Carbon source dialysis slow-release device and application thereof in sewage treatment

Abstract

The application provides a carbon source dialysis slow-release device and application thereof in sewage treatment. The carbon source dialysis slow-release device comprises a continuous flow reactor, a dialysis slow-release column and a liquid inlet tank. The continuous flow reactor comprises an anoxic chamber and an aerobic chamber. The dialysis slow-release column is located in the anoxic chamber. The dialysis slow-release column has a dialysis membrane and a containing cavity formed by the dialysis membrane. The dialysis membrane is a non-biodegradable dialysis membrane with MWCO greater than or equal to 100 Da. The containing cavity is in communication with the liquid inlet tank. The liquid inlet tank contains an organic carbon source. The device has simple and stable structure, is non-toxic and environment-friendly, is environment-friendly and low in cost. When the device is applied to sewage treatment, deep denitrification of sewage can be realized, and the problem of secondary pollution of effluent is avoided. The device is low in cost and has a wide application prospect.

Description

Technical Field

[0001] This invention relates to the application of water treatment technology and water resource regeneration, and in particular to a carbon source dialysis slow-release device and its application in wastewater treatment. Background Technology

[0002] With the continuous development of society, my country's Class A emission standard for total nitrogen in wastewater discharge has been lowered from 15 mg / L to 10 mg / L.

[0003] Currently, the mainstream process in my country's wastewater treatment plants is still denitrification. Faced with stricter emission standards, wastewater treatment plants can only increase the addition of soluble carbon sources such as starch, sodium acetate, glucose, and methanol. However, these carbon sources are expensive, and the dosage is difficult to control, leading to both excessively high denitrification costs and secondary pollution of effluent. Summary of the Invention

[0004] The main objective of this invention is to provide a carbon source dialysis slow-release device and its application in wastewater treatment, aiming to solve the problems of secondary pollution of effluent and high cost that exist in the existing technology of using denitrification treatment process for deep denitrification of wastewater.

[0005] To achieve the above objectives, the present invention provides a carbon source dialysis sustained-release device, which includes a continuous flow reactor, a dialysis sustained-release column, and an inlet tank; the continuous flow reactor includes an anoxic chamber and an aerobic chamber; the dialysis sustained-release column is located in the anoxic chamber; wherein the dialysis sustained-release column has a dialysis membrane and a containment cavity formed by the dialysis membrane, the dialysis membrane being a non-biodegradable dialysis membrane with MWCO ≥ 100 Da; the containment cavity is connected to the inlet tank.

[0006] The inlet tank contains an organic carbon source; the organic carbon source includes organic wastewater, or one or more of glucose solution, starch solution, methanol solution, and sodium acetate solution.

[0007] Furthermore, the surface area of ​​the dialysis membrane to the volume ratio of the receiving cavity is 1 to 8:1.

[0008] Furthermore, the dialysis sustained-release column includes a first dialysis sustained-release column, a second dialysis sustained-release column, a third dialysis sustained-release column, and a fourth dialysis sustained-release column.

[0009] The dialysis membrane of the first dialysis sustained-release column has a MWCO of 100-1000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing cavity is 1-5:1.

[0010] The dialysis membrane of the second dialysis sustained-release column has a MWCO of 500-1000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing cavity is 1-5:1.

[0011] The dialysis membrane of the third dialysis sustained-release column has a MWCO of 1000-5000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing cavity is 2-8:1.

[0012] The dialysis membrane of the fourth dialysis sustained-release column has a MWCO > 5000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing cavity is 1 to 2:1.

[0013] Furthermore, the carbon source dialysis sustained-release device also includes a TOC detector that is electrically connected to the dialysis sustained-release column and the inlet tank, respectively.

[0014] Furthermore, the non-biodegradable dialysis membrane includes regenerated cellulose membranes or cellulose membranes such as cellulose triacetate, polyethersulfone, polymethyl methacrylate, and polysulfone.

[0015] The present invention also provides an application of the carbon source dialysis slow-release device as described in any of the above claims in wastewater treatment, wherein the wastewater is introduced into a continuous flow reactor; the ammonia nitrogen concentration of the wastewater is >50 mg / L; the sludge concentration of the wastewater is >3000 mg / L; the dialysis slow-release column is immersed in the wastewater in the anoxic chamber, and the organic carbon source in the inlet tank is transported to the receiving cavity of the dialysis slow-release column; after the wastewater is treated in the continuous flow reactor, it is discharged.

[0016] Further, the method includes the following steps: introducing the wastewater into the continuous flow reactor, allowing it to remain for a period of time, and then discharging it. Once the total nitrogen accumulation rate in the effluent liquid of the continuous flow reactor is >20%, the dialysis slow-release column is immersed in the wastewater in the anoxic chamber for denitrification treatment; wherein the temperature of the denitrification treatment is 15-30°C.

[0017] When the cumulative rate of total nitrogen in the effluent is >20%, the MWCO of the dialysis membrane of the dialysis slow-release column is 100-1000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containment chamber is 1-5:1.

[0018] When the cumulative rate of total nitrogen in the effluent is >40%, the MWCO of the dialysis membrane of the dialysis slow-release column is 500-1000 Da, and the surface area to volume ratio of the dialysis membrane to the containment chamber is 1-5:1.

[0019] When the cumulative rate of total nitrogen in the effluent is >60%, the MWCO of the dialysis membrane of the dialysis slow-release column is 1000-5000 Da, and the surface area to volume ratio of the dialysis membrane to the containment chamber is 2-8:1.

[0020] When the cumulative rate of total nitrogen in the effluent is >80%, the MWCO of the dialysis membrane of the dialysis slow-release column is >5000 Da, and the ratio of the surface area of ​​the dialysis membrane to the volume of the accommodating chamber is 1 to 2:1.

[0021] Furthermore, the internal circulation nitrification reflux ratio of the continuous flow reactor is 600-800%; the external circulation sludge reflux ratio of the continuous flow reactor is 200-400%.

[0022] Furthermore, before the step of immersing the dialysis slow-release column in the wastewater of the anoxic chamber, the method further includes pretreatment of the dialysis slow-release column, including the steps of: providing a mixture of a metal chelating agent solution and a weak alkaline solution; heating the dialysis slow-release column in the mixture; and cleaning and drying it.

[0023] The metal chelating agent solution is a 0.3–1.0 mol / L ethylenediaminetetraacetic acid solution or an ethylenediaminetetraacetic acid salt solution; the weakly alkaline solution is a 4–6 g / L sodium bicarbonate solution.

[0024] The beneficial effects achieved by this invention are as follows:

[0025] The carbon source dialysis slow-release device provided by this invention mainly consists of a detachable dialysis slow-release column with various specifications, a continuous flow reactor, and an inlet tank. The dialysis slow-release column is made of a non-biodegradable dialysis membrane with an MWCO ≥ 100 Da. This device is simple and stable in structure, non-toxic, and environmentally friendly. It can extend the release time of soluble carbon sources from seconds to hours or days, reducing the release rate, eliminating the need to control the dosage, and allowing for timely absorption by microorganisms. Furthermore, the dialysis slow-release column in this carbon source dialysis slow-release device is made of recyclable material, offering advantages of environmental friendliness and low cost.

[0026] Applying this carbon source dialysis slow-release device to advanced wastewater denitrification (wastewater treatment) allows for the matching of the organic carbon source release rate within the device with the carbon source required for denitrification during the advanced wastewater denitrification process. This advanced wastewater denitrification method can regulate the organic matter release rate by altering the parameters of the dialysis slow-release column and changing the type of organic carbon source, based on demand. By selecting a suitable dialysis slow-release column based on the total nitrogen accumulation rate in the wastewater, the release of an appropriate amount of organic carbon source can be precisely controlled, ensuring that it precisely meets the needs of microorganisms to achieve advanced wastewater denitrification. This approach also avoids secondary pollution of the effluent, is cost-effective, and has broad application prospects. Attached Figure Description

[0027] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0028] Figure 1 For this purpose One optional embodiment of the present invention Schematic diagram of a carbon source dialysis slow-release device;

[0029] Figure 2 This is a comparison chart of the TOC concentration of organic carbon sources released by the carbon source dialysis slow-release device under different pH conditions in Example 1 of the present invention.

[0030] Figure 3 This is a comparison chart of the TOC concentration of organic carbon sources released by the carbon source dialysis slow-release device under different temperature conditions in Example 1 of the present invention.

[0031] Figure 4 This is a box plot of wastewater denitrification treatment under different conditions in Embodiment 2 of the present invention.

[0032] The realization of the objective, functional characteristics and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] It should be noted that, unless otherwise specified, the following embodiments and features can be combined with each other. It should also be understood that the terminology used in the embodiments of this invention is for describing specific implementations and not for limiting the scope of protection of this invention.

[0035] Unless otherwise defined, all technical and scientific terms used in this invention are consistent with the prior art known to those skilled in the art and the description of this invention. This invention may also be implemented using any prior art methods, devices and materials similar to or equivalent to those described, used or made by means of methods, devices and materials in the embodiments of this invention.

[0036] When numerical ranges are given in the examples, it should be understood that, unless otherwise stated in the invention, both endpoints of each range and any value between the two endpoints may be used. Test methods in the following examples that do not specify specific conditions are generally performed under conventional conditions or as recommended by the respective manufacturers. Unless otherwise specified, all materials or reagents required in the following examples are commercially available.

[0037] To address the problems of secondary pollution and high costs associated with existing denitrification processes for deep nitrogen removal in wastewater, this invention provides a carbon source dialysis slow-release device. The device includes a continuous flow reactor, a dialysis slow-release column 2, and an inlet tank 8. The continuous flow reactor includes an anoxic chamber 3 and an aerobic chamber 5. The dialysis slow-release column 2 is located in the anoxic chamber 3. The dialysis slow-release column 2 has a dialysis membrane and a surrounding cavity. The dialysis membrane is a non-biodegradable dialysis membrane with an MWCO ≥ 100 Da. The cavity is connected to the inlet tank 8. In an optional embodiment, refer to... Figure 1 The wastewater to be treated, stored in the inlet tank 1, enters the anoxic chamber 3, where it is reduced to nitrogen gas by the denitrifying sludge in the wastewater. The specific reaction formula is shown below:

[0038] NO3 - →(nitrate reductase)→NO2 - →(nitrite reductase)→NO→(nitric oxide reductase)→N2O→(nitrite reductase)→N2

[0039] The organic carbon source contained in the inlet tank 8 is introduced into the containment chamber of the dialysis slow-release column 2 through a conduit. Preferably, the organic carbon source entering the containment chamber occupies 90% or more of the volume of the containment chamber. The organic carbon source is then slowly released into the anoxic chamber 3. The release rate of the organic carbon source in the anoxic chamber 3 is limited by the dialysis slow-release column 2, and the organic carbon source is minimally affected by water flow fluctuations within the dialysis slow-release column 2, resulting in a constant release pattern. The released organic matter is adsorbed and utilized by microorganisms in the anoxic chamber 3, reducing nitrates in the nitrification liquid returned from the aerobic chamber 5 to nitrogen gas. In an optional embodiment, a portion of the liquid in the aerobic chamber 5 is directly returned to the anoxic chamber 3 as nitrification liquid, while the other portion is discharged to the sedimentation chamber 7. Most of the liquid in the sedimentation chamber 7 is directly discharged as effluent, and a small portion is treated as sludge return liquid and then returned to the anoxic chamber 3 after sedimentation treatment.

[0040] In an optional embodiment, the dialysis slow-release column 2 can be detachably connected to the inlet tank 8 so that different parameter types of the dialysis slow-release column 2 can be replaced according to different wastewater treatment conditions.

[0041] The inlet tank 8 contains an organic carbon source; the organic carbon source includes organic wastewater, or one or more of glucose solution, starch solution, methanol solution, and sodium acetate solution.

[0042] The carbon source dialysis slow-release device provided by this invention mainly consists of detachable dialysis slow-release columns 2 of various specifications, a continuous flow reactor, and an inlet tank 8. The dialysis slow-release column 2 is made of a non-biodegradable dialysis membrane with an MWCO ≥ 100 Da. This device is simple and stable, non-toxic, and environmentally friendly; it can extend the release time of soluble carbon sources from seconds to hours or days. Under normal conditions, if the carbon source (existing technology) is added too quickly, two situations will occur: first, microorganisms cannot absorb it in time, resulting in incomplete denitrification; second, the influent fluctuates, making it impossible to accurately control the dosage; both of which easily lead to subsequent treatment and effluent pollution. However, the carbon source dialysis slow-release device provided by this invention can reduce the release rate through dialysis slow release, eliminating the need to control the dosage while allowing microorganisms to absorb it in time. Furthermore, the dialysis slow-release column 2 in this carbon source dialysis slow-release device is made of recyclable material, possessing the advantages of being environmentally friendly and low-cost.

[0043] Furthermore, the surface area to volume ratio of the dialysis membrane is 1–8:1. When the surface area to volume ratio of the dialysis membrane is 1–8:1, the carbon source release rate is constant.

[0044] Furthermore, the dialysis sustained-release column 2 includes a first dialysis sustained-release column, a second dialysis sustained-release column, a third dialysis sustained-release column, and a fourth dialysis sustained-release column.

[0045] The dialysis membrane of the first dialysis sustained-release column has a MWCO of 100–1000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing chamber is 1–5:1.

[0046] The dialysis membrane of the second dialysis sustained-release column has a MWCO of 500-1000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing chamber is 1-5:1.

[0047] The dialysis membrane of the third dialysis sustained-release column has a MWCO of 1000-5000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing chamber is 2-8:1.

[0048] The dialysis membrane of the fourth dialysis sustained-release column has a MWCO > 5000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing chamber is 1 to 2:1.

[0049] Furthermore, the carbon source dialysis slow-release device also includes a TOC detector 4 electrically connected to the dialysis slow-release column 2 and the inlet tank 8, respectively. Specifically, refer to... Figure 1As shown, the inlet tank 8 can be equipped with an intelligent timed water inlet device 6 to intelligently control the amount of organic carbon source delivered from the inlet tank 8 to the dialysis slow-release column 2. Preferably, the TOC detector 4 is electrically connected to the intelligent timed water inlet device 3. When the TOC concentration in the dialysis slow-release column 2 is detected to be below 500 mg / L, the intelligent timed water inlet device 3 can automatically control the inlet of water into the dialysis slow-release column 2.

[0050] Furthermore, non-biodegradable dialysis membranes include regenerated cellulose membranes or cellulose membranes such as cellulose triacetate, polyethersulfone, polymethyl methacrylate, and polysulfone.

[0051] This invention also provides an application of the carbon source dialysis slow-release device as described above in wastewater treatment, wherein wastewater is fed into a continuous flow reactor; the ammonia nitrogen concentration in the wastewater is >50 mg / L; and the sludge concentration in the wastewater is >3000 mg / L. Specifically, in the laboratory, a mixed sludge consisting of denitrifying sludge and nitrifying sludge can be inoculated into the continuous flow reactor to simulate sludge in wastewater, and the sludge concentration is >3000 mg / L.

[0052] The dialysis slow-release column 2 is immersed in the wastewater in the anoxic chamber 3, and the organic carbon source in the inlet tank 8 is transported to the containment chamber of the dialysis slow-release column 2.

[0053] After the wastewater has been treated in the continuous flow reactor, it is discharged.

[0054] Applying this carbon source dialysis slow-release device to advanced wastewater denitrification allows for the matching of the organic carbon source release rate within the device with the carbon source required for denitrification during the process. This advanced wastewater denitrification method can regulate the organic matter release rate by altering the parameters of the dialysis slow-release column and changing the type of organic carbon source. Based on the total nitrogen accumulation rate detection results in the wastewater, a suitable dialysis slow-release column is selected to precisely control the release of an appropriate amount of organic carbon source, ensuring it precisely meets the needs of microorganisms to achieve advanced wastewater denitrification. This approach also avoids secondary pollution of the effluent, is cost-effective, and has broad application prospects.

[0055] Further, the process includes the following steps: introducing wastewater into a continuous flow reactor, allowing it to remain for a period of time, and then discharging it. Once the total nitrogen accumulation rate in the effluent from the continuous flow reactor is >20%, the dialysis slow-release column 2 is immersed in the wastewater in the anoxic chamber 3 for denitrification treatment; wherein the temperature of the denitrification treatment is 15–30°C.

[0056] When the cumulative total nitrogen in the effluent is >20%, the MWCO of the dialysis membrane in the dialysis slow-release column 2 is 100–1000 Da, and the surface area to volume ratio of the dialysis membrane to the containment chamber is 1–5:1. Preferably, when the cumulative total nitrogen in the effluent is >20%, the MWCO of the dialysis membrane in the dialysis slow-release column 2 is 100 Da, and the surface area to volume ratio of the dialysis membrane to the containment chamber is 2:1. Under these conditions, the total nitrogen content can be controlled and treated more effectively. The optimized ratio of the dialysis membrane to the containment chamber helps maintain the stability of the hydrodynamics, which is crucial for effective mass exchange during dialysis.

[0057] When the cumulative total nitrogen in the effluent is >40%, the MWCO of the dialysis membrane in the dialysis slow-release column 2 is 500–1000 Da, and the surface area to volume ratio of the dialysis membrane to the containment chamber is 1–5:1. Preferably, when the cumulative total nitrogen in the effluent is >40%, the MWCO of the dialysis membrane in the dialysis slow-release column 2 is 500 Da, and the surface area to volume ratio of the dialysis membrane to the containment chamber is 2:1. At this point, the release rate of substances within the containment chamber is suitable, and the system operates stably.

[0058] When the cumulative total nitrogen in the effluent is >60%, the MWCO of the dialysis membrane in the dialysis slow-release column 2 is 1000–5000 Da, and the surface area to volume ratio of the dialysis membrane is 2–8:1. Preferably, when the cumulative total nitrogen in the effluent is >60%, the MWCO of the dialysis membrane in the dialysis slow-release column 2 is 1000 Da, and the surface area to volume ratio of the dialysis membrane is 2:1. If the MWCO of the dialysis membrane in the dialysis slow-release column 2 exceeds 1000–5000 Da, or the surface area to volume ratio of the dialysis membrane exceeds the range of 2–8:1, the release rate of substances within the containment chamber will be too high, which is detrimental to the stability of the system.

[0059] When the cumulative total nitrogen in the effluent is >80%, the MWCO of the dialysis membrane in the dialysis slow-release column 2 is >5000 Da, and the surface area ratio of the dialysis membrane to the volume of the containment chamber is 1 to 2:1. Preferably, when the cumulative total nitrogen in the effluent is >80%, the MWCO of the dialysis membrane in the dialysis slow-release column 2 is 5000 Da, and the surface area ratio of the dialysis membrane to the volume of the containment chamber is 1:1. At this point, the release rate of substances within the containment chamber is suitable, and the system operates stably.

[0060] Furthermore, the internal circulation nitrification reflux ratio of the continuous flow reactor is 600–800% to ensure sufficient nitrate for denitrification in the anoxic chamber 3. The external circulation sludge reflux ratio of the continuous flow reactor is 200–400% to ensure sufficient sludge in the anoxic chamber 3.

[0061] Furthermore, before immersing the dialysis slow-release column 2 in the wastewater of the anoxic chamber 3, the process includes pretreatment of the dialysis slow-release column 2, comprising the steps of: providing a mixture of a metal chelating agent solution and a weakly alkaline solution; heating the dialysis slow-release column 2 in the mixture, and then washing and drying it. Specifically, the dialysis slow-release column 2 can be boiled in the mixture of the metal chelating agent solution and the weakly alkaline solution for 15 minutes, then rinsed with clean water for 2 minutes, and the dialysis membrane of the dialysis slow-release column 2 can be allowed to air dry naturally to complete the pretreatment.

[0062] Furthermore, the metal chelating agent solution is a 0.3–1.0 mol / L ethylenediaminetetraacetic acid solution or an ethylenediaminetetraacetic acid salt solution; the weakly alkaline solution is a 4–6 g / L sodium bicarbonate solution.

[0063] To further illustrate the present invention, the following examples are provided:

[0064] Example 1

[0065] Eight groups of 1000 mg / L CH3COONa solutions were loaded into... Figure 1 The carbon source dialysis slow-release device shown is placed in the dialysis slow-release column 2, and the dialysis slow-release column 2 is placed in a 1L beaker, and 1L of water is added to submerge the dialysis slow-release column 2. The column is then left to stand for 24 hours.

[0066] (1) The above operation was performed under pH 6.5, pH 7.0, pH 7.5, and pH 8.0 conditions, respectively, and the TOC of the solution in each beaker was measured at 0, 1, 2, 3, 4, 6, 8, and 12 hours, respectively. The results are as follows: Figure 2 As shown.

[0067] from Figure 2 As can be seen, the TOC concentration of the organic carbon source released by the carbon source dialysis slow-release device provided by the present invention varies very little under different pH conditions.

[0068] (2) The above operations were performed at 15℃, 20℃, 25℃, and 30℃ respectively, and the TOC of the solution in each beaker was measured at 0, 1, 2, 3, 4, 6, 8, and 12 hours respectively. The test results are as follows: Figure 3 As shown.

[0069] from Figure 3 As can be seen, the TOC rate of the organic carbon source released by the dialysis device is stable under temperature conditions of 15-30℃, with a release time of 8-12h and no obvious fluctuations.

[0070] Example 2

[0071] A mixed sludge consisting of denitrifying and nitrifying bacteria was inoculated into a 36L continuous flow reactor. After inoculation, the sludge concentration in the continuous flow reactor was 3883 mg / L, and the mixed sludge placed in the continuous flow reactor was obtained to simulate the sludge contained in the wastewater to be treated.

[0072] The continuous flow reactor was tested in stages. In the first stage, the concentrations of NH4-N and CH3COONa (added in anoxic chamber 3) in the influent were 400 mg / L and 1200 mg / L, respectively, and the dissolved oxygen in the influent was <0.5 mg / L. This stage lasted for 20 days and was named the "Influent Carbon Source" group.

[0073] In the second stage (CH3COONa was added to the anoxic chamber 3 at a concentration of 800 mg / L), the concentrations of NH4-N and CH3COONa in the influent were 400 mg / L and 400 mg / L, respectively, and the dissolved oxygen in the influent was <0.5 mg / L, which lasted for 8 days; this group was named the "carbon source addition" group.

[0074] In the third stage (adding a carbon source dialysis slow-release device to the anoxic chamber 3 - CH3COONa with a concentration of 800 mg / L to the inlet tank 8), the concentrations of NH4-N and CH3COONa in the inlet water were the same as in the second stage, and the dissolved oxygen in the inlet water was <0.5 mg / L, lasting for 14 days; this group was named the "dialysis carbon source" group.

[0075] In the fourth stage (with the same concentrations of NH4-N and CH3COONa as in the first stage), the dissolved oxygen in the influent was >1.0 mg / L for 21 days; this group was named the "dissolved oxygen + influent carbon source" group.

[0076] In the fifth stage (adding a carbon source dialysis slow-release device to the anoxic chamber 3 - CH3COONa in the inlet tank 8 at a concentration of 800 mg / L), the concentrations of NH4-N and CH3COONa in the inlet water were the same as in the second stage, and the dissolved oxygen in the inlet water was >1.0 mg / L, lasting for 64 days; this was named the "dissolved oxygen + dialysis carbon source" group.

[0077] Furthermore, the nitrification reflux ratio of each stage of the continuous flow reactor was maintained at 700%, the sludge reflux ratio was maintained at 300%, and the hydraulic retention time (HRT) was maintained at 24h.

[0078] The graph showing the changes in nitrogen content in the reactor effluent during the phased process is as follows: Figure 4 The box plot is shown below. Figure 4The results showed that in the first stage (days 0-20), the "influent carbon source" group, serving as the control group, had a lower total nitrogen accumulation rate in the effluent, indicating that the environment and conditions were favorable during this stage, allowing nitrifying and denitrifying microorganisms to function effectively. The accumulation of total nitrogen is not only determined by nitrification but also by the characteristics of the denitrification process. Nitrification (NH4-N reduction to NO3-N) consumes CO2 and produces protons, while denitrification (NO3-N reduction to N2) consumes protons and organic carbon, producing CO2 which is then supplied to the nitrification reaction.

[0079] In the second phase (days 21-29), the "carbon source addition" group reduced the influent organic matter concentration to simulate the influent of a normal wastewater treatment plant. After adding the carbon source in the anoxic zone, a significant accumulation of total nitrogen occurred. The tank volume of the "carbon source addition" group was significantly lower than that of the "influent carbon source" group. This is because the carbon source dissolves too quickly, preventing the denitrifying bacteria in the anoxic zone from adsorbing it in time. Excessive carbon source enters the aerobic zone, disrupting the environment for nitrifying bacteria and preventing the reduction of total nitrogen. Simultaneously, from... Figure 4 The total nitrogen data in the effluent from the "carbon source added" group shows a diffuse distribution, indicating that the reactor effluent is not stable enough.

[0080] In the third phase (days 30-44), the influent organic matter concentration in the "dialysis carbon source" group was reduced to simulate the influent of a normal wastewater treatment plant. The effluent data from the "dialysis carbon source" group was more concentrated, indicating that the addition of the dialysis slow-release device reduced fluctuations and anomalies in the effluent. Simultaneously, the tank size was lower than that of the "influent carbon source" group and the "carbon source addition" group, indicating a more efficient total nitrogen removal effect. By employing the carbon source dialysis slow-release device, the release of organic matter was limited, the denitrification process was enhanced, and the total nitrogen removal rate gradually increased. The sufficient and continuous release of carbon source allowed nitrifying and denitrifying microorganisms to fully function, ensuring nitrogen removal.

[0081] In the fourth stage (days 45-66), the "dissolved oxygen + influent carbon source" group reduced the concentration of organic matter in the influent to simulate the influent of a normal wastewater treatment plant, while increasing the dissolved oxygen in the influent to simulate the actual operating conditions of a normal wastewater treatment plant. Figure 4 The tank of the "dissolved oxygen + influent carbon source" group showed a significant increase in temperature, and the effluent showed a high accumulation of total nitrogen. This is because the high dissolved oxygen in the influent caused the denitrifying bacteria to continuously perform aerobic respiration and consume the carbon source. There was no equivalent denitrification reaction to consume the protons produced by the nitrification reaction, which led to a continuous decrease in the pH of the effluent and the accumulation of total nitrogen.

[0082] In the fifth phase (days 67-131), the "dissolved oxygen + dialysis carbon source" group reduced the influent organic matter concentration to simulate the influent of a normal wastewater treatment plant, while increasing the dissolved oxygen in the influent to simulate the actual operating conditions of a normal wastewater treatment plant. After adopting a dialysis slow-release device, the "dissolved oxygen + dialysis carbon source" group showed a decrease in total nitrogen. This is because the organic matter continuously released from the dialysis slow-release device allows more denitrifying bacteria to obtain electron donors, ensuring that a portion of the carbon source is used for denitrification under the high dissolved oxygen conditions of the influent. Compared to the "dissolved oxygen + influent carbon source" group, the dialysis slow-release device demonstrated superior nitrogen removal performance.

[0083] In summary, the above-described technical solutions of the present invention are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the technical concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. The application of a carbon source dialysis slow-release device in wastewater treatment, characterized in that, Including the following steps: A carbon source dialysis sustained-release device with detachable dialysis sustained-release columns of various specifications is provided. The carbon source dialysis sustained-release device includes a continuous flow reactor, a dialysis sustained-release column, an inlet tank, and a TOC detector electrically connected to the dialysis sustained-release column and the inlet tank, respectively. The continuous flow reactor includes an anoxic chamber and an aerobic chamber. The dialysis sustained-release column is located in the anoxic chamber. The dialysis sustained-release column has a dialysis membrane and a containment cavity formed by the dialysis membrane. The dialysis membrane is a non-biodegradable dialysis membrane with an MWCO ≥ 100 Da. The containment cavity is connected to the inlet tank. The inlet tank contains an organic carbon source. The dialysis sustained-release column includes a first dialysis sustained-release column, a second dialysis sustained-release column, a third dialysis sustained-release column, and a fourth dialysis sustained-release column; the MWCO of the dialysis membrane in the first dialysis sustained-release column is 100~1000 Da, and the surface area ratio of the dialysis membrane to the volume of the receiving cavity is 1~5:1; the MWCO of the dialysis membrane in the second dialysis sustained-release column is 500~1000 Da, and the surface area ratio of the dialysis membrane to the volume of the receiving cavity is 1~5:1; the MWCO of the dialysis membrane in the third dialysis sustained-release column is 1000~5000 Da, and the surface area ratio of the dialysis membrane to the volume of the receiving cavity is 2~8:1; the MWCO of the dialysis membrane in the fourth dialysis sustained-release column is >5000 Da, and the surface area ratio of the dialysis membrane to the volume of the receiving cavity is 1~2:1; Wastewater is fed into a continuous flow reactor; the ammonia nitrogen concentration of the wastewater is >50 mg / L; the sludge concentration in the wastewater is >3000 mg / L; Once the total nitrogen accumulation rate in the effluent liquid of the continuous flow reactor is >20%, the dialysis slow-release column is immersed in the wastewater in the anoxic chamber for denitrification treatment, and the organic carbon source in the inlet tank is transported to the containment cavity of the dialysis slow-release column; after the wastewater is treated in the continuous flow reactor, it is discharged; wherein, the temperature of the denitrification treatment is 15~30℃; When the cumulative rate of total nitrogen in the effluent is >20%, the MWCO of the dialysis membrane of the dialysis slow-release column is 100~1000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing chamber is 1~5:1; When the cumulative rate of total nitrogen in the effluent is >40%, the MWCO of the dialysis membrane of the dialysis slow-release column is 500~1000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing chamber is 1~5:1; When the cumulative rate of total nitrogen in the effluent is >60%, the MWCO of the dialysis membrane of the dialysis slow-release column is 1000~5000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing chamber is 2~8:1; When the cumulative rate of total nitrogen in the effluent is >80%, the MWCO of the dialysis membrane of the dialysis slow-release column is >5000 Da, and the surface area of ​​the dialysis membrane to the volume ratio of the containing chamber is 1~2:

1.

2. The application according to claim 1, characterized in that, The surface area of ​​the dialysis membrane is in the ratio of the volume of the receiving cavity to 1 to 8:

1.

3. The application according to claim 1, characterized in that, The non-biodegradable dialysis membranes include regenerated cellulose membranes or cellulose membranes such as cellulose triacetate, polyethersulfone, polymethyl methacrylate, and polysulfone.

4. The application according to claim 1, characterized in that, Before the step of immersing the dialysis slow-release column in the wastewater of the anoxic chamber, the method further includes pretreatment of the dialysis slow-release column, including the following steps: Provides a mixture of metal chelating agent solution and weak alkaline solution; The dialysis sustained-release column is heated in the mixture, then washed and dried.

5. The application according to claim 1, characterized in that, The metal chelating agent solution is a 0.3~1.0 mol / L ethylenediaminetetraacetic acid solution or an ethylenediaminetetraacetic acid salt solution; the weakly alkaline solution is a 4~6 g / L sodium bicarbonate solution.

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