CN107686203A - A kind of recycling treatment process using cross current solvent extraction method to H acid producing waste waters - Google Patents

Abstract

The invention discloses a process for resourceful treatment of H-acid production wastewater by using a cross-current extraction method. The process steps are as follows: (1) Separating inorganic salts and organic matter: adding an extractant to the collected H-acid production wastewater, stirring Mix, perform primary or secondary extraction to obtain the extract phase and raffinate phase; (2) Recover inorganic salts: the raffinate phase of step (1) is treated with MVR equipment, sodium sulfate is concentrated and crystallized for recycling, and distilled water is used for process Reuse; (3) Recycling of extractant: add back extractant to the extraction phase of step (1), regenerate the extractant in step (1), and return the obtained extract phase concentrate to the production process or incinerate. This process can not only realize the effective removal of COD in the H acid production wastewater, but also realize the recycling of a large amount of sodium sulfate in the H acid production wastewater, and can also carry out back extraction of the extractant to realize the regeneration of the extractant.

Description

A resource treatment process for H acid production wastewater by using cross-flow extraction method

technical field

The invention belongs to the technical field of waste water treatment of chemical product production, and relates to a resource treatment process of H acid waste water, in particular to a process for resource treatment of H acid production waste water by using a cross-flow extraction method.

Background technique

As an important intermediate of naphthalene-based dyes, H acid is widely used in the production of reactive dyes, direct dyes, acid dyes, and color-changing acids. During the production of H acid, H acid production wastewater will be generated, mainly after acid analysis and filtration. Process produces H acid crystallization mother liquor wastewater. Its chemical properties are stable, its pH value is about 2, and its CODcr is as high as 20,000~50,000 mg/L. It is a typical refractory organic wastewater, which is difficult to be effectively treated by general oxidation processes and biochemical processes, and the concentration of sodium sulfate in wastewater is in a supersaturated state. If it is not dealt with effectively, it will not only cause serious harm to the environment and human health, but also cause a waste of resources.

At present, the treatment methods for H-acid wastewater mainly include adsorption method, coagulation method, extraction method, photocatalytic oxidation method, ozone oxidation method, wet oxidation method, Fenton and Fenton-like technology, ultrasonic degradation method, membrane separation method, biological treatment However, because H acid wastewater has the characteristics of high salinity, strong acidity, deep color, high COD content, and high biological toxicity, there are certain limitations when using the above methods for treatment.

CN103680022 A discloses a treatment process, device and special adsorption resin material for H-acid production wastewater. Part of the COD components are removed by extraction. Double modification treatment to improve the selective adsorption of organic pigment H acid. The extraction agent used in this method cannot be recycled and recycled, resulting in waste. In addition, it is necessary to prepare an adsorption material and a preparation device, which are costly and complicated to operate.

CN105236623 A discloses a treatment method for H-acid wastewater. The Fenton method is used to treat H-acid wastewater, and calcium oxide is added to adjust the pH, and an adsorbent and a flocculant are used for flocculation and precipitation to achieve the purpose of removing COD. This method requires heating and multiple additions of chemicals, and the sodium sulfate salt in the H-acid wastewater cannot be recycled, so the operation is more complicated and the cost is higher.

Therefore, it is a problem to be solved urgently to find a treatment technology that can not only realize the effective treatment of H-acid wastewater, but also recycle a large amount of sodium sulfate contained in H-acid wastewater. Contents of the invention

The purpose of the present invention is to provide a kind of utilization cross-current extraction method to the resource treatment process of H-acid production wastewater, this technique can not only realize the effective removal of COD in the H-acid production wastewater, but also can realize a large amount of sulfuric acid in the H-acid production wastewater The recovery and utilization of sodium salt can also carry out back extraction on the extractant to realize the regeneration of the extractant.

The purpose of the present invention is achieved through the following technical solutions:

A resource treatment process for H acid production wastewater by cross-flow extraction, comprising the steps of:

(1) Separation of inorganic salts and organic matter: Add extractant to the collected H acid production wastewater, stir and mix, and perform primary or secondary extraction. The obtained extraction phase contains a large amount of organic matter, and the raffinate phase contains a large amount of inorganic salt; The extractant is composed of a complexing agent, a diluent and a cosolvent, the complexing agent is one of trioctylamine, triisooctylamine, n-octylamine and tributyl phosphate, the diluent is kerosene, and the cosolvent is n-octyl The volume ratio of alcohol, diluent, complexing agent and co-solvent is 2~5:1:0.2; the volume ratio of H acid production wastewater to extractant is 1~8:1; the stirring speed is 220~240r/min; The stage extraction temperature is 15~65℃, and the single stage extraction time is 10~40min;

(2) Recovery of inorganic salts: the raffinate phase of step (1) contains a large amount of sodium sulfate, which is processed by MVR equipment. The sodium sulfate is concentrated and crystallized and can be recycled, and the distilled water can be reused in the process;

(3) Recycling of extraction agent: adding a stripping agent to the extraction phase of step (1), reusing the extraction agent in step (1), and the obtained extract phase concentrate can be returned to the production process or incinerated; The stripping agent is sodium hydroxide solution, the volume ratio of the extraction phase to the sodium hydroxide solution is 2-4:1, and the concentration of the sodium hydroxide solution is 10-15%.

Preferably, in step (1), the extractant is prepared by mixing complexing agent trioctylamine, diluent kerosene, and cosolvent n-octanol in a volume ratio of 5:18 to 22:1.

Preferably, in step (1), the volume ratio of H acid production wastewater to extractant is 4.5-5:1.

Preferably, in step (1), the single-stage extraction temperature is 50-65°C.

Preferably, in step (1), the single-stage extraction time is 30-32 minutes.

Preferably, in step (1), the number of stages of cross-flow extraction is 2.

Preferably, in step (3), the concentration of the sodium hydroxide solution is 13%.

Preferably, in step (3), the volume ratio of the extract phase to the sodium hydroxide solution is 2:1.

Compared with the prior art, the present invention has the following advantages:

1. The extraction efficiency is high, which can effectively reduce the COD value in the H-acid wastewater, which is beneficial to the next step treatment of the H-acid wastewater.

2. The extractant is regenerated after being back-extracted by sodium hydroxide solution. The regenerated extractant still has a good extraction effect, and the extracted concentrated solution obtained after back-extraction can be returned to the production process.

3. After the inorganic salt sodium sulfate in the H-acid wastewater is treated by the MVR process, its purity is close to 100%.

4. The process design of the present invention is reasonable, the process is simple, the extractant can be recycled, and the recyclate can also be used for secondary use or other production purposes, which can effectively realize the treatment and resource utilization of H-acid wastewater.

Description of drawings

Fig. 1 is the extraction process flow chart of the present invention;

Figure 2 shows untreated H-acid wastewater precipitation crystallization (left) and sodium sulfate powder (right);

Figure 3 shows the crystallization (left) and sodium sulfate powder (right) of the treated H-acid wastewater.

detailed description

The technical solution of the present invention will be further described below in conjunction with the accompanying drawings, but it is not limited thereto. Any modification or equivalent replacement of the technical solution of the present invention without departing from the spirit and scope of the technical solution of the present invention should be covered by the present invention. within the scope of protection.

Specific implementation mode one: this implementation mode provides a kind of recycling treatment process to H acid production wastewater by using cross-flow extraction method, as shown in Figure 1, the specific implementation steps are as follows:

(1) Mix the complexing agent trioctylamine, diluent kerosene, and co-solvent n-octanol in a volume ratio of 5:18~22:1 to make an extraction agent, and mix H acid production wastewater and extractant, heat the mixed solution to a temperature of 50~65°C, stir the solution at a stirring speed of 220~240r/min, stop stirring after 30~32min of extraction, separate the extract phase and raffinate after standing still, and proceed to the second Two-stage cross-flow extraction, the extraction conditions are the same as the first-stage extraction conditions, after the extraction is completed, the extract phase and raffinate obtained by the two extractions are combined for the next step.

(2) The raffinate containing a large amount of sodium sulfate obtained in step (1) is subjected to MVR treatment, and sodium sulfate white powder is obtained after the treatment, and the purity is close to 100%.

(3) Add a sodium hydroxide solution with a concentration of 13% to the extraction phase obtained in step (1) for back extraction. The volume ratio of the extraction phase to the back extraction agent sodium hydroxide solution is 2:1. After the back extraction is completed, get The regenerated extractant is colorless and transparent, the extract phase concentrate can be reused as raw material for production, and the remaining part can be incinerated.

Specific implementation mode two: In this implementation mode, take the H acid production wastewater of a certain factory as an example, its COD value is 35000 mg/L, and the sodium sulfate content is about 20%.

Utilize the cross-flow extraction method to carry out the processing step of resource treatment to above-mentioned H acid production waste water as follows:

(1) Mix the complexing agent trioctylamine, diluent kerosene, and co-solvent n-octanol in a volume ratio of 5:18:1 to make an extraction agent, mix H acid production wastewater and extraction agent in a ratio of 4.5:1, and heat The temperature of the mixed solution is 55°C, the solution is stirred at a stirring speed of 230r/min, the stirring is stopped after 30 minutes of extraction, the extraction phase and the raffinate are separated after standing, and the second-stage cross-flow extraction is continued. The extraction conditions are the same as those of the first The primary extraction conditions are the same, and after the extraction is completed, the extraction phase and raffinate obtained from the two extractions are combined for the next step. Among them, the raffinate COD value is 5750mg/L, and the removal rate reaches 83.6%.

(2) The raffinate containing a large amount of sodium sulfate obtained in step (1) is subjected to MVR treatment, and sodium sulfate white powder is obtained after the treatment, and the purity is close to 100%.

(3) Add a sodium hydroxide solution with a concentration of 13% to the extraction phase obtained in step (1) for back extraction. The volume ratio of the extraction phase to the back extraction agent sodium hydroxide solution is 2:1. After the back extraction is completed, the obtained The regenerated extractant is colorless and transparent, the concentrated extract phase can be reused as raw material for production, and the remaining part can be incinerated.

The crystallization and sodium sulfate powder of the untreated H acid wastewater are as shown in Figure 2, and the crystallization and sodium sulfate powder of the H acid wastewater treated by the method of this embodiment are as shown in Figure 3.

Specific implementation mode three: In this implementation mode, the H-acid production wastewater of a certain factory is taken as an example, its COD value is 35000mg/L, and the sodium sulfate content is about 20%.

Utilize the cross-flow extraction method to carry out the processing step of resource treatment to above-mentioned H acid production waste water as follows:

(1) Mix the complexing agent trioctylamine, diluent kerosene, and co-solvent n-octanol in a volume ratio of 5:18:1 to make an extraction agent, mix H acid production wastewater and extraction agent in a ratio of 4.5:1, and heat The temperature of the mixed solution is 55° C., the solution is stirred at a stirring speed of 230 r/min, the stirring is stopped after 30 minutes of extraction, and the extraction phase and the raffinate are separated after standing. Among them, the raffinate COD value is 13980mg/L, and the removal rate reaches 60.0%.

(2) The raffinate containing a large amount of sodium sulfate obtained in step (1) is subjected to MVR treatment, and sodium sulfate white powder is obtained after the treatment, and the purity is close to 100%.

(3) Add a sodium hydroxide solution with a concentration of 13% to the extraction phase obtained in step (1) for back extraction. The volume ratio of the extraction phase to the back extraction agent sodium hydroxide solution is 2:1. After the back extraction is completed, the obtained The regenerated extractant is colorless and transparent.

Claims (10)

1. A kind of 1. recycling treatment process using cross current solvent extraction method to H acid producing waste waters, it is characterised in that the processing step It is as follows：

   （1）Separating inorganic salts and organic matter：Extractant is added into the H acid producing waste waters of collection, is stirred, carries out one-level Or two level extraction, extraction phase and raffinate phase are obtained, wherein：The volume ratio of H acid producing waste waters and extractant is 1 ~ 8:1, stirring turns Speed is 220 ~ 240r/min, and single-stage extraction temperature is 15 ~ 65 DEG C, 10 ~ 40min of single-stage extraction time；

   （2）Reclaim inorganic salts：Step（1）Raffinate phase handled using MVR equipment, sodium sulphate condensing crystallizing separate out recovery profit With distilled water carries out technique reuse；

   （3）Extractant regeneration utilizes：To step（1）Extraction be added to the volume ratio of strippant, extraction phase and strippant For 2 ~ 4:1, by step（1）In extractant regeneration utilize, obtained extraction phase concentrate returns to production technology or burnt Burning processing.
2. 2. the recycling treatment process according to claim 1 using cross current solvent extraction method to H acid producing waste waters, its feature exists In the step（1）In, extractant is made up of complexing agent, diluent and cosolvent, the volume of diluent, complexing agent and cosolvent Than for 2 ~ 5:1:0.2.
3. 3. the recycling treatment process according to claim 2 using cross current solvent extraction method to H acid producing waste waters, its feature exists It is one kind in trioctylamine, tri-iso-octylamine, n-octyl amine and tributyl phosphate in the complexing agent, diluent is kerosene, cosolvent For n-octyl alcohol.
4. 4. the recycling treatment process according to claim 2 using cross current solvent extraction method to H acid producing waste waters, its feature exists In the extractant by complexing agent trioctylamine, diluent kerosene, cosolvent n-octyl alcohol by volume 5:18~22:1 is mixed to prepare.
5. 5. the recycling treatment process using cross current solvent extraction method to H acid producing waste waters according to claim 1,2,3 or 4, It is characterized in that the step（1）In, the volume ratio of H acid producing waste waters and extractant is 4.5 ~ 5:1.
6. 6. the recycling treatment process according to claim 1 using cross current solvent extraction method to H acid producing waste waters, its feature exists In the step（1）In, single-stage extraction temperature is 50 ~ 65 DEG C, and the single-stage extraction time is 30 ~ 32min.
7. 7. the recycling treatment process according to claim 1 using cross current solvent extraction method to H acid producing waste waters, its feature exists In the step（1）In, cross current solvent extraction series is 2 grades.
8. 8. the recycling treatment process according to claim 1 using cross current solvent extraction method to H acid producing waste waters, its feature exists In described（3）In, strippant is sodium hydroxide solution, and concentration of sodium hydroxide solution is 10 ~ 15%.
9. 9. the recycling treatment process according to claim 8 using cross current solvent extraction method to H acid producing waste waters, its feature exists In the concentration of sodium hydroxide solution be 13%.
10. 10. the recycling treatment process using cross current solvent extraction method to H acid producing waste waters according to claim 1,8 or 9, its It is characterised by the step（3）In, the volume ratio of extraction phase and strippant is 2:1.