Process for treating industrial wastewater through high-impact-resistance hydrolysis acidification pool

Abstract

The invention relates to the technical field of industrial wastewater treatment, and discloses a process for treating industrial wastewater by a high-impact-resistance hydrolysis acidification pool, which comprises the following steps: S1, in an adjusting pool, homogenizing the water quality of the industrial wastewater, adjusting the pH value and temperature, and decomposing part of organic matters in advance; s2, treatment in a multi-stage hydrolysis acidification pool: decomposing refractory organic matters in a multi-stage hydrolysis manner; s3, in an intermediate sedimentation tank, mud-water separation is carried out. Through the coupling design of the baffle plate and the biological membrane and in combination with multi-stage degradation of the contact area, the main body acidification area and the precipitation separation area, the impact resistance to wastewater is improved, short flow is avoided, the load change of high sludge concentration is buffered, and COD fluctuation is effectively resisted; through the elastic filler in the contact area, granular organic matters can be quickly adsorbed, and through high-concentration sludge formed by sludge backflow, the sludge age can be controlled, the loss of acidizing bacteria is avoided, and the COD removal rate is greatly increased.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of industrial wastewater treatment, in particular to a process for treating industrial wastewater by using a high-impact hydrolysis acidification tank. BACKGROUND

[0002] Industrial wastewater treatment refers to a process of removing or converting harmful substances in wastewater through physical, chemical, biological and other methods to meet discharge standards or reuse requirements.

[0003] After searching, the patent with application number CN202411772535.0 discloses an industrial wastewater treatment process, which belongs to the technical field of wastewater treatment. The industrial wastewater treatment process includes the following steps: first, adjust the pH value of the wastewater to less than 5, add micro-electrolysis filler, and after stirring, standing and filtering, obtain pretreated wastewater; second, pretreated wastewater is subjected to Fenton oxidation treatment; in this method, the wastewater is treated by combining iron-carbon micro-electrolysis and Fenton oxidation, which has high COD removal rate. The granular iron-carbon filler (micro-electrolysis filler) used in the iron-carbon micro-electrolysis process has stable physical and chemical properties, which can ensure long-term and efficient treatment effect. The boron-nitrogen-doped carbon material in the micro-electrolysis filler replaces the conventional carbon material to improve the treatment efficiency of the granular iron-carbon filler, which can better connect with the Fenton oxidation treatment process and facilitate industrial treatment.

[0004] In traditional industrial wastewater treatment, the impact load resistance is poor, there is no grading buffer function, it cannot adapt to the dramatic fluctuation of COD, and the acidification bacterial population may be inactivated, which may lead to the collapse of the wastewater treatment system. Therefore, we need to propose a process for treating industrial wastewater by using a high-impact hydrolysis acidification tank. SUMMARY

[0005] The present application aims to provide a process for treating industrial wastewater by using a high-impact hydrolysis acidification tank. By coupling the baffle and the biofilm, combining the contact zone, the main acidification zone and the sedimentation separation zone for multi-stage degradation, the impact resistance of the wastewater is improved, short flow is avoided, the load change of high sludge concentration is buffered, and the COD fluctuation is effectively resisted. The elastic filler in the contact zone can quickly adsorb particulate organic matter, the high-concentration sludge formed by sludge backflow can control the sludge age, avoid the loss of acidification bacteria, and greatly improve the COD removal rate, thereby solving the problems raised in the above background technology.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solution: a process for treating industrial wastewater by using a high-impact hydrolysis acidification tank, including the following steps:

[0007] S1, adjusting pool: homogenize the water quality of industrial wastewater, adjust the PH value and temperature of industrial wastewater, and add anaerobic sludge to the adjusting pool to decompose part of the easily degradable organic matter in advance to realize pre-acidification treatment;

[0008] S2, multi-stage hydrolysis acidification pool: decompose the refractory organic matter by multi-stage hydrolysis, the hydrolysis acidification pool includes a contact zone for adsorbing and retaining particulate organic matter by elastic filler biofilm, a main acidification zone for hydrolyzing macromolecular organic matter by multiple baffles and anaerobic bacteria, and a sedimentation and separation zone for separating sludge and water body;

[0009] S3, intermediate sedimentation tank: separates the activated sludge in the effluent of the hydrolysis acidification pool, and returns the activated sludge to the front end of the hydrolysis acidification pool.

[0010] Preferably, in step S1, the adjusting pool comprises:

[0011] Mixing zone: the mixing zone is equipped with a perforated aeration pipe to forcibly mix the wastewater;

[0012] Sedimentation zone: provided with an inclined pipe for separating part of inorganic particles;

[0013] Buffered effluent zone: equipped with an online PH / COD monitor for stabilizing the effluent flow;

[0014] The adjusting pool is also provided with a temperature regulating device for maintaining the water temperature at 5-35℃, which includes a heating coil and a cooling coil;

[0015] The adjusting pool is also provided with a neutralizing liquid adding device for adding acid or alkali to the wastewater.

[0016] Preferably, the anaerobic sludge is selected from the residual sludge of an anaerobic digestion tank or the acidification sludge of a similar wastewater treatment system, and the dosage of the anaerobic sludge is 1%-3% of the volume of the adjusting pool. The wastewater with added anaerobic sludge in the adjusting pool is subjected to intermittent aeration to promote the proliferation of hydrolytic bacteria.

[0017] Preferably, in step S2, the length, width and height of the hydrolysis acidification pool are 42.6m, 28.6m and 8.9m respectively, and the interior of the hydrolysis acidification pool is partitioned into four acidification pool cells arranged in a matrix, and the length, width and height of each acidification pool cell are 21m, 14m and 8.9m respectively.

[0018] Preferably, the volume of the contact zone accounts for 20-30% of the volume of the hydrolysis acidification pool, the volume of the main acidification zone accounts for 50-60% of the volume of the hydrolysis acidification pool, and the volume of the sedimentation and separation zone accounts for 20-25% of the volume of the hydrolysis acidification pool. The hydraulic retention time of the wastewater in the contact zone is 1-2h, the hydraulic retention time of the wastewater in the main acidification zone is 6-12h, and the hydraulic retention time of the wastewater in the sedimentation and separation zone is 2-3h.

[0019] Preferably, the elastic filler in the contact zone is polyurethane elastic silk, and the filling rate is 30-40%;

[0020] The distance between the adjacent two baffles in the main acidification zone is 0.8-1.2 m, the distance between the first two baffles is 0.8 m, the distance between the last two baffles is 1.2 m, and the surface of the baffle is coated with a carbon fiber coating;

[0021] The inclination angle of the inclined pipe in the sedimentation separation zone is 55-60°.

[0022] Preferably, in step S3, the intermediate sedimentation tank comprises a coagulation zone, a flocculation zone and an inclined plate sedimentation zone, the coagulation zone is provided with a rapid mixing stirrer, the flocculation zone is provided with a slow stirrer, and the inclined plate sedimentation zone is provided with a thickening mud scraper.

[0023] Preferably, the surface load of the intermediate sedimentation tank is 0.6-1.0 m 3 / (m 2 h), the effective water depth of the intermediate sedimentation tank is 3.5-4.5 m, the inclination angle of the inclined plate in the inclined plate sedimentation zone is 55-60°, and the distance between the adjacent two inclined plates is 80-100 mm.

[0024] Preferably, the sludge is refluxed by using gas reflux, the gas reflux is based on the lifting force generated by the density difference of gas-liquid two-phase flow, compressed air is injected into the lifting pipe through the diffuser to form a gas-sludge mixture, the density of the gas-sludge mixture is less than the density of water, and the gas-sludge mixture rises under the action of static pressure, the diffuser is selected from a microporous titanium plate, the pore size of the microporous titanium plate is 50-100 mu m, and the service area of the air is 0.2-0.3 m 2 / Nm 3 .

[0025] Compared with the prior art, the beneficial effects of the present application are:

[0026] 1. The present application improves the impact resistance of wastewater by the coupling design of the baffle and the biofilm, and the multi-stage degradation of the contact zone, the main acidification zone and the sedimentation separation zone, avoids short flow, buffers the load change of high sludge concentration, and effectively resists COD fluctuation;

[0027] 2. The present application can quickly adsorb particulate organic matter through the elastic filler in the contact zone, can control the sludge age through the high-concentration sludge formed by sludge reflux, can avoid the loss of acidification bacteria, and can greatly improve the COD removal rate; BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 The flow chart of the present application. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0030] Please refer to Figure 1 The present application provides a technical solution: a process for treating industrial wastewater in a high-impact hydrolysis acidification tank, comprising the following steps:

[0031] S1, adjusting tank: homogenizing the water quality of the industrial wastewater, adjusting the pH value and temperature of the industrial wastewater, and adding anaerobic sludge to the adjusting tank to decompose part of the easily degradable organic matter in advance, reduce the load of the subsequent hydrolysis acidification tank, realize pre-acidification treatment, and reduce the subsequent load by starting the initial hydrolysis reaction;

[0032] Water quality homogenization: 24h continuous stirring + air aeration to prevent sedimentation, balance COD, and toxicity substance concentration fluctuation;

[0033] Through the design of the adjusting tank, the impact of instantaneous impact load (such as PH mutation, toxic substances) on the hydrolysis acidification tank is reduced, and the subsequent treatment pressure is reduced. The adjusting tank can reduce part of the COD in the wastewater through pretreatment, that is, the adjusting tank provides the first line of defense to avoid the collapse of acidification bacteria caused by direct high-concentration COD impact.

[0034] In step S1, the adjusting tank comprises:

[0035] Mixing area: The mixing area is equipped with a perforated aeration pipe to forcibly mix the wastewater; the gas-water ratio of the perforated aeration pipe is 0.5-1.1, and it also has a pre-oxygenation function to avoid inhibiting anaerobic bacteria.

[0036] Sedimentation area: provided with an inclined pipe for separating part of inorganic particles;

[0037] Buffered effluent area: provided with an online PH / COD monitor for stabilizing the effluent flow;

[0038] The adjusting tank is also provided with a temperature regulating device for maintaining the water temperature at 5-35℃ to avoid inhibiting microbial activity at low temperature. The temperature regulating device comprises a heating coil and a cooling coil.

[0039] The adjusting tank is also provided with a neutralizing liquid adding device for adding acid or alkali to the wastewater.

[0040] By adding acid or alkali to the regulating tank, neutralizing the extreme PH (such as PH<4 or PH>10) in the wastewater, the PH of the influent is stabilized between 6.5-7.5, which is suitable for hydrolysis acidification bacteria.

[0041] As an embodiment, when the wastewater is acidic, 10% sodium hydroxide solution is added, and when the wastewater is alkaline, 30% sulfuric acid solution is added.

[0042] The anaerobic sludge is selected from the residual sludge of the anaerobic digestion tank or the acidified sludge of the similar wastewater treatment system, and the dosage of the anaerobic sludge is 1%-3% of the volume of the regulating tank. The wastewater in the regulating tank with the added anaerobic sludge is subjected to intermittent aeration to promote the proliferation of hydrolysis bacteria.

[0043] S2, multi-stage hydrolysis acidification tank: adopting a multi-stage hydrolysis mode to decompose refractory organic matter, the hydrolysis acidification tank includes a contact zone for adsorbing and retaining particulate organic matter by an elastic filler biofilm, a main acidification zone for hydrolyzing macromolecular organic matter by a plurality of baffle plates and anaerobic bacteria, and a sedimentation and separation zone for separating sludge and water body;

[0044] The contact zone has a high hydraulic load, and the hydraulic retention time is 1-2h. By setting the elastic filler biofilm carrier, particulate organic matter is quickly adsorbed.

[0045] The main acidification zone prolongs the water flow path by the design of the baffle plate, so that the hydraulic retention time is 8-12h, and the wastewater is forced to contact the sludge multiple times. Under the action of the baffle plate, the anaerobic bacteria hydrolyze macromolecular organic matter (such as protein and cellulose) into small molecules (such as amino acids and monosaccharides), and further convert them into volatile fatty acids (VFA).

[0046] In addition, the coupling design of the baffle plate and the elastic filler biofilm can improve the impact resistance of the wastewater, avoid short flow, and buffer the changes in COD load, that is, effectively resist COD fluctuations.

[0047] The sedimentation and separation zone is internally provided with an inclined pipe, and the sludge automatically flows back to the first two stages (the contact zone and the main acidification zone), so as to maintain a high sludge concentration (MLSS≥15g / L).

[0048] Macromolecular organic matter (such as cellulose and oil) is retained in the contact zone, and small molecule acid is generated in the main acidification zone. The small molecule acid is VFA.

[0049] In step S2, the length, width and height of the hydrolysis acidification tank are 42.6m, 28.6m and 8.9m respectively, and the hydrolysis acidification tank is internally partitioned into four acidification tank cells arranged in a matrix. The length, width and height of each acidification tank cell are 21m, 14m and 8.9m respectively.

[0050] The volume of the contact zone accounts for 20-30% of the volume of the hydrolysis acidification tank, the volume of the main acidification zone accounts for 50-60% of the volume of the hydrolysis acidification tank, and the volume of the sedimentation separation zone accounts for 20-25% of the volume of the hydrolysis acidification tank; the hydraulic retention time of the wastewater in the contact zone is 1-2h, the hydraulic retention time of the wastewater in the main acidification zone is 6-12h, and the hydraulic retention time of the wastewater in the sedimentation separation zone is 2-3h.

[0051] The elastic filler in the contact zone is polyurethane elastic silk (diameter 2-3mm, porosity ≥95%), and the filling rate is 30-40%. If the filling rate is too high, it will cause blockage.

[0052] The distance between the adjacent two baffles in the main acidification zone is 0.8-1.2m, and the distance between the first two baffles is 0.8m, and the distance between the last two baffles is 1.2m, that is, from front to back, the distance between the adjacent two baffles increases, gradually reducing the flow rate to avoid sludge deposition.

[0053] The surface of the baffle is coated with a carbon fiber coating to promote DIET (inter-species direct electron transfer) and accelerate the acidification rate.

[0054] The angle of the inclined pipe in the sedimentation separation zone is 55°-60°.

[0055] Optionally, to improve the impact resistance of COD in wastewater, the salinity of wastewater is increased by 500mg / L every week until the high sludge concentration reaches 15g / L, or wood carbon (10-20mg / L) is added to adsorb phenol.

[0056] In addition, the elastic filler acts as a buffer zone and can adsorb the instantaneous COD peak.

[0057] S3, intermediate sedimentation tank: mud-water separation is carried out to separate the active sludge in the effluent of the hydrolysis acidification tank, and the active sludge is backflowed to the front end of the hydrolysis acidification tank (contact zone and main acidification zone) to maintain the concentration and activity of the bacterial flora, and then the inert sludge is discharged to prevent accumulation and cause blockage.

[0058] Through the backflow design of the active sludge, the purpose of controlling the sludge age (15-30 days) is achieved, and the loss of acidification bacteria is avoided.

[0059] Sludge age (SRT) = total amount of sludge in the tank / daily sludge discharge;

[0060] Daily sludge discharge = (1 / SRT target value * total amount of sludge in the tank);

[0061] Sludge is discharged every 4-6 days, and each time is 10-15min.

[0062] In step S3, the intermediate sedimentation tank comprises a coagulation zone, a flocculation zone and an inclined plate sedimentation zone, the coagulation zone is provided with a rapid mixing stirrer, the flocculation zone is provided with a slow stirrer, and the inclined plate sedimentation zone is provided with a concentration mud scraper.

[0063] The surface load of the intermediate sedimentation tank is 0.6-1.0 m 3 / (m 2 h), the effective water depth of the intermediate sedimentation tank is 3.5-4.5 m, the angle of inclination of the inclined plate in the inclined plate sedimentation zone is 55-60°, and the spacing between adjacent two inclined plates is 80-100 mm.

[0064] The sludge is backflowed by means of gas backflow, the gas backflow is based on the lifting force generated by the density difference of gas-liquid two-phase flow, compressed air is injected into the lifting pipe through a diffuser to form a gas-sludge mixture, the density of the gas-sludge mixture is less than the density of water, and the gas-sludge mixture rises under the action of static pressure, the diffuser is selected from a microporous titanium plate, the pore diameter of the microporous titanium plate is 50-100 µm, the service area of the air is 0.2-0.3 m 2 / Nm 3 .

[0065] The air quantity of the compressed air introduced is 0.5-1.0 m 3 / min, and the lifting height of the gas-sludge mixture is ≤3 m.

[0066] The wastewater enters the conditioning tank for homogenization and buffering, is then discharged into the multi-stage hydrolysis acidification tank for organic matter conversion, is finally discharged into the intermediate sedimentation tank for sludge-water separation operation, and the activated sludge is backflowed to the contact zone and the main acidification zone in the multi-stage hydrolysis acidification tank.

[0067] Although the embodiments of the present application have been shown and described, it can be understood by those of ordinary skill in the art that various changes, modifications, replacements and variations can be made to the embodiments without departing from the principles and spirits of the present application, and the scope of the present application is defined by the appended claims and their equivalents.

Claims

1. A process for treating industrial wastewater using a high-impact hydrolysis acidification tank, characterized in that, Includes the following steps: S1. Equalization Tank: This tank homogenizes the industrial wastewater and adjusts its pH and temperature. Anaerobic sludge is added to the equalization tank to decompose some of the easily degradable organic matter in advance, thus achieving pre-acidification treatment. S2, Multi-stage hydrolysis acidification tank: The multi-stage hydrolysis method is used to decompose recalcitrant organic matter. The hydrolysis acidification tank includes a contact zone where particulate organic matter is adsorbed and intercepted by elastic packing biofilm, a main acidification zone where macromolecular organic matter is hydrolyzed by multiple baffles and anaerobic bacteria, and a sedimentation separation zone for separating sludge from water. S3, Intermediate Sedimentation Tank: Performs sludge-water separation, precipitates and separates the activated sludge in the effluent of the hydrolysis acidification tank, and returns the activated sludge to the front end of the hydrolysis acidification tank.

2. The process for treating industrial wastewater using a high-impact hydrolysis acidification tank according to claim 1, characterized in that: In step S1, the regulating tank includes: Mixing Zone: The mixing zone is equipped with perforated aeration pipes to force the mixing of wastewater; Sedimentation zone: Equipped with inclined tubes for separating some inorganic particles; Buffer outlet zone: Equipped with an online pH / COD monitor to stabilize the outlet flow rate; The equalization tank is also equipped with temperature control equipment to maintain a constant water temperature of 5-35℃. The temperature control equipment includes heating coils and cooling coils. The equalization tank is also equipped with a neutralization solution dosing device for adding acid or alkali solutions to the wastewater.

3. The process for treating industrial wastewater using a high-impact hydrolysis acidification tank according to claim 2, characterized in that: Anaerobic sludge is selected from the residual sludge of anaerobic digesters or acidified sludge from similar wastewater treatment systems. The amount of anaerobic sludge added is 1%-3% of the volume of the equalization tank. The wastewater in the equalization tank with added anaerobic sludge is intermittently aerated to promote the proliferation of hydrolytic bacteria.

4. The process for treating industrial wastewater using a high-impact hydrolysis acidification tank according to claim 1, characterized in that: In step S2, the length, width and height of the hydrolysis acidification tank are 42.6m, 28.6m and 8.9m respectively. The hydrolysis acidification tank is divided into four acidification tank cells arranged in a matrix. The length, width and height of each acidification tank cell are 21m, 14m and 8.9m respectively.

5. The process for treating industrial wastewater using a high-impact hydrolysis acidification tank according to claim 4, characterized in that: The contact zone accounts for 20-30% of the hydrolysis acidification tank volume, the main acidification zone accounts for 50-60% of the hydrolysis acidification tank volume, and the sedimentation separation zone accounts for 20-25% of the hydrolysis acidification tank volume. The hydraulic retention time of wastewater in the contact zone is 1-2 hours, the hydraulic retention time of wastewater in the main acidification zone is 6-12 hours, and the hydraulic retention time of wastewater in the sedimentation separation zone is 2-3 hours.

6. The process for treating industrial wastewater using a high-impact hydrolysis acidification tank according to claim 5, characterized in that: The elastic filler in the contact area is made of polyurethane elastic wire, with a filling rate of 30-40%. The spacing between two adjacent baffles in the main acidification zone is 0.8-1.2m, with the spacing between the first two baffles being 0.8m and the spacing between the last two baffles being 1.2m. The surface of the baffles is coated with carbon fiber. The inclination angle of the inclined tubes in the sedimentation separation zone is 55°-60°.

7. The process for treating industrial wastewater using a high-impact hydrolysis acidification tank according to claim 1, characterized in that: In step S3, the intermediate sedimentation tank includes a coagulation zone, a flocculation zone, and an inclined plate sedimentation zone. The coagulation zone is equipped with a fast mixing agitator, the flocculation zone is equipped with a slow agitator, and the inclined plate sedimentation zone is equipped with a thickening scraper.

8. The process for treating industrial wastewater using a high-impact hydrolysis acidification tank according to claim 7, characterized in that: The surface loading rate of the intermediate sedimentation tank is 0.6-1.0 m³. 3 / (m 2 h), the effective water depth of the intermediate sedimentation tank is 3.5-4.5m, the inclination angle of the inclined plates in the inclined plate sedimentation zone is 55-60°, and the distance between two adjacent inclined plates is 80-100mm.

9. The process for treating industrial wastewater using a high-impact hydrolysis acidification tank according to claim 8, characterized in that: Sludge is recirculated using a gas recirculation method. This recirculation is based on the lifting force generated by the density difference between the gas and liquid phases. Compressed air is injected into the riser pipe through a diffuser, forming a gas-sludge mixture. Since the density of this mixture is less than that of water, it rises under static pressure. The diffuser is a microporous titanium plate with a pore size of 50-100 μm and a service area of ​​0.2-0.3 m². 2 / Nm 3 The air.

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