CN113003859A

CN113003859A - Industrial salt-containing sewage full-recycling treatment method

Info

Publication number: CN113003859A
Application number: CN202110197406.3A
Authority: CN
Inventors: 朱江; 谢勇; 李元瑞; 张戈; 李博; 张迪; 赵轩
Original assignee: Xi'an Yinneng Biotechnology Co ltd
Current assignee: Xi'an Yinneng Biotechnology Co ltd
Priority date: 2021-02-22
Filing date: 2021-02-22
Publication date: 2021-06-22

Abstract

The invention discloses a full recycling treatment method for industrial salt-containing sewage, belonging to the technical field of sewage treatment. The method comprises the following steps: step (1): filtering out pulp vegetables and fine particles from the low-salt raw material and the high-salt raw material through primary coarse filtration and secondary fine filtration to respectively obtain a first solution and a second solution; step (2): the first solution is subjected to membrane filtration and then is mixed with the second solution to obtain a first mixed solution; and (3): evaporating and concentrating the first mixed solution to obtain a supersaturated salt solution; and (4): carrying out centrifugal separation on the supersaturated salt solution to obtain primary salt particles and centrifugal mother liquor; and (5): adding water into the primary salt particles for rinsing to obtain secondary salt particles and rinsing water; and drying and dehydrating the secondary salt particles to obtain a refined salt product. In the method, various resources in the saline sewage are separated in a gradual mode of Erdingjiu, and the method takes water as a main medium, so that the cost is minimized, and the resource utilization maximization and the resource value maximization are realized.

Description

Industrial salt-containing sewage full-recycling treatment method

Technical Field

The invention relates to the technical field of sewage treatment, in particular to a full recycling treatment method for industrial salt-containing sewage.

Background

With the rapid development of modern industry, the variety and quantity of waste water are rapidly increased, the pollution to water bodies is more and more extensive and serious, and the health and safety of human beings are threatened. Industrial waste water is an important cause of environmental pollution, particularly water pollution. The composition of industrial waste water depends mainly on the raw materials used in the production process. Different industries produce waste water with different properties, and similar industries adopt different production processes and have different waste water properties. Generally divided into industrial cooling water and process waste water. The industrial cooling water is not directly contacted with the raw materials, and can be recycled only by recovering heat or slightly processing. The process wastewater directly contacts with the raw materials and is mostly harmful. The waste water can be divided into waste water containing inorganic substances, waste water containing organic substances and mixed waste water containing organic and inorganic substances according to the components. Specifically, the industrial wastewater contains complex and various pollutant components, the concentration of organic pollutants is high, and the industrial wastewater contains harmful and toxic substances such as ammonia nitrogen, petroleum, volatile phenol, heavy metals and the like, and the sewage discharged by fruit and vegetable processing enterprises contains substances such as salt.

The conventional salt-containing wastewater treatment process in the prior art comprises the following steps:

1. concentrating, drying, and making into salt or feed additive for animals

The process has no separation process for related components, only simply concentrates and dries the waste, the method has high energy consumption cost, low output and extremely low market value of related products, and once the product contains inedible or toxic substances and cannot be used, the whole product can only be treated as solid waste.

2. Concentration crystallization and biochemical aeration treatment

The salt produced in the process has low purity and low value, and the salt content in COD is still very high, so that the normal growth of microorganisms is inhibited, the biochemical treatment effect is greatly reduced, and the treatment cost is extremely high.

3. Resin adsorption method, concentration crystallization and biochemical treatment

Although the method can partially extract some small molecular components, the small molecular components cannot be normally used as a proper product, the treated wastewater still needs to be treated by a biochemical process, the defects are the same as those of the second method, the only advantage is that the quality of the salt product is better than that of the first two methods, but the treatment cost is multiplied, and the method is uneconomical and sustainable.

Disclosure of Invention

In order to solve the problems in the prior art, the invention provides a full resource treatment method for industrial salt-containing sewage. The method comprises the following steps:

step (1): filtering out pulp vegetables and fine particles from the low-salt raw material and the high-salt raw material through primary coarse filtration and secondary fine filtration to respectively obtain a first solution and a second solution;

step (2): the first solution is subjected to membrane concentration and then is mixed with the second solution to obtain a first mixed solution;

and (3): evaporating and concentrating the first mixed solution to obtain a supersaturated salt solution;

and (4): carrying out centrifugal separation on the supersaturated salt solution to obtain primary salt particles and centrifugal mother liquor;

and (5): adding water into the primary salt particles for rinsing to obtain secondary salt particles and rinsing water; drying and dehydrating the secondary salt particles to obtain a refined salt product;

and (6): mixing the centrifugal mother liquor with the rinsing water, filtering by a membrane, and concentrating to obtain a first filtrate and a closure combined solution;

and (7): rinsing the pulp vegetables and the fine particle pure water, homogenizing and crushing, and mixing with the interception combined solution to obtain a second mixed solution;

and (8): membrane concentration is carried out on the first filtrate to obtain filtered water and concentrated salt solution, the filtered water returns to the step (6), and the concentrated salt solution returns to the step (3);

and (9): carrying out enzymolysis and membrane separation on the second mixed solution to obtain a second filtrate and a cut-off solution;

step (10): returning the cut-off to step (9);

step (11): performing anaerobic fermentation on the second filtrate to obtain aged bacterial sludge, fermentation liquor and methane;

step (12): drying the aged bacterial sludge by hot air to obtain the special organic fertilizer;

step (13): concentrating the fermented liquid film to obtain a concentrated solution and filtered water; returning the concentrate to step (11); returning the filtered water to the step (5);

step (14): the marsh gas is separated by a gas membrane, and the separated CO₂Obtaining dry ice by pressure freezing; standardizing and purifying the rest gas to obtain the biogas.

Further, in the step (7), after the second mixed solution is obtained, the second mixed solution may be concentrated to obtain a concentrated cut-off solution, and the concentrated cut-off solution may be evaporated and concentrated to obtain a concentrated fruit and vegetable juice.

Further, in the step (2), the first solution is concentrated by a reverse osmosis membrane, wherein the concentration pressure is 1.5-3Mpa, and the temperature is 40-50 ℃.

Further, in the step (3), the mixed solution is evaporated and concentrated at a temperature of 50-70 ℃ to obtain the supersaturated salt solution.

Further, in the step (5), drying and dehydrating the secondary salt particles at the temperature of 40-60 ℃ to obtain the refined salt product.

Further, in the step (6), after mixing the centrifugal mother liquor and the rinsing water, filtering the mixture through an ultrafiltration membrane with the pore diameter of 0.01um at the pressure of 0.1-0.5Mpa and the temperature of 40 ℃, and concentrating the filtered mixture at the temperature of 40-70 ℃ to obtain the first filtrate and the interception combined solution.

Further, in the step (8), the first filtrate is concentrated by a reverse osmosis membrane at a concentration pressure of 1 to 3Mpa and a temperature of 30 to 50 ℃.

Further, in the step (11), the second filtrate is subjected to anaerobic fermentation in an anaerobic fermentation device for 5-15 days at 50-60 ℃ to obtain the aged bacterial sludge, the fermentation liquor and the methane.

Further, in the step (11), before the second filtrate is fermented anaerobically, KOH or K is added₂CO₃。

Further, in the step (12), drying the aged bacterial sludge at 50-70 ℃ by using a hot air dryer to obtain the special organic fertilizer.

The technical scheme provided by the embodiment of the invention has the following beneficial effects: in the invention, subtraction is used to replace addition, and various resources in saline sewage are separated in a gradual mode by Erding-plus, the method takes water as a main medium to minimize the cost, physical processing units and technologies such as membrane filtration, centrifugation and low-temperature drying are adopted as main materials, a biological technical means is used as an auxiliary material, a chemical process is used with caution, and a target product is a monomer substance as a main product form, so that the resource utilization maximization and the resource value maximization are realized. In addition, the method recycles waste and mixed sewage, changes waste into valuable, has simple production flow, zero emission, zero pollution, accurate separation, maximized resource utilization, minimized production cost, optimized product quality, maximized value, no secondary pollution and virtuous cycle.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a flow chart of the total resource treatment method of industrial salt-containing sewage provided by the invention.

Detailed Description

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention.

In order to make the objects, technical solutions and advantages of the present invention more apparent, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Example one

A full resource treatment method for industrial salt-containing sewage comprises the following steps:

step (1): the low-salt raw material and the high-salt raw material are filtered to remove pulp vegetables and fine particles through primary rough filtration and secondary fine filtration to respectively obtain a first solution and a second solution. The first-stage rough filtration can be carried out by a fiber filter, and the second-stage fine filtration can be carried out by a fine filter.

Step (2): and mixing the first solution with the second solution after membrane concentration to obtain a first mixed solution.

And (3): and evaporating and concentrating the first mixed solution to obtain a supersaturated salt solution.

And (4): and (4) carrying out centrifugal separation on the supersaturated salt solution to obtain primary salt particles and centrifugal mother liquor.

And (5): adding water into the primary salt particles for rinsing to obtain secondary salt particles and rinsing water; and drying and dehydrating the secondary salt particles to obtain a refined salt product.

And (6): and mixing the centrifugal mother liquor with rinsing water, filtering by a membrane, and concentrating to obtain a first filtrate and a combined interception liquor.

And (7): rinsing the pulp vegetables and the fine particle pure water, homogenizing and crushing, and mixing with the interception combined solution to obtain a second mixed solution.

And (8): and (3) performing membrane concentration on the first filtrate to obtain filtered water and concentrated salt solution, returning the filtered water to the step (6), and returning the concentrated salt solution to the step (3).

And (4) returning the filtered water to the step (6) to continue membrane filtration and concentration, so that substances in the water are separated more cleanly, returning the concentrated salt solution to the step (3) to be mixed with the mixed solution, and continuing evaporation and concentration, so that more salts can be separated.

And (9): and carrying out enzymolysis and membrane separation on the second mixed solution to obtain a second filtrate and a cut-off solution.

Step (10): the cut-off liquid is returned to the step (9). Returning the cut-off liquid to the step (9) for continuous enzymolysis, so that the enzymolysis is more complete.

Step (11): and performing anaerobic fermentation on the second filtrate to obtain aged bacterial sludge, fermentation liquor and methane.

Step (12): and (5) drying the aged bacterial sludge by hot air to obtain the special organic fertilizer.

Step (13): concentrating the fermented liquid film to obtain a concentrated solution and filtered water; returning the concentrated solution to the step (11); and (5) returning the filtered water to the step (5).

It should be noted that the fermentation liquor is concentrated by a reverse osmosis membrane, the concentration pressure is 1.5-3Mpa, the temperature is 40-70 ℃, and the concentrated liquor returns to the step (11) for hot air drying to prepare the special organic fertilizer, so that waste is avoided; and (5) returning the filtered water to the step (5) as water for rinsing the primary salt particles, thereby further saving resources.

It should be noted that, in the present invention, subtraction-substitution-addition method is used to separate various resources in saline wastewater in a gradual manner, and the method uses water as main medium to minimize the cost, and adopts physical processing units and technologies such as membrane filtration, centrifugation, low-temperature drying, etc. as main, and adopts biotechnology as auxiliary, and carefully uses chemical process, and the target product is monomer substance as main product form, thereby realizing the maximization of resource utilization and the maximization of resource value.

Example two

A full resource treatment method for industrial salt-containing sewage specifically comprises the following steps:

a step (101): the low-salt raw material and the high-salt raw material are filtered to remove pulp vegetables and fine particles through primary rough filtration and secondary fine filtration to respectively obtain a first solution and a second solution.

A step (102): and mixing the first solution with the second solution after membrane concentration to obtain a first mixed solution.

Step (103): and evaporating and concentrating the first mixed solution to obtain a supersaturated salt solution.

A step (104): and (4) carrying out centrifugal separation on the supersaturated salt solution to obtain primary salt particles and centrifugal mother liquor.

A step (105): adding water into the primary salt particles for rinsing to obtain secondary salt particles and rinsing water; and drying and dehydrating the secondary salt particles to obtain a refined salt product.

Step (106): and mixing the centrifugal mother liquor with rinsing water, filtering by a membrane, and concentrating to obtain a first filtrate and a combined interception liquor.

Step (107): rinsing the pulp vegetables and the fine particle pure water, homogenizing and crushing, and mixing with the interception combined solution to obtain a second mixed solution.

Step (108): and concentrating the second mixed liquid film to obtain a concentrated cut-off liquid, and evaporating and concentrating the concentrated cut-off liquid to obtain the concentrated fruit and vegetable juice.

The second mixed solution can be concentrated through a reverse osmosis membrane, the concentration pressure is 1.5-3Mpa, the temperature is 40-70 ℃, a concentrated cut-off solution is obtained, and the concentrated cut-off solution is evaporated and concentrated at the temperature of 50-60 ℃, so that the concentrated fruit and vegetable juice is obtained.

The method has the advantages of simple production process, zero emission, zero pollution, accurate separation of resource utilization maximization, product series diversification, lowest production cost, more optimized product quality and maximized value. No secondary pollution and virtuous cycle.

EXAMPLE III

The method for fully recycling industrial salt-containing sewage in the first embodiment is described in detail, and specifically comprises the following steps:

step (201): the low-salt raw material and the high-salt raw material are filtered to remove pulp vegetables and fine particles through primary rough filtration and secondary fine filtration to respectively obtain a first solution and a second solution.

Step (202): concentrating the first solution with reverse osmosis membrane at 1.5Mpa and 40 deg.C, and mixing with the second solution to obtain first mixed solution.

Step (203): the first mixed solution is evaporated and concentrated at the temperature of 50 ℃ to obtain supersaturated salt solution.

A step (204): and (4) carrying out centrifugal separation on the supersaturated salt solution to obtain primary salt particles and centrifugal mother liquor.

Step (205): adding water into the primary salt particles for rinsing to obtain secondary salt particles and rinsing water; drying and dehydrating the secondary salt particles at the temperature of 40 ℃ to obtain a refined salt product.

Step (206): mixing the centrifugal mother liquor with rinsing water, filtering with ultrafiltration membrane with pore diameter of 0.01um at 40 deg.C under 0.1Mpa, and concentrating at 40 deg.C to obtain first filtrate and combined interception solution.

Step (207): rinsing the pulp vegetables and the fine particle pure water, homogenizing and crushing, and mixing with the interception combined solution to obtain a second mixed solution.

A step (208): concentrating the first filtrate with reverse osmosis membrane at 1Mpa and 30 deg.C to obtain filtered water and concentrated salt solution, returning the filtered water to step (206), and returning the concentrated salt solution to step (203).

Step (209): and carrying out enzymolysis and membrane separation on the second mixed solution to obtain a second filtrate and a cut-off solution.

Step (210): the cut-off is returned to step (209).

A step (211): adding KOH into the second filtrate, and performing anaerobic fermentation in an anaerobic fermentation device for 5 days at 50 ℃ to obtain aged bacterial sludge, fermentation liquor and methane.

Step (212): and drying the aged bacterial sludge at 50 ℃ by a hot air dryer to obtain the special organic fertilizer.

Step (213): concentrating the fermented liquid film to obtain a concentrated solution and filtered water; returning the concentrated solution to the step (211); and (5) returning filtered water to the step (205).

Step (214): the marsh gas is separated by a gas membrane, and the separated CO₂Obtaining dry ice by pressure freezing; standardizing and purifying the rest gas to obtain the biogas.

Example four

step (301): the low-salt raw material and the high-salt raw material are filtered to remove pulp vegetables and fine particles through primary rough filtration and secondary fine filtration to respectively obtain a first solution and a second solution.

Step (302): concentrating the first solution with reverse osmosis membrane at 50 deg.C under 3Mpa, and mixing with the second solution to obtain first mixed solution.

Step (303): the first mixed solution is evaporated and concentrated at the temperature of 70 ℃ to obtain supersaturated salt solution.

Step (304): and (4) carrying out centrifugal separation on the supersaturated salt solution to obtain primary salt particles and centrifugal mother liquor.

Step (305): adding water into the primary salt particles for rinsing to obtain secondary salt particles and rinsing water; drying and dehydrating the secondary salt particles at the temperature of 60 ℃ to obtain a refined salt product.

Step (306): mixing the centrifugal mother liquor with rinsing water, filtering with ultrafiltration membrane with pore diameter of 0.01 μm at 40 deg.C under 0.5Mpa, and concentrating at 70 deg.C to obtain first filtrate and combined interception solution.

Step (307): rinsing the pulp vegetables and the fine particle pure water, homogenizing and crushing, and mixing with the interception combined solution to obtain a second mixed solution.

Step (308): concentrating the first filtrate with reverse osmosis membrane at 50 deg.C under 3Mpa to obtain filtered water and concentrated salt solution, returning the filtered water to step (306), and returning the concentrated salt solution to step (303).

Step (309): and carrying out enzymolysis and membrane separation on the second mixed solution to obtain a second filtrate and a cut-off solution.

Step (310): the cut-off is returned to step (309).

Step (311): adding K into the second filtrate₂CO₃Then carrying out anaerobic fermentation for 15 days in an anaerobic fermentation device at the temperature of 60 ℃ to obtain the aged bacterial sludge, fermentation liquor and methane.

A step (312): and drying the aged bacterial sludge at 70 ℃ by a hot air dryer to obtain the special organic fertilizer.

Step (313): concentrating the fermented liquid film to obtain a concentrated solution and filtered water; returning the concentrated solution to the step (311); the filtered water is returned to step (305).

Step (314): the marsh gas is separated by a gas membrane, and the separated CO₂Obtaining dry ice by pressure freezing; standardizing and purifying the rest gas to obtain the biogas.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.

Claims

1. The full recycling treatment method of industrial salt-containing sewage is characterized by comprising the following steps:

step (10): returning the cut-off to step (9);

2. The method as claimed in claim 1, wherein after the second mixed liquid is obtained in step (7), the second mixed liquid film is concentrated to obtain a concentrated cut-off liquid, and the concentrated cut-off liquid is evaporated and concentrated to obtain a concentrated fruit and vegetable juice.

3. The method according to claim 2, wherein in the step (2), the first solution is concentrated by a reverse osmosis membrane at a concentration pressure of 1.5-3Mpa and a temperature of 40-50 ℃.

4. The method according to claim 3, wherein in the step (3), the first mixed solution is evaporated and concentrated at a temperature of 50-70 ℃ to obtain the supersaturated salt solution.

5. The method for recycling industrial salt-containing sewage according to claim 4, wherein in the step (5), the secondary salt grains are dried and dehydrated at a temperature of 40-60 ℃ to obtain the refined salt product.

6. The method for fully recycling industrial saline sewage according to claim 5, wherein in the step (6), the centrifugal mother liquor and the rinsing water are mixed, filtered by an ultrafiltration membrane with a pore size of 0.01um at a pressure of 0.1-0.5MPa and a temperature of 40 ℃, and concentrated at a temperature of 40-70 ℃ to obtain the first filtrate and the combined cut-off solution.

7. The method for recycling industrial salt-containing sewage of claim 6, wherein in the step (8), the first filtrate is concentrated by a reverse osmosis membrane under a pressure of 1-3Mpa and at a temperature of 30-50 ℃.

8. The method for recycling industrial saline sewage according to claim 7, wherein in the step (11), the second filtrate is subjected to anaerobic fermentation in an anaerobic fermentation device for 5-15 days at 50-60 ℃ to obtain the aged bacterial sludge, the fermentation liquid and the biogas.

9. The method as claimed in claim 8, wherein KOH or K is added before the second filtrate is fermented in anaerobic manner in step (11)₂CO₃。

10. The method for fully recycling industrial saline sewage according to claim 9, wherein in the step (12), the aged bacterial sludge is dried at 50-70 ℃ by a hot air dryer to obtain the special organic fertilizer.