A high concentration of wastewater treatment system of cellulose

Abstract

The utility model discloses a kind of high-concentration hemicellulose wastewater treatment systems, it is related to high-concentration hemicellulose wastewater treatment technical field, including the adjusting pool, fenton reaction pool, fenton sedimentation tank, multistage hydrolysis acidification pool and lifting pool connected in order, the adjusting pool water inlet is connected with high-concentration hemicellulose wastewater pipeline, non-ferrous wastewater pipeline and acidic wastewater pipeline, adjusting pool and fenton reaction pool between being provided with dispensing room, and ferrous sulfate storage tank, hydrogen peroxide storage tank and PAM storage tank are provided in dispensing room, ferrous sulfate storage tank and hydrogen peroxide storage tank are connected with fenton reaction pool water inlet respectively, and PAM storage tank is connected with fenton reaction pool, fenton reaction pool is also connected with alkali tank, the fenton sedimentation tank bottom is provided with sludge pump, and the lifting pool water outlet is connected with polymeric ferric sulfate storage tank. Through pre-fenton system combination multistage anaerobic treatment unit realizes the efficient decomposition of hemicellulose, lignin and other refractory substances, and cooperates subsequent advanced treatment to ensure that effluent COD is stable and up to standard.

Description

Technical Field

[0001] This utility model relates to the field of high-concentration semi-fiber wastewater treatment technology, and in particular to a high-concentration semi-fiber wastewater treatment system. Background Technology

[0002] With the continuous tightening of environmental protection policies in my country, the viscose fiber industry is facing increasingly stringent regulatory environments in terms of energy consumption, water consumption, and pollutant emissions. Existing traditional treatment processes for the high-concentration hemicellulose wastewater generated during the industry's production process have shown significant shortcomings: on the one hand, they are limited by the influent pollutant concentration threshold, and high sulfate levels inhibit microbial activity, making them unsuitable for treating high-concentration hemicellulose wastewater; on the other hand, there are technical and economic bottlenecks such as insufficient treatment capacity and high operating costs. Furthermore, hemicellulose / lignin is difficult to degrade, and its application space is gradually narrowing under increasingly stringent environmental standards. Against this backdrop, the pre-treatment Fenton system and multi-stage anaerobic process have demonstrated strong development potential due to their significant technological advantages. This process not only achieves breakthrough and effective degradation of high-concentration hemicellulose wastewater but also significantly improves treatment efficiency through a tiered treatment structure. Compared to traditional processes, although the operating cost is slightly higher, the treatment efficiency is more advantageous, and it has now become an important technological path for the viscose fiber industry to overcome environmental constraints and achieve green transformation.

[0003] Xinjiang is a water-scarce region. The "Water Pollutant Discharge Standard for Cotton Pulp and Viscose Fiber Industry" (DB654349-2021) stipulates a long-term water consumption limit of 44 m³ / t for viscose staple fiber. Through technological innovation and strict management, the company has controlled water consumption per ton of fiber to 37 m³ / t, far below all standard limits, placing it at an industry-leading level. However, the reduced water consumption has led to a significant increase in wastewater concentration (average COD 1200 mg / L, compared to an industry average of 600 mg / L). This project's technology can solve the problem of treating high-concentration wastewater and is applicable to the treatment of organic wastewater in viscose fiber, papermaking, and biomass refining industries.

[0004] Currently, wastewater treatment systems mainly consist of "physicochemical + biochemical + Fenton" processes, which cannot treat the high-concentration hemicellulose wastewater generated from the hemicellulose extraction process in pulp.

[0005] The invention patent application with patent number CN107986492A discloses a method for improving the biodegradability of cotton pulp black liquor through heterogeneous Fenton oxidation treatment. The method involves mixing acidic wastewater discharged from viscose fiber production with cotton pulp black liquor to recover lignin through acid precipitation, using waste steel slag as a catalyst to catalyze the oxidation of difficult-to-biodegrade pollutants in cotton pulp black liquor with H2O2, and using the alkalinity of the steel slag to neutralize the black liquor after acid precipitation.

[0006] However, this patent has the following defects and shortcomings:

[0007] 1. Poor catalyst stability: Using steel waste slag as a heterogeneous catalyst results in low iron dissolution rate and large fluctuations in active components, leading to unstable Fenton reaction efficiency and difficulty in continuously degrading hemicellulose and lignin in high-concentration hemicellulose wastewater.

[0008] 2. Unresolved sulfate problem: The design did not address the inhibition of high-concentration sulfate (SO₄²⁻) in high-concentration hemicellulose wastewater. Sulfate is easily reduced to sulfides in anaerobic environments, which poisons microorganisms and reduces the efficiency of subsequent biological treatment units.

[0009] 3. Insufficient process synergy: The acid precipitation and lignin recovery process requires the addition of solid-liquid separation equipment, which is complex and has low coupling with the oxidation unit, making continuous processing impossible;

[0010] 4. Risk of secondary pollution: Steel slag contains heavy metal impurities (such as chromium and nickel), and long-term use may lead to the leaching of heavy metal ions, causing secondary pollution of water bodies.

[0011] These shortcomings stem from the fact that the process design did not focus on the core challenges of high-concentration hemicellulose wastewater (recalcitrant organic matter + high sulfate), and that it relied on non-standardized catalysts, which restricted the industrial application of the technology. Utility Model Content

[0012] This invention aims to provide a high-concentration hemicellulose wastewater treatment system, which achieves efficient decomposition of recalcitrant substances such as hemicellulose and lignin through a pre-processing Fenton system combined with multi-stage anaerobic treatment units, and ensures stable COD compliance of the effluent with subsequent advanced treatment.

[0013] To achieve the above-mentioned objectives, the technical solution of this utility model is as follows:

[0014] A high-concentration hemicellulose wastewater treatment system includes an equalization tank, a Fenton reaction tank, a Fenton sedimentation tank, a multi-stage hydrolysis acidification tank, and a booster tank connected sequentially. The inlet of the equalization tank is connected to a high-concentration hemicellulose wastewater pipeline, a colored wastewater pipeline, and an acidic wastewater pipeline. A chemical preparation room is provided between the equalization tank and the Fenton reaction tank. The chemical preparation room is equipped with a ferrous sulfate storage tank, a hydrogen peroxide storage tank, and a PAM storage tank. The ferrous sulfate storage tank and the hydrogen peroxide storage tank are respectively connected to the inlet of the Fenton reaction tank. The PAM storage tank is also connected to the Fenton reaction tank. An alkali tank is also connected to the Fenton reaction tank. A sludge pump is provided at the bottom of the Fenton sedimentation tank. A polyferric sulfate storage tank is connected to the outlet of the booster tank.

[0015] The Fenton reaction tank includes three sub-tanks, namely sub-tank I, sub-tank II, and sub-tank III, arranged sequentially along its length. A partition I is provided between adjacent sub-tanks. Sub-tanks I and sub-tank II are connected at the bottom of partition I. Sub-tank III includes two units, namely unit I and unit II, arranged side-by-side along the width of the Fenton reaction tank. A partition II is provided between unit I and unit II. Unit I and sub-tank II are connected at the bottom of partition I, and unit II is connected to unit I at the bottom of partition II. A paddle mixer I is installed in each of unit I and unit II. Sub-tank I is connected to an equalization tank, and unit II is connected to a Fenton sedimentation tank.

[0016] The alkali tank is connected to Unit I, and the PAM storage tank is connected to Unit II.

[0017] The multi-stage hydrolysis acidification tank comprises a primary hydrolysis tank, a secondary hydrolysis tank, and a tertiary hydrolysis tank connected sequentially. The primary hydrolysis acidification tank initially decomposes macromolecular organic matter (such as hemicellulose and lignin) and degrades sulfate (SO4). 2- The primary hydrolysis acidification tank further decomposes organic matter in the primary effluent, reducing TDS (Total Dissolved Solids). The secondary hydrolysis acidification tank deepens the hydrolysis acidification process, further decomposing organic matter in the primary effluent and enhancing the acid production stage. The tertiary hydrolysis acidification tank completes the methanogenesis process, thoroughly degrading organic matter and significantly reducing COD.

[0018] Four submersible mixers II are spaced around the perimeter of the primary hydrolysis tank.

[0019] The secondary hydrolysis tank includes hydrolysis tank a and hydrolysis tank b arranged sequentially along its length. A partition III is provided between hydrolysis tank a and hydrolysis tank b, and a guide channel is formed between the partition III and the bottom of the secondary hydrolysis tank. Submersible mixers III are respectively installed in hydrolysis tank a and hydrolysis tank b.

[0020] The three-stage hydrolysis tank includes three sub-hydrolysis tanks arranged sequentially along the length of the three-stage hydrolysis tank: sub-hydrolysis tank I, sub-hydrolysis tank II, and sub-hydrolysis tank III. A partition IV is provided between adjacent sub-hydrolysis tanks, and a guide channel is formed between the partition IV and the bottom of the three-stage hydrolysis tank. Sub-hydrolysis tank I is connected to the two-stage hydrolysis tank, and sub-hydrolysis tank III is connected to the lifting tank. Three submersible mixers IV are respectively provided on the opposite sides of sub-hydrolysis tanks I and III.

[0021] The outlet of the regulating tank is equipped with a flow meter. The ferrous sulfate storage tank, hydrogen peroxide storage tank, PAM storage tank and alkali tank are respectively connected to the Fenton reaction tank through metering pump I. The ferrous sulfate storage tank, hydrogen peroxide storage tank, PAM storage tank and alkali tank are respectively equipped with level gauge I.

[0022] The Fenton reactor is equipped with an online pH meter I in both sub-tank I and unit II.

[0023] The sedimentation tank is equipped with a level gauge II. The sedimentation tank is connected to the hydrolysis acidification tank through a lift pump I. The level gauge II monitors the liquid level in the sedimentation tank, thereby controlling the start and stop of the sludge discharge pump and the lift pump I in the sedimentation tank, and providing liquid level protection for the sludge discharge pump and the lift pump I.

[0024] In the three-stage hydrolysis tank, online pH meters II and ORP sensors are installed at equal intervals along the width of the three-stage hydrolysis tank I to monitor the pH and ORP values ​​in the three separate hydrolysis tanks.

[0025] In the three-stage hydrolysis tank, circulation pumps are equidistantly arranged in the secondary hydrolysis tank II along the width direction of the three-stage hydrolysis tank. The circulation pumps are installed at the bottom of the tank to circulate the wastewater in the three secondary hydrolysis tanks and increase the reaction effect.

[0026] The polyferric sulfate storage tank is connected to the outlet of the booster tank via metering pump II. The booster tank is equipped with booster pump II and level gauge III. The level gauge III monitors the liquid level in the booster tank, thereby controlling the start and stop of booster pump II in the sedimentation tank and providing liquid level protection for booster pump II.

[0027] The beneficial effects of this utility model are:

[0028] 1. This invention employs a Fenton system combined with a multi-stage anaerobic continuous operation process. First, high-concentration hemicellulose wastewater, colored wastewater, and acidic wastewater are mixed in an equalization tank. The high-concentration hemicellulose wastewater is adjusted to acidity. Then, the mixed wastewater is pumped to a Fenton reactor, where ferrous sulfate and hydrogen peroxide are added. After the reaction in the Fenton reactor, liquid alkali and PAM are added at the end of the reactor for pH adjustment and flocculation. The effluent flows by gravity to a sedimentation tank for sludge-water separation. The effluent from the sedimentation tank flows by gravity to a hydrolysis acidification tank for hydrolysis acidification. Through multi-stage reactions, the high-concentration wastewater exhibits reduced salinity and sulfate content, thus lowering the concentration of sulfides produced after sulfate reduction. This maintains the activity of microorganisms in the anaerobic hydrolysis tank and achieves efficient sulfate removal. The entire high-concentration hemicellulose wastewater treatment system achieves a COD removal rate of over 80%.

[0029] 2. In this invention, the hydrolysis acidification tank is a multi-stage hydrolysis tank, comprising a primary hydrolysis tank, a secondary hydrolysis tank, and a tertiary hydrolysis tank connected sequentially. The effluent from the sedimentation tank flows by gravity to the primary hydrolysis tank for primary anaerobic hydrolysis, initially decomposing macromolecular organic matter (such as hemicellulose and lignin) and degrading sulfate (SO4). 2- The primary hydrolysis acidification tank further decomposes organic matter in the primary effluent, reducing TDS (Total Dissolved Solids). The secondary hydrolysis acidification tank deepens the hydrolysis acidification process, further decomposing organic matter in the primary effluent and enhancing the acid production stage. The tertiary hydrolysis acidification tank completes the methanogenesis process, thoroughly degrading organic matter and significantly reducing COD.

[0030] 3. This utility model constructs a new pretreatment system with "Fenton system + multi-stage anaerobic process" as the core, which breaks through the bottleneck of efficient decomposition of hemicellulose, lignin and other difficult-to-degrade substances in high-concentration hemicellulose wastewater (COD≤18000mg / L), and achieves a stable COD of ≤60mg / L in the system effluent, fully meeting the environmental protection emission standards.

[0031] 4. In this utility model, a Fenton system coupled with a multi-stage anaerobic process is adopted. The problem of sulfate inhibition is solved by a stepped hydrolysis acidification tank (first stage for sulfate degradation, second stage for acid production, and third stage for methanogenesis) to maintain the activity of anaerobic bacteria. The system COD removal rate exceeds 80%.

[0032] 5. In this utility model, by coordinating the regulation of multiple wastewater sources (high-concentration hemicellulose wastewater + colored wastewater + acidic wastewater mixed in a ratio of 9:3:1), the pH of the acidic wastewater is naturally adjusted to 3.5±0.5, saving the cost of adding external acid, while diluting the sulfate concentration.

[0033] 6. In this invention, the Fenton reaction is enhanced through partitioning:

[0034] The dedicated reaction zones in tanks I and II ensure the efficient generation of hydroxyl radicals;

[0035] Unit I / II independently controls neutralization and flocculation to avoid chemical interference (such as the reaction between alkali and hydrogen peroxide).

[0036] A mixer is installed only in the flocculation zone to reduce energy consumption (the reagents in the reaction zone have been premixed).

[0037] 7. In this utility model, an intelligent control system is used to achieve precise dosing of reagents through flow meter linkage with metering pump; pH / ORP online monitoring of the three-stage hydrolysis tank to optimize the anaerobic environment in real time; and level gauge interlocking with pump valves to ensure safe operation of the system. Attached Figure Description

[0038] Figure 1 This is a schematic diagram of the high-concentration semi-fiber wastewater treatment system of this utility model.

[0039] Figure 2 This is a schematic diagram of the regulating tank of this utility model.

[0040] Figure 3 This is a schematic diagram of the Fenton reaction tank and the drug preparation room of this utility model.

[0041] Figure 4 This is a schematic diagram of the structure of the multi-stage hydrolysis acidification tank of this utility model.

[0042] Figure 5 This is a schematic diagram of the lifting tank of this utility model.

[0043] The components include: 1. Equalization tank; 2. Fenton reaction tank; 3. Fenton sedimentation tank; 4. Multi-stage hydrolysis acidification tank; 5. Lifting tank; 6. Chemical preparation room; 7. Alkali tank; 8. Polyferric sulfate storage tank; 9. PLC controller.

[0044] 101. High-concentration semi-fiber wastewater pipeline; 102. Colored wastewater pipeline; 103. Acidic wastewater pipeline; 104. Flow meter;

[0045] 201. Sub-tank I; 202. Sub-tank II; 203. Sub-tank III; 204. Baffle I; 205. Unit I; 206. Unit II; 207. Baffle II; 208. Paddle Agitator I; 209. Online pH Meter I;

[0046] 301. Sludge pump; 302. Level gauge II; 303. Booster pump I;

[0047] 401. Primary hydrolysis tank; 402. Secondary hydrolysis tank; 403. Tertiary hydrolysis tank; 404. Submersible mixer II; 405. Hydrolysis tank a; 406. Hydrolysis tank b; 407. Submersible mixer IV; 408. Online pH meter II; 409. ORP sensor; 410. Circulation pump;

[0048] 501. Booster Pump II; 502. Level Gauge III;

[0049] 601. Ferrous sulfate storage tank; 602. Hydrogen peroxide storage tank; 603. PAM storage tank; 604. Metering pump I; 605. Level gauge I;

[0050] 801. Metering Pump II. Detailed Implementation

[0051] The present invention will be further described in detail below with reference to the embodiments, but the implementation of the present invention is not limited thereto.

[0052] Example 1

[0053] This embodiment provides a method such as Figure 1-5The high-concentration hemicellulose wastewater treatment system shown includes an equalization tank 1, a Fenton reaction tank 2, a Fenton sedimentation tank 3, a hydrolysis acidification tank, and a booster tank 5 connected sequentially. The inlet of the equalization tank 1 is connected to a high-concentration hemicellulose wastewater pipeline 101, a colored wastewater pipeline 102, and an acidic wastewater pipeline 103. A chemical preparation room 6 is set between the equalization tank 1 and the Fenton reaction tank 2. The chemical preparation room 6 is equipped with a ferrous sulfate storage tank 601, a hydrogen peroxide storage tank 602, and a PAM storage tank 603. The ferrous sulfate storage tank 601 and the hydrogen peroxide storage tank 602 are respectively connected to the inlet of the Fenton reaction tank 2, and the PAM storage tank 603 is connected to the Fenton reaction tank 2. The Fenton reaction tank 2 is also connected to an alkali tank 7. A sludge pump 301 is set at the bottom of the Fenton sedimentation tank 3. The outlet of the booster tank 5 is connected to a polyferric sulfate storage tank 8.

[0054] In this embodiment, the treatment of high-concentration hemicellulose wastewater is accomplished through the following steps:

[0055] S1. First, mix the high-concentration semi-fiber wastewater, colored wastewater and acidic wastewater in equalization tank 1, and control the pH at 3.5±0.5. The ratio of high-concentration semi-fiber wastewater, colored wastewater and acidic wastewater is 9:3:1.

[0056] S2. The mixed wastewater is pumped to Fenton reactor 2. Ferrous sulfate and hydrogen peroxide are added to the pumping pipeline. The ferrous sulfate concentration is 30%, and the dosage is 3.0 L / m³ per cubic meter of wastewater. The hydrogen peroxide concentration is 8%, and the dosage is 2.0 L / m³ per cubic meter of wastewater.

[0057] S3. In Fenton reactor 2, mixed wastewater generates hydroxyl radicals that break down hemicellulose into macromolecules. At the end of the reactor, liquid alkali and PAM are added for pH adjustment and flocculation. The effluent flows by gravity to the sedimentation tank for sludge-water separation. (The amount of alkali added is adjusted according to the pH value. The amount of PAM is 8‰, and the amount added per cubic meter of wastewater is 0.5L / m3. The influent pH value is 3-3.5, the effluent pH value is 7-9, and the retention time is 1 hour.)

[0058] S4. The effluent from the sedimentation tank flows by gravity to the hydrolysis acidification tank for hydrolysis acidification. The sludge generated by the Fenton system settles in the sedimentation tank and is then discharged to the sludge thickening tank for desludge removal via the sludge discharge pump 301.

[0059] S5. The effluent from the acidification and hydrolysis tank flows by gravity to the booster tank 5. Polyferric sulfate is added to the outlet of booster tank 5 (to flocculate and settle colloids in the water and remove some organic matter). Finally, the effluent is boosted to the original sewage treatment system for acid precipitation, neutralization, sedimentation, biological treatment, and Fenton process system treatment to achieve discharge standards.

[0060] In this embodiment, the high-concentration hemicellulose wastewater is (wastewater containing a large amount of hemicellulose generated from the process of extracting hemicellulose from viscose fiber waste alkaline solution), the colored wastewater is (wastewater generated from the process of making cellophane from cotton pulp), and the acidic wastewater is (wastewater generated from the process of the viscose fiber acid station). The cellophane and acidic wastewater have low pH values, and the high-concentration hemicellulose wastewater is weakly acidic. After being mixed in a certain proportion, the pH can be adjusted to 3-3.5, which is within the process requirements of the Fenton system. This saves the cost of using sulfuric acid to adjust the pH. Moreover, the cellophane has a low salt content, and after mixing, the sulfate content of the high-concentration hemicellulose wastewater can be reduced, thereby reducing the risk of anaerobic bacteria inhibition in the anaerobic system.

[0061] Example 2

[0062] The difference between this embodiment and Embodiment 1 is that, in this embodiment, as... Figure 3 As shown, the Fenton reaction tank 2 includes sub-tanks I 201, II 202, and III 203 arranged sequentially along its length. A partition I 204 is provided between adjacent sub-tanks. Sub-tanks I 201 and II 202 are connected at the bottom of partition I 204. Sub-tank III 203 includes units I 205 and II 206 arranged side-by-side along the width of the Fenton reaction tank 2. A partition II 207 is provided between units I 205 and II 206. Unit I 205 and sub-tank II 202 are connected at the bottom of partition I 204, and unit II 206 is connected to unit I 205 at the bottom of partition II 207. Paddle mixers I 208 are respectively installed in units I 205 and II 206. Sub-tank I 201 is connected to the equalization tank 1, and unit II 206 is connected to the Fenton sedimentation tank 3. The alkali tank 7 is connected to unit I 205, and the PAM storage tank 603 is connected to unit II 206. The remaining structure is the same as in Example 1.

[0063] In this embodiment, in the Fenton reaction tank 2, the wastewater flows from sub-tank I 201 to sub-tank II 202, then to unit I 205, and finally to unit II 206. Sub-tanks I 201 and II 202 are Fenton reaction zones, where ferrous sulfate and hydrogen peroxide generate hydroxyl radicals to oxidize the organic matter in the wastewater. Unit I 205 is a neutralization zone, where liquid alkali is added to neutralize the pH of the wastewater to neutral. Unit II 206 is a flocculation zone, where flocculant (PAM polyacrylamide) is added to flocculate the wastewater.

[0064] The pH value in Fenton reactor 2 is 3-3.5, the pH value of the effluent from Unit II 206 is 7-9, and the residence time in Fenton reactor 2 is 1 hour.

[0065] The function of paddle mixer I208 is to rapidly mix the reagents using hydraulic agitation, thereby enhancing the reaction effect. Paddle mixer I208 is only installed in units I205 and II206 because ferrous sulfate and hydrogen peroxide are added to the pipeline and are already mixed before entering the tank. In the tank, they are simply added to increase the residence time for the reaction. However, in units I205 and II206, the reagents are added at the top of the tank. Without agitation, the reagents would only remain at the top of the wastewater tank and would not be fully mixed.

[0066] The function of alkali tank 7 is to adjust the pH value of the effluent from sub-tank II 202 in unit I 205 to 7-9. The reaction range of flocculant is weakly alkaline, and the subsequent anaerobic system also requires weak alkalinity. Therefore, alkali tank 7 is connected to unit I 205 to add alkali solution.

[0067] PAM storage tank 603 is used to prepare PAM (polyacrylamide). The effluent from the Fenton system contains sludge produced by the Fenton reaction. The sludge flocs are small and need to be flocculated into larger molecules for sedimentation using PAM.

[0068] Example 3

[0069] The difference between this embodiment and Embodiment 1 is that, in this embodiment, as... Figure 4 As shown,

[0070] The multi-stage hydrolysis acidification tank 4 includes a primary hydrolysis tank 401, a secondary hydrolysis tank 402, and a tertiary hydrolysis tank 403 connected end to end in sequence.

[0071] Four submersible mixers II 404 are spaced around the perimeter of the primary hydrolysis tank 401.

[0072] The secondary hydrolysis tank 402 includes hydrolysis tank a405 and hydrolysis tank b406 arranged sequentially along its length. A partition III is provided between hydrolysis tank a405 and hydrolysis tank b406, and a guide channel is formed between the partition III and the bottom of the secondary hydrolysis tank 402. Submersible mixers III are respectively provided in hydrolysis tank a405 and hydrolysis tank b406.

[0073] The three-stage hydrolysis tank 403 includes three sub-hydrolysis tanks arranged sequentially along its length: sub-hydrolysis tank I, sub-hydrolysis tank II, and sub-hydrolysis tank III. A partition IV is installed between adjacent sub-hydrolysis tanks, forming a guide channel between the partition IV and the bottom of the three-stage hydrolysis tank 403. Sub-hydrolysis tank I is connected to the secondary hydrolysis tank 402, and sub-hydrolysis tank III is connected to the lifting tank 5. Three submersible mixers IV 407 are respectively installed on opposite sides of sub-hydrolysis tanks I and III. The remaining structure is the same as in Example 1.

[0074] In this embodiment, the primary hydrolysis acidification tank initially decomposes macromolecular organic matter (such as hemicellulose and lignin), degrades sulfate (SO42-), and reduces TDS (total dissolved solids). The secondary hydrolysis acidification tank deepens the hydrolysis acidification process, further decomposes organic matter in the primary effluent, and intensifies the acidification stage. The tertiary hydrolysis acidification tank completes the methanogenesis process, thoroughly degrades organic matter, and significantly reduces COD. Because high-concentration hemicellulose wastewater has high COD, high SO42- content, and contains many difficult-to-degrade macromolecular organic matter, it needs to be degraded gradually, so it is divided into multiple stages of hydrolysis acidification tanks.

[0075] In this embodiment, the four mixers in the primary hydrolysis tank 401 are submersible mixers, also called submersible flow mixers, which are used to push and mix the anaerobic sludge in the tank to enhance the reaction effect. The primary hydrolysis acidification tank initially decomposes macromolecular organic matter (such as hemicellulose and lignin), degrades sulfate (SO42-), and reduces TDS (total dissolved solids).

[0076] In this embodiment, the secondary hydrolysis tank 402 deepens the hydrolysis and acidification process, further decomposes the organic matter in the primary effluent, and strengthens the acid production stage. Hydrolysis tanks a405 and b406 have the same function and are divided into two groups because the original tank structure contained partition walls.

[0077] In this embodiment, within the tertiary hydrolysis tank 403, sub-hydrolysis tanks I, II, and III are each divided into three equal smaller tanks along the width of the tertiary hydrolysis tank 403 by partitions V. This results in nine smaller tanks within the tertiary hydrolysis tank 403, each not connected to other smaller tanks within the same sub-hydrolysis tank, but connected to smaller tanks in adjacent sub-hydrolysis tanks. The three smaller tanks of sub-hydrolysis tank I are connected to the secondary hydrolysis tank 402, and the three smaller tanks of sub-hydrolysis tank III are connected to the booster tank 5. Wastewater from the three smaller tanks of sub-hydrolysis tank I flows sequentially through the smaller tanks of sub-hydrolysis tanks II and III, ultimately entering the booster tank 5. The tertiary hydrolysis tank 403 completes the methanogenesis process, thoroughly degrading organic matter and significantly reducing COD. The three sub-hydrolysis tanks in the tertiary hydrolysis tank 403 have the same function and effect. The submersible mixer, also called a submersible flow mixer, pushes and mixes the anaerobic sludge in the tank to enhance the reaction effect. The left and middle partition walls are hollow, and there is no partition wall at the bottom. The thrust of the submersible mixer on the left can cover the middle tank.

[0078] Example 4

[0079] In this embodiment, as Figure 2-5As shown, a flow meter 104 is installed at the outlet of the regulating tank 1. The ferrous sulfate storage tank 601, hydrogen peroxide storage tank 602, PAM storage tank 603, and alkali tank 7 are respectively connected to the Fenton reaction tank 2 via metering pump I 604. A level gauge I 605 is installed in each of the ferrous sulfate storage tank 601, hydrogen peroxide storage tank 602, PAM storage tank 603, and alkali tank 7. An online pH meter I 209 is installed in each of the sub-tanks I 201 and unit II 206 of the Fenton reaction tank 2. A level gauge II 302 is installed in the sedimentation tank. The sedimentation tank is connected to the hydrolysis acidification tank via a booster pump I 303. The three sub-hydrolysis tanks on the side near the secondary hydrolysis tank 402 in the tertiary hydrolysis tank 403 are respectively equipped with an online pH meter II 408 and an ORP sensor 409 for monitoring the pH and ORP values ​​in the three sub-hydrolysis tanks. The three-stage hydrolysis tank 403 is equipped with a circulation pump 410 in each of the three sub-hydrolysis tanks. The circulation pump 410 is installed at the bottom of the tank to circulate the wastewater in the three sub-hydrolysis tanks, thereby increasing the reaction effect. The polyferric sulfate storage tank 8 is connected to the outlet of the lifting tank 5 through a metering pump II 801. The lifting tank 5 is equipped with a lifting pump II 501 and a level gauge III 502.

[0080] In this embodiment, the flow meter 104 is [missing information]; metering pumps I 604 and II are [missing information]; level gauges I 605-III are [missing information]; online pH meters I 209 and II are [missing information]; booster pumps I 303 and II are [missing information]; ORP sensor 409 is [missing information]; and circulation pump 410 is [missing information].

[0081] In this embodiment, those skilled in the art can set up an external controller using conventional techniques. The external controller can be a Siemens S1200 or S1500 series PLC controller 9. The PLC controller 9 is connected to the flow meter 104, metering pump I604-II, level gauge I605-III, online pH meter I209-II, booster pump I303-II, ORP sensor 409, circulation pump 410, booster pump, and sludge pump 301. The measurement signals from the flow meter 104, level gauge I605-III, online pH meter I209-II, and ORP sensor 409 are transmitted to the PLC controller 9. The PLC controller 9 processes the signals and controls the operation of the metering pump I604-II, booster pump I303-II, circulation pump 410, booster pump, and sludge pump 301, thereby achieving automatic operation of the high-concentration semi-fiber wastewater treatment system.

[0082] In this embodiment, the water treatment of the high-concentration hemicellulose wastewater treatment system is completed through the following steps:

[0083] S1. First, mix the high-concentration semi-fiber wastewater, colored wastewater and acidic wastewater in equalization tank 1, and control the pH at 3.5±0.5. The ratio of high-concentration semi-fiber wastewater, colored wastewater and acidic wastewater is 9:3:1.

[0084] S2. The flow rate at the outlet of the equalization tank 1 is monitored by the flow meter 104, and the flow rate data at the outlet of the equalization tank 1 is transmitted to the PLC controller 9. The PLC controller 9 controls the metering pump I 604 of the ferrous sulfate storage tank 601 and the hydrogen peroxide storage tank 602 to add ferrous sulfate and hydrogen peroxide to the inlet of the Fenton reaction tank 2 according to the flow rate data. The concentration of ferrous sulfate is 30%, and the dosage is 3.0 L / m3 per cubic meter of sewage. The concentration of hydrogen peroxide is 8%, and the dosage is 2.0 L / m3 per cubic meter of sewage.

[0085] S3. The pH values ​​in sub-tanks I201 and unit II206 of Fenton reactor 2 are monitored in real time by online pH meter I209, and the pH value data is transmitted to PLC controller 9. The pH value in sub-tank I201 is used for process operation monitoring and is not involved in control. When the pH value in unit II206 is higher than the set value, PLC controller 9 stops the alkali metering pump. When the pH value in unit II206 is lower than the set value, metering pump I604 at the outlet of alkali tank is started to deliver alkali to unit I205. PLC controller 9 monitors the liquid levels in ferrous sulfate storage tank 601, hydrogen peroxide storage tank 602, PAM storage tank 603 and alkali tank 7 by level gauge I605, and transmits the liquid level data to PLC controller 9. PLC controller 9 controls the start and stop of metering pump I604 according to the liquid level data and provides liquid level protection for metering pump I604.

[0086] S4. The liquid level in the sedimentation tank is monitored in real time by the liquid level gauge II302, and the liquid level data is transmitted to the PLC controller 9. The PLC controller 9 controls the start and stop of the sludge discharge pump 301 and the lift pump I303 in the sedimentation tank by the liquid level data, and provides liquid level protection for the sludge discharge pump 301 and the lift pump I303.

[0087] S5. The pH and ORP values ​​in the three sub-hydrolysis tanks near the secondary hydrolysis tank 402 in the tertiary hydrolysis tank 403 are monitored in real time by online pH meter II 408 and ORP sensor 409. The pH and ORP data are transmitted to PLC controller 9. The pH and ORP data are displayed on site and used as a reference for process adjustment during personnel inspection. There is no automatic control operation.

[0088] S6. The liquid level in the lifting tank 5 is monitored in real time by the level gauge Ⅲ502, and the liquid level data is transmitted to the PLC controller 9. The PLC controller 9 controls the start and stop of the lifting pump Ⅱ501 in the lifting tank 5 based on the liquid level data, and protects the liquid level of the lifting pump Ⅱ501. The PLC controller 9 controls the metering pump Ⅱ801 of the polyferric sulfate storage tank 8 to add polyferric sulfate to the outlet pipe of the lifting pump Ⅱ501 according to the discharge data of the lifting pump Ⅱ501. The liquid dosage of polyferric sulfate is 4.0L / m3 per cubic meter of sewage. Finally, the effluent is lifted to the original sewage treatment system for acid precipitation, neutralization, precipitation, biochemical treatment and Fenton process system for treatment to achieve standard discharge.

[0089] Finally, it should be noted that the control of the high-concentration semi-fiber wastewater treatment system involved in this utility model is a conventional selection of chemical equipment and process control, and can be conventionally selected according to the different chemical equipment, devices, and control instruments.

[0090] It is understood that this utility model has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of this utility model. Furthermore, under the teachings of this utility model, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of this utility model. Therefore, this utility model is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of this utility model.

Claims

1. A high-concentration hemicellulose wastewater treatment system, characterized in that: The system includes an equalization tank (1), a Fenton reaction tank (2), a Fenton sedimentation tank (3), a multi-stage hydrolysis acidification tank (4), and a booster tank (5) connected sequentially. The inlet of the equalization tank (1) is connected to a high-concentration hemicellulose wastewater pipeline (101), a colored wastewater pipeline (102), and an acidic wastewater pipeline (103). A dosing room (6) is set between the equalization tank (1) and the Fenton reaction tank (2), and a ferrous sulfate storage tank (601) is set in the dosing room (6). The hydrogen peroxide storage tank (602) and the PAM storage tank (603) are connected to the inlet of the Fenton reaction tank (2), respectively. The PAM storage tank (603) is connected to the Fenton reaction tank (2). The Fenton reaction tank (2) is also connected to the alkali tank (7). The bottom of the Fenton sedimentation tank (3) is equipped with a sludge pump (301). The outlet of the lifting tank (5) is connected to the polyferric sulfate storage tank (8).

2. The high-concentration hemicellulose wastewater treatment system according to claim 1, characterized in that: The Fenton reaction tank (2) includes sub-tank I (201), sub-tank II (202), and sub-tank III (203) arranged sequentially along its length. A partition I (204) is provided between adjacent sub-tanks. Sub-tanks I (201) and sub-tank II (202) are connected at the bottom of partition I (204). Sub-tank III (203) includes unit I (205) and unit II (206) arranged side-by-side along the width of the Fenton reaction tank (2). Unit I (205) and unit II... A partition II (207) is provided between (206), and unit I (205) and sub-tank II (202) are connected at the bottom of partition I (204). Unit II (206) and unit I (205) are connected at the bottom of partition II (207). Paddle mixer I (208) is provided in unit I (205) and unit II (206) respectively. Sub-tank I (201) is connected to the regulating tank (1), and unit II (206) is connected to the Fenton sedimentation tank (3).

3. The high-concentration hemicellulose wastewater treatment system according to claim 2, characterized in that: The alkali tank (7) is connected to unit I (205), and the PAM storage tank (603) is connected to unit II (206).

4. The high-concentration hemicellulose wastewater treatment system according to claim 1, characterized in that: The multi-stage hydrolysis acidification tank (4) includes a primary hydrolysis tank (401), a secondary hydrolysis tank (402), and a tertiary hydrolysis tank (403) connected sequentially. The primary hydrolysis acidification tank initially decomposes macromolecular organic matter (such as hemicellulose and lignin), degrades sulfate (SO42-), and reduces TDS (total dissolved solids). The secondary hydrolysis acidification tank deepens the hydrolysis acidification process, further decomposes organic matter in the primary effluent, and strengthens the acid production stage. The tertiary hydrolysis acidification tank completes the methanogenesis process, thoroughly degrades organic matter, and significantly reduces COD.

5. The high-concentration hemicellulose wastewater treatment system according to claim 4, characterized in that: Four submersible mixers II (404) are spaced around the primary hydrolysis tank (401).

6. The high-concentration hemicellulose wastewater treatment system according to claim 4, characterized in that: The secondary hydrolysis tank (402) includes hydrolysis tank a (405) and hydrolysis tank b (406) arranged sequentially along its length. A partition III is provided between hydrolysis tank a (405) and hydrolysis tank b (406), and a guide channel is formed between the partition III and the bottom of the secondary hydrolysis tank (402). Submersible mixers III are respectively provided in hydrolysis tank a (405) and hydrolysis tank b (406).

7. The high-concentration hemicellulose wastewater treatment system according to claim 4, characterized in that: The three-stage hydrolysis tank (403) includes three sub-hydrolysis tanks arranged in sequence along the length of the three-stage hydrolysis tank (403): sub-hydrolysis tank I, sub-hydrolysis tank II, and sub-hydrolysis tank III. A partition IV is provided between adjacent sub-hydrolysis tanks. A guide channel is formed between the partition IV and the bottom of the three-stage hydrolysis tank (403). Sub-hydrolysis tank I is connected to the two-stage hydrolysis tank (402), and sub-hydrolysis tank III is connected to the lifting tank (5). Three submersible mixers IV (407) are respectively provided on the opposite sides of sub-hydrolysis tank I and sub-hydrolysis tank III.

8. The high-concentration hemicellulose wastewater treatment system according to claim 1, characterized in that: The outlet of the regulating tank (1) is equipped with a flow meter (104). The ferrous sulfate storage tank (601), hydrogen peroxide storage tank (602), PAM storage tank (603) and alkali tank (7) are respectively connected to the Fenton reaction tank (2) through metering pump I (604). The ferrous sulfate storage tank (601), hydrogen peroxide storage tank (602), PAM storage tank (603) and alkali tank (7) are respectively equipped with level gauge I (605).

9. The high-concentration hemicellulose wastewater treatment system according to claim 2, characterized in that: The Fenton reaction tank (2) is equipped with an online pH meter I (209) in sub-tank I (201) and unit II (206); the sedimentation tank is equipped with a level gauge II (302); and the sedimentation tank is connected to the hydrolysis acidification tank through a booster pump I (303).

10. The high-concentration hemicellulose wastewater treatment system according to claim 7, characterized in that: In the three-stage hydrolysis tank (403), in the sub-hydrolysis tank I, online pH meters II (408) and ORP sensors (409) for monitoring the pH and ORP values ​​in the three sub-hydrolysis tanks are equidistantly arranged along the width direction of the three-stage hydrolysis tank (403); in the sub-hydrolysis tank III of the three-stage hydrolysis tank (403), circulation pumps (410) are equidistantly arranged along the width direction of the three-stage hydrolysis tank (403), and the circulation pumps (410) are installed at the bottom of the tank.

11. The high-concentration hemicellulose wastewater treatment system according to claim 1, characterized in that: The polyferric sulfate storage tank (8) is connected to the outlet of the lifting tank (5) via metering pump II (801). The lifting tank (5) is equipped with lifting pump II (501) and level gauge III (502). The level gauge III (502) monitors the level in the lifting tank (5) to control the start and stop of lifting pump II (501) in the sedimentation tank and to protect the level of lifting pump II (501).

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