Dyeing sludge dechlorination synergistic upgrading process using traditional Chinese medicine residues

Abstract

The invention discloses a printing and dyeing sludge dechlorination synergistic upgrading process by using traditional Chinese medicine residues. The process comprises the following steps: crushing waste traditional Chinese medicine residues; putting the crushed waste traditional Chinese medicine residues into enzymatic hydrolysate for enzymolysis to decompose a cross-linked structure of a lignin component, and then filtering to obtain enzymolysis traditional Chinese medicine residues; uniformly mixing the enzymolysis traditional Chinese medicine residues with the printing and dyeing sludge; adjusting the water content of the mixture of the enzymolysis traditional Chinese medicine residues and the printing and dyeing sludge, and uniformly stirring to form slurry; then adding a hydrothermal additive into the slurry, and mixing to obtain mixed slurry; carrying out hydrothermal carbonization reaction on the mixed slurry; after the reaction is finished, carrying out solid-liquid separation to obtain a solid phase and a liquid phase; according to the technology, the interaction between the waste traditional Chinese medicine residues and printing and dyeing sludge components in the hydrothermal process is fully utilized, the dechlorination effect and product upgrading are promoted, the chlorine element in the printing and dyeing sludge is removed, the heat value of hydrothermal carbon is promoted to be increased, and the environmental risk and the operation cost of subsequent printing and dyeing sludge incineration are effectively reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of environmental engineering and solid waste resource utilization, and is a synergistic quality improvement process for dechlorination of printing and dyeing sludge using traditional Chinese medicine residues. Background Art

[0002] Printing and dyeing sludge is an inevitable by-product of the textile industry. If it is not properly disposed of, it can easily cause environmental pollution. At present, incineration is the main disposal route for printing and dyeing sludge, but it is limited by the characteristics of printing and dyeing sludge raw materials: on the one hand, the chlorine content of printing and dyeing sludge is relatively high, which makes it easy to produce dioxins after incineration, resulting in difficulty in treating incineration tail gas; on the other hand, the calorific value of printing and dyeing sludge is relatively low, and its incineration process requires additional auxiliary fuel, resulting in increased operating costs. Therefore, effective technology is urgently needed to achieve dechlorination and quality improvement of printing and dyeing sludge. my country has significant industrial advantages in the field of raw material drug production and processing, and produces a large amount of waste Chinese medicine residue. Waste Chinese medicine residue is rich in lignin components. Previous studies have found that lignin components can promote material dechlorination under hydrothermal conditions. Based on the above background, this process proposes to use Chinese medicine residue and printing and dyeing sludge to mix hydrothermal carbonization to achieve dechlorination and quality improvement of printing and dyeing sludge, and combine mechanical crushing and rapid enzymatic pretreatment to improve the process effect.

[0003] Compared with the existing technology, this process has significant cost advantages, which are reflected in two aspects: (1) The operating cost of this process is low: the process is based on the idea of ​​"treating waste with waste" and does not involve other additives except KOH / NaOH, so the process does not require additional reagent costs. Secondly, although this process involves a hydrothermal carbonization process that requires heating to 180°C, it has advantages over existing processes. For example, the existing technology "Dechlorination Method for Fly Ash from Incineration of Domestic Waste" (Publication No.: CN115138022A) requires continuous calcination at 1000-1200°C; (2) This process requires less investment in fixed equipment: This process does not involve non-standard customized equipment, and each process environment is based on conventional chemical structures, so the process has the advantage of less equipment investment. Existing dechlorination technologies often involve investment in non-standard equipment, such as the existing technologies "A Chlorinated Wastewater Hydrogenation Dechlorination Treatment Device" (Publication No.: CN221319392U), "A Waste Plastic Pyrolysis Dechlorination Equipment" (Publication No.: CN221344447U), "A Venturi-type Carbon Dioxide Assisted Fly Ash Dechlorination Device" (Publication No.: CN220862327U), and "A Carbon Dioxide Assisted Three-stage Countercurrent Water Washing Fly Ash Dechlorination Device and Method" (Publication No.: CN115193863A) all involve relevant equipment investment. Summary of the invention

[0004] In view of the shortcomings of the prior art, the present invention proposes a synergistic dechlorination and quality improvement process for printing and dyeing sludge using traditional Chinese medicine residues. The purpose of the present invention can be achieved through the following technical solutions:

[0005] A dechlorination and synergistic quality improvement process for printing and dyeing sludge using traditional Chinese medicine residues, characterized in that the process flow specifically includes the following steps:

[0006] Step 1 Mechanical crushing: crush the discarded Chinese medicine residue to a particle size of ≤30 mm;

[0007] Step 2: rapid enzymatic hydrolysis: placing the crushed Chinese medicine residues in step 1 in an enzymatic hydrolysis solution for rapid enzymatic hydrolysis, so that the cross-linked structure of the lignin component is preliminarily decomposed, and then filtering to obtain the enzymatic hydrolyzed Chinese medicine residues;

[0008] Step 3: mixing materials: mixing the enzymatic hydrolyzed Chinese medicine residue and the printing and dyeing sludge described in step 2;

[0009] Step 4: slurry adjustment: adjust the moisture content of the mixture of the Chinese medicine residue and the printing and dyeing sludge in step 3 to 90%, and stir to form a slurry; then add a hydrothermal additive to the slurry and mix evenly;

[0010] Step 5: Hydrothermal carbonization: the slurry mixed evenly in step 4 is transferred into a reactor for hydrothermal carbonization reaction;

[0011] Step 6: Solid-liquid separation: After the reaction is completed, the reactor is opened to perform solid-liquid separation to obtain hydrothermal charcoal (solid phase) and chlorine-containing water phase (liquid phase).

[0012] Preferably, the water content of the discarded Chinese medicinal residues and the printing and dyeing sludge is 75% to 85% (based on wet weight).

[0013] Preferably, in step 1, after completing a single crushing stage, the crushing should be checked, and materials that do not meet the particle size requirements (particle size ≥ 30 mm) should be returned to step 1 for crushing again.

[0014] Preferably, the enzymatic solution in step 2 is a laccase solution, and its active unit concentration needs to be 0.3u / mL to 0.5u / mL. When preparing the enzymatic solution, the laccase is dissolved in an acetate buffer solution with a pH between 4.5 and 5.5.

[0015] Preferably, the rapid enzymatic hydrolysis process in step 2 is 1 hour, and the enzymatic hydrolysis solution is added to the discarded Chinese medicine residue at a liquid-to-solid ratio of 5: 1. The enzymatic hydrolysis process is maintained at 25° C. and stirred continuously.

[0016] Preferably, the weight ratio of the enzymatically hydrolyzed Chinese medicinal residues to the printing and dyeing sludge in step 3 should be 1:2 to 1:1.

[0017] Preferably, in step 4, the water content of the mixture is adjusted by adding supplementary water, and the supplementary water includes distilled water and hydrothermal carbonization aqueous phase product. Distilled water is added when the aqueous phase product is insufficient. The hydrothermal additive should be any one of KOH and NaOH, added in solid phase, and the added amount is 5% of the mass of the slurry.

[0018] Preferably, in step 5, the hydrothermal carbonization is carried out in a sequencing batch reactor, the reaction temperature is 180° C., the reaction time is 2 hours, and the reaction pressure is the autogenous pressure generated by the slurry as the reaction temperature increases.

[0019] Preferably, in step 6, solid-liquid phase separation is achieved by vacuum filtration. After separation, the solid phase is hydrothermal charcoal, which has a high calorific value and can be subsequently incinerated. The liquid phase is the aqueous phase product. When the chlorine content of the aqueous phase product is greater than 1000 mg / L, it is discharged as a high-concentration chlorine liquid. When the chlorine content of the aqueous phase product is ≤1000 mg / L, it is refluxed to step 4 as supplementary water for slurry preparation.

[0020] Beneficial effects of the present invention:

[0021] The present invention can simultaneously achieve dechlorination and calorific value improvement of printing and dyeing sludge, thereby solving the environmental risk and additional fuel addition problems of subsequent incineration disposal. The process is simple, the process is mild, the additives are few and cheap, there is no non-standard equipment investment, and the raw materials are low-value waste. Therefore, the process has a significant low-cost characteristic. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 It is a process flow chart of the present invention. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in 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.

[0025] Comparative Example 1

[0026] Taking the printing and dyeing sludge from a printing and dyeing wastewater treatment plant A as the implementation object, its chlorine content was measured to be 1.455 mg / g and its higher calorific value was 6.08 MJ / kg.

[0027] Example 1

[0028] (1) When using this process to dechlorinate and improve the quality of the product, the weight ratio of enzymatic hydrolyzed Chinese medicine residue to printing and dyeing sludge should be 1:1, and the unit concentration of enzymatic hydrolyzate activity should be 0.3u / mL.

[0029] (2) The dechlorination rate (DE) is calculated based on the following formula:

[0030]

[0031] In the formula, C0 and C e Respectively represent the chlorine content (mg / g) in printing and dyeing sludge and hydrothermal charcoal.

[0032] Table 1 Dechlorination and quality improvement effect of Example 1

[0033]

[0034] In this embodiment, after being treated by this process, the dechlorination rate of printing and dyeing sludge reaches 64.93%, and the calorific value is increased by 73.68%.

[0035] Comparative Example 2

[0036] Taking the printing and dyeing sludge from a printing and dyeing wastewater treatment plant B as the implementation object, its chlorine content was measured to be 3.227 mg / g and its higher calorific value was 8.11 MJ / kg.

[0037] Example 2

[0038] (1) When using this process to dechlorinate and improve the quality of the product, the weight ratio of enzymatic hydrolyzed Chinese medicine residue to printing and dyeing sludge should be 1:1, and the unit concentration of enzymatic hydrolyzate activity should be 0.3u / mL.

[0039] (2) The dechlorination rate (DE) is calculated based on the following formula:

[0040]

[0041] In the formula, C0 and C e Respectively represent the chlorine content (mg / g) in printing and dyeing sludge and hydrothermal charcoal.

[0042] Table 2 Dechlorination and quality improvement effects of Example 2

[0043]

[0044] In this embodiment, after being treated by this process, the dechlorination rate of printing and dyeing sludge reaches 66.50%, and the calorific value is increased by 61.04%.

[0045] Comparative Example 3

[0046] Taking the printing and dyeing sludge from a printing and dyeing wastewater treatment plant A as the implementation object, its chlorine content was measured to be 1.455 mg / g and its higher calorific value was 6.08 MJ / kg.

[0047] Example 3

[0048] (1) When using this process to dechlorinate and improve the quality of the product, the weight ratio of enzymatic hydrolyzed Chinese medicine residue to printing and dyeing sludge should be 1:1, and the unit concentration of enzymatic hydrolyzate activity should be 0.5u / mL.

[0049] (2) The dechlorination rate (DE) is calculated based on the following formula:

[0050]

[0051] In the formula, C0 and C e Respectively represent the chlorine content (mg / g) in printing and dyeing sludge and hydrothermal charcoal.

[0052] Table 3 Dechlorination and quality improvement effects of Example 3

[0053]

[0054] In this embodiment, after being treated by this process, the dechlorination rate of printing and dyeing sludge reaches 65.77%, and the calorific value is increased by 81.09%.

[0055] Comparative Example 4

[0056] Taking the printing and dyeing sludge from a printing and dyeing wastewater treatment plant A as the implementation object, its chlorine content was measured to be 1.455 mg / g and its higher calorific value was 6.08 MJ / kg.

[0057] Example 4

[0058] (1) When using this process to dechlorinate and upgrade the sludge, the weight ratio of enzymatic hydrolyzed Chinese medicine residue to printing and dyeing sludge should be 1:2, and the unit concentration of enzymatic hydrolyzate activity should be 0.5u / mL.

[0059] (2) The dechlorination rate (DE) is calculated based on the following formula:

[0060]

[0061] In the formula, C0 and C e Respectively represent the chlorine content (mg / g) in printing and dyeing sludge and hydrothermal charcoal.

[0062] Table 4 Dechlorination and quality improvement effect of Example 4

[0063]

[0064]

[0065] In this embodiment, after being treated by this process, the dechlorination rate of printing and dyeing sludge reaches 50.86%, and the calorific value is increased by 61.35%.

[0066] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0067] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A synergistic dechlorination and quality improvement process for printing and dyeing sludge using traditional Chinese medicine residues, characterized in that: The following steps are involved: Crushing the discarded Chinese medicine residue; The crushed discarded Chinese medicine residue is placed in an enzymatic hydrolysis solution for enzymatic hydrolysis, so that the cross-linked structure of the lignin component is decomposed, and then filtered to obtain the enzymatic hydrolyzed Chinese medicine residue; Mixing the above enzymatically hydrolyzed Chinese medicine residue with printing and dyeing sludge; Adjusting the moisture content of the mixture of the enzymatic hydrolysis of the Chinese medicine residue and the printing and dyeing sludge, and stirring to form a slurry; then adding a hydrothermal additive to the slurry, and mixing to obtain a mixed slurry; The mixed slurry is subjected to a hydrothermal carbonization reaction; After the reaction is completed, solid-liquid separation is performed to obtain hydrothermal charcoal and chlorine-containing water phase.

2. The process according to claim 1, characterized in that The water content of the discarded Chinese medicine residue and the printing and dyeing sludge is 75% to 85%.

3. The process according to claim 1, characterized in that The enzymatic hydrolysis solution includes a laccase solution.

4. The process according to claim 1, characterized in that The activity unit concentration of the enzymatic hydrolysate is 0.3U / mL to 0.5U / mL.

5. The process according to claim 1, characterized in that The solid-liquid ratio of the enzymatic hydrolysis solution to the discarded traditional Chinese medicine residue is 5:1; the enzymatic hydrolysis time is 1 hour, and the enzymatic hydrolysis temperature is 25°C.

6. The process according to claim 1, characterized in that The mixing weight ratio of the enzymatic hydrolysis Chinese medicine residue to the printing and dyeing sludge is 1:2 to 1:

1.

7. The process according to claim 1, characterized in that The discarded traditional Chinese medicine residues include lignin.

8. The process according to claim 1, characterized in that The temperature of the hydrothermal carbonization reaction is 180° C., and the reaction time is 2 h.

9. The process according to claim 1, characterized in that The hydrothermal additive includes one or more of KOH and NaOH.

10. Use of the process according to any one of claims 1 to 9 in dechlorination and upgrading of printing and dyeing sludge.

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