Treatment method of o-phenylenediamine production wastewater

Abstract

The invention discloses a treatment method of o-phenylenediamine production wastewater, and belongs to the technical field of industrial wastewater treatment.The treatment method comprises the following steps that 1, modified activated carbon is added into wastewater, stirring, standing and filtering are conducted, and filtrate A is obtained; step 2, adsorbing and desorbing the filtrate A through macroporous adsorption resin to obtain filtrate B; 3, adjusting the pH value of the filtrate B, heating to 30-60 DEG C, adding laccase, carrying out a thermal reaction, and filtering to obtain a filtrate C; and 4, carrying out evaporation and concentration treatment on the filtrate C, and discharging. The treatment method of o-phenylenediamine production wastewater provided by the invention is simple in process, simple to operate and mild in condition, the removal rate of o-phenylenediamine reaches up to 99% or above, and the treatment effect is excellent.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial wastewater treatment, and specifically relates to a method for treating wastewater produced by o-phenylenediamine production. Background Art

[0002] O-phenylenediamine, also known as 1,2-phenylenediamine, is an important dye intermediate used in the preparation of vat dyes and cationic dyes, such as fur yellow brown M, cationic dyes, vat scarlet GG, and vat brilliant orange GR. In addition, o-phenylenediamine is also one of the important raw materials for the production of carbendazim.

[0003] The production processes of o-phenylenediamine mainly include sodium sulfide reduction method, hydrogenation reduction method and o-dichlorobenzene ammonolysis method. The catalytic hydrogenation process is immature and needs to be improved for industrialization; o-dichlorobenzene ammonolysis method is still in the laboratory research stage; the sodium sulfide reduction process is relatively mature, and the purity of the output product is relatively high. The most widely used process is the sodium sulfide reduction o-nitroaniline method. However, the wastewater produced by this method contains more o-nitroaniline, and the wastewater has the characteristics of high chroma, high acidity and alkalinity, high COD, low B / C value, etc., which is difficult to treat. O-phenylenediamine wastewater is a multi-component water body, many of which, such as o-phenylenediamine, o-nitroaniline, o-nitrochlorobenzene, etc., are toxic and carcinogenic substances. In order to protect water resources and the ecological environment, it is very important to purify the wastewater.

[0004] At present, the main treatment and utilization method for this type of wastewater is to use it as a raw material for the production of baking soda. However, o-phenylenediamine has the characteristic of easy sublimation. During the extraction of baking soda, the water evaporated from the wastewater during evaporation and concentration still contains a certain amount of o-phenylenediamine organic matter. Direct discharge will still cause serious pollution. Therefore, developing a method for treating o-phenylenediamine production wastewater with simple operation and high treatment efficiency is a technical problem that urgently needs to be solved. Summary of the invention

[0005] The purpose of the present invention is to provide a method for treating wastewater from the production of o-phenylenediamine to solve the problem.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A method for treating wastewater from o-phenylenediamine production comprises the following steps:

[0008] Step 1, adding modified activated carbon to the wastewater, stirring, standing, and filtering to obtain filtrate A;

[0009] Step 2, the filtrate A is adsorbed and analyzed by a macroporous adsorption resin to obtain a filtrate B;

[0010] Step 3, adjusting the pH of filtrate B, raising the temperature to 30-60° C., adding laccase, keeping the temperature for reaction and filtering to obtain filtrate C;

[0011] Step 4: Evaporate and concentrate the filtrate C and discharge it.

[0012] As a preferred embodiment of the present invention, the dosage of the modified activated carbon is 0.05-0.3% of the mass of the wastewater.

[0013] As a preferred embodiment of the present invention, the modified activated carbon is prepared by the following steps:

[0014] The chitosan was dissolved in acetic acid solution, activated carbon was added, ultrasonic dispersion was performed for 3-3.5 hours, pH was adjusted, stirring reaction was continued for 1-2 hours, centrifugal collection was performed, washing was performed, centrifugal collection was performed, vacuum drying was performed to constant weight, and modified activated carbon was obtained.

[0015] As a preferred embodiment of the present invention, the usage ratio of chitosan, acetic acid solution and activated carbon is 1-2 g: 200 mL: 1-1.5 g.

[0016] As a preferred embodiment of the present invention, the pH is adjusted to 10-11.

[0017] As a preferred embodiment of the present invention, the amount of laccase used is 0.01-0.05% of the mass of filtrate B.

[0018] As a preferred embodiment of the present invention, the pH value of the filtrate B is adjusted to 4.5-5.

[0019] As a preferred embodiment of the present invention, the macroporous adsorption resin is HYA-105 macroporous adsorption resin.

[0020] Beneficial effects of the present invention:

[0021] The method for treating o-phenylenediamine production wastewater provided by the present invention has simple process, simple operation, mild conditions, a removal rate of o-phenylenediamine of more than 99%, and excellent treatment effect.

[0022] Chitosan is adopted to be coated on the surface of activated carbon in the present invention, and the activated carbon particles are overcome to be smaller, which causes the disadvantages of being difficult to recycle and being easy to lose, and the action time of activated carbon is prolonged. Compared with the commonly used powdered activated carbon, the modified activated carbon has the advantages of large adsorption capacity, fast adsorption and desorption rate and easy recovery. On the other hand, there are a large amount of alkaline amino polysaccharides on the chitosan molecular chain, which can be positively charged, and has good adsorption effect on pollutants containing acidic groups, and the higher the degree of deacetylation, the larger the mechanical strength, the greater the biocompatibility, and the stronger its adsorption effect. In addition, chitosan can also produce obvious inhibitory effects on Gram-negative bacteria and fungi, prolongs the action time of activated carbon, and further improves the efficiency and economic cost of o-phenylenediamine production wastewater treatment. DETAILED DESCRIPTION

[0023] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Example 1

[0025] This embodiment provides a modified activated carbon, and the preparation steps are as follows:

[0026] 1 g of chitosan was dissolved in 200 mL of acetic acid solution (1 wt%), and then 1 g of activated carbon was added, ultrasonically dispersed for 3 h, the pH was adjusted to 10, stirring and reacting for 1 h, and centrifuged. The unreacted chitosan was washed with acetic acid solution, collected by centrifugation, and dried in a vacuum drying oven at 50 ° C to constant weight to obtain modified activated carbon.

[0027] Example 2

[0028] Compared with Example 1, the only difference is:

[0029] 1.5 g of chitosan was dissolved in 200 mL of acetic acid solution (1 wt%), and then 1.25 g of activated carbon was added, and ultrasonic dispersion was performed for 3 h. The pH was adjusted to 10, and the reaction was continued by stirring for 1 h. The unreacted chitosan was washed with acetic acid solution, collected by centrifugation, and dried in a vacuum drying oven at 50°C to constant weight to obtain modified activated carbon.

[0030] Example 3

[0031] Compared with Example 1, the only difference is:

[0032] 2 g of chitosan was dissolved in 200 mL of acetic acid solution (1 wt%), and then 1.5 g of activated carbon was added, and ultrasonic dispersion was performed for 3 h. The pH was adjusted to 11, and the reaction was continued by stirring for 1 h. The unreacted chitosan was washed with acetic acid solution, collected by centrifugation, and dried in a vacuum drying oven at 50 ° C to constant weight to obtain modified activated carbon.

[0033] Example 4

[0034] This embodiment provides a method for treating wastewater from o-phenylenediamine production, and the process steps are as follows:

[0035] Step 1, adding 0.5 g of modified activated carbon in Example 1 to 1000 g of wastewater, stirring, standing, and filtering to obtain filtrate A;

[0036] Step 2, the filtrate A is adsorbed and analyzed by HYA-105 macroporous adsorption resin to obtain filtrate B;

[0037] Step 3, adjusting the pH value of filtrate B to 4.5, raising the temperature to 35° C., adding laccase, the amount of laccase being 0.01% of the mass of filtrate B, keeping the temperature for reaction and then filtering to obtain filtrate C;

[0038] Step 4: Evaporate and concentrate the filtrate C and discharge it.

[0039] Example 5

[0040] This embodiment provides a method for treating wastewater from o-phenylenediamine production, and the process steps are as follows:

[0041] Step 1, adding 1.5 g of modified activated carbon in Example 1 to 1000 g of wastewater, stirring and standing, filtering, and obtaining filtrate A;

[0042] Step 2, the filtrate A is adsorbed and analyzed by HYA-105 macroporous adsorption resin to obtain filtrate B;

[0043] Step 3, adjusting the pH value of filtrate B to 4.5, raising the temperature to 35° C., adding laccase, the amount of laccase being 0.01% of the mass of filtrate B, keeping the temperature for reaction and then filtering to obtain filtrate C;

[0044] Step 4: Evaporate and concentrate the filtrate C and discharge it.

[0045] Example 6

[0046] This embodiment provides a method for treating wastewater from o-phenylenediamine production, and the process steps are as follows:

[0047] Step 1, adding 3 g of modified activated carbon in Example 1 to 1000 g of wastewater, stirring, standing, and filtering to obtain filtrate A;

[0048] Step 2, the filtrate A is adsorbed and analyzed by HYA-105 macroporous adsorption resin to obtain filtrate B;

[0049] Step 3, adjusting the pH value of filtrate B to 4.5, raising the temperature to 35° C., adding laccase, the amount of laccase being 0.01% of the mass of filtrate B, keeping the temperature for reaction and then filtering to obtain filtrate C;

[0050] Step 4: Evaporate and concentrate the filtrate C and discharge it.

[0051] Example 7

[0052] This embodiment provides a method for treating wastewater from o-phenylenediamine production, and the process steps are as follows:

[0053] Step 1, adding 1.5 g of modified activated carbon in Example 2 to 1000 g of wastewater, stirring, standing, and filtering to obtain filtrate A;

[0054] Step 2, the filtrate A is adsorbed and analyzed by HYA-105 macroporous adsorption resin to obtain filtrate B;

[0055] Step 3, adjusting the pH value of filtrate B to 5, raising the temperature to 55° C., adding laccase, the amount of laccase being 0.03% of the mass of filtrate B, keeping the temperature for reaction and then filtering to obtain filtrate C;

[0056] Step 4: Evaporate and concentrate the filtrate C and discharge it.

[0057] Example 8

[0058] This embodiment provides a method for treating wastewater from o-phenylenediamine production, and the process steps are as follows:

[0059] Step 1, adding 1.5 g of modified activated carbon in Example 3 to 1000 g of wastewater, stirring, standing, and filtering to obtain filtrate A;

[0060] Step 2, the filtrate A is adsorbed and analyzed by HYA-105 macroporous adsorption resin to obtain filtrate B;

[0061] Step 3, adjusting the pH value of the filtrate B to 5, raising the temperature to 55° C., adding laccase, the amount of laccase being 0.05% of the mass of the filtrate B, keeping the temperature for reaction and then filtering to obtain filtrate C;

[0062] Step 4: Evaporate and concentrate the filtrate C and discharge it.

[0063] Comparative Example 1

[0064] This comparative example provides a method for treating wastewater from o-phenylenediamine production, and the process steps are as follows:

[0065] Step 1, add 0.5 g of activated carbon to 1000 g of wastewater, stir and let stand, filter to obtain filtrate A;

[0066] Step 2, the filtrate A is adsorbed and analyzed by HYA-105 macroporous adsorption resin to obtain filtrate B;

[0067] Step 3, adjusting the pH value of filtrate B to 4.5, raising the temperature to 35° C., adding laccase, the amount of laccase being 0.01% of the mass of filtrate B, keeping the temperature for reaction and then filtering to obtain filtrate C;

[0068] Step 4: Evaporate and concentrate the filtrate C and discharge it.

[0069] Comparative Example 2

[0070] Compared with Example 4, the only difference is:

[0071] Replace 0.5 g of the modified activated carbon in Example 1 in step 1 with 0.35 g of the modified activated carbon in Example 1.

[0072] Comparative Example 3

[0073] Compared with Example 4, the only difference is:

[0074] Replace 0.5 g of the modified activated carbon in Example 1 in step 1 with 3.5 g of the modified activated carbon in Example 1.

[0075] Comparative Example 4

[0076] Compared with Example 4, the only difference is:

[0077] Step 3, adjusting the pH value of filtrate B to 3.5, raising the temperature to 35° C., adding laccase, the amount of laccase being 0.01% of the mass of filtrate B, keeping the temperature for reaction and then filtering to obtain filtrate C;

[0078] Comparative Example 5

[0079] Compared with Example 4, the only difference is:

[0080] Step 3, adjusting the pH value of filtrate B to 4.5, raising the temperature to 35° C., adding laccase, the amount of laccase used being 0.0075% of the mass of filtrate B, keeping the temperature for reaction and then filtering to obtain filtrate C;

[0081] The wastewater discharged from Examples 4 to 8 and Comparative Examples 1 to 5 was subjected to performance tests to detect the purity and yield of o-phenylenediamine. The test results are shown in Table 1:

[0082] Table 1

[0083]

[0084] It can be seen from Table 1 that compared with the treatment of o-phenylenediamine production wastewater in Comparative Examples 1-5, the treatment of o-phenylenediamine production wastewater in Examples 4-8 can achieve a yield of o-phenylenediamine of more than 99%, and the operation is simple, the conditions are mild, and it is suitable for large-scale promotion.

[0085] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device.

[0086] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A method for treating wastewater from o-phenylenediamine production, characterized in that: The following steps are involved: Step 1, adding modified activated carbon to the wastewater, stirring, standing, and filtering to obtain filtrate A; Step 2, the filtrate A is adsorbed and analyzed by a macroporous adsorption resin to obtain a filtrate B; Step 3, adjusting the pH of filtrate B, raising the temperature to 30-60° C., adding laccase, keeping the temperature for reaction and filtering to obtain filtrate C; Step 4: Evaporate and concentrate the filtrate C and discharge it.

2. The method for treating o-phenylenediamine production wastewater according to claim 1, characterized in that: The dosage of the modified activated carbon is 0.05-0.3% of the mass of the wastewater.

3. The method for treating o-phenylenediamine production wastewater according to claim 1, characterized in that: The modified activated carbon is prepared by the following steps: The chitosan was dissolved in acetic acid solution, activated carbon was added, ultrasonic dispersion was performed for 3-3.5 hours, pH was adjusted, stirring reaction was continued for 1-2 hours, centrifugal collection was performed, washing was performed, centrifugal collection was performed, vacuum drying was performed to constant weight, and modified activated carbon was obtained.

4. The method for treating o-phenylenediamine production wastewater according to claim 3, characterized in that: The dosage ratio of chitosan, acetic acid solution and activated carbon is 1-2g:200mL:1-1.5g.

5. The method for treating o-phenylenediamine production wastewater according to claim 3, characterized in that: Adjust pH to 10-11.

6. The method for treating o-phenylenediamine production wastewater according to claim 1, characterized in that: The amount of laccase used is 0.01-0.05% of the mass of the filtrate B.

7. The method for treating o-phenylenediamine production wastewater according to claim 1, characterized in that: Adjust the pH of filtrate B to 4.5-5.

8. The method for treating o-phenylenediamine production wastewater according to claim 1, characterized in that: The macroporous adsorption resin is HYA-105 macroporous adsorption resin.

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