A process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor

Abstract

The present invention relates to the technical field of chemical wastewater treatment, and proposes a treatment process for dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor, comprising the following steps: S1, dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor are acidified to obtain acidified treatment liquid; S2, after neutralizing the acidified treatment liquid, filter to obtain neutralized filtrate; S3, neutralize the filtrate and carry out ammonia removal treatment; wherein the treatment agent is composed of sodium hypochlorite and modified activated carbon; the modified activated carbon is activated carbon modified by a modifier, wherein the modifier includes 4'-amino-2'-hydroxyacetophenone and / or bis(3-amino-4-hydroxyphenyl) sulfone. Through the above technical scheme, the problem that dichloroisocyanuric acid and trichloroisocyanuric acid mother liquors in the prior art cannot be fully utilized is solved.

Description

Technical Field

[0001] The invention relates to the technical field of chemical wastewater treatment, and in particular to a treatment process for dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor. Background Art

[0002] Dichloroisocyanuric acid and trichloroisocyanuric acid are products of the chlorinated isocyanuric acid series. They are a new generation of highly efficient bleaching agents, chlorinating agents and disinfectants, with the characteristics of strong bactericidal and bleaching power, stable storage and transportation, and safe use. They are now used as disinfectants in industrial water, swimming pool water, cleaning agents, hospitals, tableware, etc., as sterilizers in sericulture and other breeding, and for bleaching wool shrink fabrics and paper in light industry. They are ideal upgraded products for traditional disinfection products, and the demand at home and abroad is increasing year by year.

[0003] The production process of dichloroisocyanuric acid and trichloroisocyanuric acid is to use cyanuric acid, water and caustic soda to react to generate disodium salt and trisodium salt solution of cyanuric acid, which reacts with chlorine in a reactor to generate chloroisocyanate, and then centrifuges to dehydrate and dry the filter cake to obtain the finished product of chloroisocyanuric acid. A large amount of mother liquor will be generated in the production process. According to statistics, about 150,000 tons of mother liquor are produced for every 15,000 tons of chloroisocyanuric acid products. The mother liquor of dichloroisocyanuric acid and trichloroisocyanuric acid contains about 8% sodium chloride, a small amount of trichloroisocyanuric acid, dichloroisocyanuric acid and inorganic ammonium salt, etc. The total ammonium content exceeds the standard and cannot be used to produce caustic soda. It can only be treated harmlessly, resulting in a large amount of waste of dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor.

[0004] Therefore, it is necessary to develop a treatment process for dichloroisocyanuric acid and trichloroisocyanuric acid mother liquors, rationally utilize dichloroisocyanuric acid and trichloroisocyanuric acid mother liquors, and reduce the waste of resources. Summary of the invention

[0005] The invention provides a treatment process for dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor, which solves the problem that dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor cannot be fully utilized in the related art.

[0006] The technical solution of the present invention is as follows:

[0007] The present invention proposes a treatment process for dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor, comprising the following steps:

[0008] S1, dichloroisocyanuric acid, trichloroisocyanuric acid mother liquor is acidified to obtain an acidified treatment liquid;

[0009] S2, neutralizing the acidified solution and filtering to obtain a neutralized filtrate;

[0010] S3, neutralize the filtrate to remove ammonia;

[0011] The treating agent is composed of sodium hypochlorite and modified activated carbon; the modified activated carbon is obtained by modifying the activated carbon with a modifier, and the modifier includes 4'-amino-2'-hydroxyacetophenone and / or bis(3-amino-4-hydroxyphenyl) sulfone.

[0012] As a further technical solution, the mass ratio of the modifier to the activated carbon is 1~2:20.

[0013] As a further technical solution, the molar ratio of the amount of sodium hypochlorite added to the cyanuric acid in the neutralization filtrate is 1.1-1.2:1.

[0014] As a further technical solution, the modifier consists of 4'-amino-2'-hydroxyacetophenone and bis(3-amino-4-hydroxyphenyl)sulfone.

[0015] As a further technical solution, the mass ratio of the 4'-amino-2'-hydroxyacetophenone to bis(3-amino-4-hydroxyphenyl)sulfone is 1:1-5.

[0016] As a further technical solution, the mass ratio of 4'-amino-2'-hydroxyacetophenone to bis(3-amino-4-hydroxyphenyl)sulfone is 1:4.

[0017] As a further technical solution, the treatment agent also includes a composite metal catalyst, which is composed of zirconium sulfide and ferric chloride.

[0018] As a further technical solution, the mass ratio of the zirconium sulfide to the ferric chloride is 2:3-5.

[0019] As a further technical solution, the added amount of the composite metal catalyst is 7% of the mass of sodium hypochlorite.

[0020] As a further technical solution, the acidification is to add hydrochloric acid to the mother liquor of dichloroisocyanuric acid and trichloroisocyanuric acid, adjust the pH to 2-4, and blow off the generated chlorine gas.

[0021] As a further technical solution, the neutralization is to add alkali to the acidified treatment liquid to adjust the pH to 6.7-7.5.

[0022] As a further technical solution, the ammonia removal treatment is to add alkali to the neutralization filtrate, adjust the pH to 10-11, raise the temperature to 45-55°C, and then add a treatment agent for deammoniation treatment.

[0023] As a further technical solution, the amount of modified activated carbon added is 10% to 15% of the amount of sodium hypochlorite added.

[0024] The working principle and beneficial effects of the present invention are:

[0025] In the present invention, the addition of sodium hypochlorite can decompose organic matter in the mother liquor into inorganic small molecules such as ammonia, water and carbon dioxide, but the oxidation effect of sodium hypochlorite is not ideal. Therefore, in order to make the total ammonium content in the mother liquor of dichloroisocyanuric acid and trichloroisocyanuric acid reach the standard, it is necessary to increase the addition amount of sodium hypochlorite to reach the standard of total ammonium content. Therefore, in the process of ammonia removal treatment, activated carbon modified with 4'-amino-2'-hydroxyacetophenone and / or bis(3-amino-4-hydroxyphenyl)sulfone is added on the basis of adding sodium hypochlorite, so as to improve the effect of sodium hypochlorite and reduce the addition amount of sodium hypochlorite. DETAILED DESCRIPTION

[0026] 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.

[0027] Example 1

[0028] A process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor comprises the following steps:

[0029] S1, add hydrochloric acid to the mother liquor of dichloroisocyanuric acid and trichloroisocyanuric acid, adjust the pH to 2, blow off the generated chlorine gas, and obtain the acidified mother liquor of dichloroisocyanuric acid and trichloroisocyanuric acid;

[0030] S2, adding alkali to the acidified dichloroisocyanuric acid and trichloroisocyanuric acid mother liquors, adjusting the pH to 6.7 and filtering to obtain a neutralized filtrate;

[0031] S3, the neutralization filtrate is heated to 45°C by heat exchange in a heat exchanger, the pH is adjusted to 10, sodium hypochlorite and modified activated carbon are added to the filtrate, stirred evenly, and then allowed to stand for 4 hours; wherein the molar ratio of the amount of sodium hypochlorite added to the cyanuric acid in the neutralization filtrate is 1.1:1; the amount of modified activated carbon added is 10% of the amount of sodium hypochlorite added;

[0032] The preparation method of modified activated carbon comprises the following steps:

[0033] 3 g of 4'-amino-2'-hydroxyacetophenone and bis(3-amino-4-hydroxyphenyl)sulfone were added to 300 mL of anhydrous ethanol, and then 60 g of activated carbon was added. After reacting at 50° C. for 8 h, the mixture was filtered and dried to obtain modified activated carbon.

[0034] Example 2

[0035] A process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor comprises the following steps:

[0036] S1, add hydrochloric acid to the mother liquor of dichloroisocyanuric acid and trichloroisocyanuric acid, adjust the pH to 3, blow off the generated chlorine gas, and obtain the acidified mother liquor of dichloroisocyanuric acid and trichloroisocyanuric acid;

[0037] S2, adding alkali to the acidified dichloroisocyanuric acid and trichloroisocyanuric acid mother liquors, adjusting the pH to 7.0 and filtering to obtain a neutralized filtrate;

[0038] S3, heating the neutralized filtrate to 50°C through a heat exchanger, adjusting the pH to 10, adding sodium hypochlorite and modified activated carbon to the filtrate, stirring evenly, and standing for 4 hours; wherein the molar ratio of the amount of sodium hypochlorite added to the cyanuric acid in the neutralized filtrate is 1.15:1; the amount of modified activated carbon added is 12% of the amount of sodium hypochlorite added;

[0039] The preparation method of modified activated carbon comprises the following steps:

[0040] 4.5 g of 4'-amino-2'-hydroxyacetophenone and bis(3-amino-4-hydroxyphenyl)sulfone were added to 300 mL of anhydrous ethanol, and then 60 g of activated carbon was added. After reacting at 55° C. for 7 h, the mixture was filtered and dried to obtain modified activated carbon.

[0041] Example 3

[0042] A process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor comprises the following steps:

[0043] S1, add hydrochloric acid to the mother liquor of dichloroisocyanuric acid and trichloroisocyanuric acid, adjust the pH to 4, blow off the generated chlorine gas, and obtain the acidified mother liquor of dichloroisocyanuric acid and trichloroisocyanuric acid;

[0044] S2, adding alkali to the acidified dichloroisocyanuric acid and trichloroisocyanuric acid mother liquors, adjusting the pH to 7.5 and filtering to obtain a neutralized filtrate;

[0045] S3, the neutralization filtrate is heated to 55°C by heat exchange in a heat exchanger, the pH is adjusted to 11, sodium hypochlorite and modified activated carbon are added to the filtrate, stirred evenly, and then allowed to stand for 4 hours; wherein the molar ratio of the amount of sodium hypochlorite added to the cyanuric acid in the neutralization filtrate is 1.2:1; the amount of modified activated carbon added is 15% of the amount of sodium hypochlorite added;

[0046] The preparation method of modified activated carbon comprises the following steps:

[0047] 6 g of 4'-amino-2'-hydroxyacetophenone and bis(3-amino-4-hydroxyphenyl)sulfone were added to 300 mL of anhydrous ethanol, and then 60 g of activated carbon was added. After reacting at 60° C. for 6 h, the mixture was filtered and dried to obtain modified activated carbon.

[0048] Example 4

[0049] The difference between this embodiment and embodiment 1 is that 4'-amino-2'-hydroxyacetophenone is replaced by an equal amount of bis(3-amino-4-hydroxyphenyl)sulfone.

[0050] Example 5

[0051] The only difference between this embodiment and embodiment 1 is that 4'-amino-2'-hydroxyacetophenone is replaced by 4'-amino-2'-hydroxyacetophenone and bis(3-amino-4-hydroxyphenyl)sulfone in a mass ratio of 1:1.

[0052] Example 6

[0053] The only difference between this embodiment and embodiment 1 is that 4'-amino-2'-hydroxyacetophenone is replaced by 4'-amino-2'-hydroxyacetophenone and bis(3-amino-4-hydroxyphenyl)sulfone in a mass ratio of 1:4.

[0054] Example 7

[0055] The only difference between this embodiment and embodiment 1 is that 4'-amino-2'-hydroxyacetophenone is replaced by 4'-amino-2'-hydroxyacetophenone and bis(3-amino-4-hydroxyphenyl)sulfone in a mass ratio of 1:5.

[0056] Example 8

[0057] The only difference between this embodiment and embodiment 1 is that zirconium sulfide is further added to S3, and the amount of zirconium sulfide added is 7% of the mass of sodium hypochlorite.

[0058] Example 9

[0059] The only difference between this embodiment and embodiment 1 is that ferric chloride is further added to S3, and the amount of ferric chloride added is 7% of the mass of sodium hypochlorite.

[0060] Example 10

[0061] The only difference between this embodiment and embodiment 1 is that zirconium sulfide and ferric chloride are further added to S3, the sum of the mass of zirconium sulfide and ferric chloride is 7% of the mass of sodium hypochlorite, and the mass ratio of zirconium sulfide to ferric chloride is 2:3.

[0062] Embodiment 11

[0063] The only difference between this embodiment and embodiment 1 is that zirconium sulfide and ferric chloride are further added to S3, the sum of the mass of zirconium sulfide and ferric chloride is 7% of the mass of sodium hypochlorite, and the mass ratio of zirconium sulfide to ferric chloride is 1:2.

[0064] Example 12

[0065] The only difference between this embodiment and embodiment 1 is that zirconium sulfide and ferric chloride are further added to S3, the sum of the mass of zirconium sulfide and ferric chloride is 7% of the mass of sodium hypochlorite, and the mass ratio of zirconium sulfide to ferric chloride is 2:5.

[0066] Comparative Example 1

[0067] The only difference between this comparative example and Example 1 is that the activated carbon is not modified.

[0068] Comparative Example 2

[0069] The only difference between this comparative example and Example 1 is that no modified activated carbon is added.

[0070] Comparative Example 3

[0071] The only difference between this comparative example and Example 1 is that the modified activated carbon is replaced by an equal amount of sodium hypochlorite.

[0072] Test example

[0073] The total ammonium content in the treated mother liquors of dichloroisocyanuric acid and trichloroisocyanuric acid in Examples 1 to 12 and Comparative Examples 1 to 3 was measured, and the total ammonium content in the mother liquors of dichloroisocyanuric acid and trichloroisocyanuric acid was 2460 ppm.

[0074] The measurement results are shown in Table 1.

[0075] Table 1 Total ammonium content after treatment in Examples 1 to 12 and Comparative Examples 1 to 3 (ppm)

[0076]

[0077] Compared with Example 1, the activated carbon in Comparative Example 1 is not modified, no modified activated carbon is added in Comparative Example 2, and the modified activated carbon is replaced with an equal amount of sodium hypochlorite in Comparative Example 3. As a result, the total ammonium content in Comparative Examples 1 to 3 is higher than that in Example 1, indicating that adding activated carbon modified with 4'-amino-2'-hydroxyacetophenone can improve the treatment effect and reduce the total ammonium content after treatment.

[0078] Compared with Example 1, Example 4 replaces 4'-amino-2'-hydroxyacetophenone with bis(3-amino-4-hydroxyphenyl)sulfone, and Example 5 replaces 4'-amino-2'-hydroxyacetophenone with 4'-amino-2'-hydroxyacetophenone and bis(3-amino-4-hydroxyphenyl)sulfone in a mass ratio. As a result, the total ammonium content in Example 5 is lower than that in Examples 1 and 4, indicating that the use of 4'-amino-2'-hydroxyacetophenone and bis(3-amino-4-hydroxyphenyl)sulfone to modify the activated carbon improves the treatment effect and reduces the total ammonium content after treatment.

[0079] Furthermore, by comparing Examples 5 to 7, the total ammonium content after treatment in Example 6 is lower than that in Examples 5 and 7, indicating that when the mass ratio of 4'-amino-2'-hydroxyacetophenone to bis(3-amino-4-hydroxyphenyl)sulfone is 1:4, the treatment effect can be further improved and the total ammonium content after treatment can be reduced.

[0080] Compared with Example 1, zirconium sulfide is further added in Example 8, ferric chloride is further added in Example 9, and zirconium sulfide and ferric chloride are added simultaneously in Examples 10 to 12. As a result, the ammonium content in Examples 10 to 12 is lower than that in Examples 1, 8, and 9, indicating that the simultaneous addition of zirconium sulfide and ferric chloride can further improve the treatment effect and reduce the total ammonium content after treatment.

[0081] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor, characterized in that: The following steps are involved: S1, dichloroisocyanuric acid, trichloroisocyanuric acid mother liquor is acidified to obtain an acidified treatment liquid; S2, neutralizing the acidified solution and filtering to obtain a neutralized filtrate; S3, neutralize the filtrate to remove ammonia; The treatment agent used in the ammonia removal treatment is composed of sodium hypochlorite and modified activated carbon; the modified activated carbon is obtained by modifying the activated carbon with a modifier, and the modifier includes 4'-amino-2'-hydroxyacetophenone and / or bis(3-amino-4-hydroxyphenyl) sulfone; The amount of modified activated carbon added is 10% to 15% of the amount of sodium hypochlorite added.

2. The process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor according to claim 1, characterized in that: The mass ratio of the modifier to the activated carbon is 1-2:

20.

3. The process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor according to claim 1, characterized in that: The modifier consists of 4'-amino-2'-hydroxyacetophenone and bis(3-amino-4-hydroxyphenyl)sulfone.

4. The process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor according to claim 1, characterized in that: The mass ratio of the 4'-amino-2'-hydroxyacetophenone to bis(3-amino-4-hydroxyphenyl)sulfone is 1:1-5.

5. The process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor according to claim 1, characterized in that: The treating agent further comprises a composite metal catalyst, which is composed of zirconium sulfide and ferric chloride.

6. The process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor according to claim 5, characterized in that: The mass ratio of the zirconium sulfide to the ferric chloride is 2:3-5.

7. The process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor according to claim 1, characterized in that: The acidification is to add hydrochloric acid to the mother liquor of dichloroisocyanuric acid and trichloroisocyanuric acid, adjust the pH to 2-4, and blow off the generated chlorine gas.

8. The process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor according to claim 1, characterized in that: The neutralization is to add alkali to the acidified treatment solution to adjust the pH to 6.7-7.

5.

9. The process for treating dichloroisocyanuric acid and trichloroisocyanuric acid mother liquor according to claim 1, characterized in that: The ammonia removal treatment is to add alkali to the neutralized filtrate, adjust the pH to 10-11, raise the temperature to 45-55° C., and then add a treatment agent to carry out ammonia removal treatment.

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