A method for recycling zinc-containing high-concentration high-salt production wastewater of gliclazide

Abstract

The application discloses a zinc-containing high-concentration high-salt production wastewater resource utilization method of gliclazide, and relates to the technical field of wastewater, and comprises the following steps: mixing raw water and dilution water according to a proportion and adjusting a pH value, removing zinc ions in the mixed wastewater to obtain treated wastewater; the treated wastewater is introduced into a running branch of a fixed bed resin adsorption device at a preset flow rate, nitrogen heterocyclic organic matter is adsorbed and separated through a resin adsorption column, the COD value of effluent water is monitored, and when the COD value exceeds a set value, the treated wastewater is switched to a standby branch to be evaporated and concentrated to recover sodium chloride; saturated resin is regenerated by countercurrent regeneration with methanol, and methanol washing liquid and water washing liquid obtained through the regeneration are recovered through a rectifying column, and the methanol recovered at the top of the rectifying column is recycled for resin regeneration. The application solves the problems, such as unstable treatment effect, high operation cost and low resource recovery rate, which are commonly present in the prior art when treating the wastewater.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of wastewater treatment, in particular to a method for recycling zinc-containing high-concentration high-salt gliclazide production wastewater. BACKGROUND

[0002] Gliclazide is a commonly used sulfonylurea hypoglycemic drug, and the wastewater generated during its production process has the characteristics of high concentration, high salinity, containing amphoteric heavy metal zinc ions and refractory nitrogen heterocyclic organic matter, etc. The treatment of such wastewater has always been a difficulty in the field of environmental engineering. Traditional treatment methods mainly include chemical precipitation method, oxidation method, biological method and membrane separation method, etc. Although the chemical precipitation method can remove part of the heavy metal ions, it is difficult to treat up to standard due to the amphoteric characteristics of zinc ions, and a large amount of secondary sludge is easily produced; the oxidation method has poor effect on the treatment of nitrogen heterocyclics, resulting in high treatment cost and instability; the biological method is greatly affected by high salt and heavy metal inhibition; and the membrane separation method is prone to membrane pollution and cannot be operated stably for a long time. At the same time, these methods generally have low resource recovery rate and poor selectivity, and it is difficult to achieve efficient recovery and utilization of valuable components in wastewater.

[0003] In recent years, the electrocoagulation-adsorption combined technology has shown good application prospects in the field of wastewater treatment. However, the current combined technology still faces many challenges in treating gliclazide production wastewater: first, the structure of the floc in the electrocoagulation process is unstable, resulting in large fluctuations in heavy metal removal efficiency; second, the resin adsorption process is easily affected by high salt environment, with low adsorption capacity and difficult regeneration; third, there is a lack of recycling and utilization scheme for valuable substances such as zinc hydroxide and sodium chloride in wastewater. In view of these problems, it is urgent to develop an integrated technology that can achieve efficient removal of heavy metals, deep treatment of organic matter and recycling of resources. SUMMARY

[0004] In view of the above problems, the present application is proposed.

[0005] Therefore, the present application provides a method for recycling zinc-containing high-concentration high-salt gliclazide production wastewater, which can solve the problems mentioned in the background art.

[0006] To solve the above technical problems, the application provides the following technical scheme: a zinc-containing high-concentration high-salt gliclazide production wastewater resource utilization method, comprising the following steps: mixing raw water and dilution water according to a preset ratio to obtain mixed wastewater, monitoring and adjusting the pH value of the mixed wastewater, and sequentially passing the adjusted mixed wastewater through an electric flocculation reactor, an intermediate aeration barrel and a coagulation sedimentation tank to remove zinc ions to obtain treated wastewater; sequentially passing the treated wastewater into running branches of a fixed-bed resin adsorption device arranged in parallel at a preset flow rate, using an upper-in lower-out mode of a resin adsorption column in the running branch to adsorb and separate nitrogen heterocyclic organic matter in the treated wastewater, monitoring the COD value of the effluent of the resin adsorption column, switching to a standby branch when the COD value is greater than a set value, and evaporating and concentrating the wastewater treated by the resin adsorption column to recover sodium chloride; and using methanol to regenerate the saturated resin adsorption column in a countercurrent mode, recovering methanol and water washing liquid obtained by the countercurrent regeneration through a rectifying column, and recycling the methanol recovered from the top of the rectifying column for the countercurrent regeneration of the resin adsorption column.

[0007] As a preferred scheme of the zinc-containing high-concentration high-salt gliclazide production wastewater resource utilization method, the method comprises the following steps: mixing the raw water and the dilution water according to a preset mixing ratio to obtain the mixed wastewater; adjusting the pH value of the mixed wastewater according to the comparison relationship between the complexation equilibrium constant of zinc ions and iron ions and the precipitation equilibrium constant of free zinc ions to form an iron-zinc complex; adjusting the current density and / or the plate spacing of the electric flocculation reactor to make the iron-zinc complex flocculation body form a target crystal structure; and sequentially passing the mixed wastewater with the iron-zinc complex flocculation body having the target crystal structure through the intermediate aeration barrel and the coagulation sedimentation tank for solid-liquid separation to obtain the treated wastewater.

[0008] As a preferred scheme of the zinc-containing high-concentration high-salt gliclazide production wastewater resource utilization method, the method comprises the following steps: controlling the ratio of the addition rate of the sulfate ions to the addition rate of the alkali liquor to be equal to the ratio of the complexation equilibrium constant of the zinc ions to the iron ions to the precipitation equilibrium constant; and synchronously adding the sulfate ions at multiple points along the tangential direction of the mixed wastewater under mechanical stirring until the ultraviolet absorption spectrum curve of the iron-zinc complex appears a characteristic peak and the peak value no longer changes, indicating that the iron-zinc complex forms a stable multi-core complex structure.

[0009] As a preferred scheme of the method for recycling zinc-containing high-concentration and high-salt gliclazide production wastewater, the adjustment of the current density comprises the following steps: taking the initial current density as the reference, when the coordination number of the iron-zinc composite floc is less than the theoretical coordination number, the adjustment amount of the current density increases in a negative exponential manner with the difference between the coordination number and the theoretical coordination number; when the change rate of the absolute value of the surface potential in three consecutive measurements is less than the resolution of the potential detector, the adjustment of the current density is stopped.

[0010] As a preferred scheme of the method for recycling zinc-containing high-concentration and high-salt gliclazide production wastewater, the adjustment of the plate spacing comprises the following steps: taking the initial plate spacing as the reference, when the surface potential of the iron-zinc composite floc is negative, the adjustment amount of the plate spacing is negatively correlated with the difference between the surface potential and the zero potential; after each adjustment, the hydraulic retention time of the electrocoagulation reactor is kept unchanged until the peak type coefficient of the particle size distribution curve of the iron-zinc composite floc is greater than the skewness of the distribution curve.

[0011] As a preferred scheme of the method for recycling zinc-containing high-concentration and high-salt gliclazide production wastewater, after the nitrogen-containing heterocyclic organic compounds in the treated wastewater are adsorbed and separated by the resin adsorption column in the running branch in an up-in and down-out manner, the method further comprises the following steps: preliminarily monitoring the COD value of the effluent of the resin adsorption column and detecting the adsorption saturation degree of the resin adsorption column in the running branch until the resin adsorption column reaches adsorption equilibrium to obtain a stable adsorption treatment system; the fixed-bed resin adsorption device comprises two running branches and one standby branch; the adsorption saturation degree is obtained by measuring the adsorption capacity distribution curve of the resin adsorption column at different heights, and when the ratio of the change amount of the slope of the adsorption capacity distribution curve to the measurement time interval is zero, it indicates that the resin adsorption column reaches adsorption equilibrium; after the resin adsorption column reaches adsorption equilibrium, the COD value of the effluent of the resin adsorption column is continuously monitored, and when the COD value is greater than a set value, the regeneration state of the standby branch is detected, if the regeneration state meets the switching condition, the running branch is switched to the standby branch, and the wastewater after switching is treated to obtain the wastewater treated by the resin adsorption column; the wastewater treated by the resin adsorption column is evaporated and concentrated to establish a linear relationship function between the evaporation temperature and the solution concentration, and when the concentration of sodium chloride in the concentrated solution reaches the saturation solubility, solid-liquid separation is performed to recover the sodium chloride.

[0012] As a preferred scheme of the zinc-containing high-concentration high-salt gliclazide production wastewater resource utilization method, the switching condition needs to meet the following conditions simultaneously: the moisture content, specific surface area and porosity of the resin adsorption column of the standby branch are restored to the initial state, and the standing time meets the requirement of sufficient expansion of the resin adsorption column.

[0013] To further solve the above technical problems, the application provides the following technical scheme: a zinc-containing high-concentration high-salt gliclazide production wastewater resource utilization system, comprising: a mixing control module for mixing raw water and dilution water at a predetermined ratio to obtain mixed wastewater, and monitoring and adjusting the pH value of the mixed wastewater; a flocculation treatment module for sequentially passing the adjusted mixed wastewater through an electrocoagulation reactor, an intermediate aeration barrel and a coagulation sedimentation tank to remove zinc ions in the mixed wastewater to obtain treated wastewater; an adsorption separation module for sequentially passing the treated wastewater into a running branch of a fixed bed resin adsorption device arranged in parallel at a predetermined flow rate, and using the resin adsorption column in the running branch to adsorb and separate nitrogen heterocyclic organic matter in the treated wastewater in an up-in and down-out manner; a monitoring switching module for monitoring the COD value of the effluent of the resin adsorption column, and switching to the standby branch when the COD value is greater than a set value; a concentration recovery module for evaporative concentration and recovery of sodium chloride from the wastewater treated by the resin adsorption column; and a regeneration circulation module for regenerating the saturated resin adsorption column by countercurrent regeneration using methanol, recovering the methanol and water washing liquid obtained by the countercurrent regeneration through a rectifying column, and recycling the methanol recovered from the top of the rectifying column for the countercurrent regeneration of the resin adsorption column.

[0014] A computer device comprises a memory and a processor, the memory stores a computer program, and the processor implements the steps of the gliclazide zinc-containing high-concentration high-salt production wastewater resource utilization method as described above when executing the computer program.

[0015] A computer readable storage medium stores a computer program, and the computer program implements the steps of the gliclazide zinc-containing high-concentration high-salt production wastewater resource utilization method as described above when executed by a processor.

[0016] The present application has the beneficial effects that the present application realizes efficient treatment and resource utilization of gliclazide production wastewater. In the wastewater pretreatment stage, based on the complexation balance regulation and flocculation structure directional conversion mechanism, the stability and separation efficiency of iron-zinc composite flocculation are improved; in the organic matter removal stage, the resin adsorption system design of "two operation and one standby" is adopted, combined with dynamic adsorption capacity monitoring and accurate switching control, the continuous and stable operation of the treatment system is ensured; in the resource recovery stage, the temperature-concentration relationship model is established to guide the evaporation crystallization process, realizing efficient recovery of sodium chloride, and the solvent consumption is reduced through the segmented regeneration and quality recovery scheme. The overall process avoids the problems of unstable treatment effect, high energy consumption and secondary pollution in traditional technology, and has the advantages of stable process, low cost, high resource recovery rate and the like. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.

[0018] Figure 1 The overall process schematic diagram of a gliclazide zinc-containing high-concentration high-salt production wastewater resource utilization method proposed by the present application;

[0019] Figure 2 The overall structure schematic diagram of a gliclazide zinc-containing high-concentration high-salt production wastewater resource utilization system proposed by the present application;

[0020] Figure 3 The computer equipment diagram in the gliclazide zinc-containing high-concentration high-salt production wastewater resource utilization method proposed by the present application. DETAILED DESCRIPTION

[0021] In order to make the above-mentioned purposes, features and advantages of the present application more apparent and easy to understand, the specific embodiments of the present application will be described in detail below with reference to the drawings of the specification. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor should be within the scope of protection of the present application.

[0022] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar generalizations without departing from the connotation of the present application, therefore the present application is not limited to the specific embodiments disclosed below.

[0023] Embodiment 1, refer to Figure 1 For an embodiment of the present application, a zinc-containing high-concentration high-salt production wastewater resource utilization method of gliclazide is provided.

[0024] Figure 1 A schematic diagram of the overall process of a zinc-containing high-concentration high-salt production wastewater resource utilization method of gliclazide is shown, which includes the following steps:

[0025] S1: Mix raw water and dilution water according to a preset ratio to obtain mixed wastewater, monitor the pH value of the mixed wastewater and adjust it, and then pass the adjusted mixed wastewater through an electric flocculation reactor, an intermediate aeration barrel and a coagulation sedimentation tank in sequence to remove zinc ions, and obtain treated wastewater.

[0026] S1.1: Mix raw water and dilution water according to a preset mixing ratio to obtain mixed wastewater, monitor the pH value of the mixed wastewater, adjust the pH value by stepwise addition of sodium hydroxide solution, detect the complexation equilibrium constant of zinc ions and iron ions in the mixed wastewater, if the complexation equilibrium constant of zinc ions and iron ions in the mixed wastewater is greater than the precipitation equilibrium constant of free zinc ions, then add alkali liquor to the mixed wastewater and introduce sulfate ions for synergistic adjustment to form iron-zinc complex, if the complexation equilibrium constant of zinc ions and iron ions in the mixed wastewater is less than the precipitation equilibrium constant of free zinc ions, then only add alkali liquor to the mixed wastewater, to obtain mixed wastewater containing iron-zinc complex.

[0027] For example, in this embodiment, a 10% by mass sodium hydroxide solution can be added dropwise to the mixed wastewater at a rate of 0.5 mL / min, and the pH value is detected every 3 min until the pH value stabilizes in the range of 6-7.

[0028] Specifically, the preset mixing ratio is a volume ratio of raw water to dilution water of 1:2; the synergistic adjustment includes: controlling the ratio of the addition rate of sulfate ions to the addition rate of alkali liquor to be equal to the ratio of the complexation equilibrium constant of zinc ions to the precipitation equilibrium constant of zinc ions, and adding the sulfate ions along the tangential direction of the mixed wastewater at multiple points simultaneously under mechanical stirring, and continuing to stir until the characteristic peak appears in the ultraviolet absorption spectrum curve of the iron-zinc complex and the peak value no longer changes, indicating that the iron-zinc complex forms a stable polynuclear complex structure. Wherein, the rotational speed of the mechanical stirring is directly proportional to the square root of the Reynolds number of the mixed wastewater.

[0029] Preferably, the present application firstly reduces the concentration of the influent by mixing raw water with dilution water to create suitable conditions for subsequent treatment. In the pH adjustment stage, the present application breaks through the limitations of the traditional direct alkali addition method, introduces a complex equilibrium constant criterion, and determines the treatment strategy according to the relationship between the complex equilibrium constant and the precipitation equilibrium constant. When the complex equilibrium constant is greater than the precipitation equilibrium constant, the formation of iron-zinc complexes is promoted by introducing sulfate ions for synergistic adjustment; otherwise, only alkali adjustment is needed. This equilibrium constant-based criterion ensures the stable formation of iron-zinc complexes and avoids the problem of easy redissolution of zinc ions in the traditional pH adjustment process.

[0030] S1.2: introducing the mixed wastewater containing iron-zinc complexes into an electrocoagulation reactor for electrocoagulation treatment, detecting the coordination number and surface potential of the iron-zinc complex floes in the electrocoagulation reactor, if the coordination number of the iron-zinc complex floes is less than the theoretical coordination number and the surface potential of the iron-zinc complex floes is greater than the zero potential, adjusting the current density of the electrocoagulation reactor to make the iron-zinc complex floes form an octahedral structure, if the coordination number of the iron-zinc complex floes is greater than the theoretical coordination number and the surface potential of the iron-zinc complex floes is less than the zero potential, adjusting the inter-electrode distance of the electrocoagulation reactor to make the iron-zinc complex floes restructure into a tetrahedral structure, if the coordination number of the iron-zinc complex floes is equal to the theoretical coordination number and the surface potential of the iron-zinc complex floes is equal to the zero potential, maintaining the current density and the inter-electrode distance of the electrocoagulation reactor unchanged, and obtaining iron-zinc complex floes with a target crystal form;

[0031] Specifically, the adjustment of the current density includes: taking the initial current density as the benchmark, when the coordination number of the iron-zinc complex floes is less than the theoretical coordination number, the adjustment amount of the current density increases with the difference between the coordination number and the theoretical coordination number in a negative exponential manner, and when the absolute value of the surface potential changes at a rate less than the resolution of the potential detector for three consecutive times, the adjustment of the current density is stopped; the adjustment of the inter-electrode distance includes: taking the initial inter-electrode distance as the benchmark, when the surface potential of the iron-zinc complex floes is negative, the adjustment amount of the inter-electrode distance is negatively correlated with the difference between the surface potential and the zero potential, the hydraulic retention time of the electrocoagulation reactor is kept unchanged after each adjustment, and this process is repeated until the peak type coefficient of the particle size distribution curve of the iron-zinc complex floes is greater than the skewness of the distribution curve.

[0032] It should be noted that in the process of treating the iron-zinc complex floes in the present application, the theoretical coordination number refers to the optimal coordination number of the central metal ion (Fe 3+ ) and the ligand (including OH - , SO4 2- and Zn 2+ from the wastewater) to form a stable complex in an ideal coordination state. This theoretical coordination number mainly depends on the electronic configuration, ionic radius of the central metal ion and the steric hindrance effect between the ligand. In the present application, since Fe 3+The complexes tend to form octahedral (coordination number 6) or tetrahedral (coordination number 4) structures, so the theoretical coordination number is usually between 4-6. In the specific calculation, the influence of the concentration of each ligand in the wastewater system, pH value, temperature and other factors on the coordination ability needs to be considered, and the coordination chemical equilibrium constant and the complex stability constant are modified. In practical application, the actual coordination number can be determined by ultraviolet-visible spectroscopy or potentiometric titration method, and compared with the theoretical coordination number, so as to adjust the operating parameters in the process of electroflocculation, and ensure the formation of the optimal coordination structure of iron-zinc composite flocculation. The accurate determination of the theoretical coordination number has important guiding significance for the subsequent regulation of flocculation structure, and is one of the key parameters to realize the efficient removal of zinc ions in wastewater.

[0033] Preferably, in the electroflocculation treatment stage, the present application establishes a flocculation structure regulation mechanism based on coordination number and surface potential. By real-time monitoring of the coordination number and surface potential of iron-zinc composite flocculation, combined with accurate adjustment of current density or inter-electrode distance, directional conversion of flocculation structure to octahedral or tetrahedral is realized. This structure regulation improves the stability of the flocculation and the adsorption capacity of zinc ions, overcoming the problem of unstable flocculation structure in the traditional electroflocculation process. In the current density adjustment process, the present application uses the negative exponential relationship of the coordination number difference as the basis for adjustment, which not only ensures the accuracy of the adjustment, but also avoids the increase of energy consumption caused by excessive adjustment.

[0034] S1.3: The mixed wastewater containing iron-zinc composite flocculation with target crystal form is sequentially subjected to aeration oxidation by an intermediate aeration barrel and solid-liquid separation by a coagulation sedimentation tank, to obtain treated wastewater with zinc ion content lower than that of the influent.

[0035] It should be noted that the solid-liquid separation stage adopts a combination of aeration oxidation and coagulation sedimentation, which further stabilizes the flocculation structure and enhances the effect of subsequent sedimentation separation. This series processing method not only improves the stability of the effluent water quality, but also reduces the operation difficulty. The whole treatment process is closely linked between each step, forming a complete technical system, and realizing the efficient removal of zinc ions. Compared with the traditional treatment method, the present application improves the stability and reliability of the treatment effect through complexation balance regulation, structure directional conversion and multi-stage separation.

[0036] S2: The treated wastewater is sequentially introduced into the running branch of the fixed bed resin adsorption device arranged in parallel at a preset flow rate, and the resin adsorption column in the running branch is used to adsorb and separate nitrogen heterocyclic organic matter in the treated wastewater in an up-in and down-out manner. The COD (Chemical Oxygen Demand) value of the effluent of the resin adsorption column is monitored, and when the COD value is greater than the set value, the standby branch is switched to, and the wastewater treated by the resin adsorption column is evaporated and concentrated to recover sodium chloride.

[0037] The fixed bed resin adsorption device comprises two running branches and one standby branch.

[0038] S2.1: The treated wastewater is sequentially introduced into the running branches of the fixed bed resin adsorption device at a preset flow rate, the resin adsorption column in the running branch is used to adsorb and separate the nitrogen-containing heterocyclic organic compounds in the treated wastewater in an up-in and down-out manner, the COD value of the effluent of the resin adsorption column is preliminarily monitored, the adsorption saturation of the resin adsorption column in the running branch is detected, until the resin adsorption column reaches adsorption equilibrium, and a stable adsorption treatment system is obtained.

[0039] Specifically, the fixed bed resin adsorption device comprises two running branches and one standby branch; the adsorption saturation is obtained by measuring the adsorption capacity distribution curve of the resin adsorption column at different heights, and when the ratio of the change amount of the slope of the adsorption capacity distribution curve to the measurement time interval is zero, it indicates that the resin adsorption column reaches adsorption equilibrium.

[0040] It should be noted that in the process for treating wastewater containing nitrogen-containing heterocyclic organic compounds, the preset flow rate directly affects the residence time of the wastewater in the resin adsorption column, and further affects the adsorption effect. The preset flow rate is obtained by calculating the empty bed contact time (EBCT), which is the ratio of the volume of the resin adsorption column to the influent flow rate. Considering the adsorption kinetics characteristics and diffusion mass transfer process of nitrogen-containing heterocyclic organic compounds on the resin surface, and the actual demand of industrial treatment scale, the preset flow rate is preferably controlled in the range of 2-10 BV / h (Bed Volume per hour). The preset flow rate can ensure sufficient mass transfer driving force, and ensure appropriate adsorption equilibrium time, while taking into account the economic requirements of industrial treatment.

[0041] S2.2: After the resin adsorption column reaches adsorption equilibrium, the COD value of the effluent of the resin adsorption column is continuously monitored, when the COD value is greater than the set value, the regeneration state of the standby branch is detected, if the regeneration state meets the switching condition, the running branch is switched to the standby branch, and the wastewater after switching is treated, to obtain the wastewater after resin adsorption column adsorption treatment.

[0042] The switching condition needs to meet the following conditions at the same time: the water content, specific surface area and porosity of the resin adsorption column in the standby branch are restored to the initial state, and the standing time meets the requirement of sufficient expansion of the resin adsorption column.

[0043] It should be noted that the set value of the resin adsorption column effluent COD in the present application is a key parameter determined based on the dynamic adsorption capacity of the resin adsorption column and the process control requirements. When the effluent COD exceeds the set value, it indicates that the resin adsorption column is close to saturation, and branch switching needs to be performed in time to ensure the treatment effect. The set value is usually 10%-20% of the influent COD, and the specific value needs to be determined comprehensively in combination with the actual influent COD concentration, wastewater treatment requirements, and the bearing capacity of the downstream process. For example, when the influent COD is 1000 mg / L, the effluent COD set value can be set to 100-200 mg / L. Such setting can not only ensure the treatment effect, but also maximize the use of the adsorption capacity of the resin, while reserving enough operation time for branch switching. In actual application, an online monitoring system for influent and effluent COD can also be established to realize dynamic adjustment of the set value, further optimizing the process operation effect.

[0044] S2.3: The wastewater treated by the resin adsorption column is evaporated and concentrated to establish a linear relationship function between the evaporation temperature and the concentration of the solution. When the concentration of sodium chloride in the concentrated solution reaches the saturation solubility, solid-liquid separation is performed to recover sodium chloride.

[0045] Specifically, the linear relationship function is represented as:

[0046]

[0047] wherein, is the evaporation temperature, in ℃ or K; is the proportional coefficient, representing the slope of the temperature change with the concentration of sodium chloride, in ℃·L / mol or K·L / mol; is the concentration of sodium chloride in the solution, in mol / L; is the initial evaporation temperature (i.e. the boiling point of pure water), when is the temperature value when the evaporation temperature is equal to the boiling point of pure water, in ℃ or K, which is about 100 ℃ (373.15 K) under standard atmospheric pressure. This linear relationship follows the principle of proportionality and reflects the boiling point elevation phenomenon of the solution, k The value is usually positive because the boiling point of the solution will increase with the increase of the concentration of sodium chloride. This relationship is applicable to the range where the concentration of sodium chloride does not reach the saturation solubility, which can help the operator to judge the concentration of sodium chloride in the solution by monitoring the evaporation temperature, providing a basis for solid-liquid separation.

[0048] ​Preferably, the resin treatment of S2 of the present application is designed with two running branches and one standby branch according to the characteristics of the nitrogen-containing heterocyclic refractory organic matter in gliclazide production wastewater, the adsorption equilibrium is judged by measuring the adsorption capacity distribution curve at different heights of the resin adsorption column, and the switching conditions including the water content and specific surface area are set. This design overcomes the defects of limited removal rate and high cost in the prior art when treating high-salt and high-COD wastewater. A linear relationship function between temperature and sodium chloride concentration is established during evaporation and concentration, providing a quantitative criterion for solid-liquid separation. The advantages are as follows:

[0049] First, according to the characteristics of high salt content and nitrogen-containing heterocyclic refractory organic matter in gliclazide production wastewater, the present application adopts the design of two running branches and one standby branch, combined with the monitoring of resin adsorption column effluent COD, to ensure the continuous and stable operation of the treatment system. In the technical scheme, the filling volume of a single resin column is 2m³, and the design treatment capacity is 15BV wastewater. Through reasonable branch switching, the treatment capacity of the resin is fully utilized, and the wastewater COD is reduced to below 500mg / L.

[0050] Secondly, by monitoring the adsorption capacity distribution curve at different heights of the resin adsorption column, the adsorption equilibrium state can be accurately judged, and the problems of insufficient or excessive use of resin are avoided. The methanol is used for countercurrent regeneration at 4 times the volume of the resin, and after regeneration, the resin is washed with 4 times the volume of water, and the methanol is recovered by rectification and recycled, reducing the operating cost. This regeneration scheme not only ensures the reuse of the resin, but also realizes the recycling of methanol.

[0051] Thirdly, the temperature-concentration linear relationship function established in the evaporation and concentration link provides a reliable control basis for the recovery of sodium chloride, avoiding the errors that may be caused by experience. This is of great significance for treating wastewater with a temperature of 50-60℃ and salt content close to or exceeding saturation in the present application, and can realize efficient recovery of sodium chloride, so that the recovered sodium chloride meets the industrial wet salt secondary standard.

[0052] The S2 step of the present application not only solves the problem of high difficulty in gliclazide production wastewater treatment, but also realizes the resource treatment of wastewater. Compared with the conventional oxidation method, membrane separation method, biological method and incineration method, the present application avoids the shortcomings of low removal rate, high cost, easy damage of equipment, and the need for a large amount of dilution water, and has stable and reliable treatment process, low operating cost and good industrial promotion value.

[0053] S3: The saturated resin adsorption column is regenerated by countercurrent regeneration with methanol, the methanol wash liquor and water wash liquor obtained by countercurrent regeneration are recovered by rectification, and the methanol recovered from the top of the rectification column is recycled for countercurrent regeneration of the resin adsorption column.

[0054] In summary, the present application realizes efficient treatment and resource utilization of gliclazide production wastewater. In the wastewater pretreatment stage, based on the complexation balance regulation and flocculation structure directional conversion mechanism, the stability and separation efficiency of iron-zinc composite flocculation are improved; in the organic matter removal stage, the resin adsorption system design of "two operation and one standby" is adopted, combined with dynamic adsorption capacity monitoring and accurate switching control, to ensure the continuous and stable operation of the treatment system; in the resource recovery stage, the temperature-concentration relationship model is established to guide the evaporation crystallization process, realizing efficient recovery of sodium chloride, and reducing solvent consumption through the segmented regeneration and quality recovery scheme. The overall process avoids the problems of unstable treatment effect, high energy consumption and secondary pollution in traditional technology, and has the advantages of stable process, low cost, high resource recovery rate, etc.

[0055] Example 2, refer to Figure 2 For an embodiment of the present application, a zinc-containing high-concentration high-salt gliclazide production wastewater resource utilization system is provided. Figure 2 The overall structure of the system is shown in the figure, which includes:

[0056] The mixed regulation module is used for mixing raw water and dilution water according to a preset ratio to obtain mixed wastewater, and monitoring and adjusting the pH value of the mixed wastewater;

[0057] The flocculation treatment module is used for removing zinc ions from the adjusted mixed wastewater by passing through the electrocoagulation reactor, the intermediate aeration barrel and the coagulation sedimentation tank in sequence to obtain treated wastewater;

[0058] The adsorption separation module is used for passing the treated wastewater through the running branch of the fixed bed resin adsorption device in parallel at a preset flow rate, and the resin adsorption column in the running branch is used for adsorbing and separating nitrogen heterocyclic organic matter in the treated wastewater by the upper-in and lower-out mode;

[0059] The monitoring and switching module is used for monitoring the COD value of the resin adsorption column effluent, and switching to the standby branch when the COD value is greater than the set value;

[0060] The concentration recovery module is used for evaporating and concentrating the wastewater treated by the resin adsorption column to recover sodium chloride;

[0061] The regeneration and circulation module is used for regenerating the saturated resin adsorption column with methanol in countercurrent, recovering the methanol wash liquor and water wash liquor obtained by countercurrent regeneration through the rectifying column respectively, and recycling the methanol recovered from the top of the rectifying column for countercurrent regeneration of the resin adsorption column.

[0062] Example 3, refer to Figure 3For one embodiment of the present application, different from the previous embodiment, the function, if realized in the form of a software function unit and sold or used as an independent product, can be stored in a computer readable storage medium. Based on such understanding, the technical solution of the present application or the part of the technical solution that essentially contributes to the prior art or the part of the technical solution can be embodied in the form of a software product, which is stored in a storage medium and includes a plurality of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method described in various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0063] The logic and / or steps represented in the flowcharts or otherwise described herein, for example, can be considered as a list of executable instructions for implementing logic functions, which can be embodied in any computer-readable medium for use by an instruction execution system, apparatus, or device, such as a computer-based system, a system including a processor, or other system that can fetch the instructions from the instruction execution system, apparatus, or device and execute the instructions, or in conjunction with these instructions execution systems, apparatuses, or devices. For the purpose of this specification, the "computer-readable medium" can be any device that can contain, store, communicate, propagate, or transport programs for use by an instruction execution system, apparatus, or device, or in conjunction with these instruction execution systems, apparatuses, or devices.

[0064] More specific examples (a non-exhaustive list) of the computer-readable medium include the following: an electrical connection having one or more wires (electrical devices), a portable computer diskette (magnetic devices), a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber device, and a portable compact disc read-only memory (CDROM). In addition, the computer-readable medium can even be paper or other suitable medium on which the program can be printed, as the program can be electronically obtained, for example, by optical scanning of the paper or other medium, followed by electronic editing, interpretation, or necessary processing, and then stored in a computer memory if necessary.

[0065] It should be understood that portions of the present application can be implemented in hardware, software, firmware, or combinations thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, implementation can be with any or a combination of the following technologies, which are all well known in the art: a discrete logic circuit having logic gates for implementing logic functions upon an application of data signals, an application specific integrated circuit having appropriate combinational logic gates, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0066] It should be noted that the above examples are only used to illustrate the technical solutions of the present application but not limit the present application. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the spirit and scope of the present application, and all of them should be covered in the scope of the claims of the present application.

Claims

1. A method for recycling zinc-containing high-concentration high-salt production wastewater of gliclazide, characterized in that, The method comprises the following steps: The raw water and the dilution water are mixed according to a preset mixing ratio to obtain mixed wastewater, the pH value of the mixed wastewater is monitored and adjusted, and the adjusted mixed wastewater is sequentially passed through an electrocoagulation reactor, an intermediate aeration barrel and a coagulation sedimentation tank to remove zinc ions, thereby obtaining treated wastewater, and the method comprises the following steps: The raw water and the dilution water are mixed according to a preset mixing ratio to obtain the mixed wastewater; The pH value of the mixed wastewater is adjusted according to the comparison relationship between the complexation equilibrium constant of zinc ions and iron ions and the precipitation equilibrium constant of free zinc ions, thereby forming iron-zinc composite flocs; The current density of the electrocoagulation reactor is adjusted to make the iron-zinc composite flocs form a target crystal structure; The mixed wastewater containing iron-zinc composite flocs with the target crystal structure is sequentially passed through the intermediate aeration barrel and the coagulation sedimentation tank, and solid-liquid separation is performed, thereby obtaining the treated wastewater; The treated wastewater is sequentially introduced into running branches of a fixed-bed resin adsorption device arranged in parallel at a preset flow rate, the resin adsorption columns in the running branches are used in an up-in and down-out manner to adsorb and separate nitrogen heterocyclic organic matter in the treated wastewater, the COD value of effluent from the resin adsorption columns is monitored, and when the COD value is greater than a set value, switching to a standby branch is performed, and the wastewater treated by the resin adsorption columns is evaporated and concentrated to recover sodium chloride; The resin adsorption columns saturated with adsorption are regenerated in a countercurrent manner by using methanol, methanol washing liquid and water washing liquid obtained by the countercurrent regeneration are recovered by a rectifying column respectively, and the methanol recovered from the top of the rectifying column is recycled for the countercurrent regeneration of the resin adsorption columns.

2. The method for resource utilization of the zinc-containing high-concentration high-salt production wastewater of gliclazide according to claim 1, characterized in that: The adjustment of the pH value of the mixed wastewater comprises the following steps, The ratio of the addition rate of sulfate ions to the addition rate of alkali is equal to the ratio of the complexation equilibrium constant of zinc ions to the precipitation equilibrium constant of iron ions; The sulfate ions are synchronously added at multiple points along the tangential direction of the mixed wastewater under mechanical stirring, and the stirring is continuously performed until a characteristic peak appears in the ultraviolet absorption spectrum curve of the iron-zinc composite flocs and the peak value no longer changes, indicating that the iron-zinc composite flocs form a stable multi-core complex structure.

3. The method for resource utilization of zinc-containing high-concentration high-salt gliclazide production wastewater according to claim 2, characterized in that: The adjustment of the current density comprises the following steps: Based on the initial current density, when the coordination number of the iron-zinc composite flocs is less than the theoretical coordination number, the adjustment amount of the current density increases in a negative exponential manner with the difference between the coordination number of the iron-zinc composite flocs and the theoretical coordination number; When the change rate of the absolute value of the surface potential in three consecutive measurement results is less than the resolution of a potential detector, the adjustment of the current density is stopped.

4. The method for resource utilization of zinc-containing high-concentration high-salt gliclazide production wastewater according to claim 3, characterized in that: The adjustment of the electrode plate spacing comprises the following steps: Based on the initial electrode plate spacing, when the surface potential of the iron-zinc composite flocs is negative, the adjustment amount of the electrode plate spacing is negatively correlated with the difference between the surface potential and the zero potential, the hydraulic retention time of the electrocoagulation reactor is kept unchanged after each adjustment, and the peak type coefficient of the particle size distribution curve of the iron-zinc composite flocs is greater than the skewness of the distribution curve.

5. The method for resource utilization of the zinc-containing high-concentration high-salt production wastewater of gliclazide according to claim 4, characterized in that: After the nitrogen heterocyclic organic matter in the treated wastewater is adsorbed and separated by the resin adsorption columns in the running branches in an up-in and down-out manner, the method further comprises the following steps: The COD value of the effluent of the resin adsorption column is preliminarily monitored, and the adsorption saturation degree of the resin adsorption column in the operation branch is detected until the resin adsorption column reaches adsorption equilibrium, so that a stable adsorption treatment system is obtained; The fixed-bed resin adsorption device comprises two operation branches and one standby branch; the adsorption saturation degree is obtained by measuring the adsorption capacity distribution curve of the resin adsorption column at different heights, and when the ratio of the change amount of the slope of the adsorption capacity distribution curve to the measurement time interval is zero, it is indicated that the resin adsorption column reaches adsorption equilibrium; After the resin adsorption column reaches adsorption equilibrium, the COD value of the effluent of the resin adsorption column is continuously monitored, and when the COD value is greater than a set value, the regeneration state of the standby branch is detected, and if the regeneration state meets the switching condition, the operation branch is switched to the standby branch, and the wastewater after switching is treated to obtain the wastewater treated by the resin adsorption column; The wastewater treated by the resin adsorption column is evaporated and concentrated to establish a linear relationship function between evaporation temperature and solution, and when the concentration of sodium chloride in the solution reaches the saturation solubility, solid-liquid separation is performed to recover the sodium chloride.

6. The method for resource utilization of zinc-containing high-concentration high-salt gliclazide production wastewater according to claim 5, characterized in that: The switching condition needs to meet the following conditions at the same time: the water content, specific surface area and porosity of the resin adsorption column in the standby branch are restored to the initial state, and the standing time meets the requirement of sufficient expansion of the resin adsorption column.

7. A gliclazide-containing high-concentration high-salt wastewater resource system, based on the gliclazide-containing high-concentration high-salt wastewater resource method according to any one of claims 1 to 6, characterized in that: It comprises, A mixing control module is used to mix raw water and dilution water at a preset ratio to obtain mixed wastewater, and the pH value of the mixed wastewater is monitored and adjusted; A flocculation treatment module is used to sequentially pass the adjusted mixed wastewater through an electrocoagulation reactor, an intermediate aeration barrel and a coagulation sedimentation tank to remove zinc ions in the mixed wastewater, thereby obtaining treated wastewater; An adsorption separation module is used to pass the treated wastewater into the operation branch of a fixed-bed resin adsorption device arranged in parallel at a preset flow rate, and the resin adsorption column in the operation branch is used to adsorb and separate nitrogen heterocyclic organic matter in the treated wastewater in an up-in and down-out manner; A monitoring and switching module is used to monitor the COD value of the effluent of the resin adsorption column, and when the COD value is greater than a set value, the standby branch is switched to; A concentration and recovery module is used to evaporate and concentrate the wastewater treated by the resin adsorption column to recover sodium chloride; A regeneration and circulation module is used to regenerate the adsorption-saturated resin adsorption column by countercurrent regeneration with methanol, and the methanol washing liquid and water washing liquid obtained by the countercurrent regeneration are recovered by a rectifying column, and the methanol recovered from the top of the rectifying column is recycled for the countercurrent regeneration of the resin adsorption column.

8. A computer device comprising a memory and a processor, the memory storing a computer program, characterized in that, The processor executes the computer program to implement the steps of the method for recycling zinc-containing, high-concentration and high-salt production wastewater of gliclazide according to any one of claims 1 to 6.

9. A computer-readable storage medium having stored thereon a computer program, characterized in that, The computer program is executed by the processor to implement the steps of the method for recycling zinc-containing, high-concentration and high-salt production wastewater of gliclazide according to any one of claims 1 to 6.

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