CN107540077B - Catalytic oxidation treatment method for neutralizing wastewater by 3, 3' -dichlorobenzidine hydrochloride - Google Patents
Catalytic oxidation treatment method for neutralizing wastewater by 3, 3' -dichlorobenzidine hydrochloride Download PDFInfo
- Publication number
- CN107540077B CN107540077B CN201610476561.8A CN201610476561A CN107540077B CN 107540077 B CN107540077 B CN 107540077B CN 201610476561 A CN201610476561 A CN 201610476561A CN 107540077 B CN107540077 B CN 107540077B
- Authority
- CN
- China
- Prior art keywords
- wastewater
- catalytic oxidation
- oxidation
- filtrate
- catalyst
- 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.)
- Active
Links
Images
Abstract
The catalytic oxidation treatment method of 3, 3' -dichlorobenzidine hydrochloride neutralized wastewater comprises the following steps: (1) mixing, suction filtering: dropwise adding the waste alkali into the neutralized wastewater until the pH value is weakly acidic, and performing suction filtration to obtain clear filtrate; (2) catalytic oxidation: filling an activated carbon catalyst in a catalytic oxidation reactor, adding tap water, distilled water or deionized water, mixing the filtrate obtained in the step (1) with the tap water, the distilled water or the deionized water according to a proportion, continuously pumping the mixture into the top of the catalytic oxidation reactor, and carrying out an oxidation reaction at normal temperature. The oxidation waste water generated after the reaction is partially reused, is mixed with the filtrate in proportion and then is continuously subjected to oxidation reaction in the catalytic oxidation reactor, and the rest oxidation waste water is subjected to biochemical treatment. The invention can effectively destroy the organic matter structure in the wastewater, so that macromolecular organic matter is changed into micromolecular organic matter with little influence on biochemistry, and the wastewater can be biochemically treated; the catalytic oxidation reaction is a normal-temperature reaction, and the energy consumption is low; the process flow is simple, and the method has a good industrialization prospect.
Description
Technical Field
The invention relates to a catalytic oxidation treatment method of 3, 3' -dichlorobenzidine hydrochloride neutralized wastewater, belonging to the technical field of chemical treatment and chemical industry.
Background
3, 3' -dichlorobenzidine, DCB for short, is an important intermediate for producing organic pigments of the dichlorobenzidine series, and the yield of series of organic pigments mainly manufactured by the intermediate accounts for about 25 percent of the total amount of the organic pigments, so the intermediate is widely applied to the production of coloring slurry and pigment dyeing slurry of coloring and pigment printing slurry such as printing ink, paint, rubber, plastic and the like. The commercial product is generally in the form of a hydrochloride salt having the formula:
the production of 3, 3' -dichlorobenzidine hydrochloride is carried out by taking o-nitrochlorobenzene as basic raw material, reducing in alkaline medium to generate 2,2’Dichlorohydrazobenzene (DHB), then 2,2’-dichlorohydrazobenzene is transposed in an acidic medium to give 3,3’-dichlorobenzidine. In the reduction process, the catalytic hydrogenation method has the advantages of high product yield, good quality, less three wastes and the like, and is the mainstream of industrial production at present. The transposition process has two functions of sulfuric acid transposition and hydrochloric acid transposition, wherein the sulfuric acid transposition has the advantages of quick reaction, standing for layering and easy further purification, but the process is complex and the yield is low because the sulfate solubility of the 3,3 '-dichlorobenzidine is high and the 3, 3' -dichlorobenzidine is required to be converted into hydrochloride after rearrangement; the transposition process of hydrochloric acid is simple, easy to operate and high in yield, and has the defects of material viscosity, large mass transfer resistance and slow reaction, but the problem of material viscosity can be improved by adding an auxiliary agent, so that the continuous reaction is ensured to be carried out without interruption. The two transposition processes have application in industrial production.
The process for producing 3, 3' -dichlorobenzidine hydrochloride by adopting a catalytic hydrogenation method and a hydrochloric acid transposition process comprises the steps of hydrogenation, separation, transposition, dissolution and decoloration, salting out, filtration, neutralization, secondary filtration product recovery and the like. The waste water produced in the production process comprises waste alkali liquid separated after hydrogenation and neutralization waste water produced after neutralization, wherein the pH value of the waste alkali liquid is about 14, the pH value of the neutralization waste water is about 2, and the COD values of the waste alkali liquid and the neutralization waste water are about 15000 ppm. The neutralization wastewater contains macromolecular organic matters with the mass fraction of 1-2%, and the macromolecular organic matters mainly comprise 3, 3' -dichlorobenzidine, reduction by-products o-chloroaniline and the like, so that direct biochemical treatment cannot be carried out. The wastewater is one of industrial organic wastewater which is extremely difficult to treat.
At present, several treatment methods for 3, 3' -dichlorobenzidine hydrochloride wastewater produced by sulfuric acid transposition are reported in China. The process method for comprehensively utilizing the waste sulfuric acid of patent CN 1629131A, 3, 3' -dichlorobenzidine hydrochloride utilizes 2,2’The sulfate generated after the transposition of the dichlorohydrazobenzene has the characteristic of small solubility in the mother liquor, is directly filtered, and then the waste acid is continuously used, so that the discharge amount of the waste acid is reduced by 80 percent. However, the organic substances produced by the waste acid can be gradually accumulated, thereby affecting the product quality. In patent CN 1752032A, in the process of treating and recycling mixed acid generated by industrial wastewater 3, 3-dichlorobenzidine hydrochloride, magnesium-containing ore is adopted to react with sulfuric acid, so that magnesium sulfate is extracted while the acidity of the wastewater is reduced, but the method cannot effectively reduce the content of organic matters in the wastewater; patent CN 101372381A, a 3, 3' -dichlorobenzidine hydrochloride wastewater resource treatment method and a device thereof, which treat wastewater through steps of evaporation, rectification, decoloration, filtration, cooling, crystallization, separation and the like, can recover hydrochloric acid and sulfuric acid therein, and obtain an o-chloroaniline sulfate byproduct. However, the method has complex process, and units such as evaporation, rectification and the like have large energy consumption, so the method has high difficulty in industrial application in the aspect of economy.
Disclosure of Invention
The invention aims to provide a catalytic oxidation method for neutralizing wastewater by 3, 3' -dichlorobenzidine hydrochloride. Aiming at the neutralization wastewater generated in the process of producing 3, 3' -dichlorobenzidine hydrochloride by a hydrochloric acid transposition process, air is used as an oxidant to destroy the organic matter structure in the wastewater in the presence of a catalyst, so that macromolecular organic matters are changed into micromolecular organic matters which have little influence on the biochemistry, and the wastewater can be biochemically treated and discharged after reaching the standard. The specific process flow diagram is shown in figure 1.
The catalytic oxidation method for treating 3, 3' -dichlorobenzidine hydrochloride neutralization wastewater comprises the following steps:
(1) mixing, suction filtering: dropwise adding alkali liquor into the acidic neutralization wastewater, uniformly stirring, stopping dropwise adding when the pH value reaches 4-5, maintaining stirring for 10-15 min, and then performing suction filtration to obtain clear filtrate;
(2) catalytic oxidation: filling an active carbon catalyst in the catalytic oxidation reactor, and adding tap water, distilled water or deionized water until the liquid level is flush with the surface of the catalyst. Mixing the filtrate obtained in the step (1) with tap water, distilled water or deionized water according to the weight ratio of 1: 2-3, and continuously pumping into the top of the catalytic oxidation reactor. Air is continuously introduced from the bottom of the reactor, gas-liquid countercurrent contact is carried out under the action of a catalyst, and an oxidation reaction is carried out at normal temperature. And (3) mechanically applying 1/2-3/4 to the oxidized wastewater generated after the reaction, mixing the oxidized wastewater with the filtrate in proportion, continuing to perform oxidation reaction in the catalytic oxidation reactor, and performing biochemical treatment on the residual oxidized wastewater.
In the step (1), the alkali liquor is waste alkali liquor separated after hydrogenation in the production process of 3, 3' -dichlorobenzidine hydrochloride;
in the step (2), the filling volume of the catalyst is 1/2-2/3 of the volume of the catalytic oxidation reactor;
in the step (2), the volume flow rate (GHSV) of air passing through the catalyst in unit time is 20-40 h-1；
In the step (2), the ratio of the mixed wastewater flow rate to the air flow rate is 1: 130 to 170;
in the step (2), the ratio of the filtrate in the mixed wastewater to the mechanically used oxidized wastewater is 1: 2 to 3.
Compared with the existing treatment method of 3, 3' -dichlorobenzidine hydrochloride wastewater, the method has the following advantages: (1) the catalytic oxidation method can effectively destroy the organic matter structure in the neutralized wastewater, so that macromolecular organic matters are changed into micromolecular organic matters with little influence on the biochemistry. After oxidation, the COD value of the wastewater is reduced from about 15000 ppm to below 1000 ppm, and the mass fraction of macromolecular organic matters (mainly 3, 3' -dichlorobenzidine and o-chloroaniline) in the wastewater is reduced from 1-2% to 0.01-0.02%, so that the wastewater can be biochemically treated; (2) the invention carries out catalytic oxidation reaction at normal temperature without unit operations such as heating, rectification and the like, and has low energy consumption; (3) the method has the advantages of simple process flow, continuous operation of the catalytic oxidation step and good industrial prospect.
Drawings
FIG. 1 is a process flow diagram of the catalytic oxidation process for treating 3, 3' -dichlorobenzidine hydrochloride neutralized wastewater in the embodiment of the invention.
Detailed Description
The process flow of the following example method is shown in figure 1.
Example 1
And adding the neutralized wastewater into a four-neck flask, starting stirring, dropwise adding alkali liquor into the neutralized wastewater by using a dropping funnel, and measuring the pH value of the neutralized wastewater after uniformly stirring. Stopping dripping when pH reaches 4, stirring for 15 min, transferring to a suction bottle for suction filtration, and filtering to remove precipitate to obtain clear filtrate.
The catalytic oxidation reactor is filled with an activated carbon catalyst, the filling volume of the catalyst is 1/2 of the volume of the reactor, and tap water is added until the liquid level is flush with the surface of the catalyst. Mixing the filtrate with tap water according to the proportion of 1: 3, continuously pumping the mixture into the top of the catalytic oxidation reactor, and continuously introducing air from the bottom of the reactor. The volumetric flow rate of air (GHSV) passing through the catalyst per unit time was 40 h-1The ratio of the mixed wastewater flow rate to the air flow rate is 1: 170. under the action of catalyst, gas-liquid countercurrent contacts, and oxidation reaction is carried out at normal temperature to generate oxidized wastewater. Through detection, the COD of the oxidation wastewater is less than 1000 ppm, the content of 3, 3' -dichlorobenzidine is less than 0.005%, the content of o-chloroaniline is less than 0.005%, and the chroma is less than 50, thereby meeting the requirement of biochemical treatment. 3/4 is used for the oxidation wastewater to be mixed with the filtrateAfter the combination (the ratio of the filtrate to the indiscriminate oxidation wastewater is 1: 3), the oxidation reaction is continuously carried out, and the rest oxidation wastewater is subjected to biochemical treatment.
Example 2
Adding the neutralized wastewater into a four-neck flask, starting stirring, dropwise adding the waste alkali into the neutralized wastewater by using a dropping funnel, and measuring the pH value of the neutralized wastewater after uniformly stirring. Stopping dripping when pH reaches 5, stirring for 10 min, transferring to a suction filtration bottle for suction filtration, and filtering to remove precipitate to obtain clear filtrate.
The catalytic oxidation reactor is filled with an activated carbon catalyst, the filling volume of the catalyst is 1/2 of the volume of the reactor, and distilled water is added until the liquid level is flush with the surface of the catalyst. Mixing the filtrate with distilled water according to the proportion of 1: 2, continuously pumping the mixture into the top of the catalytic oxidation reactor, and continuously introducing air from the bottom of the reactor. The volumetric flow rate of air (GHSV) passing through the catalyst per unit time was 20 h-1The ratio of the mixed wastewater flow rate to the air flow rate is 1: 130. under the action of catalyst, gas-liquid countercurrent contacts, and oxidation reaction occurs at normal temperature to produce oxidized waste water. Through detection, the COD of the oxidation wastewater is less than 1000 ppm, the content of 3, 3' -dichlorobenzidine is less than 0.005%, the content of o-chloroaniline is less than 0.005%, and the chroma is less than 50, thereby meeting the requirement of biochemical treatment. The oxidized wastewater is used indiscriminately 1/2, the oxidized wastewater is mixed with the filtrate (the ratio of the filtrate to the indiscriminate oxidized wastewater is 1: 2), the oxidation reaction is continued, and the rest oxidized wastewater is subjected to biochemical treatment.
Example 3
Adding the neutralized wastewater into a four-neck flask, starting stirring, dropwise adding the waste alkali into the neutralized wastewater by using a dropping funnel, and measuring the pH value of the neutralized wastewater after uniformly stirring. Stopping dripping when pH reaches 4, stirring for 10 min, transferring to a suction bottle for suction filtration, and filtering to remove precipitate to obtain clear filtrate.
Filling an activated carbon catalyst in the catalytic oxidation reactor, wherein the filling volume of the catalyst is 2/3 of the volume of the reactor, and adding deionized water until the liquid level is flush with the surface of the catalyst. Mixing the filtrate with deionized water according to the weight ratio of 1: 3, continuously pumping the mixture into the top of the catalytic oxidation reactor, and continuously introducing air from the bottom of the reactor. Volume of air passing through the catalyst per unit timeFlow rate (GHSV) of 25 h-1The ratio of the mixed wastewater flow rate to the air flow rate is 1: 140. under the action of catalyst, gas-liquid countercurrent contacts, and oxidation reaction occurs at normal temperature to produce oxidized waste water. Through detection, the COD of the oxidation wastewater is less than 1000 ppm, the content of 3, 3' -dichlorobenzidine is less than 0.005%, the content of o-chloroaniline is less than 0.005%, and the chroma is less than 50, thereby meeting the requirement of biochemical treatment. The oxidized wastewater is used indiscriminately 3/4, the oxidized wastewater is mixed with the filtrate (the ratio of the filtrate to the indiscriminate oxidized wastewater is 1: 3), the oxidation reaction is continued, and the rest oxidized wastewater is subjected to biochemical treatment.
Example 4
Adding the neutralized wastewater into a four-neck flask, starting stirring, dropwise adding the waste alkali into the neutralized wastewater by using a dropping funnel, and measuring the pH value of the neutralized wastewater after uniformly stirring. Stopping dripping when pH reaches 5, stirring for 15 min, transferring to a suction bottle for suction filtration, and filtering to remove precipitate to obtain clear filtrate.
The catalytic oxidation reactor is filled with an activated carbon catalyst, the filling volume of the catalyst is 2/3 of the volume of the reactor, and tap water is added until the liquid level is flush with the surface of the catalyst. Mixing the filtrate with tap water according to the proportion of 1: 2, continuously pumping the mixture into the top of the catalytic oxidation reactor, and continuously introducing air from the bottom of the reactor. The volumetric flow rate of air (GHSV) passing through the catalyst per unit time was 30 h-1The ratio of the mixed wastewater flow rate to the air flow rate is 1: 170. under the action of catalyst, gas-liquid countercurrent contacts, and oxidation reaction occurs at normal temperature to produce oxidized waste water. Through detection, the COD of the oxidation wastewater is less than 1000 ppm, the content of 3, 3' -dichlorobenzidine is less than 0.005%, the content of o-chloroaniline is less than 0.005%, and the chroma is less than 50, thereby meeting the requirement of biochemical treatment. The oxidized wastewater is used indiscriminately 1/2, the oxidized wastewater is mixed with the filtrate (the ratio of the filtrate to the indiscriminate oxidized wastewater is 1: 2), the oxidation reaction is continued, and the rest oxidized wastewater is subjected to biochemical treatment.
Claims (5)
1. A catalytic oxidation treatment method for neutralizing wastewater by 3, 3' -dichlorobenzidine hydrochloride is characterized by comprising the following steps:
(1) mixing, suction filtering: dropwise adding waste alkali liquor separated after hydrogenation in the production process of 3, 3' -dichlorobenzidine hydrochloride into acidic neutralization wastewater, uniformly stirring, stopping dropwise adding when the pH value reaches 4-5, maintaining stirring for 10-15 min, and then performing suction filtration to obtain clear filtrate;
(2) catalytic oxidation: filling an active carbon catalyst in a catalytic oxidation reactor, and adding tap water, distilled water or deionized water until the liquid level is flush with the surface of the catalyst; mixing the filtrate obtained in the step (1) with tap water, distilled water or deionized water according to the weight ratio of 1: 2-3, continuously feeding the mixture into the top of a catalytic oxidation reactor, and continuously introducing air from the bottom of the reactor; under the action of a catalyst, gas-liquid countercurrent contact is carried out, an oxidation reaction is carried out at normal temperature, and oxidation wastewater is generated after the reaction; and (3) mechanically applying 1/2-3/4 to the oxidation wastewater, mixing the oxidation wastewater with the filtrate in proportion, continuing to perform oxidation reaction in the catalytic oxidation reactor, and performing biochemical treatment on the residual oxidation wastewater.
2. The process for the catalytic oxidation treatment of 3, 3' -dichlorobenzidine hydrochloride neutralized wastewater according to claim 1, characterized in that: in the step (2), the filling volume of the catalyst is 1/2-2/3 of the volume of the catalytic oxidation reactor.
3. The process for the catalytic oxidation treatment of 3, 3' -dichlorobenzidine hydrochloride neutralized wastewater according to claim 1, characterized in that: in the step (2), the volume flow rate of the air passing through the catalyst in unit time is 20-40 h-1。
4. The process for the catalytic oxidation treatment of 3, 3' -dichlorobenzidine hydrochloride neutralized wastewater according to claim 1 or 3, characterized in that: in the step (2), the ratio of the mixed wastewater flow rate to the air flow rate is 1: 130 to 170.
5. The process for the catalytic oxidation treatment of 3, 3' -dichlorobenzidine hydrochloride neutralized wastewater according to claim 1, characterized in that: in the step (2), the ratio of the filtrate in the mixed wastewater to the mechanically used oxidized wastewater is 1: 2 to 3.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610476561.8A CN107540077B (en) | 2016-06-27 | 2016-06-27 | Catalytic oxidation treatment method for neutralizing wastewater by 3, 3' -dichlorobenzidine hydrochloride |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610476561.8A CN107540077B (en) | 2016-06-27 | 2016-06-27 | Catalytic oxidation treatment method for neutralizing wastewater by 3, 3' -dichlorobenzidine hydrochloride |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107540077A CN107540077A (en) | 2018-01-05 |
| CN107540077B true CN107540077B (en) | 2020-08-21 |
Family
ID=60960163
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610476561.8A Active CN107540077B (en) | 2016-06-27 | 2016-06-27 | Catalytic oxidation treatment method for neutralizing wastewater by 3, 3' -dichlorobenzidine hydrochloride |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107540077B (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113371881A (en) * | 2021-06-22 | 2021-09-10 | 中石化南京化工研究院有限公司 | Treatment method of process wastewater generated in one-step synthesis of N-phenylmaleimide |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102765801A (en) * | 2012-08-09 | 2012-11-07 | 山东聊城中盛蓝瑞化工有限公司 | Air catalytic oxidation treatment benzyl cyanide waste water method |
-
2016
- 2016-06-27 CN CN201610476561.8A patent/CN107540077B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN102765801A (en) * | 2012-08-09 | 2012-11-07 | 山东聊城中盛蓝瑞化工有限公司 | Air catalytic oxidation treatment benzyl cyanide waste water method |
Non-Patent Citations (1)
| Title |
|---|
| 湿式氧化工艺处理苯胺类废水技术研究;姜刚村等;《染料与染色》;20120430;第49卷(第2期);第39-41页和第22页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107540077A (en) | 2018-01-05 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN104876380B (en) | A kind of processing of organic copper-containing wastewater of high concentration and the recovery method of copper | |
| US10974981B2 (en) | Method for reducing pollutant discharge in phenol and acetone production | |
| CN101664665A (en) | Layered adsorbent of wastewater containing thiosulfate and treatment method thereof | |
| CN102531234A (en) | Method for pretreatment of alkaline waste water through fenton oxidation | |
| CN105016589A (en) | Resource utilization method for iron sludge | |
| CN105541016A (en) | Inorganic-ammonium-salt-containing wastewater treatment system and recycling method thereof | |
| CN105036425B (en) | The recycling processing method of salt-containing organic wastewater | |
| CN107540077B (en) | Catalytic oxidation treatment method for neutralizing wastewater by 3, 3' -dichlorobenzidine hydrochloride | |
| CN105293839B (en) | A kind of processing method of fluorescent brightener CBS waste water low boiler cut | |
| CN202415301U (en) | Printing and dyeing wastewater treatment system | |
| CN1861525B (en) | Treatment process of active hargil waste acid | |
| CN102153224A (en) | Treatment technology for industrial sewage from sodium carboxymethylcellulose | |
| CN104787933A (en) | Treatment method for gold-smelting cyanide-containing wastewater | |
| CN105110515B (en) | A kind of processing method of DSD acid waste water | |
| CN105254067B (en) | The resource utilization method of advanced treatment of wastewater Fenton process sludge | |
| CN103754958A (en) | Process for preparing black iron oxide by utilizing wastewater generated in production of chlorinated benzene | |
| CN109607915A (en) | A kind of processing method of Benzotriazole Ultraviolet Stabilizer production waste water | |
| CN102616997B (en) | Method for treating wastewater generated in production process of iron oxide pigment | |
| CN108358386A (en) | A kind for the treatment of process of antibiotic pharmaceutical wastewater | |
| CN108033505A (en) | The processing method of high-concentration ammonia nitrogenous wastewater | |
| CN209522723U (en) | Chemical nickel waste liquid and waste water treatment system | |
| CN106317251B (en) | A kind of seaweed chemical environmental protection Calcific technology | |
| CN106277414A (en) | A kind of oil-polluted water eliminates the method for foam | |
| CN104743725A (en) | Sodium saccharin wastewater and similar wastewater treatment method | |
| CN110723870A (en) | Treatment and resource utilization method of phenol wastewater |
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 | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CP01 | Change in the name or title of a patent holder | ||
| CP01 | Change in the name or title of a patent holder |
Address after: Liuhe District of Nanjing City, Jiangsu province 210048 geguan Road No. 699 Patentee after: China Petroleum & Chemical Corp. Patentee after: SINOPEC NANJING CHEMICAL RESEARCH INSTITUTE Co.,Ltd. Address before: Liuhe District of Nanjing City, Jiangsu province 210048 geguan Road No. 699 Patentee before: China Petroleum & Chemical Corp. Patentee before: Nanhua Group Research Institute |