater from nicotinic acid, the treatment process for the triacetone wastewater from nicotinic acid includes the following steps: Step 341: Remove the light components from the triacetone wastewater in nicotinamide and use the light components as a biochemical carbon source; Step 342: The wastewater after the removal of light components is filtered and then subjected to resin adsorption; In step 4, the adsorbed water obtained in step 3 is evaporated to precipitate salt and produce by-product salt. The concentrated mother liquor is then reused for resin adsorption. The resin regeneration process includes: first, adding water for pre-washing, then methanol and water analysis, the pre-wash water is sent to biochemical treatment, the analyzed methanol and analyzed water are combined and then distilled to recover methanol, the recovered methanol is reused in methanol analysis, and the residue from the distillation kettle is sent to a qualified unit for treatment.

4. The high-salinity wastewater recycling and treatment process according to claim 1, characterized in that: The conditions for adjusting the valve opening are as follows: the difference between the first ratio determined in step 304 and the first ratio determined in the subsequent resin separation state evaluation process is greater than the first preset difference; the difference between the valve loss coefficient determined in the subsequent resin separation state evaluation process and the valve loss coefficient determined in step 301 is greater than the second preset difference; or any of the following occurs:

5. The high-salinity wastewater recycling and treatment process according to claim 1, characterized in that: Step 4 includes: Step 41: Pre-treat the treated wastewater by heating; Step 42: Input the pre-treated wastewater into the evaporation device for evaporation; Step 41 is performed based on a heat exchange device, which includes: a main heat exchanger and several auxiliary heat exchangers arranged in sequence. The wastewater outlet of the preceding heat exchanger and the wastewater inlet of the following heat exchanger are connected by a pipe. A branch pipe is fixedly connected in the middle of the pipe. A valve is installed on the branch pipe. A valve is installed on the pipe near the wastewater inlet of the following heat exchanger. The branch pipe is connected to a pipe, and the pipe is connected to the wastewater inlet of the evaporation device. The main heat exchanger and several auxiliary heat exchangers are all connected to a steam inlet pipe. When each valve is working, it operates at its corresponding rated opening. During operation, each heat exchanger undergoes a second heat exchange status assessment every first time interval. The current heat exchange status assessment process includes: Based on the detection, the operating status assessment parameters are determined within the current second time period. The operating status assessment parameters include: the actual heat exchange efficiency and actual wastewater flow rate efficiency of the operating heat exchanger, and the wastewater flow rate efficiency of the wastewater inlet of the operating auxiliary heat exchanger and the wastewater outlet of the previous operating heat exchanger. If any of the operating status evaluation parameters is outside the corresponding preset range, an alarm will be triggered by alarm device two.

6. The high-salinity wastewater recycling and treatment process according to claim 5, characterized in that: Step 41 includes: Step 411: Obtain the current steam parameters of the steam inlet pipe and the current temperature of the wastewater to be evaporated before entering the main heat exchanger, and obtain the latest determined operating status evaluation parameters; Step 412: Obtain the target heat exchange parameters of the current wastewater to be evaporated, and determine the target inflow velocity of the current wastewater to be evaporated into the main heat exchanger based on the target heat exchange parameters and step 411. The target heat exchange parameters include: the target temperature entering the evaporation device and the target flow velocity range entering the evaporation device. Step 413: Obtain the wastewater flow rate-theoretical heat exchange efficiency variation curve of the current type of wastewater to be evaporated in each heat exchanger; Step 414: Based on steps 411, 412, and 413, first determine the heat exchange satisfaction value of the main heat exchanger. When the heat exchange satisfaction value of the main heat exchanger is greater than or equal to 1, control the actual flow rate of the wastewater inlet of the main heat exchanger to the target inlet flow rate, control valve one corresponding to the main heat exchanger to be closed and valve two to be opened, and control valve one and valve two corresponding to all auxiliary heat exchangers to be closed, so as to realize heat exchange for the current wastewater to be evaporated. Step 415: When the heat exchange satisfaction value of the main heat exchanger is less than 1, based on steps 411, 412, and 413, determine the number of auxiliary heat exchangers that need to be operated, and control the valve one of the last auxiliary heat exchanger that needs to be operated to be closed and the valve two to be opened, while the valve one of the other auxiliary heat exchangers that need to be operated is opened and the valve two is closed.

Images