CN113912220A - Process for treating caprolactam ammoximation wastewater by hydrogen peroxide catalytic oxidation - Google Patents
Process for treating caprolactam ammoximation wastewater by hydrogen peroxide catalytic oxidation Download PDFInfo
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- CN113912220A CN113912220A CN202111361351.1A CN202111361351A CN113912220A CN 113912220 A CN113912220 A CN 113912220A CN 202111361351 A CN202111361351 A CN 202111361351A CN 113912220 A CN113912220 A CN 113912220A
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F9/00—Multistage treatment of water, waste water or sewage
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/001—Processes for the treatment of water whereby the filtration technique is of importance
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/66—Treatment of water, waste water, or sewage by neutralisation; pH adjustment
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
- C02F1/722—Oxidation by peroxides
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
- C02F1/725—Treatment of water, waste water, or sewage by oxidation by catalytic oxidation
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/30—Organic compounds
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/34—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32
- C02F2103/36—Nature of the water, waste water, sewage or sludge to be treated from industrial activities not provided for in groups C02F2103/12 - C02F2103/32 from the manufacture of organic compounds
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- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2209/00—Controlling or monitoring parameters in water treatment
- C02F2209/08—Chemical Oxygen Demand [COD]; Biological Oxygen Demand [BOD]
Abstract
The invention provides a process for treating caprolactam ammoximation wastewater by hydrogen peroxide catalytic oxidation, which belongs to the technical field of wastewater treatment and comprises a buffer tank, a first lifting pump, a precision filter, a first pH adjusting tank, a second lifting pump, a double-screw efficient pipeline mixer, a catalytic oxidation reactor, a second pH adjusting tank, a third lifting pump, a blower, a sulfuric acid dosing device, a hydrogen peroxide dosing device and a sodium hydroxide dosing device. The invention utilizes the air blower to provide air and disturbance power for catalytic oxidation reaction, the bottom of the reactor is provided with the high-efficiency air distributor to form high-efficiency impinging stream, and the reactor is filled with high-efficiency catalyst which is matched with the strong oxidation effect of hydrogen peroxide to ensure that the added hydrogen peroxide and the residual hydrogen peroxide in the wastewater carry out full deep oxidation reaction with organic matters in the reactor, thereby improving the removal rate of the organic matters in the wastewater and being greatly higher than the traditional advanced oxidation process.
Description
Technical Field
The invention belongs to the technical field of wastewater treatment, and particularly relates to a process for treating caprolactam ammoximation wastewater by hydrogen peroxide catalytic oxidation.
Background
Caprolactam is an important production raw material for preparing nylon-6 fibers and engineering plastics and is widely applied in the field of polymer materials. With the expansion and development of application fields of engineering plastics, films, artificial leathers and the like, the production and demand thereof are continuously increasing. The caprolactam production process has long flow, large amount of circulating materials, more byproducts and intermediate products, complex components of wastewater, high toxicity and belongs to high-concentration nitrogen-containing organic wastewater, and is one of the production wastewater which is difficult to treat in the current petrochemical industry. In particular to ammoximation unit sewage, hydrogen peroxide, liquid ammonia and cyclohexanone are adopted as raw materials, cyclohexanone oxime is directly generated through one-step reaction, and caprolactam is produced under the action of fuming sulfuric acid. The process has the problems of large water quantity, high COD, low BOD/COD ratio, complex composition, difficult biochemical treatment and the like, is difficult to treat caprolactam sewage, and brings great pressure to the environmental protection of enterprises.
At present, domestic and overseas methods for treating sewage by an ammoximation unit process mainly comprise an ozone catalytic oxidation method, a Fenton oxidation method, an electrocatalytic oxidation method, an iron-carbon micro-electrolysis oxidation method and the like, and the process has the defects that: (1) residual hydrogen peroxide in the wastewater cannot be consumed in the reaction process; (2) a large amount of sludge and secondary pollution are generated in the reaction process; (3) the catalyst can be hardened in a short time, so that the treatment effect is influenced; (4) the removal rate of COD is unstable; (5) the investment cost in the early stage and the operation cost in the later stage are high.
The prior art discloses a plurality of methods for treating caprolactam ammoximation wastewater, for example, CN111268757A discloses a novel method for treating wastewater produced by a caprolactam ammoximation process, the method comprises the steps of adsorption, replacement, back flushing, regeneration and the like, the utilization rate of resin is improved by more than 60 percent compared with a fixed bed, the removal rate of organic matters is as high as more than 85 percent, but the patent does not solve the technical problems of unstable removal rate of residual hydrogen peroxide and COD in wastewater and the like.
Application number CN101618919A discloses a method for treating wastewater produced by caprolactam ammoximation process, which comprises adding an oxidant into the wastewater to be treated, oxidizing organic matters which have impact on a biochemical system in the wastewater into organic matters harmless to microorganisms through oxidation reaction, allowing the oxidized wastewater to enter a flocculation settling tank for flocculation and precipitation, and after impurities are settled, mixing effluent with other wastewater and then allowing the effluent to enter the biochemical system for further treatment. Although the method can improve the biodegradability of the wastewater and reduce the content of organic matters in the wastewater, the method also has the technical problems of large residual quantity of oxidant, high operation cost and the like.
Disclosure of Invention
The invention aims to overcome the technical defects, provides a process for treating caprolactam ammoximation wastewater by hydrogen peroxide catalytic oxidation, and solves the technical problems that in the prior art, residual hydrogen peroxide in wastewater cannot be consumed in the reaction process, a large amount of sludge and secondary pollution are generated in the reaction process, a catalyst can be hardened in a short time, the treatment effect is influenced, the COD removal rate is unstable, the early-stage investment cost and the later-stage operation cost are high, and the like.
In view of the above, the invention provides a process for treating caprolactam ammoximation wastewater by hydrogen peroxide catalytic oxidation, which comprises the following steps:
(1) conveying caprolactam production wastewater into a buffer tank, and lifting the wastewater in the buffer tank into a precision filter by using a first lifting pump for filtering;
(2) conveying the filtered wastewater into a first pH adjusting tank, and adding sulfuric acid into the first pH adjusting tank by a sulfuric acid adding device to adjust the pH of the wastewater;
(3) lifting the wastewater after pH adjustment to a water distributor at the bottom of the catalytic oxidation reactor by using a second lifting pump, adding hydrogen peroxide by using a hydrogen peroxide adding device on a double-helix-rod efficient pipeline mixer of a water outlet pipe, filling a catalyst in the reactor, and starting an air blower for catalytic oxidation treatment;
(4) and the wastewater after the catalytic oxidation treatment automatically flows to a second pH adjusting tank, sodium hydroxide is added into the second pH adjusting tank by a sodium hydroxide adding device to adjust the pH, and after the pH adjustment is finished, water is discharged by a third lift pump and is discharged to the next process unit.
The purpose of adopting the buffer tank is to play the roles of buffering, temporary storage and homogenizing.
The precision filter is mainly used for removing residual trace suspended particles, colloids, microorganisms and the like in the wastewater, and the suspended particles, the colloids, the microorganisms and the like are trapped or adsorbed on the surface and in pores of the filter element, and the SS of effluent is less than 10 mg/L.
Preferably, the pH value of the caprolactam production wastewater in the step (1) is 12-13.
Preferably, the pH value of the wastewater is adjusted to 5-6 in the step (2).
Preferably, the time of the catalytic oxidation treatment in the step (3) is 1 to 2 hours.
Preferably, the catalyst in the step (3) is formed by taking activated carbon as a carrier and loading one or more active metals, wherein the active metals are at least one of iron, calcium, magnesium, copper, manganese, cobalt, aluminum, platinum and silver, and the loading amount of the active metals is 4.5-5.0 wt%. The catalyst is used for improving the oxidizing ability of hydrogen peroxide.
The addition of the active metal can enhance the tolerance of the catalyst to P, S, prevent the catalyst from being poisoned, improve the strength of the carrier without influencing the specific surface area of the active carbon, enhance the dispersion degree of the active component, form a synergistic effect with the active component and further improve the stability and the selectivity of the catalyst. The modified high-quality active carbon is processed into high-temperature smelting different from the conventional modified high-quality active carbon and then is deeply processed into the high-quality unique catalyst.
Preferably, the pH value of the effluent in the step (4) is 7-9.
The invention utilizes the air blower to provide air and disturbance power for catalytic oxidation reaction, the bottom of the reactor is provided with the high-efficiency air distributor to form high-efficiency impinging stream, the reactor is filled with high-efficiency catalyst, and the high-efficiency catalyst is matched with the strong oxidation effect of hydrogen peroxide, so that the added hydrogen peroxide and the residual hydrogen peroxide in the wastewater are subjected to full deep oxidation reaction with organic matters in the reactor, a plurality of catalytic oxidation modes are adopted to treat caprolactam production wastewater, and the broken bonds of organic polymers are changed into micromolecular organic matters or monomolecular substances by effectively breaking the atomic bonds, so that the difficultly-degradable pollutants in the wastewater are degraded to the maximum extent, thereby improving the removal rate of the organic matters in the wastewater and being greatly higher than that of the traditional advanced oxidation process.
Compared with the prior art, the invention has the following beneficial effects: (1) residual hydrogen peroxide in the wastewater is effectively utilized, and the concentration of the peroxide in the effluent is reduced to below 10 mmol/L; (2) sludge and secondary pollution are not generated in the treatment process; (3) the catalyst is not hardened after long-term use; (4) the COD removal rate is stabilized to 50 percent, the COD of the inlet water is about 5000mg/L, and the outlet water can be reduced to 2500 mg/L; (5) the investment cost in the early stage and the operation cost in the later stage are low.
Drawings
FIG. 1 is a schematic structural diagram of a process for treating caprolactam ammoximation wastewater by hydrogen peroxide catalytic oxidation;
the reference signs are:
1. a buffer tank; 2. a first lifting pump; 3. a precision filter; 4. a first pH adjusting tank; 5. a second lifting pump; 6. a double helix rod high efficiency pipeline mixer; 7. a catalytic oxidation reactor; 8. a pH adjusting tank II; 9. a third lifting pump; 10. a blower; 11. a sulfuric acid dosing device; 12. a hydrogen peroxide dosing device; 13. sodium hydroxide medicine device.
Detailed Description
In order to make the objects, technical solutions and advantages of the present invention more apparent, the technical solutions of the present invention will be clearly and completely described below. It is to be understood that the described embodiments are merely exemplary of the invention, and not restrictive of the full scope of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The test methods or test methods described in the following examples are conventional methods unless otherwise specified; the starting materials and auxiliaries are, unless otherwise specified, obtained from customary commercial sources or prepared in customary manner.
It should be noted that the terms "front," "back," "left," "right," "upper" and "lower" used in the following description refer to directions in the drawings, and the terms "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.
In order to make the content of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings of the present invention.
The connection relationship between the devices of the present invention is as follows:
the caprolactam ammoximation wastewater automatically flows to 1, a buffer tank is lifted to 3 by a first lifting pump 2, a precision filter is used for discharging water to 4, a pH adjusting tank I is lifted to 7 by a second lifting pump 5, a catalytic oxidation reactor is connected between the first lifting pump and the second lifting pump, 6 and a double-screw efficient pipeline mixer are connected between the first lifting pump and the second lifting pump, the discharging water automatically flows to 8, the pH adjusting tank II is lifted to the next process unit by a third lifting pump 9;
10. and aerating the catalytic oxidation reactor 7 and the air blower to provide air required by the catalytic oxidation reaction, adding sulfuric acid into the pH adjusting tank I4 and the sulfuric acid adding device 11, adjusting the pH of the wastewater, adding hydrogen peroxide into the double-helix-rod efficient pipeline mixer 6 and the hydrogen peroxide adding device 12, adding sodium hydroxide into the pH adjusting tank II 8 and the sodium hydroxide adding device 13, and adjusting the pH of the effluent.
Example 1
(1) Conveying caprolactam production wastewater with the pH value of 12 to a buffer tank, and lifting the wastewater in the buffer tank to a precision filter by using a first lifting pump for filtering;
(2) conveying the filtered wastewater into a first pH adjusting tank, adding 98% sulfuric acid into the first pH adjusting tank by a sulfuric acid adding device, wherein the adding proportion is 0.06% of the volume of the wastewater, and adjusting the pH of the wastewater to 5-6;
(3) lifting the wastewater after pH adjustment to a water distributor at the bottom of the catalytic oxidation reactor by using a second lifting pump, simultaneously adding 30% of hydrogen peroxide on a double-helix-rod efficient pipeline mixer of a water outlet pipe by using a hydrogen peroxide adding device, wherein the adding proportion is 0.2% of the volume of the wastewater, filling a catalyst into the reactor, the filling proportion of the catalyst is 50%, starting an air blower, and aerating at 2L/(m) with the aeration amount2S), the wind pressure is 6-10 m, and catalytic oxidation treatment is carried out for 2 h;
(4) the wastewater after catalytic oxidation treatment automatically flows to a second pH adjusting tank, a sodium hydroxide solution with the concentration of 30% is added into the second pH adjusting tank by a sodium hydroxide dosing device, the adding proportion is 0.001% of the volume of the wastewater, the pH is adjusted to 7-9, after the pH adjustment is finished, water is pumped out by a third lift pump, and the effluent is discharged to the next process unit;
(5) the air outlet of the blower is connected with the high-efficiency air distributor at the bottom of the reactor, and disturbance power and required oxygen are provided for the catalytic oxidation reaction.
The water quality index and operation cost comparison data of the wastewater before and after treatment are shown in Table 1.
TABLE 1 comparison data of wastewater quality and operation cost in hydrogen peroxide treatment
The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.
Claims (5)
1. A process for treating caprolactam ammoximation wastewater by hydrogen peroxide catalytic oxidation is characterized by comprising the following steps:
(1) conveying caprolactam production wastewater into a buffer tank, and lifting the wastewater in the buffer tank into a precision filter by using a first lifting pump for filtering;
(2) conveying the filtered wastewater into a first pH adjusting tank, and adding sulfuric acid into the first pH adjusting tank by a sulfuric acid adding device to adjust the pH of the wastewater;
(3) lifting the wastewater after pH adjustment to a water distributor at the bottom of the catalytic oxidation reactor by using a second lifting pump, adding hydrogen peroxide by using a hydrogen peroxide adding device on a double-helix-rod efficient pipeline mixer of a water outlet pipe, filling a catalyst in the reactor, and starting an air blower for catalytic oxidation treatment;
(4) and the wastewater after the catalytic oxidation treatment automatically flows to a second pH adjusting tank, sodium hydroxide is added into the second pH adjusting tank by a sodium hydroxide adding device to adjust the pH, and after the pH adjustment is finished, water is discharged by a third lift pump and is discharged to the next process unit.
2. The process for treating caprolactam ammoximation wastewater by using hydrogen peroxide through catalytic oxidation according to claim 1, wherein the pH of the caprolactam production wastewater in the step (1) is 12-13.
3. The process for treating caprolactam ammoximation wastewater by using hydrogen peroxide through catalytic oxidation according to claim 1, wherein the pH value of the wastewater in the step (2) is adjusted to 5-6.
4. The process for treating caprolactam ammoximation wastewater by catalytic oxidation with hydrogen peroxide as claimed in claim 1, wherein the catalytic oxidation treatment time in the step (3) is 1-2 h.
5. The process for treating caprolactam ammoximation wastewater by catalytic oxidation with hydrogen peroxide as claimed in claim 1, wherein the pH of the effluent in the step (4) is 7-9.
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| Application Number | Priority Date | Filing Date | Title |
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| CN202111361351.1A CN113912220A (en) | 2021-11-17 | 2021-11-17 | Process for treating caprolactam ammoximation wastewater by hydrogen peroxide catalytic oxidation |
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| CN202111361351.1A CN113912220A (en) | 2021-11-17 | 2021-11-17 | Process for treating caprolactam ammoximation wastewater by hydrogen peroxide catalytic oxidation |
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101618919A (en) * | 2008-06-30 | 2010-01-06 | 中国石油化工股份有限公司 | Method for processing waste water produced by caprolactam ammoximation process |
| CN101734825A (en) * | 2008-11-20 | 2010-06-16 | 中国石油化工股份有限公司 | Method for treating wastewater generated by cyclohexanone ammoximation process |
| CN104556344A (en) * | 2014-12-22 | 2015-04-29 | 中国天辰工程有限公司 | Treatment method for sewage produced in caprolactam ammoximation process |
| CN105347549A (en) * | 2015-11-09 | 2016-02-24 | 中油辽河工程有限公司 | Device for processing thickened oil produced water by utilization of composite advanced oxidation process and technology |
| CN105502732A (en) * | 2015-12-01 | 2016-04-20 | 上海明诺环境科技有限公司 | Advanced treatment technology for caprolactam wastewater and device |
| CN108275825A (en) * | 2017-09-29 | 2018-07-13 | 聊城煤泗新材料科技有限公司 | A kind of caprolactam oximate wastewater treatment method |
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2021
- 2021-11-17 CN CN202111361351.1A patent/CN113912220A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101618919A (en) * | 2008-06-30 | 2010-01-06 | 中国石油化工股份有限公司 | Method for processing waste water produced by caprolactam ammoximation process |
| CN101734825A (en) * | 2008-11-20 | 2010-06-16 | 中国石油化工股份有限公司 | Method for treating wastewater generated by cyclohexanone ammoximation process |
| CN104556344A (en) * | 2014-12-22 | 2015-04-29 | 中国天辰工程有限公司 | Treatment method for sewage produced in caprolactam ammoximation process |
| CN105347549A (en) * | 2015-11-09 | 2016-02-24 | 中油辽河工程有限公司 | Device for processing thickened oil produced water by utilization of composite advanced oxidation process and technology |
| CN105502732A (en) * | 2015-12-01 | 2016-04-20 | 上海明诺环境科技有限公司 | Advanced treatment technology for caprolactam wastewater and device |
| CN108275825A (en) * | 2017-09-29 | 2018-07-13 | 聊城煤泗新材料科技有限公司 | A kind of caprolactam oximate wastewater treatment method |
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