CN110835196A - Treatment method of rubber auxiliary production wastewater - Google Patents

Abstract

The invention relates to a method for treating rubber auxiliary production wastewater. The processing method comprises the following steps: (1) removing impurities from rubber auxiliary production wastewater; (2) extracting the wastewater subjected to impurity removal in the step (1); (3) evaporating and concentrating the wastewater extracted in the step (2), and filtering to obtain industrial wet salt and an evaporation mother liquor; (4) and (4) carrying out catalytic oxidation treatment on the evaporation mother liquor obtained in the step (3), and reusing the obtained treatment liquor for evaporation concentration in the step (3). The treatment method is used for treating inorganic salt and organic matters in the rubber auxiliary production wastewater in steps, so that harmless treatment and zero discharge of the rubber auxiliary production wastewater can be realized. In addition, the treatment method is wide in application range, and can be used for treating rubber auxiliary production wastewater with the COD content of 1000-100000 mg/L and the inorganic salt content of 15-300 g/L.

Description

Treatment method of rubber auxiliary production wastewater

Technical Field

The invention relates to the field of wastewater treatment, in particular to a method for treating rubber auxiliary agent production wastewater.

Background

The industrial wastewater with high salt content and high organic matter content is common wastewater which is difficult to treat, and generally refers to wastewater with the total salt content of more than 1 percent, high organic matter content and complex components. The high-salinity high-organic matter industrial wastewater can cause harm to the growth of microorganisms due to high salinity, and is difficult to be directly treated by a biological method; in addition, the organic matter content is high, the components are complex, the boiling point of some organic matters is lower than that of water, and the boiling point of some organic matters is higher than that of water, so that the organic matters are more difficult to effectively treat. Once entering the environment, the high-salt high-organic matter industrial wastewater can cause great damage to surrounding ecosystems, and is a well-recognized problem in the field of domestic and foreign wastewater treatment at present.

Compared with high-salt high-organic matter industrial wastewater containing other inorganic salts, the high-sodium chloride high-organic matter industrial wastewater is one of the most difficult to treat, and the main reasons are as follows: 1) the high sodium chloride wastewater has strong corrosivity, so that the temperature-resistant and corrosion-resistant investment of equipment is increased, and the service life is shortened; 2) the solubility of the sodium chloride has small change along with the temperature, and the adoption of the evaporation concentration process can cause large amount of evaporated water and high operation energy consumption; 3) compared with other inorganic salts, the sodium chloride has limited market demand, and the domestic by-product sodium chloride has large waste salt amount, extremely limited market path and deviation of waste salt recycling effect; 4) the existing process for treating the industrial wastewater with high sodium chloride and high organic matters is difficult to effectively remove the organic matters in the sodium chloride aqueous solution or the sodium chloride wet salt, so that the downstream applicable field is extremely limited. Therefore, compared with the high-salt high-organic industrial wastewater containing other inorganic salts, the high-sodium chloride high-organic industrial wastewater not only further improves the treatment requirement, but also greatly improves the development difficulty of the treatment process.

The rubber additive production wastewater is used as common industrial wastewater with high sodium chloride and high organic matter, and mainly contains benzothiazole substances, a small amount of raw material organic matter, sodium chloride and other various pollutants. Because the wastewater contains amine substances, the biochemical treatment needs to consider denitrification, and the conventional denitrification process is an A/O (anaerobic-aerobic) process, namely an anoxic-aerobic biological treatment process. Since the wastewater is industrial wastewater, the nutrients therein are incomplete, and additional nutrients, such as inorganic salts such as phosphorus and potassium, are required. Meanwhile, aeration is needed, a large amount of electric energy is consumed, and according to incomplete statistics, the aeration cost accounts for 60-80% of the cost of biochemical treatment of sewage. Meanwhile, the biological treatment process can also generate a large amount of sludge, and if the treatment is not timely, secondary pollution can be generated.

Researchers have conducted a great deal of research based on rubber auxiliary production wastewater and have disclosed various treatment methods. For example, CN104291506A discloses a method for treating rubber auxiliary wastewater by microwave-enhanced microelectrolysis combined oxidation, which includes acidification reaction treatment, oxidation treatment, microelectrolysis reaction treatment, microwave reaction treatment, neutralization reaction treatment, separation treatment and water storage tank treatment. Although the treatment method can realize effective treatment of the rubber auxiliary wastewater, the recycling of inorganic salt and raw material organic matters is not realized, a large amount of sludge is generated to cause secondary pollution, and the treatment method has the defects of long process flow, high operation cost and the like. CN108218146A discloses a treatment process and a treatment system for rubber auxiliary agent type high-concentration organic wastewater, wherein the treatment process comprises precipitation treatment, catalytic oxidation treatment, coagulation and flocculation treatment, evaporation treatment, condensed water purification treatment and purified water deep oxidation treatment. Although the treatment process can realize effective treatment of the rubber auxiliary wastewater and is beneficial to large-scale implementation, the treatment process does not realize recycling of inorganic salt and raw material organic matters, and has the defects of long process flow, high operation cost and the like. CN106277519A discloses a rubber auxiliary agent wastewater resourceful treatment system and method, and the treatment method comprises precipitation air flotation, MVR evaporation, resin adsorption, rectification and Fenton oxidation. Although the treatment method has low energy and medicine consumption and can effectively recover the residual raw materials of the rubber auxiliary agent, the waste water to be discharged can be obtained, and harmless treatment and zero discharge are not realized.

Although the prior art discloses a treatment method for rubber auxiliary production wastewater, the problems of high equipment input cost or process operation cost, insufficient removal of organic matters, ineffective utilization of inorganic salt resources and the like still exist. Therefore, how to develop an effective method for treating rubber auxiliary production wastewater, which can remove organic matters with complex components and difficult treatment and can realize effective recycling of inorganic salt resources and raw material organic matter resources, is a problem to be solved at present.

Disclosure of Invention

In view of the problems in the prior art, the invention provides a treatment method of rubber auxiliary production wastewater, which comprises the steps of impurity removal, extraction, evaporation concentration and catalytic oxidation, combines the technical characteristics of multi-operation treatment, and can separate inorganic salt and organic matters in steps through the mutual synergistic effect of the steps, thereby realizing the effective recycling of inorganic salt resources and raw material organic matter resources, and finally realizing the harmless treatment and zero discharge of the rubber auxiliary production wastewater.

In order to achieve the purpose, the invention adopts the following technical scheme:

one of the purposes of the invention is to provide a treatment method of rubber auxiliary production wastewater, which comprises the following steps:

(1) removing impurities from rubber auxiliary production wastewater;

(2) extracting the wastewater subjected to impurity removal in the step (1);

(3) evaporating and concentrating the wastewater extracted in the step (2), and filtering to obtain industrial wet salt and an evaporation mother liquor;

(4) and (4) carrying out catalytic oxidation treatment on the evaporation mother liquor obtained in the step (3), and reusing the obtained treatment liquor for evaporation concentration in the step (3).

The rubber auxiliary agent production wastewater mentioned in the invention is wastewater with COD content of 1000-100000 mg/L and inorganic salt content of 15-300 g/L, and especially wastewater with COD content of 5000-100000 mg/L and inorganic salt content of 50-250 g/L. Specifically, the COD content may be 1000mg/L, 3000mg/L, 5000mg/L, 7000mg/L, 10000mg/L, 25000mg/L, 30000mg/L, 50000mg/L, 70000mg/L, 100000mg/L, or the like, and the inorganic salt content may be 15g/L, 25g/L, 50g/L, 70g/L, 100g/L, 130g/L, 150g/L, 180g/L, 200g/L, 250g/L, or 300g/L, or the like, but is not limited to the recited values, and other values not recited in the above numerical ranges are also applicable.

The treatment method provided by the invention combines impurity removal, extraction, evaporation concentration and catalytic oxidation, and the steps are mutually synergistic, so that the effective separation of inorganic salt and organic matter can be realized, the inorganic salt meeting the industrial standard can be obtained and used for preparing the raw material saline water required by the ionic membrane caustic soda industry, the raw material organic matter obtained by condensate water rectification can be recycled, the effective recycling of inorganic salt resources and raw material organic matter resources is really realized, and the harmless treatment and zero discharge of the rubber auxiliary agent production wastewater are ensured.

As a preferred technical scheme of the invention, the impurity removal in the step (1) comprises any one or a combination of at least two of sedimentation, centrifugation, filtration and membrane filtration, and typical but non-limiting examples of the combination are as follows: a combination of sedimentation and filtration, a combination of sedimentation and membrane filtration or a combination of centrifugation and filtration, etc.

Preferably, the impurity removal in the step (1) is standing sedimentation and filtration.

Preferably, the time for standing and settling is 0.5 to 100 hours, such as 0.5 hour, 1 hour, 5 hours, 10 hours, 24 hours, 30 hours, 36 hours, 48 hours, 60 hours, 70 hours or 100 hours, but is not limited to the recited values, and other values not recited in the numerical range are also applicable, preferably 24 to 48 hours.

Preferably, the filtration pore size of the filtration is 10 to 15000 mesh, for example, 10 mesh, 30 mesh, 50 mesh, 100 mesh, 300 mesh, 500 mesh, 2000 mesh, 5000 mesh, 10000 mesh, or 15000 mesh, but not limited to the recited values, and other values within the range of the recited values are also applicable, preferably 50 to 500 mesh.

The treatment method provided by the invention can effectively remove suspended matters in the rubber auxiliary agent production wastewater through standing sedimentation and filtration operation, thereby creating good conditions for subsequent extraction.

As a preferable technical scheme of the invention, the extraction in the step (2) is at least one-stage extraction.

Preferably, the extraction in the step (2) is two-stage extraction, including one-stage extraction and two-stage extraction.

Preferably, the pH environment of the first stage extraction is 1 to 5, such as 1, 2, 3, 4, or 5, but not limited to the recited values, and other values not recited within this range are equally applicable, preferably 1 to 3.

Preferably, the volume ratio of the first-stage extractant to the filtered wastewater of step (1) is 0.01 to 0.3:1, such as 0.01:1, 0.05:1, 0.1:1, 0.13:1, 0.15:1, 0.2:1, 0.25:1, or 0.3:1, but not limited to the recited values, and other values not recited within this range are equally applicable, preferably 0.1 to 0.2: 1.

Preferably, the pH environment of the secondary extraction is 7 to 11, such as 7, 8, 9, 10 or 11, but not limited to the recited values, and other values not recited within this range are equally applicable, preferably 9 to 11.

Preferably, the volume ratio of the secondary extractant to the wastewater after the primary extraction is 0.01 to 0.3:1, such as 0.01:1, 0.05:1, 0.1:1, 0.13:1, 0.15:1, 0.2:1, 0.25:1, or 0.3:1, but not limited to the recited values, and other values within this range are equally applicable, preferably 0.1 to 0.2: 1.

The treatment method provided by the invention adopts at least one stage of extraction treatment, and the extraction stage number can be adjusted according to the specific composition of the rubber auxiliary agent production wastewater. The two-stage extraction comprises the operations of first-stage extraction and second-stage extraction, macromolecular organic matters in the wastewater are removed through the first-stage extraction, and then organic amine compounds in the wastewater are removed through the second-stage extraction, so that the organic matters are efficiently removed under the synergistic extraction effect, and favorable conditions are provided for greatly improving the extraction rate of inorganic salts through subsequent evaporation and concentration.

In a preferred embodiment of the present invention, the concentration ratio of the evaporation concentration in the step (3) is 40 to 90%, for example, 40%, 50%, 65%, 70%, 80%, 85%, or 90%, but the concentration ratio is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable, preferably 80 to 85%.

Preferably, the evaporation manner of the evaporation concentration in the step (3) is any one or a combination of at least two of simple evaporation, multi-effect evaporation or MVR evaporation, and typical but non-limiting examples of the combination are: a combination of simple evaporation and multiple effect evaporation, a combination of simple evaporation and MVR evaporation or a combination of multiple effect evaporation and MVR evaporation, etc., preferably MVR evaporation.

Preferably, the condensed water obtained by the evaporation and concentration in the step (3) is rectified.

The rectification treatment can realize the separation of organic matters of different raw materials by recovering fractions at different temperatures, and the organic matters of the raw materials are recycled in the production process. Meanwhile, the rectified mother liquor can be reused as pure water in the production process.

In a preferred embodiment of the present invention, the pH environment of the catalytic oxidation in step (4) is 1 to 6, for example, 1, 2, 3, 4, 5, or 6, but the pH environment is not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable, and preferably 3 to 4.

Preferably, the regulator of the pH environment is hydrochloric acid.

Preferably, the hydrochloric acid has a mass concentration of 1 to 35.5%, for example, 1%, 5%, 10%, 18%, 28%, 31%, 33%, 35.5%, etc., but not limited to the recited values, and other values not recited within the range of the values are also applicable, preferably 28 to 31%.

As a preferable technical scheme of the invention, the catalyst adopted in the catalytic oxidation in the step (4) is soluble transition metal chloride.

Preferably, the catalyst is any one or a mixture of at least two of ferric chloride, cobalt chloride, copper chloride, zinc chloride or manganese chloride, typical but non-limiting examples of which are: mixtures of ferric chloride and cobalt chloride, mixtures of ferric chloride and copper chloride, mixtures of zinc chloride and manganese chloride or mixtures of cobalt chloride and manganese chloride, and the like.

Preferably, the mass ratio of the catalyst to the vaporization mother liquor obtained in step (3) is 1:100 to 100000, for example, 1:100, 1:500, 1:1000, 1:3000, 1:5000, 1:7000, 1:10000, 1:20000, 1:50000, 1:80000 or 1:100000, but is not limited to the recited values, and other values not recited in the range of the values are also applicable, preferably 1:5000 to 20000.

As a preferred technical solution of the present invention, the oxidant used in the catalytic oxidation in step (4) is any one or a mixture of at least two of air, oxygen, hydrogen peroxide, sodium hypochlorite and ozone, and typical but non-limiting examples of the mixture are: a mixture of air and oxygen, a mixture of air and hydrogen peroxide, a mixture of air and sodium hypochlorite, a mixture of hydrogen peroxide and sodium hypochlorite, a mixture of air and ozone or a mixture of oxygen and ozone, etc., preferably a mixture of air and oxygen.

Preferably, the mass ratio of the available oxygen in the oxidant to the COD content in the evaporation mother liquor obtained in step (3) is 1 to 20:1, for example, 1:1, 5:1, 7:1, 10:1, 15:1, 18:1, or 20:1, but is not limited to the recited values, and other values not recited in the above range are also applicable, preferably 1 to 10: 1.

In a preferred embodiment of the present invention, the reaction temperature of the catalytic oxidation in the step (4) is 50 to 500 ℃, for example, 50 ℃, 100 ℃, 150 ℃, 200 ℃, 300 ℃, 400 ℃ or 500 ℃, but not limited to the above-mentioned values, and other values not shown in the above-mentioned range are also applicable, preferably 200 to 300 ℃.

Preferably, the reaction pressure of the catalytic oxidation in the step (4) is 0 to 100MPa gauge, for example, 0MPa, 2MPa, 4MPa, 6MPa, 10MPa, 20MPa, 30MPa, 50MPa or 100MPa gauge, but not limited to the recited values, and other values not recited in the above range are also applicable, and preferably 2 to 6MPa gauge.

Preferably, the catalytic oxidation in step (4) has a reaction residence time of 0.001 to 10 hours, such as 0.001 hour, 0.005 hour, 0.01 hour, 0.05 hour, 0.1 hour, 0.5 hour, 1 hour, 5 hours, or 10 hours, but not limited to the recited values, and other values not recited in the range of the values are also applicable, preferably 0.01 to 1 hour.

Preferably, the reactor for catalytic oxidation in step (4) is any one of a tank reactor, a tubular reactor, a tower reactor or a microchannel reactor or a combination of at least two of them, and typical but non-limiting examples of the combination are: a combination of a tank reactor and a tubular reactor, a combination of a tubular reactor and a tower reactor, a combination of a tower reactor and a microchannel reactor, a combination of a microchannel reactor and a tank reactor, and the like, preferably a microchannel reactor.

The treatment method provided by the invention adopts catalytic oxidation to treat the evaporation mother liquor, and can accelerate oxidation and decomposition of organic matters under the action of the catalyst, thereby realizing high-efficiency removal of the organic matters in the evaporation mother liquor. Meanwhile, the evaporation mother liquor from which the organic matters are removed is recycled to the evaporation concentration step, so that the recycling of high-concentration inorganic salt in the evaporation mother liquor is ensured, and the full recycling of inorganic salt resources is really realized.

As a preferred technical solution of the present invention, the processing method comprises the steps of:

(1) standing and settling the rubber auxiliary production wastewater for 0.5-100 h, and then filtering with the filtering aperture of 10-15000 meshes;

(2) performing primary extraction and secondary extraction on the wastewater filtered in the step (1), wherein the pH environment of the primary extraction is 1-5, and the volume ratio of the primary extraction agent to the wastewater filtered in the step (1) is 0.01-0.3: 1; the pH environment of the secondary extraction is 7-11, and the volume ratio of the secondary extraction agent to the primary extracted wastewater is 0.01-0.3: 1;

(3) evaporating and concentrating the wastewater extracted in the step (2), wherein the concentration ratio is 40-90%, the evaporation mode is MVR evaporation, and filtering to obtain industrial wet salt and evaporation mother liquor;

rectifying condensed water obtained by evaporation and concentration in the step (3);

(4) and (3) carrying out catalytic oxidation treatment on the evaporation mother liquor obtained in the step (3), adjusting the pH environment to be 1-6 by adopting hydrochloric acid with the mass concentration of 1-35.5%, adding a catalyst and an oxidant, carrying out catalytic oxidation at the temperature of 50-500 ℃ and the gauge pressure of 0-100 MPa, keeping the reaction residence time of 0.001-10 h, and recycling the obtained treatment liquor for evaporation concentration in the step (3).

The other purpose of the invention is to provide the industrial wet salt obtained by the treatment method of the first purpose, which is used for preparing raw material brine meeting the requirements of the ionic membrane caustic soda industry.

Compared with the prior art, the invention has at least the following beneficial effects:

(1) the rubber auxiliary production wastewater treatment method disclosed by the invention is wide in application range, and can be used for treating rubber auxiliary production wastewater with the COD content of 1000-100000 mg/L and the inorganic salt content of 15-300 g/L;

(2) the industrial wet salt obtained by the treatment method meets the relevant regulations in the national standard GB/T5462-2015, and can be used for preparing raw material brine meeting the requirements of the ionic membrane caustic soda industry;

(3) the treatment method can recycle the raw material organic matters in the wastewater;

(4) the treatment method has the advantages of simple operation, short reaction period and low energy consumption, does not produce secondary pollution, and basically realizes 100 percent recycling and harmless treatment.

Drawings

FIG. 1 is a flow chart of a rubber auxiliary production wastewater treatment method provided by the invention.

Detailed Description

The technical scheme of the invention is further explained by the specific implementation mode in combination with the attached drawings. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

The flow of the treatment method of rubber auxiliary production wastewater provided by the invention is shown in figure 1, and the treatment method specifically comprises the following steps:

(1) standing, settling and filtering the rubber auxiliary agent production wastewater;

(2) performing primary extraction and secondary extraction on the wastewater filtered in the step (1);

(3) evaporating and concentrating the wastewater extracted in the step (2), and filtering to obtain industrial wet salt and an evaporation mother liquor;

rectifying condensed water obtained by evaporation and concentration in the step (3) to obtain raw material organic matters and pure water;

(4) and (4) carrying out catalytic oxidation treatment on the evaporation mother liquor obtained in the step (3), and reusing the obtained treatment liquor for evaporation concentration in the step (3).

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples.

Example 1

A treatment method of rubber antioxidant TMQ production wastewater with COD content of 35000mg/L and sodium chloride content of 230g/L comprises the following steps:

(1) standing and settling the rubber antioxidant TMQ production wastewater for 24 hours, and then filtering with the filter aperture of 500 meshes;

(2) performing primary extraction on the wastewater filtered in the step (1), wherein the pH environment of the primary extraction is 1, a primary extracting agent is an extracting agent toluene, and the volume ratio of the primary extracting agent to the wastewater filtered in the step (1) is 0.3: 1;

(3) evaporating and concentrating the wastewater extracted in the step (2), wherein the concentration ratio is 85%, the evaporation mode is MVR evaporation, and filtering to obtain industrial wet salt and evaporation mother liquor;

rectifying condensed water obtained by evaporation and concentration in the step (3), obtaining acetone through fraction at 50-70 ℃, obtaining aniline through fraction at 70-90 ℃, and collecting rectification mother liquor as pure water;

(4) and (3) carrying out catalytic oxidation treatment on the evaporation mother liquor obtained in the step (3), adjusting the pH environment to be 3 by adopting hydrochloric acid with the mass concentration of 28%, adding copper chloride as a catalyst, wherein the mass ratio of the catalyst to the evaporation mother liquor obtained in the step (3) is 1:20000, uniformly stirring, pumping into a microchannel reactor, carrying out catalytic oxidation reaction by using air as an oxidant at 200 ℃ and 6MPa of gauge pressure, wherein the mass ratio of available oxygen in the air to the COD content in the evaporation mother liquor obtained in the step (3) is 10:1, and the reaction retention time is 1h, and recycling the obtained treatment liquid for evaporation concentration in the step (3).

Example 2

A rubber vulcanization accelerator DCBS production wastewater with COD content of 33000mg/L and sodium chloride content of 105g/L is treated by the following steps:

(1) standing and settling the rubber vulcanization accelerator DCBS production wastewater for 10h at 30 ℃, and then filtering with the filter aperture of 1500 meshes;

(2) performing primary extraction and secondary extraction on the wastewater filtered in the step (1), wherein the pH environment of the primary extraction is 3, the primary extractant is isopropanol, and the volume ratio of the primary extractant to the wastewater filtered in the step (1) is 0.15: 1; the pH environment of the secondary extraction is 8, the secondary extracting agent is dicyclohexylamine, and the volume ratio of the secondary extracting agent to the waste water after the primary extraction is 0.2: 1;

(3) evaporating and concentrating the wastewater extracted in the step (2), wherein the concentration ratio is 90%, the evaporation mode is MVR evaporation, and filtering to obtain industrial wet salt and evaporation mother liquor;

rectifying condensed water obtained by evaporation and concentration in the step (3), wherein isopropanol is obtained by distillation at 50-60 ℃, dicyclohexylamine is obtained by distillation at 60-95 ℃, and rectifying mother liquor is collected as pure water;

(4) and (3) carrying out catalytic oxidation treatment on the evaporation mother liquor obtained in the step (3), adjusting the pH environment to be 5 by adopting hydrochloric acid with the mass concentration of 30%, adding copper chloride and cobalt chloride which are used as catalysts in the mass ratio of 5:1, wherein the mass ratio of the catalysts to the evaporation mother liquor obtained in the step (3) is 1:10000, uniformly stirring, pumping into a microchannel reactor, carrying out catalytic oxidation reaction by using oxygen as an oxidant at 500 ℃ and 10MPa gauge pressure, wherein the mass ratio of the available oxygen in the air to the COD content in the evaporation mother liquor obtained in the step (3) is 15:1, and the reaction retention time is 0.01h, and recycling the obtained treatment liquid for evaporation concentration in the step (3).

Example 3

A rubber accelerator CBS production wastewater with COD content of 30000mg/L and sodium chloride content of 153g/L is treated by the following steps:

(1) standing and settling the rubber accelerator CBS production wastewater for 60h at 10 ℃, and then filtering with the filter aperture of 5000 meshes;

(2) performing primary extraction and secondary extraction on the wastewater filtered in the step (1), wherein the pH environment of the primary extraction is 5, the primary extracting agent is cyclohexylamine serving as an extracting agent, and the volume ratio of the primary extracting agent to the wastewater filtered in the step (1) is 0.25: 1; the pH environment of the secondary extraction is 9, the secondary extracting agent is SFLJ-336, and the volume ratio of the secondary extracting agent to the waste water after the primary extraction is 0.1: 1;

(3) evaporating and concentrating the wastewater extracted in the step (2), wherein the concentration ratio is 75%, the evaporation mode is MVR evaporation, and filtering to obtain industrial wet salt and evaporation mother liquor;

rectifying condensed water obtained by evaporation and concentration in the step (3), obtaining cyclohexylamine by using distillate at 6075 ℃, obtaining methylbenzene by using distillate at 75-90 ℃, and collecting rectification mother liquor as pure water;

(4) and (3) carrying out catalytic oxidation treatment on the evaporation mother liquor obtained in the step (3), adjusting the pH environment to be 2 by adopting hydrochloric acid with the mass concentration of 31%, adding copper chloride and cobalt chloride which are used as catalysts in the mass ratio of 1:1, wherein the mass ratio of the catalysts to the evaporation mother liquor obtained in the step (3) is 1:100000, uniformly stirring, pumping into a microchannel reactor, carrying out catalytic oxidation reaction by using oxygen as an oxidant at 300 ℃ and at the gauge pressure of 4MPa, wherein the mass ratio of the available oxygen in the air to the COD content in the evaporation mother liquor obtained in the step (3) is 2:1, the reaction retention time is 1h, and recycling the obtained treatment liquid for evaporation concentration in the step (3).

Example 4

A treatment method of rubber accelerator TBBS production wastewater with COD content of 25000mg/L and sodium chloride content of 250g/L comprises the following steps:

(1) standing and settling the rubber accelerator TBBS production wastewater for 48h, and then filtering with the filter aperture of 500 meshes;

(2) performing primary extraction and secondary extraction on the wastewater filtered in the step (1), wherein the pH environment of the primary extraction is 2, the primary extractant is an extractant FLJ-332, and the volume ratio of the primary extractant to the wastewater filtered in the step (1) is 0.2: 1; the pH environment of the secondary extraction is 11, the secondary extracting agent is SFLJ-336, and the volume ratio of the secondary extracting agent to the waste water after the primary extraction is 0.15: 1;

(3) evaporating and concentrating the wastewater extracted in the step (2), wherein the concentration ratio is 80%, the evaporation mode is MVR evaporation, and filtering to obtain industrial wet salt and evaporation mother liquor;

rectifying condensed water obtained by evaporation and concentration in the step (3), obtaining tert-butylamine through fraction at 50-70 ℃, obtaining toluene through fraction at 70-85 ℃, and collecting rectification mother liquor as pure water;

(4) and (3) carrying out catalytic oxidation treatment on the evaporation mother liquor obtained in the step (3), adjusting the pH environment to be 4 by adopting hydrochloric acid with the mass concentration of 10%, adding copper chloride, ferric chloride and cobalt chloride as catalysts with the mass ratio of 20:1:1, wherein the mass ratio of the catalysts to the evaporation mother liquor obtained in the step (3) is 1:15000, uniformly stirring, pumping into a microchannel reactor, carrying out catalytic oxidation reaction at 260 ℃ and 5.5MPa gauge pressure by using air as an oxidant, wherein the mass ratio of the available oxygen in the air to the COD content in the evaporation mother liquor obtained in the step (3) is 5:1, the reaction retention time is 0.2h, and recycling the obtained treatment liquid for evaporation concentration in the step (3).

Example 5

The embodiment provides a treatment method of rubber accelerator TBBS production wastewater with a COD content of 25000mg/L and a sodium chloride content of 250g/L, which is as described in the embodiment 4, and is characterized in that:

(2) and (2) only performing primary extraction on the wastewater filtered in the step (1), wherein the pH environment of the primary extraction is 2, the primary extracting agent is an extracting agent FLJ-332, and the volume ratio of the primary extracting agent to the wastewater filtered in the step (1) is 0.2: 1.

In the national standard GB/T5462-2015, industrial wet salt in refined industrial salt is described, and the specific description is shown in Table 1.

TABLE 1

Item	Super grade	First stage	Second stage
				Chlorination ofSodium/(g/100 g) ≥ sodium	96.0	95.0	93.3
The water content/(g/100 g) is less than or equal to	3.00	3.50	4.00
				Water insoluble substance/(g/100 g) is less than or equal to	0.05	0.10	0.20
The total content of calcium and magnesium ions/(g/100 g) is less than or equal to	0.30	0.50	0.70
				Sulfate radical ion/(g/100 g) is less than or equal to	0.50	0.70	1.00

The content of the industrial wet salt obtained in the above examples is measured, and grade judgment is performed according to national standard GB/T5462-2015, and the specific results are shown in Table 2.

TABLE 2

Item	Example 1	Example 2	Example 3	Example 4	Example 5
						Sodium chloride/(g/100 g)	95.5	96.3	97.3	96.5	93.5
Water content/(g/100 g)	3.24	2.86	2.98	2.53	3.12
						Water-insoluble substance/(g/100 g)	0.08	0.05	0.05	0.04	0.19
Total calcium and magnesium ion amount/(g/100 g)	0.45	0.28	0.25	0.21	0.57
						Sulfate ion/(g/100 g)	0.08	0.06	0.12	0.08	0.41
Grade	First stage	Super grade	Super grade	Super grade	Second stage

The results of COD detection measured in the above examples are shown in Table 3.

TABLE 3

Item	Example 1	Example 2	Example 3	Example 4	Example 5
						Wastewater from rubber auxiliary production	35000mg/L	33000mg/L	30000mg/L	25000mg/L	25000mg/L
Rectification mother liquor	350mg/L	130mg/L	210mg/L	150mg/L	490mg/L
						Catalytic oxidation treatment liquid	4000mg/L	2700mg/L	3500mg/L	3000mg/L	5600mg/L

Comparing examples 4 and 5, it can be seen that example 4 using two-stage extraction can obtain superior industrial wet salt for the same rubber auxiliary production wastewater, but example 5 using only one-stage extraction can obtain secondary industrial wet salt. In addition, the rectification mother liquor and the catalytic oxidation treatment liquid with lower COD content can be obtained by adopting the two-stage extraction embodiment 4. However, the same example 1 using only one stage of extraction can obtain one stage of industrial wet salt, rectification mother liquor with lower COD content and catalytic oxidation treatment liquor. Therefore, although two-stage extraction is preferred in the treatment method of the invention, the one-stage extraction can achieve effective treatment effect for wastewater with certain specific composition.

As can be seen from the results in tables 2 and 3, examples 1 to 5 can effectively treat various rubber auxiliary production wastewater by using the treatment method of the present invention, and not only industrial wet salt meeting the requirements of the national standard GB/T5462-2015 can be obtained, but also rectification mother liquor with COD content of less than 500mg/L can be obtained as pure water by rectification treatment of condensed water, and high salinity treatment liquor with COD content of less than 6000mg/L can be obtained by catalytic oxidation treatment of evaporation mother liquor, and further, the full recovery of inorganic salt resources is realized by recycling of the high salinity treatment liquor.

The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above embodiments, but the present invention is not limited to the above detailed structural features, that is, it does not mean that the present invention must be implemented depending on the above detailed structural features. It should be understood by those skilled in the art that any modifications of the present invention, equivalent substitutions of selected components of the present invention, additions of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

The preferred embodiments of the present invention have been described in detail, however, the present invention is not limited to the specific details of the above embodiments, and various simple modifications may be made to the technical solution of the present invention within the technical idea of the present invention, and these simple modifications are within the protective scope of the present invention.

It should be noted that the various technical features described in the above embodiments can be combined in any suitable manner without contradiction, and the invention is not described in any way for the possible combinations in order to avoid unnecessary repetition.

In addition, any combination of the various embodiments of the present invention is also possible, and the same should be considered as the disclosure of the present invention as long as it does not depart from the spirit of the present invention.

Claims (10)

1. The treatment method of the rubber auxiliary production wastewater is characterized by comprising the following steps:

(1) removing impurities from rubber auxiliary production wastewater;

(2) extracting the wastewater subjected to impurity removal in the step (1);

(3) evaporating and concentrating the wastewater extracted in the step (2), and filtering to obtain industrial wet salt and an evaporation mother liquor;

(4) and (4) carrying out catalytic oxidation treatment on the evaporation mother liquor obtained in the step (3), and reusing the obtained treatment liquor for evaporation concentration in the step (3).

2. The process of claim 1, wherein the removing of impurities in step (1) comprises any one or a combination of at least two of settling, centrifugation, filtration or membrane filtration;

preferably, the impurity removal in the step (1) is standing, settling and filtering;

preferably, the standing and settling time is 0.5-100 h, preferably 24-48 h;

preferably, the filtering pore size of the filtering is 10-15000 meshes, preferably 50-500 meshes.

3. The process of claim 1 or 2, wherein the extraction of step (2) is at least one stage of extraction;

preferably, the extraction in the step (2) is two-stage extraction, including first-stage extraction and second-stage extraction;

preferably, the pH environment of the primary extraction is 1-5, preferably 1-3;

preferably, the volume ratio of the primary extracting agent to the filtered wastewater in the step (1) is 0.01-0.3: 1, preferably 0.1-0.2: 1;

preferably, the pH environment of the secondary extraction is 7-11, and preferably 9-11;

preferably, the volume ratio of the secondary extracting agent to the waste water after primary extraction is 0.01-0.3: 1, and preferably 0.1-0.2: 1.

4. The process according to any one of claims 1 to 3, wherein the concentration ratio of the evaporation concentration in step (3) is 40 to 90%, preferably 80 to 85%;

preferably, the evaporation manner of the evaporation concentration in the step (3) is any one or a combination of at least two of simple evaporation, multiple-effect evaporation or MVR evaporation, and preferably MVR evaporation;

preferably, the condensed water obtained by the evaporation and concentration in the step (3) is rectified.

5. The treatment process according to any one of claims 1 to 4, wherein the catalytic oxidation in step (4) is carried out in a pH environment of 1 to 6, preferably 3 to 4;

preferably, the regulator of the pH environment is hydrochloric acid;

preferably, the mass concentration of the hydrochloric acid is 1-35.5%, and preferably 28-31%.

6. The process according to any one of claims 1 to 5, wherein the catalyst used in the catalytic oxidation in step (4) is a soluble transition metal chloride;

preferably, the catalyst is any one or a mixture of at least two of ferric chloride, cobalt chloride, copper chloride, zinc chloride or manganese chloride;

preferably, the mass ratio of the catalyst to the evaporation mother liquor obtained in the step (3) is 1: 100-100000, and preferably 1: 5000-20000.

7. The treatment method according to any one of claims 1 to 6, wherein the oxidant used in the catalytic oxidation in the step (4) is any one or a mixture of at least two of air, oxygen, hydrogen peroxide, sodium hypochlorite and ozone, preferably a mixture of air and oxygen;

preferably, the mass ratio of the available oxygen in the oxidant to the COD content in the evaporation mother liquor obtained in the step (3) is 1-20: 1, and preferably 1-10: 1.

8. The process according to any one of claims 1 to 7, wherein the catalytic oxidation in step (4) is carried out at a reaction temperature of 50 to 500 ℃, preferably 200 to 300 ℃;

preferably, the reaction pressure of the catalytic oxidation in the step (4) is 0-100 MPa gauge pressure, preferably 2-6 MPa gauge pressure;

preferably, the reaction residence time of the catalytic oxidation in the step (4) is 0.001-10 h, preferably 0.01-1 h;

preferably, the reactor for catalytic oxidation in step (4) is any one or a combination of at least two of a tank reactor, a tubular reactor, a tower reactor and a microchannel reactor, and is preferably a microchannel reactor.

9. The processing method according to any one of claims 1 to 8, characterized in that it comprises the steps of:

(1) standing and settling the rubber auxiliary production wastewater for 0.5-100 h, and then filtering with the filtering aperture of 10-15000 meshes;

(2) performing primary extraction and secondary extraction on the wastewater filtered in the step (1), wherein the pH environment of the primary extraction is 1-5, and the volume ratio of the primary extraction agent to the wastewater filtered in the step (1) is 0.01-0.3: 1; the pH environment of the secondary extraction is 7-11, and the volume ratio of the secondary extraction agent to the primary extracted wastewater is 0.01-0.3: 1;

(3) evaporating and concentrating the wastewater extracted in the step (2), wherein the concentration ratio is 40-90%, the evaporation mode is MVR evaporation, and filtering to obtain industrial wet salt and evaporation mother liquor;

rectifying condensed water obtained by evaporation and concentration in the step (3);

(4) and (3) carrying out catalytic oxidation treatment on the evaporation mother liquor obtained in the step (3), adjusting the pH environment to be 1-6 by adopting hydrochloric acid with the mass concentration of 1-35.5%, adding a catalyst and an oxidant, carrying out catalytic oxidation at the temperature of 50-500 ℃ and the gauge pressure of 0-100 MPa, keeping the reaction residence time of 0.001-10 h, and recycling the obtained treatment liquor for evaporation concentration in the step (3).

10. Industrial wet salt obtained by the treatment method according to any one of claims 1 to 9, wherein the industrial wet salt is used for preparing raw brine meeting the requirements of the ionic membrane caustic soda industry.