CN116768301A - Pretreatment method of nitrobenzene wastewater - Google Patents
Pretreatment method of nitrobenzene wastewater Download PDFInfo
- Publication number
- CN116768301A CN116768301A CN202310704550.0A CN202310704550A CN116768301A CN 116768301 A CN116768301 A CN 116768301A CN 202310704550 A CN202310704550 A CN 202310704550A CN 116768301 A CN116768301 A CN 116768301A
- Authority
- CN
- China
- Prior art keywords
- nitrobenzene wastewater
- wastewater
- nitrobenzene
- pretreatment method
- heating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- LQNUZADURLCDLV-UHFFFAOYSA-N nitrobenzene Chemical compound [O-][N+](=O)C1=CC=CC=C1 LQNUZADURLCDLV-UHFFFAOYSA-N 0.000 title claims abstract description 292
- 239000002351 wastewater Substances 0.000 title claims abstract description 160
- 238000002203 pretreatment Methods 0.000 title claims abstract description 38
- 238000000034 method Methods 0.000 claims abstract description 61
- IOVCWXUNBOPUCH-UHFFFAOYSA-M Nitrite anion Chemical compound [O-]N=O IOVCWXUNBOPUCH-UHFFFAOYSA-M 0.000 claims abstract description 34
- 238000010438 heat treatment Methods 0.000 claims abstract description 34
- 230000008569 process Effects 0.000 claims abstract description 33
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 32
- 239000003513 alkali Substances 0.000 claims abstract description 21
- 238000002347 injection Methods 0.000 claims abstract description 15
- 239000007924 injection Substances 0.000 claims abstract description 15
- 238000002360 preparation method Methods 0.000 claims abstract description 14
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 claims description 33
- QAOWNCQODCNURD-UHFFFAOYSA-N Sulfuric acid Chemical compound OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 claims description 22
- 239000003245 coal Substances 0.000 claims description 22
- 230000020477 pH reduction Effects 0.000 claims description 20
- 239000002002 slurry Substances 0.000 claims description 19
- 235000011121 sodium hydroxide Nutrition 0.000 claims description 11
- 238000010025 steaming Methods 0.000 claims description 10
- ODINCKMPIJJUCX-UHFFFAOYSA-N Calcium oxide Chemical compound [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 claims description 6
- 239000002253 acid Substances 0.000 claims description 5
- 150000007522 mineralic acids Chemical class 0.000 claims description 4
- 230000007363 regulatory process Effects 0.000 claims description 4
- 239000000243 solution Substances 0.000 claims description 4
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims description 3
- 235000011941 Tilia x europaea Nutrition 0.000 claims description 3
- 239000000292 calcium oxide Substances 0.000 claims description 3
- 235000012255 calcium oxide Nutrition 0.000 claims description 3
- 238000005485 electric heating Methods 0.000 claims description 3
- 150000007529 inorganic bases Chemical class 0.000 claims description 3
- 239000004571 lime Substances 0.000 claims description 3
- 239000008267 milk Substances 0.000 claims description 3
- 210000004080 milk Anatomy 0.000 claims description 3
- 235000013336 milk Nutrition 0.000 claims description 3
- 230000001276 controlling effect Effects 0.000 claims description 2
- 230000007797 corrosion Effects 0.000 abstract description 18
- 238000005260 corrosion Methods 0.000 abstract description 18
- 239000003250 coal slurry Substances 0.000 abstract description 14
- 230000002378 acidificating effect Effects 0.000 abstract description 4
- 238000004064 recycling Methods 0.000 abstract description 4
- 230000009286 beneficial effect Effects 0.000 abstract description 3
- 238000012423 maintenance Methods 0.000 abstract description 3
- 238000004537 pulping Methods 0.000 abstract description 3
- 230000000052 comparative effect Effects 0.000 description 19
- LSNNMFCWUKXFEE-UHFFFAOYSA-N Sulfurous acid Chemical compound OS(O)=O LSNNMFCWUKXFEE-UHFFFAOYSA-N 0.000 description 9
- 238000005457 optimization Methods 0.000 description 9
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 8
- 238000004821 distillation Methods 0.000 description 8
- 230000000694 effects Effects 0.000 description 7
- 239000000126 substance Substances 0.000 description 7
- 238000005516 engineering process Methods 0.000 description 6
- 238000004519 manufacturing process Methods 0.000 description 6
- 230000009467 reduction Effects 0.000 description 5
- 229910052742 iron Inorganic materials 0.000 description 4
- 239000005416 organic matter Substances 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 239000000654 additive Substances 0.000 description 3
- 239000003463 adsorbent Substances 0.000 description 3
- 238000009835 boiling Methods 0.000 description 3
- 238000006243 chemical reaction Methods 0.000 description 3
- 239000003344 environmental pollutant Substances 0.000 description 3
- 238000002309 gasification Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 239000000047 product Substances 0.000 description 3
- 238000004065 wastewater treatment Methods 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 2
- 238000000605 extraction Methods 0.000 description 2
- 244000005700 microbiome Species 0.000 description 2
- 229940005654 nitrite ion Drugs 0.000 description 2
- 239000007800 oxidant agent Substances 0.000 description 2
- 231100000719 pollutant Toxicity 0.000 description 2
- 150000003839 salts Chemical class 0.000 description 2
- 238000001179 sorption measurement Methods 0.000 description 2
- IOVCWXUNBOPUCH-UHFFFAOYSA-N Nitrous acid Chemical compound ON=O IOVCWXUNBOPUCH-UHFFFAOYSA-N 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 1
- 239000000440 bentonite Substances 0.000 description 1
- 229910000278 bentonite Inorganic materials 0.000 description 1
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 description 1
- 238000002306 biochemical method Methods 0.000 description 1
- 238000010170 biological method Methods 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 231100000357 carcinogen Toxicity 0.000 description 1
- 239000003183 carcinogenic agent Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000000356 contaminant Substances 0.000 description 1
- 238000010924 continuous production Methods 0.000 description 1
- 239000012043 crude product Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 238000010528 free radical solution polymerization reaction Methods 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000006386 neutralization reaction Methods 0.000 description 1
- -1 nitrite ions Chemical class 0.000 description 1
- 230000008520 organization Effects 0.000 description 1
- 238000000053 physical method Methods 0.000 description 1
- 238000004886 process control Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000003786 synthesis reaction Methods 0.000 description 1
- 238000005406 washing Methods 0.000 description 1
Classifications
-
- 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
- C02F1/02—Treatment of water, waste water, or sewage by heating
- C02F1/04—Treatment of water, waste water, or sewage by heating by distillation or evaporation
-
- 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
-
- 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
- C02F2101/38—Organic compounds containing nitrogen
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
Abstract
The invention discloses a pretreatment method of nitrobenzene wastewater, which specifically comprises the following steps: 1) Firstly, acidizing nitrobenzene wastewater; 2) The characteristic that nitrite is unstable under an acidic condition is utilized, and nitrite in the system is removed in a heating steaming-out mode, so that the corrosion cause is effectively controlled; 3) And (5) feeding the treated water-coal-slurry into a preparation system of the water-coal-slurry after alkali injection adjustment treatment. The pretreatment method has the advantages that: 1) The method reduces the corrosiveness of pulping water from the root, realizes the long-acting property of recycling the nitrobenzene wastewater, and is beneficial to saving water resources; 2) The method can effectively solve or slow down the corrosion problem of equipment, reduce the risk of unplanned shutdown and reduce the maintenance cost; 3) Compared with the existing nitrobenzene wastewater pretreatment process, the process has the advantages of high efficiency, easy implementation and low cost.
Description
Technical Field
The invention relates to the technical field of wastewater treatment, in particular to a pretreatment method of nitrobenzene wastewater.
Background
Nitrobenzene is an extremely important intermediate in chemical synthesis processes, but is also listed in the carcinogen list by the world health organization international cancer research institute, belonging to the priority control of environmental pollutants.
Conventional treatment techniques for nitrobenzene wastewater include biochemical, electrolytic, redox, reduction, advanced oxidation, extraction, adsorption, and the like. The biochemical method is to degrade organic matters in a bioreactor by means of domesticated microorganisms or special microorganisms. Electrolytic processes are processes that degrade organic matter using electrochemical generation of atomic oxygen. The reduction-oxidation method is to reduce the organic matter with reducing agent and then oxidize and degrade the organic matter with oxidizing agent. The reduction method is a biological or chemical method for reducing an organic substance. Advanced oxidation is a method of decomposing organic matter using a chemical oxidizing agent. The extraction method utilizes the selective distribution of solutes in two immiscible solvents to achieve separation of contaminants. The adsorption method is to adsorb pollutants on the adsorbent by using the adsorbent, so as to remove the pollutants in the wastewater. Commonly used adsorbents are activated carbon, fly ash, organic bentonite, resin, etc.
At present, the conventional oxidation method, reduction method and other combined treatment methods have a certain effect on reducing nitrobenzene, but are often high in cost and low in income for enterprises, and the environment protection situation is still severe.
Along with the continuous promotion of the concept of recycling wastewater, the conventional water is replaced by wastewater to prepare the coal water slurry, and the recycling utilization of the wastewater is realized in a gasification mode, so that the method becomes a high-efficiency technical means with strong universality, good economy and simple and convenient operation flow, and has positive significance in the aspects of greatly reducing the conventional wastewater treatment cost, sites, saving water resources and the like. For a method for cooperatively treating nitrobenzene wastewater by using a coal water slurry technology, reference is made to reference 1:
reference 1: chinese patent document with patent publication No. CN102417249 a.
Reference 1 discloses a method for treating nitrobenzene wastewater, which is to prepare a water-coal-slurry additive by utilizing solution polymerization in the wastewater phase, thereby avoiding pollution of nitrobenzene wastewater discharge to the environment and realizing reutilization of nitrobenzene wastewater.
However, in the actual production process of cooperatively treating nitrobenzene wastewater by using the water-coal-slurry technology, the corrosion of the coal slurry is increased due to the high salt content and complex components of the nitrobenzene wastewater, so that a series of production problems caused by corrosion occur in equipment such as a mill, for example, the slurry leakage phenomenon at the bolted joint of a cylinder body is increased, the maintenance frequency of the equipment is increased, and the continuous and stable operation of the production of a coal gasification device is severely restricted.
In order to solve the above technical problems, the applicant has proposed a solution, see reference 2 for details:
reference 2: chinese patent document with patent publication No. CN114772794 a.
Reference 2 discloses a method for cooperatively treating nitrobenzene wastewater by using a coal water slurry technology, which is characterized in that the nitrobenzene wastewater is deoxidized, then nitrite in the iron and nitrobenzene wastewater is utilized to react, and then the reacted nitrobenzene wastewater, coal and additives are subjected to preparation of the coal water slurry. According to the technical scheme, a corrosion control method is provided from the technical point of view, corrosion causes are eliminated, unplanned shutdown caused by corrosion problems is reduced, excessive investment cost of enterprise material resources, manpower, financial resources and other costs is avoided, safe, stable and long-period operation of the coal gasification device is ensured, and meanwhile, water resource saving and wastewater resource utilization capacity is steadily improved.
However, in the technical scheme, iron-containing filler is consumed in pretreatment of the nitrobenzene wastewater, so that the cost for cooperatively treating the nitrobenzene wastewater by the coal water slurry technology is increased.
Disclosure of Invention
The invention aims to solve the problem of high operation cost of nitrobenzene wastewater pretreatment when nitrobenzene wastewater is cooperatively treated by using a water-coal slurry technology in the prior art, and provides a nitrobenzene wastewater pretreatment method.
The invention solves the technical problems, and adopts the following technical scheme: a pretreatment method of nitrobenzene wastewater comprises the steps of firstly carrying out acidification treatment on the nitrobenzene wastewater, and then removing nitrite in the nitrobenzene wastewater in a heating and steaming-out mode.
As a further optimization of the nitrobenzene wastewater pretreatment method, the invention: and controlling the pH value of the nitrobenzene wastewater to be less than or equal to 3 in the acidification process.
As a further optimization of the nitrobenzene wastewater pretreatment method, the invention: the acid used in the acidification process contains H + Is an inorganic acid of (a).
As a further optimization of the nitrobenzene wastewater pretreatment method, the invention: the acid used in the acidification process is sulfuric acid.
As a further optimization of the nitrobenzene wastewater pretreatment method, the invention: the heating means used in the heating and steaming process is electric heating or superheated steam heating.
As a further optimization of the nitrobenzene wastewater pretreatment method, the invention: the temperature of nitrobenzene wastewater in the heating and steaming-out process is not less than 90 ℃.
As a further optimization of the nitrobenzene wastewater pretreatment method, the invention: the heating steaming time is more than or equal to 10min, preferably more than or equal to 15min.
As a further optimization of the nitrobenzene wastewater pretreatment method, the invention: the nitrobenzene wastewater after nitrite removal is sent into a preparation system of the coal water slurry after alkali injection adjustment, and the pH value of the nitrobenzene wastewater is controlled to be 7-10 in the alkali injection adjustment process.
As a further optimization of the nitrobenzene wastewater pretreatment method, the invention: the alkali used in the alkali injection regulating process is OH-containing - Is an inorganic base of (a).
As a further optimization of the nitrobenzene wastewater pretreatment method, the invention: the alkali used in the alkali injection regulating process is one or more of caustic soda flakes, quicklime or lime milk and a solution thereof.
The invention has the following beneficial effects: compared with the existing treatment process, the nitrobenzene wastewater pretreatment method has the advantages of more efficient treatment process, easy implementation and low cost.
Detailed Description
For a better understanding of the present invention, the following examples are set forth to illustrate, but are not to be construed as limiting the invention.
Coal water slurries are typically composed of 60-70% coal, 30-40% water, and small amounts of additives. Because a large amount of water is needed for preparing the water-coal-slurry, nitrobenzene wastewater is adopted to replace conventional water to prepare the water-coal-slurry at present based on the resource utilization of wastewater, but the corrosion of the water-coal-slurry is increased in the actual production process due to the high salt content and complex components of the nitrobenzene wastewater, so that production equipment is corroded.
The nitrobenzene wastewater mainly refers to wastewater generated in the processes of alkali liquor neutralization, water washing and rectification of nitrobenzene crude products. The applicant finds that nitrite ions in nitrobenzene wastewater are the main cause of corrosion, and when the nitrite ion content in nitrobenzene wastewater is reduced, the corrosiveness of the water coal slurry technology on equipment is greatly reduced when the nitrobenzene wastewater is cooperatively treated. In the prior technical scheme, the applicant utilizes nitrite in iron and nitrobenzene wastewater to react, so that the nitrite ion content in the nitrobenzene wastewater can be reduced, and particularly when the nitrite content in the wastewater is reduced to less than or equal to 50 mug/g, the corrosion damage to equipment such as a mill and the like in the preparation process of the coal water slurry is greatly reduced.
The nitrobenzene wastewater pretreatment method specifically comprises the following steps:
1) Firstly, acidizing nitrobenzene wastewater;
wherein, the corrosion of nitrobenzene wastewater to the mill is nitrite, and the mill for coal water slurry mainly refers to a wet overflow type mill, and can be a rod mill or other type mills.
Wherein the nitrite process control index is less than or equal to 50 mug/g, more preferably less than or equal to 40 mug/g;
wherein the temperature of the nitrobenzene wastewater is normal temperature.
Wherein the pH control index of nitrobenzene wastewater in the acidification process is less than or equal to 3;
wherein the acid in the acidification process contains H + Is an inorganic acid;
wherein the inorganic acid in the acidification process is sulfuric acid;
2) By utilizing the characteristic that nitrite is unstable under an acidic condition, nitrite in the system is removed in a heating and steaming-out mode, so that the corrosion cause is effectively controlled.
The heating mode is not limited, and electric heating can be performed or superheated steam heating can be performed;
the heating temperature is not less than 90 ℃;
the heating steaming time is more than or equal to 10min, more preferably more than or equal to 15min;
3) And (5) feeding the treated water-coal-slurry into a preparation system of the water-coal-slurry after alkali injection adjustment treatment.
The pH control index of nitrobenzene wastewater in alkali injection adjustment is 7-10;
the alkali in alkali injection regulation contains OH - An inorganic base of (2);
the inorganic alkali in alkali injection regulation is one or more of caustic soda flakes, quicklime or lime milk and solution thereof.
The acidification process and the alkali injection adjustment process can be performed in a tank or in-line injection.
When nitrobenzene wastewater is not used as coal slurry water, the core of nitrobenzene wastewater treatment technology (physical method, chemical method and biological method) is to remove nitrobenzene, so that the discharge of wastewater meets the environmental index requirement, and therefore, the nitrite content and whether corrosion influence exists are not considered. When nitrobenzene wastewater becomes coal slurry water, the problem of corrosion of mill equipment occurs, and the corrosion cause is nitrite which is first proposed after research, and then an iron reduction method (comparison document 2) is proposed to remove by a chemical method, but the chemical method has higher cost, so an acidification boiling method is proposed.
The acidification boiling method only aims at nitrous acid, and the method is the resource utilization of the wastewater, so that the corrosiveness of the wastewater is reduced, and other substances in the wastewater are not needed to be considered. The method is not applicable to all systems because of different starting angles, for example, whether decomposition, reaction and the like of the target product exist under the acidification condition is required to be considered, so that not only nitrite removal is required to be considered, but also reduction of the target product is required to be considered, and the situation that the target product is not lost is avoided. In addition, nitrite is a corrosion cause in the pulping process of the mill, the changing environment is not necessarily specific to a certain extent, in other words, the nitrite is a similar environment for determining the corrosion cause, and the nitrite has certain universality.
Nitrite is unstable and easily decomposed under acidic conditions, but requires time, and cannot be given enough time to slowly decompose in a practical continuous production process. Thus, it is known to those skilled in the art that nitrite is unstable and readily breaks down under acidic conditions, but is not readily achieved in production, and that acidification is not feasible in light of the considerations, in combination with other processes, such as boiling as set forth in this patent.
3HNO 2 ＝HNO 3 +2NO+H 2 O (acidification primary reaction), partial removal can be seen.
2HNO 2 ＝NO+NO 2 +H 2 O (acidification heating main reaction), all removal can be seen.
The heating and steaming out function is an enhancement of efficiency and practicality.
Example 1 ]
The nitrobenzene wastewater pretreatment method specifically comprises the following steps:
1) And (3) acidizing the nitrobenzene wastewater by utilizing sulfuric acid to enable the pH value of the nitrobenzene wastewater to be 2.
2) Transferring the acidified nitrobenzene wastewater to a removal tower, and heating by utilizing superheated steam to realize top distillation of nitrite in the nitrobenzene wastewater, wherein the bottom temperature of the removal tower is controlled at 100 ℃ and the removal time is 30min.
3) And (3) adjusting the nitrobenzene wastewater after the removal treatment by using caustic soda flakes to ensure that the pH control index is 7-10, and then sending the nitrobenzene wastewater into a preparation system of the coal water slurry.
Example 2 ]
The nitrobenzene wastewater pretreatment method specifically comprises the following steps:
1) And (3) acidizing the nitrobenzene wastewater by utilizing sulfuric acid to enable the pH value of the nitrobenzene wastewater to be 3.
2) Transferring the acidified nitrobenzene wastewater to a removal tower, and heating by utilizing superheated steam to realize top distillation of nitrite in the nitrobenzene wastewater, wherein the bottom temperature of the removal tower is controlled at 100 ℃ and the removal time is 30min.
3) And (3) adjusting the nitrobenzene wastewater after the removal treatment by using caustic soda flakes to ensure that the pH control index is 7-10, and then sending the nitrobenzene wastewater into a preparation system of the coal water slurry.
Example 3 ]
The nitrobenzene wastewater pretreatment method specifically comprises the following steps:
1) And (3) acidizing the nitrobenzene wastewater by utilizing sulfuric acid to enable the pH value of the nitrobenzene wastewater to be 3.
2) Transferring the acidified nitrobenzene wastewater to a removal tower, and heating by utilizing superheated steam to realize top distillation of nitrite in the nitrobenzene wastewater, wherein the bottom temperature of the removal tower is controlled at 90 ℃ and the removal time is 30min.
3) And (3) adjusting the nitrobenzene wastewater after the removal treatment by using caustic soda flakes to ensure that the pH control index is 7-10, and then sending the nitrobenzene wastewater into a preparation system of the coal water slurry.
Example 4 ]
The nitrobenzene wastewater pretreatment method specifically comprises the following steps:
1) And (3) acidizing the nitrobenzene wastewater by utilizing sulfuric acid to enable the pH value of the nitrobenzene wastewater to be 3.
2) Transferring the acidified nitrobenzene wastewater to a removal tower, and heating by utilizing superheated steam to realize top distillation of nitrite in the nitrobenzene wastewater, wherein the bottom temperature of the removal tower is controlled at 100 ℃ and the removal time is 30min.
3) And (3) adjusting the nitrobenzene wastewater after the removal treatment by using caustic soda flakes to ensure that the pH control index is 7-10, and then sending the nitrobenzene wastewater into a preparation system of the coal water slurry.
Example 5 ]
The nitrobenzene wastewater pretreatment method specifically comprises the following steps:
1) And (3) acidizing the nitrobenzene wastewater by utilizing sulfuric acid to enable the pH value of the nitrobenzene wastewater to be 3.
2) Transferring the acidified nitrobenzene wastewater to a removal tower, and heating by utilizing superheated steam to realize top distillation of nitrite in the nitrobenzene wastewater, wherein the bottom temperature of the removal tower is controlled at 100 ℃ and the removal time is 10min.
3) And (3) adjusting the nitrobenzene wastewater after the removal treatment by using caustic soda flakes to ensure that the pH control index is 7-10, and then sending the nitrobenzene wastewater into a preparation system of the coal water slurry.
Example 6 ]
The nitrobenzene wastewater pretreatment method specifically comprises the following steps:
1) And (3) acidizing the nitrobenzene wastewater by utilizing sulfuric acid to enable the pH value of the nitrobenzene wastewater to be 3.
2) Transferring the acidified nitrobenzene wastewater to a removal tower, and heating by utilizing superheated steam to realize top distillation of nitrite in the nitrobenzene wastewater, wherein the bottom temperature of the removal tower is controlled at 100 ℃ and the removal time is 15min.
3) And (3) adjusting the nitrobenzene wastewater after the removal treatment by using caustic soda flakes to ensure that the pH control index is 7-10, and then sending the nitrobenzene wastewater into a preparation system of the coal water slurry.
Example 7 ]
The nitrobenzene wastewater pretreatment method specifically comprises the following steps:
1) And (3) acidizing the nitrobenzene wastewater by utilizing sulfuric acid to enable the pH value of the nitrobenzene wastewater to be 3.
2) Transferring the acidified nitrobenzene wastewater to a removal tower, and heating by utilizing superheated steam to realize top distillation of nitrite in the nitrobenzene wastewater, wherein the bottom temperature of the removal tower is controlled at 100 ℃ and the removal time is 20min.
3) And (3) adjusting the nitrobenzene wastewater after the removal treatment by using caustic soda flakes to ensure that the pH control index is 7-10, and then sending the nitrobenzene wastewater into a preparation system of the coal water slurry.
Example 8 ]
The nitrobenzene wastewater pretreatment method specifically comprises the following steps:
1) And (3) acidizing the nitrobenzene wastewater by utilizing sulfuric acid to enable the pH value of the nitrobenzene wastewater to be 3.
2) Transferring the acidified nitrobenzene wastewater to a removal tower, and heating by utilizing superheated steam to realize top distillation of nitrite in the nitrobenzene wastewater, wherein the bottom temperature of the removal tower is controlled at 100 ℃ and the removal time is 30min.
3) And (3) adjusting the nitrobenzene wastewater after the removal treatment by using caustic soda flakes to ensure that the pH control index is 7-10, and then sending the nitrobenzene wastewater into a preparation system of the coal water slurry.
Comparative examples 1 to 3
The pretreatment method of comparative examples 1 to 3 was substantially the same as that of < example 1> except that: the pH values of the nitrobenzene wastewater in comparative examples 1-3 after acidification treatment were 4, 5 and 6, respectively.
Comparative examples 4 to 6 ]
The pretreatment method of comparative examples 4 to 6 was substantially the same as that of < example 3> except that: the bottom temperatures of the removal columns in comparative examples 4 to 6 were controlled at 60℃at 70℃and 80 ℃.
Comparative example 7 ]
The pretreatment method of comparative example 7 was substantially the same as that of < example 5> except that: the treatment time of the removal column in comparative example 7 was 5min.
The pretreatment wastewater of < examples 1, 2> and < comparative examples 1-3> was tested, and the sulfite content data obtained are shown in the following table:
| group of | Nitrite concentration (μg/g) |
| Untreated waste water | 400 |
| Example 1 (ph=2) | 35 |
| Example 2 (ph=3) | 48 |
| Comparative example 1 (ph=4) | 303 |
| Comparative example 2 (ph=5) | 323 |
| Comparative example 3 (ph=6) | 327 |
As can be seen from the table above: when the pH value of the nitrobenzene wastewater is less than or equal to 3 through acidification treatment, the removal effect of the sulfite is better. When the pH value of the nitrobenzene wastewater after acidification is more than 3, the removal effect of the sulfite is obviously poor, so that the pH value needs to be limited to be within 3 when the nitrobenzene wastewater is acidified.
The pretreatment wastewater of < examples 3, 4> and < comparative examples 4-6> was tested, and the sulfite content data obtained are shown in the following table:
| group of | Nitrite concentration (μg/g) |
| Untreated waste water | 400 |
| Example 3 (90 ℃ C.) | 50 |
| Example 4 (100 ℃ C.) | 40 |
| Comparative example 4 (60 ℃ C.) | 174.9 |
| Comparative example 5 (70 ℃ C.) | 172.6 |
| Comparative example 6 (80 ℃ C.) | 150.6 |
As can be seen from the table above: when the temperature of the nitrobenzene wastewater is more than or equal to 90 ℃ in the heating and steaming-out process, the removal effect of the sulfite is better. When the temperature of the nitrobenzene waste water is lower than 90 ℃ in the heating and steaming process, the removal effect of the sulfite is obviously deteriorated, so that the temperature of the nitrobenzene waste water needs to be controlled to be higher than 90 ℃ in the heating and steaming process of the nitrobenzene waste water.
The pretreatment wastewater of < examples 5-8> and < comparative example 7> was tested, and the sulfite content data obtained are shown in the following table:
| group of | Nitrite concentration (μg/g) |
| Untreated waste water | 415 |
| Example 5 (10 min) | 48.1 |
| Example 6 (15 min) | 35.4 |
| Example 7 (20 min) | 32.1 |
| Example 8 (30 min) | 31.8 |
| Comparative example 7 (5 min) | 128 |
As can be seen from the table above: when the heating and steaming-out duration of nitrobenzene wastewater exceeds 10min, the removal effect of the sulfite is better. When the heating and steaming duration of nitrobenzene wastewater is less than 5min, the removal effect of sulfite is obviously deteriorated, so that the removal time is not less than 10min in the heating and steaming process of nitrobenzene wastewater.
The pretreatment method has the advantages that:
1) The method reduces the corrosiveness of pulping water from the root, realizes the long-acting property of recycling the nitrobenzene wastewater, and is beneficial to saving water resources;
2) The method can effectively solve or slow down the corrosion problem of equipment, reduce the risk of unplanned shutdown and reduce the maintenance cost;
3) Compared with the existing nitrobenzene wastewater pretreatment process, the process has the advantages of high efficiency, easy implementation and low cost.
The foregoing describes specific embodiments of the present invention. It is to be understood that the invention is not limited to the particular embodiments described above, and that various changes and modifications may be made by one skilled in the art within the scope of the claims without affecting the spirit of the invention.
Claims (10)
1. A pretreatment method of nitrobenzene wastewater is characterized in that: firstly, acidizing the nitrobenzene wastewater, and then removing nitrite in the nitrobenzene wastewater in a heating and steaming-out mode.
2. The pretreatment method of nitrobenzene wastewater as defined in claim 1, wherein: and controlling the pH value of the nitrobenzene wastewater to be less than or equal to 3 in the acidification process.
3. The pretreatment method of nitrobenzene wastewater according to claim 1 or 2, characterized in that: the acid used in the acidification process contains H + Is an inorganic acid of (a).
4. A method for pretreating nitrobenzene wastewater as defined in claim 3, wherein: the acid used in the acidification process is sulfuric acid.
5. The pretreatment method of nitrobenzene wastewater as defined in claim 1, wherein: the heating means used in the heating and steaming process is electric heating or superheated steam heating.
6. The pretreatment method of nitrobenzene wastewater as defined in claim 5, wherein: the temperature of nitrobenzene wastewater in the heating and steaming-out process is not less than 90 ℃.
7. The pretreatment method of nitrobenzene wastewater as defined in claim 1, 5 or 6, wherein: the heating steaming time is more than or equal to 10min, preferably more than or equal to 15min.
8. The pretreatment method of nitrobenzene wastewater as defined in claim 1, wherein: the nitrobenzene wastewater after nitrite removal is sent into a preparation system of the coal water slurry after alkali injection adjustment, and the pH value of the nitrobenzene wastewater is controlled to be 7-10 in the alkali injection adjustment process.
9. The pretreatment method of nitrobenzene wastewater as defined in claim 8, wherein: the alkali used in the alkali injection regulating process is OH-containing - Is an inorganic base of (a).
10. The method for pretreating nitrobenzene wastewater according to claim 9, wherein: the alkali used in the alkali injection regulating process is one or more of caustic soda flakes, quicklime or lime milk and a solution thereof.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310704550.0A CN116768301A (en) | 2023-06-14 | 2023-06-14 | Pretreatment method of nitrobenzene wastewater |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310704550.0A CN116768301A (en) | 2023-06-14 | 2023-06-14 | Pretreatment method of nitrobenzene wastewater |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116768301A true CN116768301A (en) | 2023-09-19 |
Family
ID=87985331
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310704550.0A Pending CN116768301A (en) | 2023-06-14 | 2023-06-14 | Pretreatment method of nitrobenzene wastewater |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116768301A (en) |
-
2023
- 2023-06-14 CN CN202310704550.0A patent/CN116768301A/en active Pending
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110171876B (en) | Preparation method and application of nitrogen-doped sludge carbon-supported nano ferroferric oxide | |
| CN112474707A (en) | Efficient single-stage washing method and harmless treatment process for fly ash | |
| CN103045288B (en) | Comprehensive treatment method of high-sulphur high-COD (Chemical Oxygen Demand) caustic sludge waste liquid | |
| CN102134139A (en) | Comprehensive control process of black liquor | |
| CN108529819B (en) | Resource comprehensive utilization method of refined caustic sludge | |
| CN102344225B (en) | Processing method of salty wastewater in cellulose ether production | |
| CN103102033A (en) | Sulfur and ammonia-containing wastewater treatment method | |
| CN103771608B (en) | A kind for the treatment of process of refinery alkaline residue | |
| CN203820581U (en) | High-concentration coking desulfurization waste liquid treatment device | |
| CN116768301A (en) | Pretreatment method of nitrobenzene wastewater | |
| CN115745266A (en) | System and method for treating high-calcium high-salt wastewater by capturing carbon dioxide in smelting plant flue gas | |
| CN116692981A (en) | Recycling treatment process and treatment system for nitrobenzene wastewater | |
| CN103771609B (en) | A kind for the treatment of process of naphthenic acid alkali residue waste liquid | |
| CN104724881A (en) | Treatment method for high salinity industrial wastewater | |
| CN114772794A (en) | Method for cooperatively treating nitrobenzene wastewater by coal water slurry technology | |
| CN111153550B (en) | High-concentration wastewater treatment method and system for high-chlorine salt, high-ammonia nitrogen and high-organic matters | |
| CN111333224A (en) | Pretreatment method and device for semi-coke wastewater | |
| Sun et al. | Current advances in coal chemical wastewater treatment technology | |
| CN114684953A (en) | Method and device for treating ethylene waste alkali liquor | |
| CN109160660B (en) | Method for recovering glycolic acid from sodium carboxymethylcellulose production wastewater | |
| CN112624537A (en) | Method and system for decrement treatment of biochemical excess sludge | |
| CN112358900A (en) | Fenton reagent oxidized coal desulfurization method | |
| CN111592161A (en) | Novel integrated treatment method for zero discharge of high-salinity wastewater in coal chemical industry | |
| CN104891622A (en) | Complexing agent for removing phenolic compounds in water | |
| CN220183013U (en) | Energy-saving and environment-friendly PTA wastewater treatment device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |