White spirit wastewater treatment method

Abstract

The invention relates to a white spirit wastewater treatment method, and belongs to the technical field of wastewater treatment. According to the white spirit wastewater treatment method disclosed by the invention, by combining a pretreatment process, a biological treatment process and an advanced treatment process, pollutants in water can be effectively removed, and various indexes of effluent are ensured to stably reach the standard; according to the method, the anaerobic process is taken as a core, and the iron-carbon micro-electrolysis and oxidation reflux processes are combined, so that refractory organic matters which cannot be removed by the original anaerobic process can be effectively removed, the biological treatment load of the system is reduced, the biodegradability of the subsequent wastewater is improved, and the treatment benefit of the wastewater is further improved.

Description

Technical Field

[0001] The invention relates to the technical field of wastewater treatment, and in particular to a method for treating liquor wastewater. Background Art

[0002] The wastewater generated during the production of liquor has the characteristics of large discharge volume, strong volatility, high organic matter concentration, complex water quality, high nitrogen and phosphorus content, and high chroma, which leads to complicated treatment process, high operating cost, and the effluent quality cannot stably meet the discharge requirements. At present, the "physical and chemical pretreatment + anaerobic + aerobic" method is generally used to treat liquor wastewater. This treatment method not only has a high load in the anaerobic and aerobic treatment stages, but also cannot effectively remove the large molecules and difficult-to-degrade organic matter in the liquor wastewater, such as long-chain proteins, fibers, starch, etc., resulting in the effluent quality cannot stably meet the standards, and the effluent needs to be deeply treated. Common methods for deep treatment of difficult-to-degrade organic matter include ozone, Fenton and other advanced oxidation methods, which make the treatment cost high. Summary of the invention

[0003] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a method for treating liquor wastewater.

[0004] To achieve the above object, the technical solution adopted by the present invention is:

[0005] A method for treating liquor wastewater comprises the following steps:

[0006] S1, pre-treating liquor wastewater to obtain pre-treated effluent;

[0007] S2, the pre-treated effluent enters the IC anaerobic reactor for anaerobic reaction; the effluent of the anaerobic reactor enters the anaerobic sedimentation tank for mud and water separation, part of the wastewater after mud and water separation is used as anaerobic sedimentation effluent, and the other part is used as return water, and the return water is oxidized and then returned to the anaerobic reactor for anaerobic reaction;

[0008] S3, the anaerobic precipitation effluent enters the A / O reactor for biological denitrification treatment to obtain biological denitrification effluent;

[0009] S4, subjecting the biological denitrification effluent to physicochemical precipitation treatment to obtain physicochemical precipitation effluent;

[0010] S5. The effluent from the physicochemical precipitation enters the denitrification filter tank for denitrification treatment to obtain denitrified effluent.

[0011] As a preferred embodiment of the present invention, step S1 includes:

[0012] S11, filtering and treating the liquor wastewater;

[0013] S12, adjusting the water quality and quantity of the liquor wastewater filtered in step S11;

[0014] S13, adding an inorganic base to the liquor wastewater adjusted in step S12, adjusting the pH value of the wastewater to 7-9, adding a coagulant, a flocculant and a hardness remover, mixing and reacting, and then allowing to settle;

[0015] S14. The liquor wastewater treated in step S13 enters an iron-carbon micro-electrolysis cell for iron-carbon micro-electrolysis treatment to obtain pretreated effluent.

[0016] In step S11, the liquor wastewater is wastewater generated in the liquor brewing process, and the chemical oxygen demand (COD) of the liquor wastewater is not less than 5000 mg / L, the total nitrogen content is not less than 200 mg / L, the total phosphorus content is not less than 40 mg / L, and the suspended solids content (Suspended Solids) is not less than 300 mg / L.

[0017] Furthermore, in step S13, the inorganic base is at least one of sodium hydroxide and quicklime.

[0018] Furthermore, in step S13, the coagulant includes at least one of polyaluminium chloride and polyferric sulfate, and the mass concentration of the coagulant in the liquor wastewater after filtering in step S11 is 100-300 ppm. The coagulant aggregates the suspended particles in the water to form flocs through charge neutralization, adsorption, bridging and other effects.

[0019] Furthermore, in step S13, the flocculant includes polyacrylamide, and the mass concentration of the flocculant in the liquor wastewater after filtering in step S11 is 2-10 ppm. The flocculant can aggregate the fine flocs in the wastewater into larger particles, thereby facilitating subsequent precipitation.

[0020] Furthermore, in step S13, the mass concentration of the de-hardening agent in the liquor wastewater after filtering in step S11 is 50-100 ppm, and the de-hardening agent is used to reduce the hardness of the wastewater.

[0021] Furthermore, in step S14, the iron-carbon micro-electrolysis treatment time is 1 to 3 hours, the iron-carbon micro-electrolysis cell is filled with micro-electrolysis filler, the ratio between the mass of the micro-electrolysis filler and the volume of the wastewater in the iron-carbon micro-electrolysis cell is (20 to 100) g: 1L, and the micro-electrolysis filler includes iron and carbon, and the mass ratio of iron to carbon is (0.5 to 4): 1. In the absence of electricity, due to the electrode potential difference between iron and carbon, iron particles and carbon particles will form countless tiny primary cells in the wastewater. These primary cells use low-potential iron as the anode and high-potential carbon as the cathode, and electrochemical reactions occur in the wastewater, producing a large amount of Fe2+, H2 O 2 , hydroxyl radical (·OH), hydrogen radical (·H) and H + These products have extremely high chemical activity and can undergo redox reactions with organic pollutants in wastewater, thereby achieving the purpose of degrading organic pollutants.

[0022] Furthermore, step S14 includes the following steps before entering the iron-carbon micro-electrolysis cell: adjusting the pH value of the liquor wastewater treated in step S13 to 2-4.

[0023] As a preferred embodiment of the present invention, in step S2, the sludge concentration in the anaerobic reactor is 10000-30000 mg / L, the hydraulic retention time of the anaerobic reactor is 6-18 h, and the temperature is 30-35°C.

[0024] As a preferred embodiment of the present invention, the volume ratio between the return water and the anaerobic precipitation effluent (ie, the return ratio) is 0.05 to 0.3.

[0025] The present invention sequentially subjects the pretreated effluent to anaerobic reaction and mud-water separation, wherein a part of the wastewater after the mud-water separation is used as anaerobic precipitation effluent and the other part is used as return water, and the return water is subjected to oxidation treatment and then returned to the anaerobic reactor for anaerobic reaction; organic matter that still cannot be removed during the anaerobic reaction can be removed by oxidation treatment; and the pollutant concentration in the return water after oxidation treatment is very low by reflux, and the return water is combined with the pretreated effluent to enter the anaerobic reactor, thereby achieving a dilution effect, reducing the water inlet load of the anaerobic reactor, and improving the anaerobic reaction efficiency.

[0026] The inventors have found through research that if the reflow ratio is too low, the difficult-to-degrade organic matter cannot be effectively removed. If the reflow ratio is too high, although it will reduce the influent load of the anaerobic process, it is not conducive to the anaerobic reaction.

[0027] Further, if the ratio of chemical oxygen demand between the effluent of the anaerobic reactor and the effluent of the pretreatment is less than 0.4, the volume ratio between the return water and the effluent of the anaerobic precipitation is 0.05 to 0.1;

[0028] If the chemical oxygen demand ratio between the effluent of the anaerobic reactor and the pre-treated effluent is 0.4-0.6, the volume ratio between the return water and the anaerobic precipitation effluent is 0.1-0.2;

[0029] If the ratio of chemical oxygen demand between the effluent of the anaerobic reactor and the pre-treated effluent is greater than 0.6, the volume ratio between the return water and the anaerobic precipitation effluent is 0.2-0.3.

[0030] As a preferred embodiment of the present invention, the oxidation treatment step includes: adding ferrous sulfate and hydrogen peroxide to the reflux water, adding sulfuric acid to adjust the pH value to 3.5-5, and performing Fenton reaction under stirring. The ferrous sulfate accounts for 0.01-0.10% of the mass of the reflux water, and the hydrogen peroxide in the hydrogen peroxide accounts for 0.01-0.10% of the mass of the reflux water.

[0031] As a preferred embodiment of the present invention, in step S3, the A / O reactor includes an anaerobic section and an aerobic section arranged in sequence; the sludge concentration in the anaerobic section is 3000-5000 mg / L, the dissolved oxygen concentration is not more than 0.2 mg / L, the hydraulic retention time is 6-18 hours, and the temperature is 20-35°C;

[0032] The sludge concentration in the aerobic section is 3000-5000 mg / L, the dissolved oxygen concentration is 2-4 mg / L, the hydraulic retention time is 6-18 hours, and the temperature is 20-35°C.

[0033] As a preferred embodiment of the present invention, step S4 comprises: adding a coagulant and a flocculant to the biological denitrification effluent, mixing and reacting, and then standing and settling to obtain a physicochemical precipitation effluent.

[0034] Furthermore, in the biological denitrification effluent, the mass concentration of the coagulant is 80-150 ppm, and the mass concentration of the flocculant is 2-8 ppm.

[0035] By adding coagulants and flocculants again after biological denitrification, the phosphorus removal effect can be enhanced and suspended matter in the wastewater can be further removed.

[0036] As a preferred embodiment of the present invention, when performing denitrification treatment in step S5, a carbon source is added into the denitrification filter to make the carbon-nitrogen ratio in the denitrification filter be (3-5):1.

[0037] Furthermore, the carbon source includes sodium acetate.

[0038] As a preferred embodiment of the present invention, in step S5, a short-range denitrification anaerobic ammonium oxidation biofilm is arranged in the denitrification filter, and the short-range denitrification anaerobic ammonium oxidation biofilm occupies 80-100% of the volume of the reaction zone of the denitrification filter; the hydraulic retention time of the denitrification filter is 2-6 hours, and the temperature is 20-35°C.

[0039] Compared with the prior art, the present invention has the following beneficial effects:

[0040] (1) The liquor wastewater treatment method of the present invention can effectively remove pollutants in the water and ensure that various indicators of the effluent meet the standards by combining the "pretreatment + biological treatment + deep treatment" processes.

[0041] (2) The present invention takes the anaerobic process as the core, and by combining iron-carbon micro-electrolysis and oxidation reflux processes, it can effectively remove the difficult-to-degrade organic matter that cannot be removed by the original anaerobic process, reduce the load of the system's biological treatment, and improve the subsequent biodegradability of wastewater, thereby improving the treatment efficiency of wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] Figure 1 The present invention provides a flow chart of liquor wastewater treatment. DETAILED DESCRIPTION

[0043] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments.

[0044] Example 1

[0045] The embodiment and comparative example of the liquor wastewater treatment method of the present invention are as follows: Figure 1 As shown, the liquor wastewater treatment method comprises the following steps:

[0046] S1, perform steps S11 to S14 in sequence to obtain pre-treated water;

[0047] S11, grid filtering liquor wastewater, the liquor wastewater comes from the wastewater generated in the liquor brewing process of a certain factory, the chemical oxygen demand (COD) of the liquor wastewater is 8616mg / L, the total nitrogen (TN) content is 242mg / L, the ammonia nitrogen (NH 3 -N) content is 184mg / L, total phosphorus (TP) content is 46mg / L, and suspended solids content is 325mg / L;

[0048] S12, inputting the liquor wastewater filtered in step S11 into a regulating tank for water quality and quantity regulation;

[0049] S13, the liquor wastewater after adjustment in step S12 enters the physicochemical sedimentation tank A, sodium hydroxide is added to adjust the pH value of the wastewater to 7-9, coagulant polyaluminium chloride, flocculant polyacrylamide and de-hardening agent are added, mixed and reacted, and then allowed to stand for precipitation; in the wastewater of the physicochemical sedimentation tank A, the mass concentration of the coagulant is 200ppm, the mass concentration of the flocculant is 4ppm, and the mass concentration of the de-hardening agent is 80ppm;

[0050] S14. The liquor wastewater treated in step S13 (i.e., the upper effluent after precipitation in step S13) is adjusted to pH 3 with sulfuric acid solution and then input into an iron-carbon micro-electrolysis cell for iron-carbon micro-electrolysis treatment to obtain pretreated effluent; the iron-carbon micro-electrolysis treatment time is 1.5h, and the iron-carbon micro-electrolysis cell is filled with micro-electrolysis filler, and the ratio between the mass of the micro-electrolysis filler and the volume of the wastewater in the iron-carbon micro-electrolysis cell is 50g:1L, and the micro-electrolysis filler includes iron and carbon, and the mass ratio of iron to carbon is 1:1.

[0051] S2, the pre-treated effluent enters the IC anaerobic reactor for anaerobic reaction; the effluent of the anaerobic reactor enters the anaerobic sedimentation tank for mud and water separation, a part of the wastewater after the mud and water separation is used as anaerobic sedimentation effluent, and the other part is used as return water, the return water is transported to the Fenton tank, ferrous sulfate and hydrogen peroxide are added, sulfuric acid is added to adjust the pH value to 3.5-5, and the Fenton reaction is carried out under stirring conditions, and the effluent of the Fenton tank is transported to the anaerobic reactor for anaerobic reaction; the ferrous sulfate accounts for 0.05% of the mass of the return water, and the hydrogen peroxide in the hydrogen peroxide accounts for 0.05% of the mass of the return water;

[0052] The hydraulic retention time of the IC anaerobic reactor is 10 h, and the temperature is 35° C.; the sludge concentration in the IC anaerobic reactor is 10000 mg / L;

[0053] In step S2, the chemical oxygen demand of the influent of the anaerobic reactor (i.e., the pretreated effluent obtained in step S1) and the effluent of the anaerobic reactor are detected respectively, and the ratio of the chemical oxygen demand between the effluent of the anaerobic reactor and the pretreated effluent (i.e., COD 出水 / COD 进水 ), and according to this ratio, the reflow ratio (i.e., the volume ratio between the reflow water and the anaerobic precipitation effluent) is controlled, as shown in Table 1 below.

[0054] S3, the anaerobic precipitation effluent enters the A / O reactor for biological denitrification treatment to obtain biological denitrification effluent;

[0055] In step S3, the A / O reactor includes an anaerobic section and an aerobic section arranged in sequence; the sludge concentration in the anaerobic section is 3000 mg / L, the dissolved oxygen concentration is not more than 0.2 mg / L, the hydraulic retention time is 12 hours, and the temperature is 25°C;

[0056] The sludge concentration in the aerobic section is 3000 mg / L, the dissolved oxygen concentration is 3 mg / L, the hydraulic retention time is 12 hours, and the temperature is 25°C.

[0057] S4. The effluent from biological denitrification enters the physicochemical sedimentation tank B, and the coagulant polyaluminium chloride and the flocculant polyacrylamide are added. After the mixed reaction, the effluent is allowed to stand and settle to obtain the physicochemical sedimentation effluent. In the wastewater in the physicochemical sedimentation tank B, the mass concentration of the coagulant is 120ppm, and the mass concentration of the flocculant is 2ppm.

[0058] S5, the effluent from the physical and chemical precipitation enters the denitrification filter for denitrification treatment, and at the same time, a carbon source is added to the denitrification filter to make the carbon-nitrogen ratio in the denitrification filter 4:1, and denitrification effluent is obtained; a short-range denitrification anaerobic ammonium oxidation biofilm is arranged in the denitrification filter, and the short-range denitrification anaerobic ammonium oxidation biofilm occupies 80% of the volume of the reaction zone of the denitrification filter; the hydraulic retention time of the denitrification filter is 2h, and the temperature is 25°C;

[0059] The denitrification effluent enters the clean water tank.

[0060] In this embodiment, the precipitates produced in each sedimentation tank and denitrification filter tank can be transported to the sludge concentration tank for concentration treatment, the concentrated precipitates are transported to the filter press for filtration, and the effluent from the filter press is transported to the regulating tank.

[0061] Example 2

[0062] The difference between Example 2 and Example 1 is that in Example 2, in the wastewater of the physicochemical sedimentation tank A, the mass concentration of the coagulant is 300ppm, the mass concentration of the flocculant is 6ppm, and the mass concentration of the de-hardening agent is 80ppm; the time of the iron-carbon micro-electrolysis treatment is 3h, and the iron-carbon micro-electrolysis cell is filled with micro-electrolysis filler, and the ratio between the mass of the micro-electrolysis filler and the volume of the wastewater in the iron-carbon micro-electrolysis cell is 80g:1L, and the micro-electrolysis filler includes iron and carbon, and the mass ratio of iron to carbon is 2:1.

[0063] Comparative Examples 1-2

[0064] The difference between Comparative Examples 1-2 and Example 1 is that the reflux ratios of Comparative Examples 1-2 are as shown in Table 1.

[0065] The water in the clear water tanks of Examples 1-2 and Comparative Examples 1-2 was tested, and the test results are shown in Table 1.

[0066] Table 1

[0067]

[0068] Example 3

[0069] The embodiment of the liquor wastewater treatment method of the present invention has the following process: Figure 1 As shown, the liquor wastewater treatment method comprises the following steps:

[0070] S1, perform steps S11 to S14 in sequence to obtain pre-treated water;

[0071] S11, grid filtering the liquor wastewater, the liquor wastewater comes from the wastewater generated in the liquor brewing process of a certain factory, the chemical oxygen demand (COD) of the liquor wastewater is 12480 mg / L, the total nitrogen (TN) content is 300 mg / L, the ammonia nitrogen (NH 3 -N) content is 254mg / L, total phosphorus (TP) content is 71mg / L, and suspended solids content is 421mg / L;

[0072] S12, inputting the liquor wastewater filtered in step S11 into a regulating tank for water quality and quantity regulation;

[0073] S13, the liquor wastewater after adjustment in step S12 enters the physical and chemical sedimentation tank A, sodium hydroxide is added to adjust the pH value of the wastewater to 7-9, coagulant polyaluminium chloride, flocculant polyacrylamide and de-hardening agent are added, mixed and reacted, and then allowed to stand for precipitation; in the wastewater of the physical and chemical sedimentation tank A, the mass concentration of the coagulant is 200ppm, the mass concentration of the flocculant is 6ppm, and the mass concentration of the de-hardening agent is 80ppm;

[0074] S14. The liquor wastewater treated in step S13 (i.e., the upper effluent after precipitation in step S13) is adjusted to pH 3 with sulfuric acid solution and then input into an iron-carbon micro-electrolysis cell for iron-carbon micro-electrolysis treatment to obtain pretreated effluent; the iron-carbon micro-electrolysis treatment time is 2h, and the iron-carbon micro-electrolysis cell is filled with micro-electrolysis filler, the ratio between the mass of the micro-electrolysis filler and the volume of the wastewater in the iron-carbon micro-electrolysis cell is 80g:1L, and the micro-electrolysis filler includes iron and carbon, and the mass ratio of iron to carbon is 2:1.

[0075] S2, the pre-treated effluent enters the IC anaerobic reactor for anaerobic reaction; the effluent of the anaerobic reactor enters the anaerobic sedimentation tank for mud and water separation, a part of the wastewater after the mud and water separation is used as anaerobic sedimentation effluent, and the other part is used as return water, the return water is transported to the Fenton tank, ferrous sulfate and hydrogen peroxide are added, sulfuric acid is added to adjust the pH value to 3.5-5, and the Fenton reaction is carried out under stirring conditions, and the effluent of the Fenton tank is transported to the anaerobic reactor for anaerobic reaction; the ferrous sulfate accounts for 0.08% of the mass of the return water, and the hydrogen peroxide in the hydrogen peroxide accounts for 0.08% of the mass of the return water;

[0076] The hydraulic retention time of the IC anaerobic reactor is 15h, and the temperature is 30-35°C; the sludge concentration in the IC anaerobic reactor is 20000mg / L;

[0077] In step S2, the chemical oxygen demand of the influent of the anaerobic reactor (i.e., the pre-treated effluent obtained in step S1) and the effluent of the anaerobic reactor are detected respectively, and the ratio of the chemical oxygen demand between the effluent of the anaerobic reactor and the pre-treated effluent (denoted as COD 出水 / COD 进水 ), and according to this ratio, the reflow ratio (i.e., the volume ratio between the reflow water and the anaerobic precipitation effluent) is controlled, as shown in Table 2 below.

[0078] S3, the anaerobic precipitation effluent enters the A / O reactor for biological denitrification treatment to obtain biological denitrification effluent;

[0079] In step S3, the A / O reactor includes an anaerobic section and an aerobic section arranged in sequence; the sludge concentration in the anaerobic section is 4000 mg / L, the dissolved oxygen concentration is not greater than 0.2 mg / L, the hydraulic retention time is 15 h, and the temperature is 25°C;

[0080] The sludge concentration in the aerobic section is 4000 mg / L, the dissolved oxygen concentration is 2-4 mg / L, the hydraulic retention time is 15 hours, and the temperature is 25°C.

[0081] S4. The effluent from biological denitrification enters the physicochemical sedimentation tank B, and the coagulant polyaluminium chloride and the flocculant polyacrylamide are added. After the mixed reaction, the effluent is allowed to stand and settle to obtain the physicochemical sedimentation effluent. In the wastewater in the physicochemical sedimentation tank B, the mass concentration of the coagulant is 120ppm, and the mass concentration of the flocculant is 2ppm.

[0082] S5, the effluent from the physical and chemical precipitation enters the denitrification filter for denitrification treatment, and at the same time, a carbon source is added to the denitrification filter to make the carbon-nitrogen ratio in the denitrification filter 4:1, and denitrification effluent is obtained; a short-range denitrification anaerobic ammonium oxidation biofilm is arranged in the denitrification filter, and the short-range denitrification anaerobic ammonium oxidation biofilm occupies 80% of the volume of the reaction zone of the denitrification filter; the hydraulic retention time of the denitrification filter is 4h, and the temperature is 25°C;

[0083] The denitrification effluent enters the clear water tank, and the water in the clear water tank is tested. The test results are shown in Table 2.

[0084] In this embodiment, the precipitates produced in each sedimentation tank and denitrification filter tank can be transported to the sludge concentration tank for concentration treatment, the concentrated precipitates are transported to the filter press for filtration, and the effluent from the filter press is transported to the regulating tank.

[0085] Example 4

[0086] The difference between this embodiment and Embodiment 3 is that, in this embodiment, in the wastewater of physicochemical sedimentation tank A, the mass concentration of the coagulant is 300ppm, the mass concentration of the flocculant is 6ppm, and the mass concentration of the de-hardening agent is 80ppm; the time of the iron-carbon micro-electrolysis treatment is 3h, the iron-carbon micro-electrolysis cell is filled with micro-electrolysis filler, the ratio between the mass of the micro-electrolysis filler and the volume of the wastewater in the iron-carbon micro-electrolysis cell is 100g:1L, the micro-electrolysis filler includes iron and carbon, and the mass ratio of iron to carbon is 3:1.

[0087] Comparative Examples 3-4

[0088] The difference between Comparative Examples 3-4 and Example 3 is that the reflux ratios of Comparative Examples 3-4 are as shown in Table 2.

[0089] The water in the clear water tanks of Examples 3 to 4 and Comparative Examples 3 to 4 was tested, and the test results are shown in Table 2.

[0090] Table 2

[0091]

[0092] Example 5

[0093] This embodiment provides a method for treating liquor wastewater, and its process is as follows: Figure 1 As shown, the liquor wastewater treatment method comprises the following steps:

[0094] S1, perform steps S11 to S14 in sequence to obtain pre-treated water;

[0095] S11, grid filtering the liquor wastewater, the liquor wastewater is wastewater generated in the liquor brewing process of a certain factory, the chemical oxygen demand (COD) of the liquor wastewater is 15600 mg / L, the total nitrogen (TN) content is 386 mg / L, the ammonia nitrogen (NH 3 -N) content is 315mg / L, total phosphorus (TP) content is 86mg / L, and suspended solids content is 436mg / L;

[0096] S12, inputting the liquor wastewater filtered in step S11 into a regulating tank for water quality and quantity regulation;

[0097] S13, the liquor wastewater after adjustment in step S12 enters the physicochemical sedimentation tank A, sodium hydroxide is added to adjust the pH value of the wastewater to 7-9, coagulant polyaluminium chloride, flocculant polyacrylamide and de-hardening agent are added, mixed and reacted and then precipitated; in the wastewater of the physicochemical sedimentation tank A, the mass concentration of the coagulant is 300ppm, the mass concentration of the flocculant is 10ppm, and the mass concentration of the de-hardening agent is 80ppm;

[0098] S14. The liquor wastewater treated in step S13 (i.e., the upper effluent after precipitation in step S13) is adjusted to pH 3 with sulfuric acid and then input into an iron-carbon micro-electrolysis cell for iron-carbon micro-electrolysis treatment to obtain pretreated effluent; the iron-carbon micro-electrolysis treatment time is 2h, and the iron-carbon micro-electrolysis cell is filled with micro-electrolysis filler, and the ratio between the mass of the micro-electrolysis filler and the volume of the wastewater in the iron-carbon micro-electrolysis cell is 80g:1L, and the micro-electrolysis filler includes iron and carbon, and the mass ratio of iron to carbon is 3:1.

[0099] S2, the pre-treated effluent enters the IC anaerobic reactor for anaerobic reaction; the effluent of the anaerobic reactor enters the anaerobic sedimentation tank for mud and water separation, a part of the wastewater after the mud and water separation is used as anaerobic sedimentation effluent, and the other part is used as return water, the return water is transported to the Fenton tank, ferrous sulfate and hydrogen peroxide are added, sulfuric acid is added to adjust the pH value to 3.5-5, and the Fenton reaction is carried out under stirring conditions, and the effluent of the Fenton tank is transported to the anaerobic reactor for anaerobic reaction; the ferrous sulfate accounts for 0.1% of the mass of the return water, and the hydrogen peroxide in the hydrogen peroxide accounts for 0.1% of the mass of the return water;

[0100] The hydraulic retention time of the IC anaerobic reactor is 18 hours, and the temperature is 30-35° C.; the sludge concentration in the IC anaerobic reactor is 30,000 mg / L;

[0101] In step S2, the chemical oxygen demand of the influent of the anaerobic reactor (i.e., the pre-treated effluent obtained in step S1) and the effluent of the anaerobic reactor are detected respectively, and the ratio of the chemical oxygen demand between the effluent of the anaerobic reactor and the pre-treated effluent (denoted as COD 出水 / COD 进水 ), and according to this ratio, the reflow ratio (i.e., the volume ratio between the reflow water and the anaerobic precipitation effluent) is controlled, as shown in Table 3 below.

[0102] S3, the anaerobic precipitation effluent enters the A / O reactor for biological denitrification treatment to obtain biological denitrification effluent;

[0103] In step S3, the A / O reactor includes an anaerobic section and an aerobic section arranged in sequence; the sludge concentration in the anaerobic section is 5000 mg / L, the dissolved oxygen concentration is not greater than 0.2 mg / L, the hydraulic retention time is 18 hours, and the temperature is 25°C;

[0104] The sludge concentration in the aerobic section is 5000 mg / L, the dissolved oxygen concentration is 2 mg / L, the hydraulic retention time is 18 hours, and the temperature is 25°C.

[0105] S4. The effluent from biological denitrification enters the physicochemical sedimentation tank B, and the coagulant polyaluminium chloride and the flocculant polyacrylamide are added. After the mixed reaction, the effluent is allowed to settle to obtain the physicochemical sedimentation effluent. In the wastewater in the physicochemical sedimentation tank B, the mass concentration of the coagulant is 120ppm, and the mass concentration of the flocculant is 6ppm.

[0106] S5, the effluent from the physical and chemical precipitation enters the denitrification filter for denitrification treatment, and at the same time, a carbon source is added to the denitrification filter to make the carbon-nitrogen ratio in the denitrification filter 4:1, and denitrification effluent is obtained; a short-range denitrification anaerobic ammonium oxidation biofilm is arranged in the denitrification filter, and the short-range denitrification anaerobic ammonium oxidation biofilm occupies 80% of the volume of the reaction zone of the denitrification filter; the hydraulic retention time of the denitrification filter is 6 hours, and the temperature is 25°C;

[0107] The denitrification effluent enters the clear water tank, and the water in the clear water tank is tested. The test results are shown in Table 3.

[0108] In this embodiment, the precipitates produced in each sedimentation tank and denitrification filter tank can be transported to the sludge concentration tank for concentration treatment, the concentrated precipitates are transported to the filter press for filtration, and the effluent from the filter press is transported to the regulating tank.

[0109] Example 6

[0110] The difference between this embodiment and Embodiment 5 is that, in this embodiment, in the wastewater of physicochemical sedimentation tank A, the mass concentration of the coagulant is 300ppm, the mass concentration of the flocculant is 6ppm, and the mass concentration of the de-hardening agent is 80ppm; the time of the iron-carbon micro-electrolysis treatment is 3h, the iron-carbon micro-electrolysis cell is filled with micro-electrolysis filler, the ratio between the mass of the micro-electrolysis filler and the volume of the wastewater in the iron-carbon micro-electrolysis cell is 100g:1L, the micro-electrolysis filler includes iron and carbon, and the mass ratio of iron to carbon is 4:1.

[0111] Comparative Examples 5-6

[0112] The difference between Comparative Examples 5 and 6 and Example 5 is that the reflux ratios of Comparative Examples 5 and 6 are as shown in Table 3.

[0113] The water in the clear water tanks of Examples 5-6 and Comparative Examples 5-6 was tested, and the test results are shown in Table 3.

[0114] Table 3

[0115]

[0116]

[0117] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the essence and scope of the technical solution of the present invention.

Claims

1. A method for treating liquor wastewater, characterized in that: The steps include: S1, pre-treating liquor wastewater to obtain pre-treated effluent; S2, the pre-treated effluent enters the IC anaerobic reactor for anaerobic reaction; the effluent of the anaerobic reactor enters the anaerobic sedimentation tank for mud and water separation, part of the wastewater after mud and water separation is used as anaerobic sedimentation effluent, and the other part is used as return water, and the return water is oxidized and then returned to the anaerobic reactor for anaerobic reaction; S3, the anaerobic precipitation effluent enters the A / O reactor for biological denitrification treatment to obtain biological denitrification effluent; S4, subjecting the biological denitrification effluent to physicochemical precipitation treatment to obtain physicochemical precipitation effluent; S5. The effluent from the physicochemical precipitation enters the denitrification filter tank for denitrification treatment to obtain denitrified effluent.

2. The method for treating liquor wastewater according to claim 1, characterized in that: Step S1 includes: S11, filtering and treating the liquor wastewater; S12, adjusting the water quality and quantity of the liquor wastewater filtered in step S11; S13, adding an inorganic base to the liquor wastewater adjusted in step S12, adjusting the pH value of the wastewater to 7-9, adding a coagulant, a flocculant and a hardness remover, mixing and reacting, and then allowing to settle; S14. The liquor wastewater treated in step S13 enters an iron-carbon micro-electrolysis cell for iron-carbon micro-electrolysis treatment to obtain pretreated effluent.

3. The method for treating liquor wastewater according to claim 2, characterized in that: In step S14, the iron-carbon micro-electrolysis treatment time is 1 to 3 hours, the iron-carbon micro-electrolysis cell is filled with micro-electrolysis filler, the ratio between the mass of the micro-electrolysis filler and the volume of the wastewater in the iron-carbon micro-electrolysis cell is (20 to 100) g: 1L, the micro-electrolysis filler includes iron and carbon, and the mass ratio of iron to carbon is (0.5 to 4):

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4. The method for treating liquor wastewater according to claim 1, characterized in that: In step S2, the sludge concentration in the anaerobic reactor is 10000-30000 mg / L, the hydraulic retention time of the anaerobic reactor is 6-18 hours, and the temperature is 30-35°C.

5. The method for treating liquor wastewater according to claim 1, characterized in that: The volume ratio between the return water and the anaerobic precipitation effluent is 0.05 to 0.

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6. The method for treating liquor wastewater according to claim 5, characterized in that: If the ratio of chemical oxygen demand between the effluent of the anaerobic reactor and the effluent of the pretreatment is less than 0.4, the volume ratio between the return water and the effluent of the anaerobic precipitation is 0.05 to 0.1; If the chemical oxygen demand ratio between the effluent of the anaerobic reactor and the pre-treated effluent is 0.4-0.6, the volume ratio between the return water and the anaerobic precipitation effluent is 0.1-0.2; If the ratio of chemical oxygen demand between the effluent of the anaerobic reactor and the pre-treated effluent is greater than 0.6, the volume ratio between the return water and the anaerobic precipitation effluent is 0.2-0.

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7. The method for treating liquor wastewater according to claim 1, characterized in that: In step S3, the A / O reactor includes an anaerobic section and an aerobic section arranged in sequence; the sludge concentration in the anaerobic section is 3000-5000 mg / L, the dissolved oxygen concentration is not more than 0.2 mg / L, the hydraulic retention time is 6-18 hours, and the temperature is 20-35°C; The sludge concentration in the aerobic section is 3000-5000 mg / L, the dissolved oxygen concentration is 2-4 mg / L, the hydraulic retention time is 6-18 hours, and the temperature is 20-35°C.

8. The method for treating liquor wastewater according to claim 1, characterized in that: Step S4 comprises: adding a coagulant and a flocculant to the biological denitrification effluent, mixing and reacting, and then standing and settling to obtain a physicochemical precipitation effluent.

9. The method for treating liquor wastewater according to claim 1, characterized in that: When performing denitrification treatment in step S5, a carbon source is added into the denitrification filter to make the carbon-nitrogen ratio in the denitrification filter be (3-5):

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10. The method for treating liquor wastewater according to claim 1, characterized in that: In step S5, a short-range denitrification anaerobic ammonium oxidation biofilm is arranged in the denitrification filter, and the short-range denitrification anaerobic ammonium oxidation biofilm occupies 80-100% of the volume of the reaction zone of the denitrification filter; the hydraulic retention time of the denitrification filter is 2-6 hours, and the temperature is 20-35°C.

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