Biomass methanol sewage treatment process and device

Abstract

The invention provides a biomass methanol sewage treatment process and device, and the process comprises the following steps: S1, generating gasification wastewater, ground flushing water, methanol rectification wastewater, test wastewater and domestic sewage 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 method has the beneficial effects that classified and quality-divided treatment is adopted, the high-concentration gasified wastewater is pretreated, 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] The invention belongs to the field of sewage treatment, and in particular relates to a biomass methanol sewage treatment process and a device. Background Art

[0002] As my country's environmental protection quality requirements increase, traditional heavy industrial energy cannot meet environmental protection requirements. Coal and oil are the main energy materials at present. However, coal and oil not only consume a large amount of materials and have a small production capacity during the combustion process, but also pollute the environment and destroy the ecosystem. Therefore, clean new energy replacing fossil fuels is of great significance to reducing energy consumption and improving environmental protection quality. Using green raw material biomass pellets as raw materials, green production is achieved and pollutant emissions are reduced.

[0003] However, in addition to the necessary raw gas generated during the gasification process, biomass raw materials also contain other harmful impurities, such as tar, H2S, NH3, cyanide and ash. The water quality of tar wastewater is complex. It not only contains high concentrations of ammonia nitrogen, cyanide, solid particles and other pollutants, but also contains a variety of polycyclic and condensed aromatic organics such as phenol, indole, naphthalene, pyridine, alkane organics and colloids. The pollutant concentration is high and the toxicity is high. It is a typical difficult-to-treat industrial wastewater. At present, the relevant patents are only about some indicators of treatment processes and devices such as methanol recovery, oil content reduction, and ammonia nitrogen content reduction. The effluent cannot fully meet the petrochemical industry pollutant emission standards (GB31571-2015).

[0004] Chinese patent application CN202020087858 discloses a methanol wastewater treatment device for oil and gas fields. The device uses heat exchange and oil separation treatment for pre-treated wastewater, and dealcoholization treatment for methanol wastewater, thereby realizing methanol recovery. It has no obvious removal effect on other pollutants in the wastewater, and the effluent cannot fully meet the petrochemical industry pollutant emission standards (GB31571-2015).

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

[0006] Chinese patent application CN201020128572 discloses a device for pre-treatment of oil-containing and methanol-containing wastewater by adding chemicals. Through a regulating tank-oil separator-flotation treatment, the content of harmful substances such as divalent iron ions, crude oil, and suspended solids in the wastewater is reduced, and the methanol content of the reinjection water is reduced. However, there is no obvious removal effect on other pollutants in the wastewater, and the effluent cannot fully meet the petrochemical industry pollutant emission standards (GB31571-2015).

[0007] Chinese patent application CN202311187694 discloses a biomass gasification furnace wastewater treatment process, which achieves the reduction of oil content and ammonia nitrogen content through the demulsification-flocculation-flotation-low-temperature evaporation process. It has no obvious removal effect on other pollutants in the wastewater, and the effluent cannot fully meet the petrochemical industry pollutant emission standards (GB31571-2015).

[0008] Chinese patent application CN202010796001 discloses a differentiated treatment process and system for a coal-to-methanol process production wastewater series and a saline wastewater series. The production wastewater and saline wastewater were subjected to full-process biochemical treatment. The article only mentioned that the total nitrogen in the effluent was less than 20 mg / L, and the content of other effluent indicators was not mentioned, and the specific effluent water quality was unknown. At the same time, although the quality-differentiation treatment solves the impact of high-difficulty wastewater, the full-process quality-differentiation treatment increases the investment cost and operating cost of sewage treatment, and increases the floor space. The economic evaluation of this process needs to be improved. Summary of the invention

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

[0010] To achieve the above object, the technical solution of the present invention is achieved as follows: A biomass methanol wastewater treatment process comprises the following steps: S1: wastewater is generated in the biomass methanol production process, the wastewater includes gasification wastewater and other wastewater; the other wastewater includes ground washing water, methanol distillation wastewater, laboratory wastewater, and domestic sewage; the gasification wastewater is subjected to oil separation, two-stage flotation reaction treatment, deammoniation reaction treatment, coagulation and cyanide destruction treatment, and Fenton pre-oxidation treatment to obtain pretreated gasification wastewater; S2: Comprehensively treat the pre-treated gasification wastewater and other wastewater, and discharge them after meeting the discharge conditions.

[0011] Furthermore, the production process of biomass methanol in step S1 includes biomass raw material transportation and air separation, biomass gasification, pre-purification, purification and desulfurization, CO conversion and decarbonization, methanol synthesis and methanol distillation to obtain biomass methanol, enter the methanol tank area, and conduct laboratory testing; Among them, the biomass gasification process produces gasification wastewater; Ground flushing water is generated in the pre-purification, purification desulfurization, CO conversion and decarbonization workshops and the methanol tank area; Methanol synthesis and methanol distillation processes produce methanol distillation wastewater; Laboratory testing generates laboratory wastewater; Domestic sewage is generated in the front area of ​​the factory.

[0012] Furthermore, in step S1, the oil separation treatment is carried out in a grease separation tank, and the treated oil residue is separately treated in an oil residue storage tank; And / or, the residence time of the gasified wastewater in the grease trap is at least 8 hours.

[0013] Furthermore, the two-stage flotation reaction treatment in step S1 includes cavitation flotation reaction and dissolved air flotation reaction; And / or, demulsifier, PAC and PAM are added to the cavitation flotation reaction, the demulsifier dosage is 90-110 mg / L, the PAC dosage is 90-110 mg / L, and the PAM dosage is 4-6 mg / L.

[0014] And / or, demulsifier, PAC and PAM are added to the dissolved air flotation reaction, the demulsifier dosage is 40~60mg / L, the PAC dosage is 40~60mg / L, and the PAM dosage is 2~4mg / L; And / or, the floating sludge from the cavitation flotation reaction and the dissolved air flotation reaction enters the floating sludge storage tank, and then the sludge is dehydrated and then transported out; Preferably, the two-stage flotation reaction treatment also includes gasification wastewater conditioning; and / or, the gasification wastewater conditioning includes adjusting the wastewater to a neutral pH with a wastewater retention time of at least 48 hours; Preferably, the two-stage flotation reaction treatment further includes an intermediate water tank reaction treatment.

[0015] Furthermore, the ammonia nitrogen content in the wastewater after the deamination reaction treatment in step S1 is reduced to below 200 mg / L; And / or, add a complexing agent during the coagulation and cyanide destruction treatment to ensure that the cyanide content in the effluent is less than 2 mg / L; And / or, the complexing agent is a cyanide complexing agent: And / or, the Fenton pre-oxidation treatment includes adding 98% concentrated sulfuric acid to adjust the pH of the wastewater to 3-4, and then sequentially adding ferrous sulfate and hydrogen peroxide reagents; Preferably, the amount of hydrogen peroxide added is in a ratio of 1:0.8-1.2 to the mass ratio of COD in the wastewater, and the amount of ferrous sulfate added is in a ratio of 1:4.8-5.2 to the mass ratio of ferrous sulfate to hydrogen peroxide.

[0016] Furthermore, the comprehensive treatment method in step S2 includes: comprehensive regulation, hydrolysis and acidification, AO reaction and precipitation, catalytic oxidation, and activated carbon adsorption treatment of the pretreated gasification wastewater and other wastewater; Preferably, the comprehensive regulation is to treat the sewage in a homogeneous and uniform manner; And / or, the hydrolysis acidification treatment includes at least two stages, wherein the wastewater retention time in a single-stage hydrolysis acidification tank is 18-24 hours; Sulfuric acid is added during the hydrolysis and acidification treatment to adjust the pH of the wastewater to 4.5-5.5 and the temperature to 15-30°C; And / or, the wastewater after hydrolysis and acidification treatment flows by gravity into the AO and sedimentation tank, and the AO and sedimentation tank include anoxic zone, aerobic zone, and sedimentation zone; Preferably, the sludge in the sedimentation zone is discharged into the sludge thickening tank via a sludge discharge pump; And / or, the sludge return ratio of the sedimentation zone is 50%-100%, and the sludge in the sedimentation zone enters the anoxic zone and the aerobic zone; The reflux ratio of the nitrifying solution is 200%-400%.

[0017] The air-water ratio in the aerobic zone is 35-45:1, the total residence time in the anoxic and aerobic zones is greater than or equal to 100 hours, and the surface load in the sedimentation zone is 0.4-0.6m 3 / (m 2 h); And / or, sulfuric acid and hydrogen peroxide are added in the catalytic oxidation treatment to adjust the pH of the wastewater to 3.5-4.0, the amount of hydrogen peroxide added is based on the mass ratio of hydrogen peroxide to COD in the wastewater (1.4-1.6):1, NaOH is added in the effluent section to adjust the pH of the wastewater to 7.5-8, and PAM is added to flocculate and precipitate the suspended matter to ensure that the effluent SS is less than 20 mg / L, and the effluent of the catalytic oxidation reaction enters the activated carbon reactor; The activated carbon reactor is provided with activated carbon filler.

[0018] A biomass methanol wastewater treatment device, comprising a gasification wastewater pretreatment device and a comprehensive wastewater treatment device; The gasification wastewater pretreatment device is used to perform oil separation, two-stage flotation reaction treatment, deammoniation reaction treatment, coagulation and cyanide destruction treatment, and Fenton pre-oxidation treatment on the gasification wastewater to obtain pretreated gasification wastewater; The comprehensive sewage treatment device is used to comprehensively treat the pre-treated gasification wastewater and other wastewater, and discharge them after meeting the discharge conditions.

[0019] Furthermore, the gasification wastewater pretreatment device includes a grease trap, a gasification wastewater regulating tank, a vortex flotation device, a dissolved air flotation device, a first intermediate water tank, a deammonification device, a coagulation reaction device, and a Fenton pre-oxidation device, which are arranged in sequence; And / or, the grease trap is connected to the oil residue storage tank, and the oil residue storage tank is connected to the sludge delivery pump through a pipeline; And / or, the bottom of the gasification wastewater regulating tank is connected to the cavitation flotation device via a first lifting pump; And / or, the cavitation flotation device and the dissolved air flotation device are provided with demulsifier, PAC and PAM delivery pipes; And / or, the cavitation flotation device and the dissolved air flotation device are both connected to the floating mud storage tank, the floating mud storage tank is connected to the sludge conveying pump, the sludge conveying pump is connected to the sludge dewatering device, and the sludge treated by the sludge dewatering device is transported out.

[0020] And / or, the first intermediate water tank is connected to the deammonification device via a second lift pump.

[0021] And / or, a complexing agent delivery pipe is provided on the coagulation reaction device.

[0022] Furthermore, the comprehensive sewage treatment device includes a comprehensive regulating 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 which are arranged in sequence.

[0023] Furthermore, the hydrolysis acidification tank, the AO and sedimentation tank, and the catalytic oxidation tank are connected to the sludge thickening tank through 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 out; And / or, the comprehensive regulating tank is connected to the hydrolysis acidification tank via a third lift pump; And / or, the second intermediate water tank is connected to the catalytic oxidation tank via a fourth lift pump; And / or, the catalytic oxidation tank is connected to the activated carbon reactor, the activated carbon reactor is connected to the external drainage tank, 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; And / or, the external drainage tank is connected to the integrated regulating tank via a fifth lifting pump.

[0024] Compared with the prior art, the biomass methanol wastewater treatment process and device described in the present invention has the following advantages: The biomass methanol wastewater treatment process and device of the present invention adopts a classification and quality-based treatment process to pretreat the high-concentration gasification wastewater that is difficult to treat in the methanol wastewater, effectively reducing the oil content, ammonia nitrogen content, cyanide content and difficult-to-degrade organic pollutant content in the wastewater, so that the biological toxicity and biodegradability of the gasification wastewater are effectively improved, creating favorable conditions for subsequent comprehensive wastewater biochemical treatment.

[0025] The pre-treated gasification wastewater, methanol distillation wastewater, ground washing water, laboratory wastewater and domestic sewage are all biodegradable wastewater, so the traditional biochemical process can effectively remove most of the pollutants in the wastewater, reducing the construction cost and operation cost of comprehensive sewage treatment. At the same time, the biological method can completely remove pollutants such as COD, nitrogen and phosphorus in the sewage, and achieve efficient treatment of pollutants in the sewage. The small amount of difficult-to-degrade macromolecular pollutants remaining in the biochemical treatment process are protected by advanced oxidation treatment technology to effectively ensure that the effluent fully and stably meets the petrochemical industry pollutant emission standards (GB31571-2015).

[0026] The use of this process device can comprehensively solve the problem of biomass methanol wastewater treatment, so that the effluent meets the petrochemical industry pollutant emission standards (GB31571-2015), saving about 20%-30% in construction costs and about 10%-20% in operating costs compared with other devices. At the same time, it has the characteristics of stable operation and high degree of automation. In addition, the various devices used in the present invention cannot meet the wastewater treatment requirements when used alone, and can only meet the petrochemical industry pollutant emission standards (GB31571-2015) after being combined and used in a specific order of this process device. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the accompanying drawings: Figure 1 It is a schematic diagram of a biomass methanol wastewater treatment gasification wastewater pretreatment device according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the biomass methanol wastewater treatment structure according to an embodiment of the present invention; Figure 3 This is a flow chart of the production and pollution generation of the substance methanol described in an embodiment of the present invention; Figure 4 This is a flow chart of the wastewater treatment process for the production of methanol as described in an embodiment of the present invention.

[0028] Description of reference numerals: 1. Grease trap; 2. Gasification wastewater regulating tank; 3. Vortex flotation device; 4. Dissolved air flotation device; 5. First intermediate water tank; 6. Deammonification device; 7. Coagulation reaction tank; 8. Fenton pre-oxidation device; 9. Comprehensive regulating 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 DESCRIPTION

[0029] It should be noted that, in the absence of conflict, the embodiments of the present invention and the features in the embodiments may be combined with each other.

[0030] The present invention will be described in detail below with reference to the accompanying drawings and in conjunction with embodiments.

[0031] Example 1 The production process of biomass methanol in this embodiment includes biomass gasification, pre-purification, purification and desulfurization, CO conversion, decarbonization, methanol synthesis, methanol distillation and other processes; the wastewater generated in the production process consists of gasification wastewater W1, methanol distillation wastewater W2, floor cleaning wastewater W3, laboratory test wastewater W4 and domestic sewage W5, etc. The wastewater in this embodiment adopts a comprehensive treatment process of gasification wastewater pretreatment-gasification wastewater pretreatment effluent mixed with other sewage.

[0032] This embodiment provides a biomass methanol wastewater treatment process, comprising the following steps: 1) The gasification wastewater W1 has the characteristics of high tar content, high ammonia nitrogen content, high cyanide content, large fluctuations in water quality and quantity, and poor biodegradability. The pretreatment method of oil separation-two-stage flotation-deammoniation-coagulation and cyanide destruction-Fenton pre-oxidation is adopted to remove oil, deammonify and destroy cyanide from the gasification wastewater, reduce the toxicity of the gasification wastewater, and improve the biodegradability of the gasification wastewater.

[0033] The pre-treatment effluent of gasification wastewater is mixed with methanol distillation wastewater W2, floor cleaning wastewater W3, laboratory test wastewater W4 and domestic sewage W5 and enters the comprehensive regulating tank for comprehensive treatment. The process of the comprehensive sewage treatment device is hydrolysis acidification-AO and precipitation-catalytic oxidation-activated carbon filtration.

[0034] The oil residue produced by oil separation in the pretreatment unit is collected and recycled separately; the floating sludge produced by flotation in the pretreatment unit is collected, dehydrated and transported away separately; the discharged sludge from the hydrolysis acidification tank, AO and sedimentation tank, and photocatalytic oxidation tank enters the sludge thickening tank, and after being treated by the sludge dehydration device, it is transported away for centralized treatment and disposal.

[0035] In the biomass methanol wastewater treatment process and device described in this embodiment, the wastewater generated in the production process needs to be classified and treated according to quality. The high-difficulty gasification wastewater adopts the treatment method of oil separation-flotation-ammonia evaporation-cyanide destruction-Fenton pre-oxidation to effectively solve the problems of high oil content, high ammonia nitrogen and cyanide toxicity. The effluent of the pre-treated gasification wastewater is mixed with other wastewater for comprehensive treatment. The hydrolysis acidification-AO and precipitation-catalytic oxidation-activated carbon adsorption treatment processes are adopted, which can effectively reduce the total cost and ensure that the effluent fully and stably meets the petrochemical industry pollutant emission standards (GB31571-2015).

[0036] In the biomass methanol production in step 1), oxygen and water vapor are used as gasifying agents to react with biomass to produce a gasification reaction, and the biomass gasification green methanol process is completed through processes such as washing and decoking, rough desulfurization, TSA temperature swing adsorption purification, fine desulfurization, CO conversion, MDEA decarbonization, methanol synthesis, and methanol distillation.

[0037] In the production of biomass methanol, different process sections produce different types of wastewater. The biomass gasification section mainly produces gasification wastewater W1, the methanol distillation section mainly produces methanol distillation wastewater W2, the floor washing of each device area and tank area produces floor washing water W3, the laboratory produces laboratory test wastewater W4, and the front-of-plant employees produce domestic sewage W5, etc. In view of different wastewaters, characteristic pollutants and different treatment difficulties, the wastewater of this device adopts a comprehensive treatment process of gasification wastewater pretreatment-gasification wastewater pretreatment effluent mixed with other sewage.

[0038] In the pretreatment of gasification wastewater, the 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 flotation-deamination-complexing agent cyanide destruction is adopted to carry out oil separation pretreatment on the wastewater to reduce the tar content, ammonia nitrogen content, and cyanide toxicity, and improve the biodegradability of the gasification wastewater. The effluent can be mixed with other sewage for comprehensive treatment.

[0039] In the comprehensive sewage treatment, the effluent from the pretreatment of gasification wastewater is mixed with methanol distillation wastewater W2, ground washing water W3, laboratory test wastewater W4 and domestic sewage W5 and enters the comprehensive regulating tank for comprehensive treatment. The comprehensive sewage treatment adopts biochemical treatment as the main process, and adopts a combined process of hydrolysis acidification-AO and precipitation-photocatalytic oxidation-activated carbon adsorption to ensure that the effluent can stably meet the petrochemical industry pollutant emission standards (GB31571-2015).

[0040] The floating scum produced by oil separation in the pretreatment of gasification wastewater is collected separately and recycled for use in the front-end process section; the oily sludge produced by flotation in the pretreatment of gasification wastewater is collected separately, dehydrated and transported out for disposal; the sludge discharged from the hydrolysis acidification tank, AO and sedimentation tank, and photocatalytic oxidation tank enters the sludge thickening tank, and after being treated by the sludge dehydration device, it is transported out for centralized treatment and disposal.

[0041] A biomass methanol wastewater treatment process comprises the following steps: S1: After biomass methanol production, gasification wastewater, ground washing water, methanol distillation wastewater, laboratory wastewater, and domestic sewage are generated. The gasification wastewater is subjected to oil separation, two-stage flotation reaction, deammoniation reaction, coagulation and cyanide destruction, and Fenton pre-oxidation treatment to obtain pretreated gasification wastewater; S2: Comprehensively regulate the ground washing water, methanol distillation wastewater, laboratory wastewater, domestic sewage and pre-treated gasification wastewater, including hydrolysis and acidification, AO reaction and precipitation, photocatalytic oxidation and activated carbon adsorption, and discharge them after meeting the discharge conditions.

[0042] like Figure 3 As shown, the preparation of biomass methanol in step S1 includes biomass raw material transportation and air separation for biomass gasification, pre-purification, purification desulfurization, CO conversion and decarbonization, methanol synthesis and methanol distillation to obtain biomass methanol, which is temporarily stored in the methanol tank area and subjected to laboratory testing in front of the plant area; gasification wastewater is generated in the biomass gasification process; ground flushing water is generated in the pre-purification, purification desulfurization, CO conversion and decarbonization workshops and the methanol tank area; methanol synthesis and methanol distillation processes generate methanol distillation wastewater; the laboratory generates laboratory wastewater; and domestic sewage is generated in the front area of ​​the plant.

[0043] The oil residue after the oil separation treatment in step S1 is treated separately in an oil residue storage tank; the residence time of the wastewater in the oil separation is at least 8 hours.

[0044] like Figure 4 As shown, the two-stage flotation reaction in step S1 includes sequentially performing gasification wastewater adjustment, cavitation flotation reaction, dissolved air flotation reaction, and intermediate water pool reaction; the gasification wastewater adjustment adjusts the wastewater to a neutral pH, and the wastewater retention time is at least 48 hours; demulsifier, PAC and PAM are added to the cavitation flotation reaction, the demulsifier dosage is 90-110 mg / L, the PAC dosage is 90-110 mg / L, and the PAM dosage is 4-6 mg / L.

[0045] Demulsifier, PAC and PAM are added to the dissolved air flotation reaction, with a demulsifier dosage of 50 mg / L, a PAC dosage of 50 mg / L, and a PAM dosage of 3 mg / L; the floating sludge from the cavitation flotation reaction and the dissolved air flotation reaction enters the floating sludge storage tank and the sludge is dehydrated in turn, and then the sludge is transported out.

[0046] In step S1, after the wastewater is deaminated by deamination reaction, the ammonia nitrogen content of the effluent can be reduced to less than 200 mg / L; a complexing agent is added in the coagulation and cyanide breaking reaction to ensure that the HCN content of the effluent is less than 2 mg / L; the type of the complexing agent is a cyanide complexing agent: the acid is adjusted to a pH of 3-4 in the Fenton pre-oxidation treatment, and ferrous sulfate and hydrogen peroxide are added in sequence, the amount of hydrogen peroxide added is according to the mass ratio of hydrogen peroxide to COD of 1:0.8-1.2, and the amount of ferrous sulfate added is according to the mass ratio of ferrous sulfate to hydrogen peroxide of 1:4.8-5.2.

[0047] The comprehensive adjustment in step S2 is to treat the sewage in a homogenous and uniform manner; the hydrolysis and acidification reaction in step S2 includes two stages, the wastewater retention time in the single-stage hydrolysis and acidification tank 10 is 24 hours, and the two stages are 48 hours in total; The wastewater after the hydrolysis and acidification reaction treatment flows by gravity into the AO reaction and sedimentation tank, which includes an anoxic zone, an aerobic zone, and a sedimentation tank. The sludge in the sedimentation tank is discharged to the sludge thickening tank 16 through a sludge discharge pump; The sludge return ratio of the AO pool is 50%-100%, the mixed liquor return ratio is 200%-400%, the air-water ratio of the aerobic zone is 40:1, the total residence time of the anoxic zone and the aerobic zone is 100 hours, and the surface load of the sedimentation tank is 0.5m3 / m2.h; sulfuric acid and hydrogen peroxide are added to the photocatalytic oxidation reaction to adjust the pH of the wastewater to 3.5-4.0, the amount of hydrogen peroxide added is added according to the mass ratio of hydrogen peroxide to COD of 1.5:1, PAM is added to the effluent section to flocculate and precipitate the suspended matter to ensure that the effluent SS is less than 20mg / l, the effluent of the photocatalytic oxidation reaction enters the activated carbon reactor, and the photocatalytic oxidation reaction discharges the sludge into the sludge thickening tank 16 for reaction through the first sludge pump; activated carbon filler is provided in the activated carbon reactor 14.

[0048] Example 2 The biomass methanol wastewater treatment device of the present invention comprises two parts: a gasification wastewater pretreatment device and a comprehensive wastewater treatment device.

[0049] The gasification wastewater pretreatment device comprises a grease trap 1, a gasification wastewater regulating tank 2, a vortex flotation device 3, a dissolved air flotation device 4, a first intermediate water tank 5, a deammonification device 6, a coagulation reaction tank 7, and a Fenton pre-oxidation device 8. The grease trap 1, the gasification wastewater regulating tank 2, the vortex flotation device 3, the dissolved air flotation device 4, the first intermediate water tank 5, the deammonification device 6, the coagulation reaction tank 7, and the Fenton pre-oxidation device 8 are sequentially connected via pipelines.

[0050] The comprehensive sewage treatment device includes a comprehensive regulating 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. The comprehensive regulating tank 9, the hydrolysis acidification tank 10, the AO and sedimentation tank 11, the second intermediate water tank 12, the photocatalytic oxidation tank 13, and the activated carbon reactor 14 are connected in sequence.

[0051] It includes a first lift pump P1 connected to the water inlet of the vortex flotation device 3 through a pipeline, a second lift pump P2 connected to the water inlet of the deammonification device 6 through a pipeline, a third lift pump P5 connected to the water inlet of the hydrolysis acidification device 10 through a pipeline, a fourth lift pump P6 connected to the photocatalytic oxidation tank 13 through a pipeline, a fifth lift pump P7 connected to the external drainage tank through a pipeline, and a sludge pump connected to the hydrolysis acidification tank 10, AO and sedimentation tank 11, and photocatalytic oxidation tank 13 through a pipeline.

[0052] It also includes a sludge conveying pump P3 connected to the outlet of the oil residue storage tank V1 via a pipeline, a floating mud conveying pump P4 connected to the outlet of the floating mud storage tank device via a pipeline, and a sludge dewatering device connected to the floating mud storage tank via the conveying pump.

[0053] It also includes a sludge concentration tank 16 connected to the hydrolysis acidification tank 10, the AO and sedimentation tank 11, and the photocatalytic oxidation tank 13 through a pipeline and a first sludge pump P8, and a sludge dehydration device connected to the sludge concentration tank 16 through a second sludge pump P9.

[0054] Example 3 This embodiment adopts the process in Example 1 and the device in Example 2. Industrial wastewater enters the grease trap 1 through pressure flow, and oil and water are separated in the grease trap 1. After separation, the wastewater flows into the gasification wastewater regulating tank 2 by gravity. The floating oil after oil and water separation in the grease trap 1 enters the oil residue storage tank V1, and the oil residue is sent out for recycling and treatment through the sludge delivery pump P3. The wastewater retention time in the grease trap 1 is 8 hours.

[0055] The gasification wastewater regulating tank 2 is used to regulate the amount of wastewater and the quality of wastewater. The wastewater retention time in the gasification wastewater regulating tank 2 is 48 hours. The effluent from the gasification wastewater regulating tank is sent to the cavitation flotation device 3 via the lifting pump P1.

[0056] Demulsifier, PAC and PAM are added to the vortex flotation device 3 to demulsify and flocculate the wastewater to remove the remaining emulsified oil and a large amount of suspended matter in the wastewater. The demulsifier dosage is 100 mg / L, the PAC dosage is 100 mg / L, and the PAM dosage is 5 mg / L. The effluent of the vortex flotation device 3 enters the dissolved air flotation device 4 by gravity, and the sludge produced by the vortex flotation device 3 enters the sludge storage tank V2. The sludge is transported to the sludge dehydration reaction device X1 through the sludge delivery pump P4 for dehydration and external disposal.

[0057] Demulsifier, PAC and PAM are added to the dissolved air flotation device 4 to perform secondary demulsification and flocculation precipitation reactions on the wastewater to remove the remaining small amount of emulsified oil and a small amount of suspended matter in the wastewater. 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 of the device 3 and the device 4, the oil content can be reduced to below 45 mg / L. The effluent of the dissolved air flotation device 4 enters the first intermediate water tank 5 by gravity, and the sludge produced by the dissolved air flotation device 4 enters the sludge storage tank V2. The sludge is transported to the sludge dehydration reaction device X1 through the sludge delivery pump P4 for dehydration and then transported for disposal.

[0058] The first intermediate water tank 5 is a wastewater lifting tank, and a lifting pump P2 is arranged outside the tank to lift the wastewater in the first intermediate water tank 5 into the deammonification device 6.

[0059] The deammoniation device 6 performs deammoniation treatment on the wastewater, and the ammonia nitrogen content of the effluent can be reduced to below 200 mg / L after treatment by the device. The effluent of the deammoniation device 6 enters the coagulation reaction tank 7 by gravity.

[0060] A complexing agent is added to the coagulation reaction tank 7 to carry out complexing reaction on cyanide, so as to ensure that the cyanide content of the effluent is less than 2 mg / L. The effluent of the coagulation reaction tank 7 enters the Fenton pre-oxidation device 88 by gravity.

[0061] The Fenton pre-oxidation device 8 is used to adjust the acid to a pH of about 3.5, and ferrous sulfate, hydrogen peroxide and other agents are added in sequence. The amount of hydrogen peroxide added is in a ratio of 1:1 to COD, and the amount of ferrous sulfate added is in a ratio of 1:5 to ferrous sulfate to hydrogen peroxide. The macromolecular organic matter that is difficult to degrade is subjected to ring-opening and chain-breaking advanced oxidation treatment to improve the biodegradability of the wastewater. Then, neutralization, degassing and flocculation precipitation reactions are carried out. The effluent of the Fenton pre-oxidation device 8 enters the comprehensive regulating tank 9 by gravity.

[0062] like Figure 2 The comprehensive sewage treatment device shown comprises a comprehensive regulating tank 9, a hydrolysis acidification tank 10, an AO and sedimentation tank 11, an intermediate water tank reaction device 12, a photocatalytic oxidation tank 13, an activated carbon reactor 14, and an external drainage tank 15. It is characterized in that the comprehensive regulating tank 9, the hydrolysis acidification tank 10, the AO and sedimentation tank 11, the intermediate water tank reaction device, the photocatalytic oxidation tank 13, the activated carbon reactor 14, and the external drainage tank 15 are sequentially connected through pipelines.

[0063] The effluent from the gasification wastewater pretreatment device, methanol distillation wastewater W2, ground flushing water W3, laboratory wastewater W4, and domestic sewage W5 all enter the comprehensive regulating tank 9, and are homogenized and treated in the comprehensive regulating tank 9. The effluent from the comprehensive regulating tank 9 is lifted by the lifting pump P5 and enters the hydrolysis acidification reaction device 10. The wastewater retention time in the comprehensive regulating tank 9 is 24 hours.

[0064] The wastewater in the hydrolysis acidification tank 10 is decomposed into easily degradable small molecules by the biological hydrolysis of anaerobic microorganisms, thereby improving the biodegradability of industrial wastewater. A sludge discharge pipeline is connected to the end of the hydrolysis acidification tank, and the sludge is discharged into the sludge concentration tank 16 through the sludge pump P8. The hydrolysis acidification tank 10 is set up in two stages. The wastewater retention time of the single-stage hydrolysis acidification tank is 24 hours, and the two-stage hydrolysis acidification tank has a total retention time of 48 hours. Fillers are set in the tank.

[0065] 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. In this process, BOD5, SS and nitrogen and phosphorus in various forms will be removed in large quantities. The hydrolysis acidification treatment includes at least two stages, wherein the wastewater retention time in the single-stage hydrolysis acidification tank 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°C.

[0066] The sludge in the sedimentation tank is discharged to the sludge thickening tank 16 through the first sludge discharge pump P8. The sludge return ratio of the AO tank is 50%-100%, the nitrification liquid return ratio is 200%-400%, the gas-water ratio of the O tank is 40:1, the total residence time of the AO tank is 100 hours, and the surface load of the sedimentation tank is 0.5m 3 / (m 2 h).

[0067] The effluent from the AO and the 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 arranged outside the tank to lift the wastewater from the intermediate water tank 1 reaction device 5 into the photocatalytic oxidation reaction device 13.

[0068] Sulfuric acid and hydrogen peroxide are added to the photocatalytic oxidation reaction device 13 to adjust the pH of the wastewater to about 4. The amount of hydrogen peroxide added is based on a mass ratio of hydrogen peroxide to COD of 1.5:1. NaQH is added to the effluent section to adjust the pH of the wastewater to 7.5-8, and PAM is added to perform flocculation and precipitation reaction on the suspended matter to ensure that the effluent SS is less than 20 mg / L. The effluent of the photocatalytic oxidation reaction device 13 enters the activated carbon reactor 14. The photocatalytic oxidation reaction 13 discharges the sludge into the sludge thickening tank 16 through the first sludge pump 8.

[0069] The activated carbon reactor 14 is provided with activated carbon filler to further adsorb and remove the refractory organic pollutants, and serves as a safety measure for the entire process device to ensure that the pollutants in the external drainage pool 15 meet the discharge requirements.

[0070] The external drainage pool 15 is a temporary storage pool for clean water. Online monitoring facilities are arranged outside the pool to carry out real-time water quality monitoring of the sewage in the external drainage pool 15. The qualified drainage is lifted and discharged to the outside by the external lifting pump P7, and the unqualified drainage is lifted and discharged to the comprehensive regulating pool 9 by the external lifting pump P7 for reprocessing.

[0071] The sludge thickening tank 16 transports the concentrated sludge to the sludge dehydration reaction device X2 through the sludge delivery pump P9 for dehydration and external transportation. According to the needs of sludge dehydration, PAM can be added to improve the dehydration performance of the sludge. The effluent of the sludge dehydration reaction device X2 is returned to the front-end comprehensive regulating tank 9 for treatment.

[0072] Using the implementation method described in this embodiment, the water quality of the gasification wastewater inlet and outlet water can be found in the gasification wastewater inlet and outlet water quality table, and the water quality of the comprehensive wastewater inlet and outlet water can be found in the comprehensive wastewater inlet and outlet water quality table.

[0073] Table 1 Water quality of gasification wastewater inlet and outlet project COD (mg / L) BOD5 (mg / L) SS (mg / L) <![CDATA[NH3-N(mg / L)]]> TN (mg / L) TP (mg / L) Petroleum (mg / L) pH Influent water quality 4000 600 80 2500 3000 9 1000 6~9 Water quality after pretreatment 1200 400 30 200 220 4.5 45 6~9 Table 2 Comprehensive wastewater inlet and outlet water quality table The above data show that after biomass methanol wastewater is treated by the process and device of the present invention, the effluent from the production wastewater can stably meet the petrochemical industry pollutant emission standards (GB31571-2015), effectively solving the current problem of biomass methanol wastewater treatment, and has a very broad application market and guiding significance for biomass methanol wastewater treatment.

[0074] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A biomass methanol wastewater treatment process, characterized in that: The method comprises the following steps: S1: wastewater is generated during the production of biomass methanol, and the wastewater includes gasification wastewater and other wastewater; the other wastewater includes ground washing water, methanol distillation wastewater, laboratory wastewater, and domestic sewage; The gasification wastewater is subjected to oil separation, two-stage flotation reaction treatment, deammoniation reaction treatment, coagulation and cyanide destruction treatment, and Fenton pre-oxidation treatment to obtain pretreated gasification wastewater; S2: Comprehensively treat the pre-treated gasification wastewater and other wastewater, and discharge them after meeting the discharge conditions.

2. A biomass methanol wastewater treatment process according to claim 1, characterized in that: The production process of biomass methanol in step S1 includes biomass raw material transportation and air separation, biomass gasification, pre-purification, purification and desulfurization, CO conversion and decarbonization, methanol synthesis and methanol distillation to obtain biomass methanol, enter the methanol tank area, and conduct laboratory testing; Among them, the biomass gasification process produces gasification wastewater; Ground flushing water is generated in the pre-purification, purification desulfurization, CO conversion and decarbonization workshops and the methanol tank area; Methanol synthesis and methanol distillation processes produce methanol distillation wastewater; Laboratory testing generates laboratory wastewater; Domestic sewage is generated in the front area of ​​the factory.

3. A biomass methanol wastewater treatment process according to claim 1, characterized in that: In step S1, the oil separation treatment is carried out in the oil separation tank, and the treated oil residue is separately processed in the oil residue storage tank; And / or, the residence time of the gasified wastewater in the grease trap is at least 8 hours.

4. A biomass methanol wastewater treatment process according to claim 1, characterized in that: The two-stage flotation reaction treatment in step S1 includes cavitation flotation reaction and dissolved air flotation reaction; And / or, demulsifier, PAC and PAM are added to the cavitation flotation reaction, the demulsifier dosage is 90-110 mg / L, the PAC dosage is 90-110 mg / L, and the PAM dosage is 4-6 mg / L; And / or, demulsifier, PAC and PAM are added to the dissolved air flotation reaction, the demulsifier dosage is 40~60mg / L, the PAC dosage is 40~60mg / L, and the PAM dosage is 2~4mg / L; And / or, the floating sludge from the cavitation flotation reaction and the dissolved air flotation reaction enters the floating sludge storage tank, and then the sludge is dehydrated and then transported out; Preferably, the two-stage flotation reaction treatment also includes gasification wastewater conditioning; and / or, the gasification wastewater conditioning includes adjusting the wastewater to a neutral pH with a wastewater retention time of at least 48 hours; Preferably, the two-stage flotation reaction treatment further includes an intermediate water tank reaction treatment.

5. A biomass methanol wastewater treatment process according to claim 1, characterized in that: After the deamination reaction treatment in step S1, the ammonia nitrogen content in the wastewater is reduced to below 200 mg / L; And / or, add a complexing agent during the coagulation and cyanide destruction treatment to ensure that the cyanide content in the effluent is less than 2 mg / L; And / or, the complexing agent is a cyanide complexing agent: And / or, the Fenton pre-oxidation treatment includes adding sulfuric acid to adjust the pH of the wastewater to 3-4, and then sequentially adding ferrous sulfate and hydrogen peroxide reagents; Preferably, the amount of hydrogen peroxide added is in a ratio of 1:0.8-1.2 to the mass ratio of COD in the wastewater, and the amount of ferrous sulfate added is in a ratio of 1:4.8-5.2 to the mass ratio of ferrous sulfate to hydrogen peroxide.

6. A biomass methanol wastewater treatment process according to claim 1, characterized in that: The comprehensive treatment method in step S2 includes: comprehensive regulation, hydrolysis and acidification, AO reaction and precipitation, catalytic oxidation, and activated carbon adsorption treatment of the pretreated gasification wastewater and other wastewater; Preferably, the comprehensive regulation is to treat the sewage in a homogeneous and uniform manner; And / or, the hydrolysis acidification treatment includes at least two stages, wherein the wastewater retention time in a single-stage hydrolysis acidification tank is 18-24 hours; Sulfuric acid is added during the hydrolysis and acidification treatment to adjust the pH of the wastewater to 4.5-5.5 and the temperature to 15-30°C; And / or, the wastewater after hydrolysis and acidification treatment flows by gravity into the AO and sedimentation tank, and the AO and sedimentation tank include anoxic zone, aerobic zone, and sedimentation zone; Preferably, the sludge in the sedimentation zone is discharged into the sludge thickening tank via a sludge discharge pump; And / or, the sludge return ratio of the sedimentation zone is 50%-100%, and the sludge in the sedimentation zone enters the anoxic zone and the aerobic zone; The reflux ratio of the nitrification solution is 200%-400%; The air-water ratio in the aerobic zone is 35-45:1, the total residence time in the anoxic and aerobic zones is greater than or equal to 100 hours, and the surface load in the sedimentation zone is 0.4-0.6m 3 / (m 2 h); And / or, sulfuric acid and hydrogen peroxide are added in the catalytic oxidation treatment to adjust the pH of the wastewater to 3.5-4.0, the amount of hydrogen peroxide added is based on the mass ratio of hydrogen peroxide to COD in the wastewater (1.4-1.6):1, NaOH is added in the effluent section to adjust the pH of the wastewater to 7.5-8, and PAM is added to flocculate and precipitate the suspended matter to ensure that the effluent SS is less than 20 mg / L, and the effluent of the catalytic oxidation reaction enters the activated carbon reactor; The activated carbon reactor is provided with activated carbon filler.

7. A biomass methanol wastewater treatment device, characterized in that: It includes gasification wastewater pretreatment device and comprehensive sewage treatment device; The gasification wastewater pretreatment device is used to perform oil separation, two-stage flotation reaction treatment, deammoniation reaction treatment, coagulation and cyanide destruction treatment, and Fenton pre-oxidation treatment on the gasification wastewater to obtain pretreated gasification wastewater; The comprehensive sewage treatment device is used to comprehensively treat the pre-treated gasification wastewater and other wastewater, and discharge them after meeting the discharge conditions.

8. The device according to claim 7, characterized in that: The gasification wastewater pretreatment device includes a grease trap, a gasification wastewater regulating tank, a vortex flotation device, a dissolved air flotation device, a first intermediate water tank, a deammonification device, a coagulation reaction device, and a Fenton pre-oxidation device, which are arranged in sequence; And / or, the grease trap is connected to the oil residue storage tank, and the oil residue storage tank is connected to the sludge delivery pump through a pipeline; And / or, the bottom of the gasification wastewater regulating tank is connected to the cavitation flotation device via a first lifting pump; And / or, the cavitation flotation device and the dissolved air flotation device are provided with demulsifier, PAC and PAM delivery pipes; And / or, the cavitation flotation device and the dissolved air flotation device are both connected to a floating mud storage tank, the floating mud storage tank is connected to a sludge delivery pump, the sludge delivery pump is connected to a sludge dewatering device, and the sludge treated by the sludge dewatering device is transported out; And / or, the first intermediate water tank is connected to the deammonification device via a second lift pump; And / or, a complexing agent delivery pipe is provided on the coagulation reaction device.

9. The device according to claim 7, characterized in that: The comprehensive sewage treatment device includes a comprehensive regulating 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 which are arranged in sequence.

10. The device according to claim 7, characterized in that: The hydrolysis acidification tank, AO and sedimentation tank, and catalytic oxidation tank are connected to the sludge thickening tank through the second sludge pump, and the sludge thickening tank is connected to the dewatering device, and the sludge treated by the sludge dewatering device is transported out; And / or, the comprehensive regulating tank is connected to the hydrolysis acidification tank via a third lift pump; And / or, the second intermediate water tank is connected to the catalytic oxidation tank via a fourth lift pump; And / or, the catalytic oxidation tank is connected to the activated carbon reactor, the activated carbon reactor is connected to the external drainage tank, 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; And / or, the external drainage tank is connected to the integrated regulating tank via a fifth lifting pump.

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