CN112939279A

CN112939279A - Method for automatically adjusting Fenton process parameters based on PH and ORP linkage

Info

Publication number: CN112939279A
Application number: CN202110165607.5A
Authority: CN
Inventors: 毛睿涛; 徐红; 张朝明; 韩振明; 冯晓勇; 李冬
Original assignee: Huzhou Guangzheng Water Purification Co ltd
Current assignee: Huzhou Guangzheng Water Purification Co ltd
Priority date: 2021-02-06
Filing date: 2021-02-06
Publication date: 2021-06-11
Anticipated expiration: 2041-02-06
Also published as: CN112939279B

Abstract

The application relates to the technical field of sewage treatment, in particular to a method for automatically adjusting Fenton process parameters based on PH and ORP linkage, which comprises the following steps: step one, pretreatment, testing the COD value of the wastewater; pumping the wastewater in the water quality adjusting tank into a dosing mixing tank, adding an acid regulating agent, controlling the pH value to be 4.0-4.5, adding a ferrous reagent, and uniformly mixing; transferring to a catalytic reaction tank, adding hydrogen peroxide, uniformly mixing, controlling the pH value to be 4.0-4.5, and controlling the ORP value to be more than or equal to 450mV, and carrying out Fenton oxidation reaction for 6-8 h; detecting the chroma of the sewage treated by the Fenton oxidation reaction, and adding an aluminum sulfate solution for regulation and control; transferring to a neutralization tank, adding a calcium hydroxide solution, uniformly mixing, and controlling the pH value to be 6.0-6.5; and sixthly, transferring to a sedimentation tank, adding PAM, uniformly mixing, standing for sedimentation, and testing the COD value of the purified water. The method can effectively remove COD in the water body, thereby ensuring the sewage treatment efficiency and the treatment quality.

Description

Method for automatically adjusting Fenton process parameters based on PH and ORP linkage

Technical Field

The application relates to the technical field of sewage treatment, in particular to a method for automatically adjusting Fenton process parameters based on PH and ORP linkage.

Background

With the improvement of the economic level, the requirements of the national people on the clothes are higher and higher. The clothing manufacturing industry inevitably involves textile dyeing and finishing of fabrics. In recent years, with the advancement of national environmental protection policy, the pollution problem of printing and dyeing textile wastewater becomes a main contradiction in the garment manufacturing industry. The textile dyeing and finishing wastewater not only has complex pollutant composition, large water quality change, large water quantity and high treatment difficulty, but also has serious harm to the received water body because the common physical chemical method and biochemical method are difficult to work. In the traditional secondary treatment and biochemical treatment, due to the existence of organic dyes and auxiliaries which are difficult to biodegrade in the printing and dyeing textile wastewater, the COD of the discharged water after the conventional treatment reaches 150-350 mg/L, and cannot reach the special discharge limit value of water pollutants in the discharge Standard of Water pollutants for dyeing and finishing industry of textiles (GB/T4287-2012).

At present, the textile dyeing and finishing wastewater treatment generally adopts a pretreatment-anaerobic biological treatment-aerobic biological treatment-coagulation method, which has low operation cost but is difficult to achieve ideal treatment effect. Chinese patent CN1569694A 'advanced purification and recycling device and method for printing and dyeing wastewater', which comprises a regulating tank, an anaerobic tank, an aerobic aeration tank and a sedimentation tank, and is additionally provided with a chlorine dioxide oxidation tank, a dosing coagulation tank, a biological activated carbon filter and a fiber ball filter; the treatment method combining biochemistry and materialization is adopted, and the effluent is further purified by dosing coagulation sedimentation and filtering of biological activated carbon and fiber balls, so that the textile dyeing and finishing wastewater meets the water quality requirement of process reuse.

In view of the above-mentioned related art solutions, the inventors found that the following drawbacks exist: COD degradation efficiency is lower in the actual sewage treatment process, and the whole water treatment effect is not ideal.

Disclosure of Invention

In order to solve the problem that COD degradation efficiency is lower in the prior art, the application aims to provide a method for automatically adjusting Fenton process parameters based on PH and ORP linkage.

The application purpose of the application is realized by the following technical scheme:

a method for automatically adjusting Fenton process parameters based on PH and ORP linkage comprises the following steps:

firstly, pretreating printing and dyeing textile wastewater, storing the pretreated printing and dyeing textile wastewater in a water quality regulating tank, and testing the COD value of the wastewater in the water quality regulating tank; pumping the wastewater in the water quality adjusting tank into a dosing mixing tank, adding an acid regulating agent, controlling the pH value to be 4.0-4.5, adding a ferrous reagent, and uniformly mixing;

transferring the wastewater to a catalytic reaction tank, adding hydrogen peroxide, uniformly mixing, controlling the pH value to be 4.0-4.5, and controlling the ORP value to be not less than 450mV, and performing Fenton oxidation reaction for 6-8 hours to remove COD in the wastewater;

detecting the chroma of the sewage treated by the Fenton oxidation reaction, and adding an aluminum sulfate solution for regulation and control;

transferring to a neutralization tank, adding a calcium hydroxide solution, uniformly mixing, and controlling the pH value to be 6.0-6.5;

and sixthly, transferring to a sedimentation tank, adding PAM, uniformly mixing, standing for sedimentation, and testing the COD value of the purified water.

Through adopting above-mentioned technical scheme, the COD value of the textile printing and dyeing waste water of processing through this application reduces to below 50mg/L7, and the colourity reduces to below 25 times, and the SS index is less than 20mg/L, accords with national ring row standard, has better COD degradation efficiency, has guaranteed the quality of handling waste water.

Preferably, the printing and dyeing textile wastewater is subjected to the following pretreatment, hydrolysis acidification treatment, A2O method treatment, secondary sedimentation tank treatment and filtration treatment in sequence in the step one, the pretreatment time is 2-6 hours, the pretreated wastewater is transferred to a water quality adjusting tank, and the COD value of the wastewater in the water quality adjusting tank is tested to be 300-500 mg/L.

By adopting the technical scheme, through hydrolytic acidification treatment, A2O method treatment, secondary sedimentation tank treatment and filtration treatment, sulfide ions, cyanide ions, easily-decomposed organic matters, oil substances, most of suspended impurities and soluble phosphate in the wastewater can be removed, the quality of the wastewater to be subjected to Fenton oxidation treatment is ensured, and the treatment quality of the whole wastewater is further ensured.

Preferably, the acid regulating agent in the second step is 5-30% of sulfuric acid; the ferrous reagent is 15-20% ferrous sulfate; the concentration ratio of hydrogen peroxide to ferrous sulfate in the third step is (1.50-8.50): 1; and the COD value concentration ratio of the hydrogen peroxide solution in the third step to the wastewater in the water quality regulating tank is (1.15-2.20): 1.

through adopting above-mentioned technical scheme, can guarantee the quality of the waste water of fenton oxidation treatment, under guaranteeing treatment quality, the actual quantity is comparatively economical and practical simultaneously.

Preferably, the solute mass fraction of the aluminum sulfate solution in the fourth step is 15-20%; and the mass fraction of the solute of the calcium hydroxide solution in the fifth step is 3.0-5.5%.

By adopting the technical scheme, the pipeline blockage can be avoided, and the continuity of wastewater treatment is ensured.

Preferably, the combined filter body is adopted in the filtration treatment, and the SS index of the sewage filtered by the combined filter body is reduced to below 50 mg/L.

Through adopting above-mentioned technical scheme, can comparatively effectively reduce the volume of suspended particle impurity, guarantee the quality of handling waste water.

Preferably, in the third step, during the fenton oxidation reaction, ozone/nitrogen gas is introduced in a ratio of 1: (1-3) introducing the promoting gas to the bottom of the catalytic reaction tank; the intake amount of the promoting gas is 8.0-20ml/(L × s).

Through adopting above-mentioned technical scheme, further remove the content of COD in the sewage, promote sewage treatment efficiency.

Preferably, in the fourth step, the chromaticity of the sewage is detected in real time, the aluminum sulfate solution is continuously added into the sewage at the adding speed of 2.0-5.0 kg/min, the mixture is stirred and mixed uniformly, and the aluminum sulfate solution is stopped to be added when the chromaticity is lower than 20 times.

By adopting the technical scheme, the chroma of the wastewater can be accurately reduced, and the wastewater treatment quality is ensured.

Preferably, the temperature of the sewage in the catalytic reaction tank in the fourth step is controlled to be 20-35 ℃.

By adopting the technical scheme.

In summary, the present application has the following advantages:

1. this application has better COD degradation efficiency, has guaranteed the quality of handling waste water.

2. The technical parameters of the application are controlled, the sewage can be purified with higher quality, and the same batch of sewage treatment is ensured to meet the ring discharge standard.

Drawings

Fig. 1 is a schematic view of the overall structure of the modular filter body of the present application.

Fig. 2 is a schematic view of a first filter in the modular filter of the present application.

Fig. 3 is a schematic structural view of the gas-promoting addition device in the present application.

In the figure, 1, a first filtering pipe; 10. a first filter body; 101. a second filter body; 102. a third filter body; 103. a fourth filter body; 11. a second filtering pipe; 12. the head end is connected with a bent pipe; 13. the tail end is connected with a bent pipe; 14. a first solenoid valve; 15. a water pumping pipe; 16. a water pump; 17. a cylindrical inner barrel; 171. filtering felt cloth; 18. sealing the cover; 181. a flow-through hole; 19. a filling area; 2. a nitrogen storage tank; 21. a nitrogen gas output pipe; 22. a second solenoid valve; 23. a first gas flow meter; 3. an ozone storage tank; 31. an ozone output pipe; 32. a third electromagnetic valve; 33. a second gas flow meter; 4. a header; 5. a main promotion gas transmission pipe; 50. a boost gas delivery manifold; 6. an air outlet column; 60. and air vents.

Detailed Description

The present application will be described in further detail with reference to the following drawings and examples.

Device

Device 1

Referring to fig. 1, the combined filter body in the present application includes a first filter pipe 1, a second filter pipe 11, and a head end connection bent pipe 12, where the first filter pipe 1 and the second filter pipe 11 are arranged in parallel, a first electromagnetic valve 14 is fixedly communicated with a flange at one end of the first filter pipe 1, and a head end connection bent pipe 12 is fixedly communicated with a flange at the other end of the first electromagnetic valve 14. The second filtering pipe 11 and the first filtering pipe 1 are fixedly communicated with a first electromagnetic valve 14 through a flange at one end in the same direction, and the other end of the first electromagnetic valve 14 is fixedly communicated with a head end connecting bent pipe 12 through a flange. The head end connecting bent pipe 12 is fixedly communicated with a water pumping pipe 15 in the circumferential direction. The other end flange of the first filtering pipe 1 is fixedly communicated with a tail end connecting bent pipe 13, and the other end flange of the second filtering pipe 11 is fixedly communicated with the tail end connecting bent pipe 13. The tail end connecting elbow 13 is fixedly communicated with a water suction pump 16 in the circumferential direction, and water passing through the first filtering pipe 1 or the second filtering pipe 11 is input into the water quality adjusting tank.

Referring to fig. 2, the first filtering pipe 1 and the second filtering pipe 11 have the same structure, and a first filtering body 10, a second filtering body 101, a third filtering body 102 and a fourth filtering body 103 are sequentially disposed inside the first filtering pipe 1 and the second filtering pipe 11 along a flowing direction of the sewage. The first filter 10, the second filter 101, the third filter 102 and the fourth filter 103 have the same structure. Taking the first filter body 10 as an example, the first filter body 10 includes a cylindrical inner cylinder 17, and two ends of the cylindrical inner cylinder 17 are screwed with sealing caps 18. The sealing cover 18 is provided with a through hole 151 in a penetrating manner, the diameter of the through hole 151 is 1mm, and the opening rate is 75%. Two filter felt cloths 171 are filled in the cylindrical inner cylinder 17, and a filling area 19 is arranged between the filter felt cloths 171 in the circumferential direction. The filter felt 171 is a felt formed by acrylonitrile-based activated carbon fiber and hollow polypropylene fiber in a mass ratio of 2:1, and has a thickness of 30 mm.

Referring to fig. 1, the packed region 19 of the first filter body 10 is filled with water-treated zeolite (model ss-fs-012, flourishing water purification materials ltd., of the well-being market) having a particle size of 2-4mm, the packed region 19 of the second filter body 101 is filled with quartz sand having a particle size of 0.5-1mm, the packed region 19 of the third filter body 102 is filled with honeycomb activated carbon (iodine adsorption value (mg/g) ≥ 950 specific surface area (m2/g) of 1050, and bulk density (g/cm3) of 0.35-0.6), the packed region 19 of the fourth filter body 103 is filled with molecular sieve powder selected from 150 mesh to 200 mesh sieves having a mass ratio of 1:0.8: 1.2: 5, molecular sieve: 10Z molecular sieve.

When the combined filter body is actually operated and filtered, the first filter pipe 1 or the second filter pipe 11 generally operates independently, sewage flows to the first filter pipe 1 or the second filter pipe 11 through the water suction pipe 15 under the action of the water suction pump 16, is sequentially filtered and degraded through the first filter body 10, the second filter body 101, the third filter body 102 and the fourth filter body 103, and flows to the water quality adjusting tank through the water suction pump 16 for standby. When the sewage treatment pressure is higher, the first filtering pipe 1 and the second filtering pipe 11 can be both opened to carry out the filtering treatment on the sewage.

Device 2

Referring to fig. 3, the device for promoting gas addition in the present application includes a nitrogen storage tank 2 and an ozone storage tank 3, the nitrogen storage tank 2 is fixedly communicated with a nitrogen output pipe 21, and the nitrogen output pipe 21 is sequentially communicated with a second electromagnetic valve 22 and a first gas flowmeter 23 along a nitrogen conveying direction. The ozone storage tank 3 is fixedly communicated with an ozone output pipe 31, and the ozone output pipe 31 is sequentially communicated with a third electromagnetic valve 32 and a second gas flowmeter 33 along the ozone conveying direction. One end of the nitrogen output pipe 21, which is back to the nitrogen storage tank 2, is fixedly communicated with the collecting pipe 4, and one end of the ozone storage tank 3, which is back to the ozone storage tank 3, is fixedly communicated with the collecting pipe 4. The main promotion gas transmission pipe 5 is fixedly communicated with the collecting pipe 4, and a plurality of branch promotion gas transmission pipes 50 which are mutually spaced and equally spaced are fixedly communicated with the main promotion gas transmission pipe 5 along the axial direction of the main promotion gas transmission pipe 5 in the circumferential direction. Each of the branch gas-promoting pipes 50 is fixedly communicated with a gas outlet column 6 arranged at the bottom of the catalytic reaction tank. The gas outlet column 6 is circumferentially provided with a plurality of gas guide holes 60 which are mutually spaced and are equally spaced along the axial direction of the gas outlet column 6, the gas guide holes 60 are vertically upward, and the aperture of the gas guide holes 60 is 1.5 mm.

When the adding device for the promoting gas operates, the second electromagnetic valve 22 controls the flow of nitrogen, and the third electromagnetic valve 32 controls the flow of ozone, so that the proportion of the promoting gas is adjusted in the collecting pipe 4, the promoting gas is transmitted to the main promoting gas transmission pipe 5, is shunted to the branch promoting gas transmission pipe 50 and the gas outlet column 6, and flows to the catalytic reaction tank from the gas guide hole 60 to further degrade COD (chemical oxygen demand) substances, suspended matters and dye auxiliaries in the water body.

Examples

Example 1

The method for automatically adjusting Fenton process parameters based on the PH and ORP linkage disclosed by the application comprises the following steps of:

step one, sequentially carrying out the following pretreatment, hydrolytic acidification treatment, A2O method treatment and secondary sedimentation tank treatment on printing and dyeing textile wastewater (wastewater discharged from a dyeing and finishing enterprise in an industrial park of Zhejiang), wherein a water body in the secondary sedimentation tank is filtered by a combined filter body, the pretreatment time is 5-6 h, the pretreated wastewater is pumped into a water quality regulating tank for later use, the COD value of the wastewater in the water quality regulating tank is 313mg/L, the chroma is 161 times, and the SS index is 41 mg/L;

step two, pumping the wastewater in the water quality adjusting tank into a dosing mixing tank, adding 12% sulfuric acid, continuously stirring, controlling the pH value of the wastewater in the dosing mixing tank within 4.0-4.5, suspending the addition of 12% sulfuric acid, adding 20% ferrous sulfate and 20% ferrous sulfate after controlling the pH value within 4.0-4.5, measuring the pH value after stirring and mixing for 2 minutes after completing the addition, adding 12% sulfuric acid until controlling the pH value within 4.0-4.5 when the pH value is higher than 4.5, and performing the next treatment when the pH value is within 4.0-4.5;

pumping the sewage in the chemical adding mixing tank in the second step into a catalytic reaction tank, adding hydrogen peroxide, controlling the adding amount of the hydrogen peroxide to be 360.0mg/L, stirring and mixing for 2min, testing the pH value and ORP of the sewage, entering the next step for treating the Fenton oxidation reaction when the pH value is 4.0-4.5 and the ORP is not less than 450mV, adding 12% of sulfuric acid until the pH value is 4.0-4.5 when the pH value is more than 4.5, entering the next step for treating the Fenton oxidation reaction when the ORP value is not less than 450mV, and if the ORP value is still less than 450mV, adding hydrogen peroxide until the ORP value is not less than 450mV, wherein the duration time of the Fenton oxidation reaction is 6 hours, controlling the pH value to be 4.0-4.5 and the ORP value to be not less than 450mV during the period, and controlling the pH value and the ORP value according to the scheme if the parameter detection parameter changes, thereby effectively removing COD in the wastewater;

step four, carrying out a chromaticity test on the sewage treated by the Fenton oxidation reaction, wherein the chromaticity is 36 times, and adding 15% of aluminum sulfate solution at the speed of 3.0kg/min until the chromaticity is lower than 25 times;

pumping the sewage in the catalytic reaction tank into a neutralization tank, adding 4% of calcium hydroxide solution, continuously stirring until the pH value is within 6.0-6.5, and stopping adding the calcium hydroxide solution;

pumping the sewage in the neutralization tank into a sedimentation tank, adding 120mg/L PAC and 20mg/L PAM, stirring for 5 minutes, standing and precipitating for 1 hour, and taking the supernatant to perform COD value test.

Example 2

step one, sequentially carrying out the following pretreatment, hydrolytic acidification treatment, A2O method treatment and secondary sedimentation tank treatment on printing and dyeing textile wastewater (wastewater discharged from a dyeing and finishing enterprise in an industrial park of Zhejiang), wherein a water body in the secondary sedimentation tank is filtered by a combined filter body, the pretreatment time is 5-6 h, the pretreated wastewater is pumped into a water quality regulating tank for later use, and the tested water quality regulating tank is used for testing the COD value of the wastewater to be 321mg/L, the chroma to be 163 times and the SS index to be 45 mg/L;

pumping the sewage in the chemical adding mixing tank in the second step into a catalytic reaction tank, adding hydrogen peroxide, controlling the adding amount of the hydrogen peroxide to be 410.0mg/L, stirring and mixing for 2min, testing the pH value and ORP of the sewage, entering the next step for treating the Fenton oxidation reaction when the pH value is 4.0-4.5 and the ORP is not less than 450mV, adding 12% of sulfuric acid until the pH value is 4.0-4.5 when the pH value is more than 4.5, entering the next step for treating the Fenton oxidation reaction when the ORP value is not less than 450mV, and if the ORP value is still less than 450mV, adding hydrogen peroxide until the ORP value is not less than 450mV, wherein the duration time of the Fenton oxidation reaction is 6 hours, controlling the pH value to be 4.0-4.5 and the ORP value to be not less than 450mV during the period, and controlling the pH value and the ORP value according to the scheme if the parameter detection parameter changes, thereby effectively removing COD in the wastewater;

step four, carrying out a chromaticity test on the sewage treated by the Fenton oxidation reaction, wherein the chromaticity is 35 times, and adding 15% of aluminum sulfate solution at the speed of 3.0kg/min until the chromaticity is lower than 25 times;

Example 3

step one, sequentially carrying out the following pretreatment, hydrolytic acidification treatment, A2O method treatment and secondary sedimentation tank treatment on printing and dyeing textile wastewater (wastewater discharged from a dyeing and finishing enterprise in an industrial park of Zhejiang), wherein a water body in the secondary sedimentation tank is filtered by a combined filter body, the pretreatment time is 5-6 h, the pretreated wastewater is pumped into a water quality regulating tank for later use, and the tested water quality regulating tank is used for testing the COD value of the wastewater to be 304mg/L, the chroma to be 158 times and the SS index to be 45 mg/L;

pumping the sewage in the chemical adding mixing tank in the second step into a catalytic reaction tank, adding hydrogen peroxide, controlling the adding amount of the hydrogen peroxide to be 450.0mg/L, stirring and mixing for 2min, testing the pH value and ORP of the sewage, entering the next step for treating the Fenton oxidation reaction when the pH value is 4.0-4.5 and the ORP is not less than 450mV, adding 12% of sulfuric acid until the pH value is 4.0-4.5 when the pH value is more than 4.5, entering the next step for treating the Fenton oxidation reaction when the ORP value is not less than 450mV, and if the ORP value is still less than 450mV, adding hydrogen peroxide until the ORP value is not less than 450mV, wherein the duration time of the Fenton oxidation reaction is 6 hours, controlling the pH value to be 4.0-4.5 and the ORP value to be not less than 450mV during the period, and controlling the pH value and the ORP value according to the scheme if the parameter detection parameter changes, thereby effectively removing COD in the wastewater;

step four, carrying out a chromaticity test on the sewage treated by the Fenton oxidation reaction, wherein the chromaticity is 39 times, and adding 15% of aluminum sulfate solution at the speed of 3.0kg/min until the chromaticity is lower than 25 times;

Example 4

step one, sequentially carrying out the following pretreatment, hydrolytic acidification treatment, A2O method treatment and secondary sedimentation tank treatment on printing and dyeing textile wastewater (wastewater discharged from a dyeing and finishing enterprise in an industrial park of Zhejiang), wherein a water body in the secondary sedimentation tank is filtered by a combined filter body, the pretreatment time is 5-6 h, the pretreated wastewater is pumped into a water quality regulating tank for later use, the COD value of the wastewater in the water quality regulating tank is tested to be 316mg/L, the chroma is 160 times, and the SS index is 38 mg/L;

step two, pumping the wastewater in the water quality adjusting tank into a dosing mixing tank, adding 12% sulfuric acid, continuously stirring, controlling the pH value of the wastewater in the dosing mixing tank within 4.0-4.5, suspending the addition of 12% sulfuric acid, adding 20% ferrous sulfate and 20% ferrous sulfate when the pH value is controlled within 4.0-4.5, measuring the pH value after stirring and mixing for 2 minutes after the addition is finished, adding 12% sulfuric acid until the pH value is controlled within 4.0-4.5 when the pH value is higher than 4.5, and performing next treatment when the pH value is within 4.0-4.5;

pumping the sewage in the chemical adding mixing tank in the second step into a catalytic reaction tank, adding hydrogen peroxide, controlling the adding amount of the hydrogen peroxide to 530.0mg/L, stirring and mixing for 2min, testing the pH value and ORP of the sewage, entering the next step for treating the Fenton oxidation reaction when the pH value is 4.0-4.5 and the ORP is not less than 450mV, adding 12% of sulfuric acid until the pH value is 4.0-4.5 when the pH value is more than 4.5, entering the next step for treating the Fenton oxidation reaction when the ORP value is not less than 450mV, and if the ORP value is still less than 450mV, adding hydrogen peroxide until the ORP value is not less than 450mV, wherein the duration time of the Fenton oxidation reaction is 6 hours, controlling the pH value to be 4.0-4.5 and the ORP value to be not less than 450mV during the period, and controlling the pH value and the ORP value according to the scheme if the parameter detection parameter changes, thereby effectively removing COD in the wastewater;

step four, carrying out a chromaticity test on the sewage treated by the Fenton oxidation reaction, wherein the chromaticity is 43 times, and adding 15% of aluminum sulfate solution at the speed of 3.0kg/min until the chromaticity is lower than 25 times;

Example 5

step one, sequentially carrying out the following pretreatment, hydrolytic acidification treatment, A2O method treatment and secondary sedimentation tank treatment on printing and dyeing textile wastewater (wastewater discharged from a dyeing and finishing enterprise in an industrial park of Zhejiang), wherein a water body in the secondary sedimentation tank is filtered by a combined filter body, the pretreatment time is 5-6 h, the pretreated wastewater is pumped into a water quality regulating tank for later use, the COD value of the wastewater in the water quality regulating tank is tested to be 322mg/L, the chroma is 165 times, and the SS index is 44 mg/L;

step three, pumping the sewage in the dosing mixing tank in the step two into a catalytic reaction tank, adding hydrogen peroxide, controlling the adding amount of the hydrogen peroxide to be 410.0mg/L, stirring and mixing for 2min, testing the pH value and ORP of the sewage, entering the next step for treating the Fenton oxidation reaction when the pH value is 4.0-4.5 and the ORP is not less than 450mV, adding 12% of sulfuric acid until the pH value is 4.0-4.5 when the pH value is more than 4.5, entering the next step for treating the Fenton oxidation reaction when the ORP value is not less than 450mV, adding hydrogen peroxide until the ORP value is not less than 450mV if the ORP value is still less than 450mV, keeping the duration of the Fenton oxidation reaction for 6 hours, starting to adopt an adding device for promoting gas after the Fenton oxidation reaction is carried out for 1 hour, and introducing ozone/nitrogen into the catalytic reaction tank at a ratio of 1: 2.5, the gas inlet amount of the promoting gas is 16ml/(L & s), the promoting gas is used for further removing COD, the pH value is controlled within 4.0-4.5 in the period, the ORP value is more than or equal to 450mV, and if the parameter detection parameter changes, the pH value and the ORP value are controlled according to the scheme, so that the COD in the wastewater is effectively removed;

step four, carrying out a chromaticity test on the sewage treated by the Fenton oxidation reaction, wherein the chromaticity is 28 times, and adding 15% of aluminum sulfate solution at the speed of 3.0kg/min until the chromaticity is lower than 25 times;

Comparative example

Comparative example 1

sequentially carrying out the following pretreatment, hydrolytic acidification treatment, A2O method treatment and secondary sedimentation tank treatment on printing and dyeing textile wastewater (wastewater discharged from a dyeing and finishing enterprise in a certain industrial park of Zhejiang), wherein a water body in the secondary sedimentation tank is filtered by a commercially available non-woven fabric instead of a combined filter body, the pretreatment time is 5-6 h, the pretreated wastewater is pumped into a water quality regulating tank for later use, and the tested water quality regulating tank has the COD value of 368mg/L, the chromaticity of 194 times and the SS index of 118 mg/L; step two, pumping the wastewater in the water quality adjusting tank into a dosing mixing tank, adding 12% sulfuric acid, continuously stirring, controlling the pH value of the wastewater in the dosing mixing tank within 4.0-4.5, suspending the addition of 12% sulfuric acid, adding 20% ferrous sulfate and 20% ferrous sulfate when the pH value is controlled within 4.0-4.5, measuring the pH value after stirring and mixing for 2 minutes after the addition is finished, adding 12% sulfuric acid until the pH value is controlled within 4.0-4.5 when the pH value is higher than 4.5, and performing next treatment when the pH value is within 4.0-4.5;

pumping the sewage in the chemical adding mixing tank in the second step into a catalytic reaction tank, adding hydrogen peroxide, controlling the adding amount of the hydrogen peroxide to 423.5.0mg/L, stirring and mixing for 2min, testing the pH value and ORP of the sewage, entering the next step for treating the Fenton oxidation reaction when the pH value is 4.0-4.5 and the ORP is not less than 450mV, adding 12% of sulfuric acid until the pH value is 4.0-4.5 when the pH value is more than 4.5, entering the next step for treating the Fenton oxidation reaction when the ORP value is not less than 450mV, adding hydrogen peroxide until the ORP value is not less than 450mV if the ORP value is still less than 450mV, lasting for 6 hours, controlling the pH value to be 4.0-4.5 and the ORP value to be not less than 450mV during the period, and controlling the pH value and the ORP value according to the scheme if the parameter detection parameter changes, thereby effectively removing COD in the wastewater;

step four, carrying out chromaticity test on the sewage treated by the Fenton oxidation reaction, wherein the chromaticity is 72 times, and adding 15% of aluminum sulfate solution at the speed of 3.0kg/min until the chromaticity is lower than 25 times;

Comparative example 2

step one, sequentially carrying out the following pretreatment, hydrolytic acidification treatment, A2O method treatment and secondary sedimentation tank treatment on printing and dyeing textile wastewater (wastewater discharged from a dyeing and finishing enterprise in an industrial park of Zhejiang), wherein a water body in the secondary sedimentation tank is filtered by a combined filter body, the pretreatment time is 5-6 h, the pretreated wastewater is pumped into a water quality regulating tank for later use, the COD value of the wastewater in the water quality regulating tank is 324mg/L, the chroma is 165 times, and the SS index is 46 mg/L;

pumping the sewage in the chemical adding and mixing tank in the step two into a catalytic reaction tank, adding hydrogen peroxide, wherein the addition amount of the hydrogen peroxide is 415.0mg/L, continuously stirring and mixing, and performing Fenton oxidation reaction for 6 hours to remove COD in the wastewater;

step four, carrying out a chromaticity test on the sewage treated by the Fenton oxidation reaction, wherein the chromaticity is 67 times, and adding 15% of aluminum sulfate solution at the speed of 3.0kg/min until the chromaticity is lower than 25 times;

Comparative example 3

sequentially carrying out the following pretreatment, hydrolytic acidification treatment, A2O method treatment and secondary sedimentation tank treatment on printing and dyeing textile wastewater (discharged sewage from a dyeing and finishing enterprise in a certain industrial park of Zhejiang), wherein a water body in the secondary sedimentation tank is filtered by a commercially available non-woven fabric instead of a combined filter body, the pretreatment time is 5-6 h, the pretreated sewage is pumped into a water quality regulating tank for later use, and the COD value, the chromaticity and the SS index of the wastewater in the water quality regulating tank are tested to be 352mg/L, 183 times and 107 mg/L; step two, pumping the wastewater in the water quality adjusting tank into a dosing mixing tank, adding 12% sulfuric acid, continuously stirring, controlling the pH value of the wastewater in the dosing mixing tank within 4.0-4.5, suspending the addition of 12% sulfuric acid, adding 20% ferrous sulfate and 20% ferrous sulfate after controlling the pH value within 4.0-4.5, measuring the pH value after stirring and mixing for 2 minutes after completing the addition, adding 12% sulfuric acid until controlling the pH value within 4.0-4.5 when the pH value is higher than 4.5, and performing the next treatment when the pH value is within 4.0-4.5;

pumping the sewage in the chemical adding and mixing tank in the step two into a catalytic reaction tank, adding hydrogen peroxide, wherein the addition amount of the hydrogen peroxide is 405.5mg/L, continuously stirring and mixing, and performing Fenton oxidation reaction for 6 hours to remove COD in the wastewater;

step four, carrying out a chromaticity test on the sewage treated by the Fenton oxidation reaction, wherein the chromaticity is 77 times, and adding 15% of aluminum sulfate solution at the speed of 3.0kg/min until the chromaticity is lower than 25 times;

Performance test

1. And (3) detecting a COD value: COD value detection was performed according to GB11914 test dichromate method for determination of chemical oxygen demand for Water.

2. And (3) chroma detection: colorimetric detection was carried out according to GB11903-1989, "determination of Water quality chromaticity".

3. Determination of suspended matter (SS) in wastewater: firstly, the determination principle of suspended solid is that the suspended solid refers to the solid which is left on the filter material and is dried to constant weight at the temperature of 103-105 ℃. The determination method comprises the steps of drying the solid residues and the filter material after a water sample passes through the filter material, and subtracting the weight of the filter material from the weighed amount to obtain suspended solids (non-filtering residues). Secondly, the apparatus comprises an oven, an analytical balance, a dryer, a filter membrane with the aperture of 0.45 μm and a corresponding filter or medium-speed filter paper, a glass funnel and a weighing bottle with the inner diameter of 30-50 m. Thirdly, determination step: 1. placing the filter membrane in a weighing bottle, opening the bottle cap, drying at the temperature of 103-; 2. shaking the water sample after removing the suspended matters, measuring a uniform and proper amount of water sample (making the suspended matters more than 2.5mg), and filtering through the filter membrane which is weighed to be constant weight; washing the residue with distilled water for 3-5 times. If the sample contains grease, the residue is rinsed twice with 10M1 petroleum ether. 3. Carefully taking down the filter membrane, putting the filter membrane into an original weighing bottle, opening the bottle cap in an oven at the temperature of 103-. Calculating suspended solid (mg/L) { (A-B) × 1000 {/V, wherein A-suspended solid + filter membrane and weighing bottle weight (g); b-filter membrane and weighing bottle weight (g); v — water sample volume. Attention points that 1, impurities such as leaves, sticks, aquatic weeds and the like are removed from a water sample; 2. when the viscosity of the wastewater is high, 2-4 times of distilled water can be added for dilution, the mixture is uniformly vibrated, and after the precipitate is reduced, the mixture is filtered; 3. asbestos crucibles can also be used for filtration.

Detecting data and analyzing

Table 1 shows the test parameters of examples 1 to 5 and comparative examples 1 to 3

As can be seen by combining examples 1-5 and comparative examples 1-3 with Table 1, the SS index of the inlet water in examples 1-5 of the present application is below 50mg, while the SS index of the inlet water in comparative examples 1 and 3 is above 100mg/L, therefore, the suspended impurities in the water body can be effectively removed by filtering with the combined filter.

As can be seen by combining examples 1 to 5 and comparative examples 1 to 3 and by combining Table 1, the chroma of the influent water in examples 1 to 5 of the present application is about 160 times, and the chroma of the influent water in comparative examples 1 and 3 is about 180 times or more, and therefore, the dye and the auxiliary agent in the decomposable wastewater are filtered by using the combined filter.

As can be seen by combining examples 1-5 and table 1, in example 5 of the present application, the accelerating gas is used for treatment, the obtained effluent COD value is 24mg/L, the chromaticity is 19 times, and the SS index is 11mg/L, which are all superior to the effluent quality of examples 1-4, so that the accelerating gas is added by the accelerating gas adding device to accelerate the degradation of COD, dye, auxiliary agent and suspended matter in the water body, and the effluent quality is improved.

By combining examples 1-5 and comparative example 2 and table 1, the dyeing and printing textile wastewater is treated by automatically adjusting Fenton process parameters based on the pH and ORP linkage, the COD value of the effluent is below 45mg/L, the chroma is below 25 times, and the SS index is below 20mg/L, while the effluent of comparative examples 2 and 3 which are not controlled by automatically adjusting Fenton process parameters based on the pH and ORP linkage has the COD value of above 60mg/L and the SS index of above 30mg/L, and the water quality can not reach the national discharge standard under the Fenton oxidation reaction treatment of 6 hours. Therefore, the application adopts the chain automatic adjustment Fenton technological parameter based on PH and ORP to handle printing and dyeing textile wastewater and can guarantee that the effluent quality accords with the national ring discharge standard and can promote sewage treatment efficiency.

The embodiments of the present invention are preferred embodiments of the present application, and the scope of protection of the present application is not limited by the embodiments, so: all equivalent changes made according to the structure, shape and principle of the present application shall be covered by the protection scope of the present application.

Claims

1. A method for automatically adjusting Fenton process parameters based on PH and ORP linkage is characterized in that: the method comprises the following steps:

firstly, pretreating printing and dyeing textile wastewater, storing the pretreated printing and dyeing textile wastewater in a water quality regulating tank, and testing the COD value of the wastewater in the water quality regulating tank;

pumping the wastewater in the water quality adjusting tank into a dosing mixing tank, adding an acid regulating agent, controlling the pH value to be 4.0-4.5, adding a ferrous reagent, and uniformly mixing;

2. The method for automatically adjusting Fenton process parameters based on the chain of PH and ORP according to claim 1, wherein the method comprises the following steps: and in the first step, the printing and dyeing textile wastewater is sequentially subjected to the following pretreatment, hydrolysis acidification treatment, A2O method treatment, secondary sedimentation tank treatment and filtration treatment, wherein the pretreatment time is 2-6 h, the pretreated wastewater is transferred to a water quality regulating tank, and the COD value of the wastewater in the water quality regulating tank is tested to be 300-500 mg/L.

3. The method for automatically adjusting Fenton process parameters based on the chain of PH and ORP according to claim 2, wherein the method comprises the following steps: the acid regulating agent in the second step is 5-30% of sulfuric acid; the ferrous reagent is 15-20% ferrous sulfate; the concentration ratio of hydrogen peroxide to ferrous sulfate in the third step is (1.50-8.50): 1; and the COD value concentration ratio of the hydrogen peroxide solution in the third step to the wastewater in the water quality regulating tank is (1.15-2.20): 1.

4. the method for automatically adjusting Fenton process parameters based on the chain of PH and ORP according to claim 1, wherein the method comprises the following steps: the solute mass fraction of the aluminum sulfate solution in the fourth step is 15-20%; and the mass fraction of the solute of the calcium hydroxide solution in the fifth step is 3.0-5.5%.

5. The method for automatically adjusting Fenton process parameters based on the chain of PH and ORP according to claim 2, wherein the method comprises the following steps: the filtering treatment adopts a combined filtering body, and the SS index of the sewage filtered by the combined filtering body is reduced to below 50 mg/L.

6. The method for automatically adjusting Fenton process parameters based on the chain of PH and ORP according to claim 1, wherein the method comprises the following steps: and step three, introducing an ozone/nitrogen gas ratio of 1: (1-3) introducing the promoting gas to the bottom of the catalytic reaction tank; the intake amount of the promoting gas is 8.0-20ml/(L × s).

7. The method for automatically adjusting Fenton process parameters based on the chain of PH and ORP according to claim 1, wherein the method comprises the following steps: and in the fourth step, the chromaticity of the sewage is detected in real time, the aluminum sulfate solution is continuously added into the sewage at the adding speed of 2.0-5.0 kg/min, the mixture is stirred and mixed uniformly, and when the chromaticity is lower than 20 times, the aluminum sulfate solution is stopped being added.

8. The method for automatically adjusting Fenton process parameters based on the chain of PH and ORP according to claim 1, wherein the method comprises the following steps: and controlling the temperature of the sewage in the catalytic reaction tank in the fourth step to be 20-35 ℃.