CN101659467B

CN101659467B - Method for treating sewage by Fenton process

Info

Publication number: CN101659467B
Application number: CN 200810119444
Authority: CN
Inventors: 侯钰; 李本高; 桑军强
Original assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Current assignee: Sinopec Research Institute of Petroleum Processing; China Petroleum and Chemical Corp
Priority date: 2008-08-29
Filing date: 2008-08-29
Publication date: 2013-01-09
Anticipated expiration: 2028-08-29
Also published as: CN101659467A

Abstract

The invention provides a method for treating sewage by Fenton process, which comprises: adopting a multistage serial reactor or a single-stage continuous reactor; adding a catalyst in the initial stage of a reaction; adjusting the pH value to 1.5 to 6.5; sequentially adding an oxidizer in the multistage serial reactor or adding the oxidizer at a plurality of points along water flow direction in the single-stage continuous reactor; and controlling the total additive amount of the oxidizer calculated by mg/L to be smaller than sewage COD value calculated by mg/L. Compared with the conventional method using a single-stage Fenton process, the method requires a greatly reduced amount of the oxidizer and the catalyst for achieving the same treatment effect and reduces treatment cost.

Description

A kind of method of utilizing Fenton process to dispose of sewage

Technical field

The present invention relates to a kind of method of sewage disposal, especially a kind of method of utilizing Fenton process to dispose of sewage.

Background technology

Fenton (Fenton) method is a kind of in the wastewater treatment technology of advanced oxidation, refers to H ₂O ₂At Fe ²⁺Katalysis under produce the OH with strong oxidizing property, OH makes organism generation chain rupture or open loop by attack c h bond, C=C key or C ≡ C key, and by the process of rapid oxygenolysis.High and the toxicological harmless of this method efficient especially has outstanding advantage aspect the difficult biochemical sewage processing, and can be CO with the refractory organic exhaustive oxidation both ₂And H ₂O, thereby the COD of reduction sewage; Also can be the small molecules oxygen-bearing organic matter (such as alcohol, aldehyde, ketone, carboxylic acid etc.) of readily biodegradable with the refractory organic partial oxidation, thereby improve the biodegradability of sewage.But because the Fenton method need to be used the H of higher concentration ₂O ₂And Fe ²⁺Catalyzer makes processing cost higher and produce more iron mud, has limited applying of Fenton method.Therefore, need to improve the Fenton method, to improve treatment effect, reduce H ₂O ₂And Fe ²⁺The usage quantity of catalyzer, reduce mud amount and reduction running cost.

At present, domestic and foreign literature has in a large number about improving the report of Fenton method, for example:

1) proposes a kind of method and apparatus that ultrasonic wave is used for promoting Fenton method processing high concentration organic sewage among the CN1270979C, utilize flexible ultrasonic ripple, aeration, atomic state iron coupling, form little aeration-ultrasonic-iron-Fenton system.Adopt this device that alkaline straw-pulp black liquid is processed, at frequency 20Hz, sound intensity 2w/cm ²Lower ultrasonic wave aeration 5min is at frequency 20kHz, sound intensity 2w/cm ²Lower ultrasonic irradiation 10min can make the comprehensive toxicity of water outlet obviously descend, and biodegradability improves 50%, COD clearance and improves 30%.Present method need add ultrasonic generator, and investment and running cost increase, and Technical Economy is relatively poor, and processing power is less, is not suitable for for the treatment of sewage in enormous quantities.

2), propose among the CN1179889C electrochemical method is introduced the Fenton system, utilize dull and stereotyped return-flow type electrolysis mode, improve Fe ³⁺In the speed of reaction of negative electrode, and in reaction process, add continuously H ₂O ₂, make n (Fe in the solution ³⁺)/n (Fe ²⁺)-directly maintains high value, at Fe ³⁺Dosage is 1000mg/L, H ₂O ₂Dosage 7.7g/h increases behind the electrolytic reaction 3h aniline clearance and reaches 100%, COD clearance and reach 80.2%, obviously is better than not adding behind the electrolysis reaction 3h aniline clearance and reaches 90%, COD clearance and reach-13.0% treatment effect.The pH of present method operation is lower than conventional Fenton method, and adds the electrolytic reaction pond less than 2.5, and investment and running cost are increased.

3), propose Fe among the US2006/0138057A1 ³⁺Load on the HY type molecular sieve, be used for catalysis light and help the Fenton method, the processing rear catalyst still in solid phase, easily separates with sewage, thereby makes treating processes no longer be subjected to the restriction of pH.Operation pH is 6, and when processing 30min, the clearance of phenol reaches 93.8%, 37% phenol clearance when helping Fenton method 30min apparently higher than former light.Present method becomes heterogeneous catalysis with traditional homogeneous catalysis, has solved the iron sludge problem, but has the problem of catalyzer preparation and regeneration, in addition, and the mass transfer problem in the use procedure and Fe ³⁺The stripping problem also needs present method is carried out further perfect.

In sum, the thinking of improving at present the Fenton method mainly concentrates on to increase other householder methods and become homogeneous catalysis and is the heterogeneous catalysis aspect.Although these methods can improve treatment effect to a certain extent, it brings investment and running cost significantly to increase, and makes the economy variation of technology, is restricted thereby make to apply.

Summary of the invention

The invention provides a kind of method of utilizing Fenton process to dispose of sewage, the method adopts plural serial stage tandem type reactor or single-stage flow reactor, can improve the utilization ratio of oxygenant and catalyzer, reaches the purpose that reduces processing cost and reduce mud amount.

The method of utilizing Fenton process to dispose of sewage provided by the invention comprises: adopt plural serial stage tandem type reactor or single-stage flow reactor, add catalyzer in the reaction starting stage, regulate pH between 1.5～6.5, oxygenant is added successively at the plural serial stage tandem type reactor, or at the single-stage flow reactor along the water (flow) direction multi-point adding, the control total dosage of oxygenant (in mg/L) is less than the COD value (in mg/L) of sewage.

Said oxygenant is hydrogen peroxide.Also can be a kind of in clorox, potassium hypochlorite and the ozone.

Said plural serial stage tandem type reactor can be intermittently tank reactor, continuous flow tank reactor etc.According to the COD that COD and the needs of initial sewage are removed, reactor progression is generally 2～10 grades.Under the identical condition of the total dosage of oxygenant, progression is higher, and the removal effect of COD is better.

Said single-stage flow reactor can be tubular reactor or tower reactor etc., and according to the COD that COD and the needs of initial sewage are removed, oxygenant adds to count and can be 2～10 points.Under the identical condition of the total dosage of oxygenant, add and count manyly, the removal effect of COD is better.

According to the inventive method, the total dosage of oxygenant (in mg/L) is less than the COD value (in mg/L) of sewage, the oxidant content that at every turn adds (in mg/L) preferably is no more than current COD value (in mg/L), is more preferably less than current COD value (in mg/L).The oxidant content that at every turn adds can equivalent, also can successively decrease in current COD ratio.

Said catalyzer can be to be selected from the metal ion of IB, IIB, VIB, VIIB and VIII family or to be selected from MnO ₂, TiO ₂And Al ₂O ₃A kind of in the metal oxide, preferred Fe ²⁺, Fe ³⁺, Mn ²⁺, Ni ²⁺, Co ²⁺, Cd ²⁺, Cu ²⁺, Ag ⁺, Cr ³⁺And Zn ²⁺In a kind of, Fe particularly preferably ²⁺Fe ²⁺Catalyzer can be by being selected from FeSO ₄, FeCl ₂, Fe (NO ₃) ₂, Fe ₃(PO ₄) ₂, Ferrox and ferrous citrate etc. molysite preferred FeSO is provided ₄And FeCl ₂Catalyzer and H ₂O ₂Mol ratio between 0.1～5.0, preferred 0.5～1.5.

React initial pH value between 1.5～6.5, preferred 2.0～5.0.Regulating the used acid solution of pH can be H ₂SO ₄, HNO ₃Or other mineral acids, preferred H ₂SO ₄

Hydraulic detention time in each stage reactor between 0.1～5.0h, preferred 0.3～1.5h.

The present invention has following advantage:

1), compare with traditional single stage Fenton method technique, oxygenant and catalyst levels when reaching the same treatment effect significantly reduce, and processing cost reduces;

2), compare with traditional single stage Fenton method technique, sludge quantity significantly reduces;

3), can process various concentration, various types of sewage.

Embodiment

The present invention will be further described in detail below in conjunction with embodiment, the scope that the claimed scope of the present invention represents including, but not limited to embodiment.

Embodiment 1

Process the still water outlet not up to standard after secondary biochemical treatment of certain oil refining enterprise high-concentration sewage, adopt two-stage tandem complete mixing flow reactor to carry out Fenton reaction, every grade of dosage 50mg/LH ₂O ₂, total dosage is 100mg/L, catalyzer is selected FeSO ₄, and make n (Fe ²⁺)/n (H ₂O ₂) [Fe ²⁺Ion and H ₂O ₂Mol ratio] reach 0.7, use H ₂SO ₄The pH that disposes of sewage is controlled at about 3.0 hydraulic detention time 1h.The traditional F enton method technique that contrasts therewith, the disposable 100mg/LH that adds ₂O ₂, other condition is identical with the inventive method.The result of two kinds of methods is as shown in table 1.Table 1 result demonstration, influent COD is 135.7mg/L, H ₂O ₂When dosage was identical, the water outlet COD of the inventive method was 78.4mg/L, and the water outlet COD of traditional F enton method is 93.8mg/L.

Two kinds of Fenton methods of table 1 are processed petroleum chemical enterprise's sewage effect not up to standard relatively

Embodiment 2

Process certain chemical enterprise difficult biochemical sewage not up to standard still after three grades of BAF process, adopt level Four series connection complete mixing flow reactor to carry out Fenton reaction, every grade of dosage 25mg/LH ₂O ₂, total dosage is 100mg/L, catalyzer is selected Fe (NO ₃) ₂, and make n (Fe ²⁺)/n (H ₂O ₂) reach 1.0, use rare HNO ₃PH is controlled at about 4.0 hydraulic detention time 1h.The traditional F enton method technique that contrasts therewith, the disposable 100mg/LH that adds ₂O ₂, other condition is identical with the inventive method.The result of two kinds of method processing is as shown in table 2.Table 2 result demonstration, influent COD is 124.1mg/L, and the water outlet COD of the inventive method is 53.0mg/L, and the water outlet COD of traditional F enton method is 85.1mg/L.

Two kinds of Fenton methods of table 2 are processed in the oil refining enterprise sewage effect not up to standard and are compared

Embodiment 3

Process the still water outlet not up to standard after secondary biochemical treatment of certain oil refining enterprise high-concentration sewage, adopt six grades of series connection complete mixing flow reactors, every grade of H ₂O ₂Dosage is 1/10 of current C OD value, and total dosage is 105mg/L, and catalyzer is selected Fe (NO ₃) ₂, and make n (Fe ²⁺)/n (H ₂O ₂) reach 0.8, use rare HNO ₃PH is controlled at about 2.0 hydraulic detention time 1.5h.The traditional F enton method technique that contrasts therewith, the disposable 105mg/LH that adds ₂O ₂, other condition is identical with the inventive method.The result of two kinds of method processing is as shown in table 3.Table 3 result demonstration, influent COD is 254.2mg/L, and the water outlet COD of the inventive method is 99.3mg/L, and the water outlet COD of traditional F enton method is 183.5mg/L.

Two kinds of Fenton methods of table 3 are processed petroleum chemical enterprise's sewage effect not up to standard relatively

Embodiment 4

Process the sewage of certain oil refining enterprise after three grades of air supportings are processed, adopt plug flow reactor, divide add H at 9 along water (flow) direction ₂O ₂, each dosage is 10mg/L, amounts to 90mg/L, catalyzer is selected FeSO ₄, and make n (Fe ²⁺)/n (H ₂O ₂) reach 1.0, use rare H ₂SO ₄PH is controlled at about 3.0 hydraulic detention time 1h.The traditional F enton method technique that contrasts therewith, the disposable 90mg/LH that adds ₂O ₂, other condition is identical with the inventive method.The result of two kinds of methods is as shown in table 4.Table 4 result demonstration, influent COD is 156.4mg/L, and the water outlet COD of the inventive method is 43.3mg/L, and the water outlet COD of traditional F enton method is 111.4mg/L.

Two kinds of Fenton methods of table 4 are processed the difficult biochemical sewage effect of oil refining enterprise relatively

Claims

1. method of utilizing Fenton process to dispose of sewage, comprise: adopt plural serial stage tandem type complete mixing flow reactor or single-stage continous way plug flow reactor, add catalyzer in the reaction starting stage, regulate pH between 1.5～6.5, oxygenant is added successively at the plural serial stage tandem type reactor, or at the single-stage flow reactor along the water (flow) direction multi-point adding, control in the total dosage of the oxygenant of mg/L less than the COD of sewage value in mg/L, wherein, catalyzer is selected from Fe ²⁺, Fe ³⁺, Mn ²⁺, Ni ²⁺, Co ²⁺, Cd ²⁺, Cu ²⁺, Ag ⁺, Cr ³⁺And Zn ²⁺In a kind of, hydraulic detention time in each stage reactor between 0.1～5.0h, described sewage be the oil refining enterprise high-concentration sewage through still water outlet not up to standard, chemical enterprise after the secondary biochemical treatment after three grades of BAF process still difficult biochemical sewage not up to standard, oil refining enterprise high-concentration sewage through water outlet or the sewage of oil refining enterprise after three grades of air supportings are processed not up to standard still after the secondary biochemical treatment.

2. in accordance with the method for claim 1, it is characterized in that, said plural serial stage tandem type complete mixing flow reactor, progression is 2～10 grades.

3. in accordance with the method for claim 1, it is characterized in that, said single-stage continous way plug flow reactor, oxygenant add and count is 2～10 points.

4. in accordance with the method for claim 1, it is characterized in that, said oxygenant is hydrogen peroxide.

5. in accordance with the method for claim 1, it is characterized in that, the oxidant content that at every turn adds is no more than current COD value.

6. in accordance with the method for claim 1, it is characterized in that, the oxidant content that at every turn adds is less than current COD value.

7. in accordance with the method for claim 1, it is characterized in that, the oxidant content that at every turn adds is equivalent, or successively decreases in current COD ratio.

8. in accordance with the method for claim 1, it is characterized in that catalyzer and H ₂O ₂Mol ratio between 0.1～5.0.

9. in accordance with the method for claim 1, it is characterized in that catalyzer and H ₂O ₂Mol ratio between 0.5～1.5.

10. in accordance with the method for claim 1, it is characterized in that, the reaction initial pH value is between 1.5～6.5.