Biomass methanol sewage treatment device

Abstract

The utility model provides a biomass methanol sewage treatment device which comprises the following steps: S1, gasification wastewater, ground flushing water, methanol rectification wastewater, test wastewater and domestic sewage are generated in a biomass methanol production process; carrying out oil removal, two-stage air flotation reaction, deamination reaction, coagulation cyanogen breaking and Fenton pre-oxidation treatment on the gasified wastewater to obtain pretreated gasified wastewater; s2, performing comprehensive treatment on the ground flushing water, the methanol rectification wastewater, the test wastewater, the domestic sewage and the pretreated gasification wastewater. The biomass methanol wastewater treatment system has the beneficial effects that the high-concentration gasified wastewater is pretreated by adopting classified and quality-divided treatment, the pretreated wastewater is biodegradable wastewater, and a comprehensive treatment process which mainly adopts biochemical treatment and is high-grade oxidation security is adopted, so that the treatment cost of the biomass methanol wastewater is reduced, and the effluent is ensured to reach the emission standard of pollutants in the petrochemical industry.

Description

Technical Field

[0001] This utility model belongs to the field of wastewater treatment, and in particular relates to a biomass methanol wastewater treatment device. Background Technology

[0002] As my country's environmental protection standards become increasingly stringent, traditional heavy industrial energy sources can no longer meet these requirements. Coal and oil remain the primary energy materials, but their combustion processes are not only resource-intensive and low-yield, but also pollute the environment and damage ecosystems. Therefore, clean new energy sources are crucial for replacing fossil fuels, significantly reducing energy consumption and improving environmental quality. Using green biomass pellets as raw material enables green production and reduces pollutant emissions.

[0003] However, in addition to generating the necessary feed gases, biomass feedstocks also contain other harmful impurities during gasification, such as tar, H2S, NH3, cyanide, and ash. Tar wastewater is complex, containing not only high concentrations of ammonia nitrogen, cyanide, and particulate matter, but also various polycyclic and fused-ring aromatic hydrocarbons such as phenols, indole, naphthalene, and pyridine, as well as alkane organic matter and colloids. The high concentration and toxicity of pollutants make it a typical difficult-to-treat industrial wastewater. Currently, relevant patents only address treatment processes and devices for some indicators such as methanol recovery, oil content reduction, and ammonia nitrogen content reduction; the effluent cannot fully meet the emission standards for pollutants from the petrochemical industry (GB31571-2015).

[0004] Chinese patent application CN202020087858 discloses an oil and gas field methanol wastewater treatment device. The device uses heat exchange and oil separation to treat pre-treated wastewater and performs methanol removal treatment to recover methanol. However, it has no significant removal effect on other pollutants in the wastewater, and the effluent cannot fully meet the emission standards for pollutants in the petrochemical industry (GB31571-2015).

[0005] Chinese patent application CN202322667008 discloses a wastewater treatment device and a methanol production system. During the methanol wastewater treatment process, methane gas is generated in the anaerobic tank. The device achieves the separation and collection of methane gas.

[0006] Chinese patent application CN201020128572 discloses a pretreatment device for oily and methanoly wastewater. Through equalization tank-oil separator-air flotation treatment, it reduces the content of harmful substances such as divalent iron ions, crude oil, and suspended solids in wastewater and reduces the methanol content in reinjected water. However, it has no significant removal effect on other pollutants in wastewater, and the effluent cannot fully meet the emission standards for pollutants from the petrochemical industry (GB31571-2015).

[0007] Chinese patent application CN202311187694 discloses a wastewater treatment process for biomass gasification furnaces. Through demulsification-flocculation-air flotation-low temperature evaporation, it achieves a reduction in oil content and ammonia nitrogen content, but has no significant removal effect on other pollutants in the wastewater, and the effluent cannot fully meet the emission standards for pollutants from the petrochemical industry (GB31571-2015).

[0008] Chinese patent application CN202010796001 discloses a separate treatment process and system for wastewater from coal-to-methanol production and saline wastewater. The process involves full-process biochemical treatment of both wastewater and saline wastewater. The paper only mentions that the total nitrogen in the effluent is less than 20 mg / L; other effluent indicators are not mentioned, and the specific effluent quality is unknown. While separate treatment addresses the impact of highly challenging wastewater, the full-process separate treatment increases investment and operating costs, and also requires a larger land area. Therefore, the economic viability of this process requires further improvement. Utility Model Content

[0009] In view of this, the present invention aims to provide a biomass methanol wastewater treatment device to solve at least one technical problem in the background art.

[0010] To achieve the above objectives, the technical solution of this utility model is implemented as follows:

[0011] A biomass methanol wastewater treatment device includes a gasification wastewater pretreatment device and a comprehensive wastewater treatment device;

[0012] The gasification wastewater pretreatment device is used to treat gasification wastewater by oil separation, two-stage air flotation reaction, ammonia removal reaction, coagulation and cyanide breaking, and Fenton pre-oxidation to obtain pretreated gasification wastewater.

[0013] The integrated wastewater treatment unit is used to comprehensively treat pretreated gasification wastewater and other wastewater, and then discharge it after meeting the discharge conditions.

[0014] Furthermore, the gasification wastewater pretreatment device includes, in sequence, an oil separator, a gasification wastewater equalization tank, a vortex flotation device, a dissolved air flotation device, a first intermediate water tank, an ammonia removal device, a coagulation reaction device, and a Fenton pre-oxidation device.

[0015] And / or, the grease trap is connected to the sludge storage tank, and the sludge storage tank is connected to the sludge transfer pump via a pipeline;

[0016] And / or, the bottom of the gasification wastewater equalization tank is connected to the vortex air flotation device via a first lift pump;

[0017] And / or, the vortex air flotation device and the dissolved air flotation device are equipped with demulsifier, PAC and PAM delivery pipes;

[0018] Furthermore / or, the vortex-induced air flotation device and the dissolved air flotation device are both connected to the sludge storage tank, the sludge storage tank is connected to the sludge transfer pump, the sludge transfer pump is connected to the sludge dewatering device, and the sludge treated by the sludge dewatering device is transported off-site.

[0019] And / or, the first intermediate water tank is connected to the ammonia removal unit via a second booster pump.

[0020] And / or, the coagulation reaction device is equipped with a complexing agent delivery pipe.

[0021] Furthermore, the integrated wastewater treatment device includes, in sequence, an integrated equalization tank, a hydrolysis acidification tank, an AO and sedimentation tank, a second intermediate water tank, a catalytic oxidation tank, an activated carbon reactor, and an external drainage tank.

[0022] Furthermore, the hydrolysis acidification tank, AO and sedimentation tank, and catalytic oxidation tank are connected to the sludge thickening tank via a second sludge pump. The sludge thickening tank is connected to the dewatering device, and the sludge treated by the sludge dewatering device is transported off-site.

[0023] And / or, the integrated equalization tank is connected to the hydrolysis acidification tank via a third booster pump;

[0024] And / or, the second intermediate water tank is connected to the catalytic oxidation tank via a fourth booster pump;

[0025] And / or, the catalytic oxidation tank is connected to the activated carbon reactor, the activated carbon reactor is connected to the external drainage tank, and the effluent from the catalytic oxidation tank enters the activated carbon reactor by gravity; the effluent from the activated carbon reactor enters the external drainage tank by gravity.

[0026] And / or, the external drainage tank is connected to the integrated regulating tank via a fifth lift pump.

[0027] Compared with existing technologies, the biomass methanol wastewater treatment device of this utility model has the following advantages:

[0028] The biomass methanol wastewater treatment process and apparatus of this invention adopts a classified and differentiated treatment process to pretreat the high-concentration gasification wastewater that is difficult to treat in methanol wastewater. This effectively reduces the oil content, ammonia nitrogen content, cyanide content, and content of recalcitrant organic pollutants in the wastewater, thereby effectively improving the biotoxicity and biodegradability of the gasification wastewater and creating favorable conditions for subsequent comprehensive wastewater biochemical treatment.

[0029] The pretreated gasification wastewater, methanol distillation wastewater, floor washing water, laboratory testing wastewater, and domestic sewage are all easily biodegradable wastewater. Therefore, traditional biochemical processes can effectively remove most pollutants from this wastewater, reducing the construction and operating costs of integrated wastewater treatment. Simultaneously, biological methods can comprehensively remove pollutants such as COD, nitrogen, and phosphorus from the wastewater, achieving efficient pollutant treatment. A small amount of recalcitrant macromolecular pollutants remaining after biochemical treatment are mitigated through advanced oxidation processes, ensuring that the effluent consistently meets the petrochemical industry pollutant discharge standards (GB31571-2015).

[0030] This application can comprehensively solve the wastewater treatment of biomass methanol, enabling the effluent to meet the emission standards for pollutants in the petrochemical industry (GB31571-2015). Compared with other devices, it saves about 20%-30% in construction costs and about 10%-20% in operating costs. It also features stable operation and a high degree of automation. Furthermore, the individual devices used in this utility model cannot meet the wastewater treatment requirements when used alone. Only when combined and used in the specific sequence of this process device can they meet the emission standards for pollutants in the petrochemical industry (GB31571-2015). Attached Figure Description

[0031] The accompanying drawings, which form part of this utility model, are used to provide a further understanding of the utility model. The illustrative embodiments of the utility model and their descriptions are used to explain the utility model and do not constitute an undue limitation of the utility model. In the drawings:

[0032] Figure 1 This is a schematic diagram of the biomass methanol wastewater treatment gasification wastewater pretreatment device according to an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the biomass methanol wastewater treatment structure according to an embodiment of the present invention;

[0034] Figure 3 This is a flowchart illustrating the methanol production and pollution generation process described in this embodiment of the invention.

[0035] Figure 4 This is a flowchart of the wastewater treatment process for methanol production according to an embodiment of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] 1. Oil separator; 2. Gasification wastewater equalization tank; 3. Vortex flotation device; 4. Dissolved air flotation device; 5. First intermediate water tank; 6. Ammonia removal device; 7. Coagulation reaction tank; 8. Fenton pre-oxidation device; 9. Comprehensive equalization tank; 10. Hydrolysis acidification tank; 11. AO and sedimentation tank; 12. Second intermediate water tank; 13. Photocatalytic oxidation tank; 14. Activated carbon reactor; 15. External drainage tank; 16. Sludge thickening tank. Detailed Implementation

[0038] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0039] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0040] Example 1

[0041] In this embodiment, the biomass methanol production process includes biomass gasification, pre-purification, purification and desulfurization, CO conversion, decarbonization, methanol synthesis, and methanol distillation. The wastewater generated during the production process consists of gasification wastewater W1, methanol distillation wastewater W2, floor cleaning wastewater W3, laboratory testing wastewater W4, and domestic sewage W5. This embodiment employs a comprehensive wastewater treatment process involving pre-treatment of gasification wastewater followed by mixing the pre-treated wastewater with other wastewater.

[0042] This embodiment provides a biomass methanol wastewater treatment process, including the following steps:

[0043] 1) Gasification wastewater W1 is characterized by high tar content, high ammonia nitrogen content, relatively high cyanide content, large fluctuations in water quality and quantity, and poor biodegradability. A pretreatment method of oil separation-two-stage air flotation-ammonia removal-coagulation and cyanide breaking-Fenton pre-oxidation is adopted to pretreat the gasification wastewater for oil removal, ammonia removal and cyanide breaking, thereby reducing the toxicity of the gasification wastewater and improving its biodegradability.

[0044] The pretreated effluent from gasification wastewater, mixed with methanol distillation wastewater W2, floor cleaning wastewater W3, laboratory testing wastewater W4, and domestic sewage W5, enters a comprehensive equalization tank for integrated treatment. The integrated wastewater treatment process is hydrolysis acidification-AO and precipitation-catalytic oxidation-activated carbon adsorption.

[0045] Oil sludge generated from the oil separation in the pretreatment unit is collected and recycled separately; floating sludge generated from the air flotation in the pretreatment unit is collected, dewatered, and transported separately; sludge discharged from the hydrolysis acidification tank, AO and sedimentation tank, as well as the photocatalytic oxidation tank, enters the sludge thickening tank, and after being treated by the sludge dewatering device, it is transported to the outside for centralized treatment and disposal.

[0046] The biomass methanol wastewater treatment device described in this embodiment requires the wastewater generated during the production process to be treated separately according to its quality. The high-difficulty gasification wastewater can be effectively treated by using the oil-water separation-air flotation-ammonia stripping-cyanide breaking-Fenton pre-oxidation method, which can effectively solve the problems of high oil content, high ammonia nitrogen and cyanide toxicity. The pretreated gasification wastewater is mixed with other wastewater for comprehensive treatment. The process of hydrolysis acidification-AO and precipitation-catalytic oxidation-activated carbon adsorption can effectively reduce the total cost and ensure that the effluent fully and stably meets the emission standards for pollutants in the petrochemical industry (GB31571-2015).

[0047] In step 1) of biomass methanol production, oxygen and water vapor are used as gasifying agents to react with biomass. The biomass gasification green methanol process is completed through processes such as washing and decoking, crude desulfurization, TSA temperature-switched adsorption purification, fine desulfurization, CO conversion, MDEA decarbonization, methanol synthesis, and methanol distillation.

[0048] In biomass methanol production, different process stages generate different types of wastewater. The biomass gasification stage mainly produces gasification wastewater (W1), the methanol distillation stage mainly produces methanol distillation wastewater (W2), floor washing water (W3) is generated from washing the floors of various unit areas and tank areas, laboratory testing wastewater (W4) is generated from the laboratory, and domestic sewage (W5) is generated by employees in the plant's outskirts. Given the different characteristic pollutants and treatment difficulties of these various wastewaters, this unit employs a comprehensive wastewater treatment process: pretreatment of gasification wastewater followed by mixing of the pretreatment effluent with other wastewater.

[0049] In the pretreatment of gasification wastewater, gasification wastewater W1 contains a large amount of tar, high ammonia nitrogen content, and high cyanide content. The pretreatment process of oil separation-two-stage air flotation-ammonia removal-complexing agent cyanide removal is adopted to reduce the tar content, ammonia nitrogen content, and cyanide toxicity of the wastewater, improve the biodegradability of the gasification wastewater, and the effluent can be mixed with other sewage for comprehensive treatment.

[0050] In the integrated wastewater treatment process, the pretreated effluent from gasification wastewater, mixed with methanol distillation wastewater W2, surface flushing water W3, laboratory testing wastewater W4, and domestic sewage W5, enters the integrated equalization tank for comprehensive treatment. The integrated wastewater treatment primarily employs biochemical treatment, utilizing a combination of hydrolysis acidification-AO and precipitation-photocatalytic oxidation-activated carbon adsorption processes to ensure that the effluent consistently meets the emission standards for pollutants from the petrochemical industry (GB31571-2015).

[0051] The scum generated from oil separation in the pretreatment of gasification wastewater is collected separately and recycled for use in the front-end process section; the oil sludge generated from air flotation in the pretreatment of gasification wastewater is collected separately, dewatered, and transported off-site for disposal; the sludge discharged from the hydrolysis acidification tank, AO and sedimentation tank, as well as the photocatalytic oxidation tank, enters the sludge thickening tank, is treated by the sludge dewatering device, and is then transported off-site for centralized treatment and disposal.

[0052] A biomass methanol wastewater treatment process includes the following steps:

[0053] S1: After biomass methanol production, gasification wastewater, ground washing water, methanol distillation wastewater, laboratory wastewater and domestic sewage are generated. The gasification wastewater is treated by oil separation, two-stage air flotation reaction, ammonia removal reaction, coagulation and cyanide removal, and Fenton pre-oxidation to obtain pretreated gasification wastewater.

[0054] S2: Comprehensive adjustment, hydrolysis acidification, AO reaction and precipitation, photocatalytic oxidation and activated carbon adsorption are carried out on ground washing water, methanol distillation wastewater, laboratory wastewater, domestic sewage and pretreated gasification wastewater to meet the discharge conditions before discharge.

[0055] like Figure 3 As shown, the preparation of biomass methanol in step S1 includes biomass feedstock transportation and air separation for biomass gasification, pre-purification, purification and desulfurization, CO conversion and decarbonization, methanol synthesis and methanol distillation to obtain biomass methanol, which is temporarily stored in the methanol tank area and tested in the laboratory in front of the plant area; gasification wastewater is generated in the biomass gasification process; ground washing water is generated in the pre-purification, purification and desulfurization, CO conversion and decarbonization workshops and methanol tank area; methanol distillation wastewater is generated in the methanol synthesis and methanol distillation process; laboratory wastewater is generated in the laboratory; and domestic sewage is generated in the front area of ​​the plant.

[0056] The oil residue after oil separation in step S1 is treated separately in an oil residue storage tank; the wastewater in the oil separator has a retention time of at least 8 hours.

[0057] like Figure 4 As shown, the two-stage air flotation reaction in step S1 includes sequentially performing gasification wastewater conditioning, vortex air flotation reaction, dissolved air flotation reaction, and intermediate water tank reaction; the gasification wastewater conditioning adjusts the wastewater to neutral pH, and the wastewater retention time is at least 48 hours; in the vortex air flotation reaction, demulsifier, PAC, and PAM are added, with the demulsifier dosage being 90-110 mg / L, the PAC dosage being 90-110 mg / L, and the PAM dosage being 4-6 mg / L.

[0058] In the dissolved air flotation reaction, demulsifier, PAC and PAM are added. The dosage of demulsifier is 50 mg / L, the dosage of PAC is 50 mg / L, and the dosage of PAM is 3 mg / L. The sludge from the vortex flotation reaction and the dissolved air flotation reaction are successively sent to the sludge storage tank, sludge dewatering, and then the sludge is transported off-site.

[0059] In step S1, after the ammonia removal reaction of the wastewater, the ammonia nitrogen content in the effluent can be reduced to below 200 mg / L; a complexing agent is added in the coagulation and cyanide-breaking reaction to ensure that the HCN content in the effluent is below 2 mg / L; the type of complexing agent is a cyanide complexing agent: in the Fenton pre-oxidation treatment, the pH is adjusted to 3-4, and ferrous sulfate and hydrogen peroxide are added in sequence. The amount of hydrogen peroxide added is 1:0.8-1.2 according to the mass ratio of hydrogen peroxide to COD, and the amount of ferrous sulfate added is 1:4.8-5.2 according to the mass ratio of ferrous sulfate to hydrogen peroxide.

[0060] In step S2, the comprehensive adjustment is to treat the wastewater in a homogenized manner and in a uniform quantity; the hydrolysis acidification reaction in step S2 includes two stages, with the wastewater retention time in the single-stage hydrolysis acidification tank 10 being 24 hours, and the total retention time for both stages being 48 hours.

[0061] The wastewater after hydrolysis and acidification reaction flows by gravity into the AO reaction and sedimentation tank, which includes an anoxic zone, an aerobic zone, and a sedimentation tank. The sludge from the sedimentation tank is discharged to the sludge thickening tank 16 via a sludge discharge pump.

[0062] The sludge return ratio in the AO tank is 50%-100%, the mixed liquor return ratio is 200%-400%, the air-to-water ratio in the aerobic zone is 40:1, the total retention time in the anoxic and aerobic zones is 100 hours, and the surface loading rate in the sedimentation tank is 0.5 m³ / m²·h. Sulfuric acid and hydrogen peroxide are added to the photocatalytic oxidation reaction to adjust the wastewater pH to 3.5-4.0. The hydrogen peroxide dosage is based on a hydrogen peroxide to COD mass ratio of 1.5:1. PAM is added to the effluent section to flocculate and settle suspended solids, ensuring that the effluent SS is less than 20 mg / L. The effluent from the photocatalytic oxidation reaction enters the activated carbon reactor. The sludge from the photocatalytic oxidation reaction is discharged into the sludge thickening tank 16 via the first sludge pump. The activated carbon reactor 14 is equipped with activated carbon packing.

[0063] Example 2

[0064] The biomass methanol wastewater treatment device of this utility model includes two parts: a gasification wastewater pretreatment device and a comprehensive wastewater treatment device.

[0065] The gasification wastewater pretreatment device consists of an oil separator 1, a gasification wastewater equalization tank 2, a vortex flotation device 3, a dissolved air flotation device 4, a first intermediate water tank 5, an ammonia removal device 6, a coagulation reaction tank 7, and a Fenton pre-oxidation device 8. These components are sequentially connected via pipelines.

[0066] The integrated wastewater treatment unit comprises an integrated equalization tank 9, a hydrolysis acidification tank 10, an AO and sedimentation tank 11, a second intermediate water tank 12, a photocatalytic oxidation tank 13, and an activated carbon reactor 14. These components are sequentially connected.

[0067] It includes a first lift pump P1 connected to the inlet of the vortex air flotation device 3 via a pipeline, a second lift pump P2 connected to the inlet of the ammonia removal device 6 via a pipeline, a third lift pump P5 connected to the inlet of the hydrolysis acidification device 10 via a pipeline, a fourth lift pump P6 connected to the photocatalytic oxidation tank 13 via a pipeline, a fifth lift pump P7 connected to the external drainage tank via a pipeline, and a sludge pump connected to the hydrolysis acidification tank 10, AO and sedimentation tank 11, and photocatalytic oxidation tank 13 via a pipeline.

[0068] It also includes a sludge transfer pump P3 connected via a pipeline to the outlet of the oil residue storage tank V1, a floating sludge transfer pump P4 connected via a pipeline to the outlet of the floating sludge storage tank device, and a sludge dewatering device connected to the floating sludge storage tank via the transfer pumps.

[0069] It also includes a sludge thickening tank 16 connected to the hydrolysis acidification tank 10, AO, sedimentation tank 11, and photocatalytic oxidation tank 13 via a pipeline and a first sludge pump P8, and a sludge dewatering device connected to the sludge thickening tank 16 via a second sludge pump P9.

[0070] Example 3

[0071] This embodiment uses the process in Embodiment 1 and the apparatus in Embodiment 2. Industrial wastewater enters the oil separator 1 under pressure, where oil and water are separated. After separation, the wastewater flows by gravity into the gasification wastewater equalization tank 2. The floating oil after oil-water separation in the oil separator 1 enters the oil sludge storage tank V1, and the oil sludge is sent for recycling and treatment via the sludge transfer pump P3. The wastewater retention time in the oil separator 1 is 8 hours.

[0072] The gasification wastewater equalization tank 2 is used to regulate the wastewater volume and homogenize the wastewater quality. The wastewater retention time in the gasification wastewater equalization tank 2 is 48 hours. The effluent from the gasification wastewater equalization tank is sent to the vortex flotation device 3 via the lift pump P1.

[0073] The vortex-induced air flotation unit 3 is equipped with demulsifier, PAC, and PAM to demulsify and flocculate the wastewater, removing residual emulsified oil and a large amount of suspended solids. The dosage of demulsifier is 100 mg / L, PAC is 100 mg / L, and PAM is 5 mg / L. The effluent from the vortex-induced air flotation unit 3 enters the dissolved air flotation unit 4 by gravity, and the oily sludge produced by the vortex-induced air flotation unit 3 enters the oily sludge storage tank V2. The oily sludge is then transported to the sludge dewatering reactor X1 via the sludge transfer pump P4 for dewatering and subsequent disposal.

[0074] The dissolved air flotation (DAF) unit 4 incorporates demulsifier, PAC, and PAM to perform a two-stage demulsification, flocculation, and sedimentation reaction on the wastewater, removing any remaining traces of emulsified oil and suspended solids. The demulsifier dosage is 50 mg / L, the PAC dosage is 50 mg / L, and the PAM dosage is 3 mg / L. Through the two-stage flotation treatment in units 3 and 4, the oil content can be reduced to below 45 mg / L. The effluent from DAF unit 4 flows by gravity into the first intermediate water tank 5, while the oily sludge produced by DAF unit 4 enters the oily sludge storage tank V2. The oily sludge is then transported to the sludge dewatering reactor X1 via sludge transfer pump P4 for dewatering and subsequent disposal.

[0075] The first intermediate water tank 5 is a wastewater lifting tank. A lifting pump P2 is installed outside the tank to lift the wastewater from the first intermediate water tank 5 into the ammonia removal device 6.

[0076] The ammonia removal device 6 treats the wastewater to remove ammonia, reducing the ammonia nitrogen content in the effluent to below 200 mg / L. The effluent from the ammonia removal device 6 enters the coagulation reaction tank 7 by gravity.

[0077] A complexing agent is added to the coagulation reaction tank 7 to perform a complexation reaction on cyanide, ensuring that the cyanide content in the effluent is below 2 mg / L. The effluent from the coagulation reaction tank 7 enters the Fenton pre-oxidation unit 88 by gravity.

[0078] In the Fenton pre-oxidation unit 8, the pH is adjusted to approximately 3.5. Ferrous sulfate and hydrogen peroxide are then added sequentially. The hydrogen peroxide is added at a 1:1 mass ratio to COD, and the ferrous sulfate is added at a 1:5 mass ratio to hydrogen peroxide. This process performs ring-opening and chain-breaking advanced oxidation on recalcitrant macromolecular organic matter, improving the biodegradability of the wastewater. Neutralization, degassing, and flocculation sedimentation reactions then occur. The effluent from the Fenton pre-oxidation unit 8 enters the integrated equalization tank 9 by gravity.

[0079] like Figure 2The integrated wastewater treatment device shown includes a general equalization tank 9, a hydrolysis acidification tank 10, an AO and sedimentation tank 11, an intermediate water tank reactor 12, a photocatalytic oxidation tank 13, an activated carbon reactor 14, and an external drainage tank 15. Its distinguishing feature is that the general equalization tank 9, the hydrolysis acidification tank 10, the AO and sedimentation tank 11, the intermediate water tank reactor, the photocatalytic oxidation tank 13, the activated carbon reactor 14, and the external drainage tank 15 are sequentially connected by pipelines.

[0080] The effluent from the gasification wastewater pretreatment unit, methanol distillation wastewater W2, floor flushing water W3, laboratory wastewater W4, and domestic sewage W5 all enter the integrated equalization tank 9 for homogenization and equalization treatment. The effluent from the integrated equalization tank 9 is then pumped by the booster pump P5 into the hydrolysis acidification reaction unit 10. The wastewater retention time in the integrated equalization tank 9 is 24 hours.

[0081] In the hydrolysis acidification tank 10, the wastewater undergoes biological hydrolysis by anaerobic microorganisms, breaking down recalcitrant macromolecules into easily degradable small molecules, thus improving the biodegradability of the industrial wastewater. A sludge discharge pipe is connected to the end of the hydrolysis acidification tank, and sludge is discharged into the sludge thickening tank 16 via sludge pump P8. The hydrolysis acidification tank 10 is configured in two stages, with a wastewater retention time of 24 hours in each stage, totaling 48 hours for both stages. The tank is equipped with packing material.

[0082] The wastewater treated in the hydrolysis acidification tank 10 flows by gravity into the AO and sedimentation tank 11, which includes anoxic and aerobic zones. During this process, BOD5, SS, and nitrogen and phosphorus in various forms are largely removed. The hydrolysis acidification treatment includes at least two stages. In a single-stage hydrolysis acidification tank, the wastewater retention time is 18-24 hours. Sulfuric acid is added during the hydrolysis acidification treatment to adjust the pH of the wastewater to 4.5-5.5 and the temperature to 15-30℃.

[0083] The sludge from the sedimentation tank is discharged to the sludge thickening tank 16 via the first sludge discharge pump P8. The sludge return ratio in the AO tank is 50%-100%, the nitrification liquor return ratio is 200%-400%, the air-to-water ratio in the O tank is 40:1, the total retention time in the AO tank is 100 hours, and the surface loading rate of the sedimentation tank is 0.5 m³. 3 / (m 2 h).

[0084] The effluent from the AO and sedimentation tank 11 flows by gravity to the intermediate water tank reaction device 12. The intermediate water tank reaction device 12 is a wastewater lifting tank. A fifth lifting pump P6 is installed outside the tank to lift the wastewater from the intermediate water tank 1 reaction device 5 into the photocatalytic oxidation reaction device 13.

[0085] Sulfuric acid and hydrogen peroxide are added to the photocatalytic oxidation reactor 13 to adjust the pH of the wastewater to approximately 4. The hydrogen peroxide is added at a ratio of 1.5:1 (hydrogen peroxide to COD mass). NaQH is added to the effluent to adjust the pH to 7.5-8, and PAM is added to flocculate and settle suspended solids, ensuring that the effluent SS is less than 20 mg / L. The effluent from the photocatalytic oxidation reactor 13 enters the activated carbon reactor 14. The sludge from the photocatalytic oxidation reactor 13 is discharged into the sludge thickening tank 16 via the first sludge pump 8.

[0086] The activated carbon reactor 14 is equipped with activated carbon packing to further adsorb and remove recalcitrant organic pollutants. As a safety measure for the entire process unit, it ensures that the pollutants in the external drainage pool 15 meet the discharge requirements.

[0087] The external drainage pool 15 is a clear water temporary storage pool. Online monitoring facilities are installed outside the pool to monitor the wastewater in the external drainage pool 15 in real time. Wastewater that passes the test is lifted and discharged by the external lift pump P7. Wastewater that fails the test is lifted by the external lift pump P7 to the comprehensive regulating pool 9 for reprocessing.

[0088] The sludge thickening tank 16 uses sludge transfer pump P9 to transport the thickened sludge to the sludge dewatering reactor X2 for dewatering and subsequent disposal. Depending on the sludge dewatering requirements, PAM (Polymer Acetate Amide) can be added to improve the sludge dewatering performance. The effluent from the sludge dewatering reactor X2 is returned to the upstream equalization tank 9 for further treatment.

[0089] Using the implementation method described in this embodiment, the water quality of the gasification wastewater inlet and outlet is detailed in the Gasification Wastewater Inlet and Outlet Water Quality Table, and the water quality of the combined wastewater inlet and outlet is detailed in the Combined Wastewater Inlet and Outlet Water Quality Table.

[0090] Table 1. Water Quality Table of Gasification Wastewater Influent and Effluent

[0091] project COD (mg / L) BOD5 (mg / L) SS (mg / L) <![CDATA[NH3-N(mg / L)]]> TN (mg / L) TP (mg / L) Petroleum products (mg / L) pH Influent water quality 4000 600 80 2500 3000 9 1000 6~9 Pretreated water quality 1200 400 30 200 220 4.5 45 6~9

[0092] Table 2. Water Quality Table of Integrated Wastewater Influent and Effluent

[0093]

[0094] The above data shows that after treating biomass methanol wastewater using the process and device of this utility model, the effluent from the production wastewater can stably meet the emission standards for pollutants from the petrochemical industry (GB31571-2015), effectively solving the current problem of biomass methanol wastewater treatment. It has a very broad application market and guiding significance for biomass methanol wastewater treatment.

[0095] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A biomass methanol wastewater treatment device, characterized in that: The gasification wastewater pretreatment device is used for oil separation, two-stage air floatation reaction treatment, deamination reaction treatment, coagulation cyanide breaking treatment and Fenton pre-oxidation treatment on the gasification wastewater, so as to obtain pretreated gasification wastewater. The comprehensive wastewater treatment device is used for comprehensively treating the pretreated gasification wastewater and other wastewater, and discharging after meeting the discharge conditions. The gasification wastewater pretreatment device comprises an oil separation tank, a gasification wastewater adjusting tank, a vortex-cavity air floatation device, a dissolved air floatation device, a first intermediate water tank, a deamination device, a coagulation reaction device and a Fenton pre-oxidation device which are sequentially arranged.

2. The biomass methanol wastewater treatment device according to claim 1, characterized in that: The oil separation tank is connected with an oil residue storage tank, and the oil residue storage tank is connected with a sludge conveying pump through a pipeline.

3. The biomass methanol wastewater treatment device according to claim 2, characterized in that: The bottom of the gasification wastewater adjusting tank is connected with the vortex-cavity air floatation device through a first lifting pump. The vortex-cavity air floatation device and the dissolved air floatation device are provided with demulsifier, PAC and PAM conveying pipes.

4. The biomass methanol wastewater treatment device according to claim 2, characterized in that: Furthermore, the vortex-cavity air floatation device and the dissolved air floatation device are connected with a floating sludge storage tank, the floating sludge storage tank is connected with the sludge conveying pump, the sludge conveying pump is connected with a sludge dewatering device, and the sludge dewatering device is connected with a sludge conveying device. The first intermediate water tank is connected with the deamination device through a second lifting pump.

5. The biomass methanol wastewater treatment device according to claim 4, characterized in that: Furthermore, the coagulation reaction device is provided with a complexing agent conveying pipe. The comprehensive wastewater treatment device comprises a comprehensive adjusting tank, a hydrolysis acidification tank, an AO and sedimentation tank, a second intermediate water tank, a catalytic oxidation tank, an activated carbon reactor and an external discharge tank which are sequentially arranged.

6. The biomass methanol wastewater treatment device according to claim 1, characterized in that: The hydrolysis acidification tank, the AO and sedimentation tank and the catalytic oxidation tank are connected with a sludge concentration tank through a second sludge pump, the sludge concentration tank is connected with a dewatering device, and the dewatering device is connected with a sludge conveying device.

7. The biomass methanol wastewater treatment device according to claim 1, characterized in that: Furthermore, the comprehensive adjusting tank is connected with the hydrolysis acidification tank through a third lifting pump. The second intermediate water tank is connected with the catalytic oxidation tank through a fourth lifting pump, the catalytic oxidation tank is communicated with the activated carbon reactor, the activated carbon reactor is communicated with the external discharge tank, the water from the catalytic oxidation tank gravitates into the activated carbon reactor, and the water from the activated carbon reactor gravitates into the external discharge tank.

8. The biomass methanol wastewater treatment device according to claim 7, characterized in that: The external discharge tank is connected with the comprehensive adjusting tank through a fifth lifting pump.

9. The biomass methanol wastewater treatment device according to claim 8, characterized in that: ​

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