CN219079306U

CN219079306U - High-salt wastewater zero-discharge device

Info

Publication number: CN219079306U
Application number: CN202320135154.6U
Authority: CN
Inventors: 曹成
Original assignee: Individual
Current assignee: Individual
Priority date: 2023-01-16
Filing date: 2023-01-16
Publication date: 2023-05-26
Anticipated expiration: 2033-01-16

Abstract

The utility model particularly relates to a high-salt wastewater zero-emission device which comprises a wastewater pretreatment unit, an RO pre-concentration unit and a low-pressure nanofiltration salt separation unit which are sequentially connected, and is characterized in that the water producing end of the low-pressure nanofiltration salt separation unit is connected with the inlet end of a sodium sulfate salt water preparation tank through a pipeline, the outlet end of the sodium sulfate salt water preparation tank is connected with the inlet end of a first double decomposition reaction device through a pipeline, the concentrated water end of the low-pressure nanofiltration salt separation unit is connected with the inlet end of a sodium chloride salt water preparation tank through a pipeline, the outlet end of the sodium chloride salt water preparation tank is connected with a second double decomposition reaction device through a pipeline, and the first double decomposition reaction device comprises a first reaction kettle and a first crystallizer, and the second double decomposition reaction device comprises a second reaction kettle and a second crystallizer. The utility model has the advantages of low cost and environmental protection. The utility model has no secondary pollution such as industrial waste salt, hazardous waste mother liquor mixed salt and the like, and realizes the full cyclic utilization of water and materials.

Description

High-salt wastewater zero-discharge device

Technical Field

The utility model belongs to the technical field of high-salt wastewater reclamation, and particularly relates to a high-salt wastewater zero-discharge device.

Background

The high-salt wastewater is wastewater with the total salt content of at least 1 percent, is mainly from chemical plants, oil and gas collection and processing and the like, contains various substances (including salt, oil, organic heavy metals and radioactive substances), and is of great importance to the environmental impact of removing organic pollutants in the salt-containing wastewater. The high-salinity wastewater zero-emission device comprises a wastewater pretreatment unit, an RO preconcentration unit, a low-pressure nanofiltration salt separation unit and one branch of the low-pressure nanofiltration salt separation unit which are sequentially connected, wherein the high-pressure nanofiltration unit and the freezing crystallizer are sequentially connected, sodium sulfate is produced, and the other branch of the low-pressure nanofiltration salt separation unit is sequentially connected with a nanofiltration water-producing reverse osmosis unit, an electrodialysis unit and an MVR evaporation crystallizer and is used for producing sodium chloride.

The high-salt wastewater zero-discharge device with the structure has a plurality of defects, and the aims of pollution reduction, emission reduction and recycling are difficult to truly realize:

1) The pretreatment, multistage membrane concentration, nanofiltration and salt separation, freezing crystallization, ED concentration, evaporation and other processes are needed, the process is long, the investment is huge, and the operation cost is too high;

2) The operation reliability of the evaporation system and the freezing crystallization system is poor, and the management is complicated;

3) The generated large amount of industrial waste salt and a small amount of dangerous waste mother liquor are difficult to utilize, and dangerous solid waste is formed actually, so that the actual running cost of the system is uncontrollable, and if the system runs continuously for a long time, enterprises cannot bear the environmental protection cost of high enterprises.

Disclosure of Invention

The utility model aims to provide a high-salt wastewater zero-emission device, which abandons the process sections of nanofiltration and salt separation, subsequent RO re-concentration, ED concentration, evaporation, freezing crystallization and the like in the existing high-salt wastewater zero-emission device, greatly reduces the investment and the operation cost of environmental protection facilities, simultaneously realizes the emission reduction and the recycling utilization of high-salt wastewater pollutants by chemical technical means, and uses the RO concentrated water or the produced water and the concentrated water after nanofiltration and salt separation as one of raw materials of chemical production to produce industrial sodium bicarbonate, ammonium chloride, ammonium sulfate or potassium sulfate, thereby realizing negative benefit to positive benefit, simultaneously taking into account ecological environmental protection and economic benefit, and promoting environmental protection projects to truly realize the synergy of pollution control, emission reduction and long-term sustainable operation.

The utility model is realized by the following technical scheme:

namely a high-salt wastewater zero-emission device, including the pretreatment of wastewater unit, RO preconcentration unit, low pressure nanofiltration divides salt unit that connects gradually, its characterized in that the water end that produces of low pressure nanofiltration divides salt unit is connected with the entry end of sodium sulfate water allotment jar through the pipeline, the exit end of sodium sulfate water allotment jar is connected with the entry end of first double decomposition reaction device through the pipeline, the dense water end of low pressure nanofiltration divides salt unit to be connected with the entry end of sodium chloride water allotment jar through the pipeline, the exit end of sodium chloride water allotment jar is connected with second double decomposition reaction device through the pipeline, first double decomposition reaction device includes first reation kettle and first crystallizer, second double decomposition reaction device includes second reation kettle and second crystallizer.

The reaction vessel and crystallizer of the metathesis reaction apparatus of the present utility model are well known in the art as commercial products, the structure and method of use of which are known to those skilled in the art.

The present utility model adopts double decomposition heat combined alkali, and is characterized by that it adopts saturated salt water and solid ammonium bicarbonate to make double decomposition reaction so as to produce sodium bicarbonate precipitate, and adopts the processes of filtering, washing and obtaining NaHCO3 crystal, then calcining so as to obtain the soda product, and its filtrate is the solution containing ammonium chloride and sodium chloride (ammonium sulfate and sodium sulfate). The filtered mother liquor is firstly heated to remove ammonia and carbon dioxide, then evaporated, salted out and cooled to separate out ammonium chloride. The mother liquor after separating out ammonium chloride is returned to the evaporation and then mixed with deamination mother liquor, and is circulated in the second process.

The combined soda process of the double decomposition heat method is adopted to produce the sodium carbonate and the ammonium chloride, so that the environmental protection problem of waste salt and waste liquid treatment is effectively solved, the resources are reasonably configured, the requirements of national proposed recycling economy development are met, and the method is environment-friendly.

The utility model realizes zero discharge of high-salt wastewater and has two schemes.

Scheme 1: the inlet ends of the first reaction kettle and the second reaction kettle are respectively connected with an ammonium bicarbonate input pipe.

The high-salt wastewater is subjected to hard removal, impurity removal and COD reduction pretreatment by a wastewater pretreatment unit, and then concentrated by an RO pre-concentration unit, the produced pure water is recycled, and the concentrated brine is subjected to nanofiltration and salt separation by a low-pressure nanofiltration salt separation unit and is divided into two production sections, namely section one: the nanofiltration produced water is sodium chloride concentrated brine, enters a sodium chloride water blending tank as a production raw material, ammonium bicarbonate is added, sodium bicarbonate and ammonium chloride are produced through a second reaction kettle, and evaporation condensed water is recycled; section II: the nanofiltration concentrated water is sodium sulfate concentrated brine, enters a sodium sulfate salt water blending tank as a production raw material, ammonium bicarbonate is added, sodium bicarbonate and ammonium sulfate are produced through a first reaction kettle, and evaporation condensed water is recycled.

In the scheme 1, products such as sodium bicarbonate, ammonium chloride, ammonia sulfate and the like are produced by nano-filtering and salt-separating water and concentrated water through a double decomposition reaction device, water and materials in the process are recycled, and no hazardous solid waste is produced.

Scheme 2: the inlet end of the first reaction kettle is connected with a potassium chloride input pipe, the inlet end of the second reaction kettle is connected with an ammonium bicarbonate input pipe, and the outlet end of the first reaction kettle is connected with the inlet end of a sodium chloride salt water blending tank through a pipeline.

The high-salt wastewater is subjected to hard removal, impurity removal and COD reduction pretreatment by a wastewater pretreatment unit, and then concentrated by an RO pre-concentration unit, the produced pure water is recycled, and the concentrated brine is subjected to nanofiltration and salt separation by a low-pressure nanofiltration salt separation unit and is divided into two production sections, namely section one: the nanofiltration produced water is sodium chloride concentrated brine, enters a sodium chloride water blending tank as a production raw material, ammonium bicarbonate is added, sodium bicarbonate and ammonium chloride are produced through a second reaction kettle, and evaporation condensed water is recycled; section II: the nanofiltration concentrated water is sodium sulfate concentrated brine, enters a sodium sulfate water blending tank to serve as a production raw material, potassium chloride is added, potassium sulfate is produced through a first reaction kettle, and simultaneously, the produced sodium chloride saturated solution is connected with the inlet end of the sodium chloride water blending tank through a pipeline to serve as a raw material of the production section 1.

In the scheme 2, products such as sodium bicarbonate, ammonium chloride, potassium sulfate and the like are produced by nano-filtering and salt-separating water and concentrated water through a double decomposition reaction device, water and materials in the process are recycled, and no hazardous solid waste is produced.

The utility model has the following advantages:

1) The utility model abandons the process sections of RO re-concentration, ED concentration, evaporation, freezing crystallization and the like which follow-up nanofiltration and salt separation in the existing high-salt wastewater zero discharge device, and the abandoned process sections account for nearly 70% -80% of the investment of the whole system, and the running cost accounts for nearly 85%, so that the facility investment and the running cost are greatly reduced, and enterprises realize the recycling of industrial wastewater with very low cost;

2) The utility model realizes the emission reduction and resource utilization of high-salt wastewater pollutants by chemical technical means, takes the membrane concentrated high-salt water as one of raw materials of chemical production, produces industrial sodium bicarbonate, ammonium chloride, ammonium sulfate or potassium sulfate, generates economic benefit, converts the negative benefit of the existing high-salt wastewater zero-emission device into positive benefit, takes ecological environmental protection and economic benefit into consideration, and promotes environmental protection projects to truly realize the synergy of pollution control, emission reduction and carbon reduction and long-term sustainable operation;

3) The utility model does not produce any secondary pollution such as industrial waste salt, hazardous waste mother liquor mixed salt and the like, realizes the full cyclic utilization of water and materials, and thoroughly solves the pain point existing in the existing high-salt wastewater zero-emission device.

Drawings

FIG. 1 is a schematic diagram of a prior art high salt wastewater zero release device;

FIG. 2 is a schematic structural diagram of embodiment 1 of the present utility model;

fig. 3 is a schematic structural diagram of embodiment 2 of the present utility model.

As shown in the figure: 1. a wastewater pretreatment unit; RO pre-concentration unit; 3. a low pressure nanofiltration salt separation unit; 4. a sodium sulfate brine blending tank; 4-1, a high-pressure nanofiltration unit; 5. a first metathesis reaction apparatus; 5-1, freezing a crystallizer; 6. a sodium chloride brine mixing tank; 6-1, a nanofiltration water-producing reverse osmosis unit; 7. a second metathesis reaction apparatus; 7-1, an electrodialysis unit; MVR evaporative crystallizer.

Detailed Description

Embodiments of the technical scheme of the present utility model will be described in detail below with reference to the accompanying drawings. The following examples are only for more clearly illustrating the technical aspects of the present utility model, and thus are merely examples, and are not intended to limit the scope of the present utility model. It is noted that unless otherwise indicated, technical or scientific terms used herein should be given the ordinary meaning as understood by one of ordinary skill in the art to which this utility model pertains.

As shown in fig. 1: the high-salinity wastewater zero-emission device in the prior art comprises a wastewater pretreatment unit 1, an RO preconcentration unit 2, a low-pressure nanofiltration salt separation unit 3 and one branch of the low-pressure nanofiltration salt separation unit 3 which are sequentially connected, wherein the high-pressure nanofiltration unit 4-1 and the freezing crystallizer 5-1 are sequentially connected, and the other branch of the low-pressure nanofiltration salt separation unit 3 is sequentially connected with a nanofiltration water-producing reverse osmosis unit 6-1, an electrodialysis unit 7-1 and an MVR evaporation crystallizer 8-1 and is used for producing sodium chloride.

Example 1

As shown in fig. 2: the wastewater pretreatment unit 1, the RO pre-concentration unit 2 and the low-pressure nanofiltration salt separation unit 3 are sequentially connected through pipelines, the water producing end of the low-pressure nanofiltration salt separation unit 3 is connected with the inlet end of the sodium sulfate water preparation tank 4 through a pipeline, the outlet end of the sodium sulfate water preparation tank 4 is connected with the inlet end of the first double decomposition reaction device 5 through a pipeline, the concentrated water end of the low-pressure nanofiltration salt separation unit 3 is connected with the inlet end of the sodium chloride water preparation tank 6 through a pipeline, the outlet end of the sodium chloride water preparation tank 6 is connected with the second double decomposition reaction device 7 through a pipeline, the first double decomposition reaction device 5 comprises a first reaction kettle and a first crystallizer, and the second double decomposition reaction device 6 comprises a second reaction kettle and a second crystallizer.

When the embodiment is used, the high-salt wastewater enters the RO pre-concentration unit 2 after being subjected to the hard removal and impurity removal and COD reduction by the wastewater pretreatment unit 1, the produced water is recycled, the concentrated water passes through the low-pressure nanofiltration membrane salt separation unit 3, the produced water is sodium chloride concentrated solution, and the concentrated water is sodium sulfate concentrated solution. The subsequent process is divided into two production sections, namely a section I: the nanofiltration produced water is sodium chloride concentrated brine, enters a sodium chloride salt water blending tank 6 to be blended and is used as a production raw material, ammonium bicarbonate is added through an ammonium bicarbonate input pipe, sodium bicarbonate (sodium bicarbonate) precipitation crystallization is generated through a second reaction kettle, filtrate is evaporated, salt is separated out, ammonium chloride is separated out by cooling, and evaporated condensate water is recycled. Section II: the nanofiltration concentrated water is sodium sulfate concentrated brine, and enters a sodium sulfate brine mixing tank 4 to be mixed and then is used as a production raw material, ammonium bicarbonate is added through an ammonium bicarbonate input pipe, sodium bicarbonate (sodium bicarbonate) precipitation crystallization is generated through a first reaction kettle, filtrate is evaporated, salt is separated out, ammonium sulfate is separated out by cooling, and evaporated condensate water is recycled.

Example 2

As shown in fig. 3: the wastewater pretreatment unit 1, the RO pre-concentration unit 2 and the low-pressure nanofiltration salt separation unit 3 are sequentially connected through pipelines, the water producing end of the low-pressure nanofiltration salt separation unit 3 is connected with the inlet end of the sodium sulfate water preparation tank 4 through a pipeline, the outlet end of the sodium sulfate water preparation tank 4 is connected with the inlet end of the first double decomposition reaction device 5 through a pipeline, the concentrated water end of the low-pressure nanofiltration salt separation unit 3 is connected with the inlet end of the sodium chloride water preparation tank 6 through a pipeline, the outlet end of the sodium chloride water preparation tank 6 is connected with the second double decomposition reaction device 7 through a pipeline, the first double decomposition reaction device 5 comprises a first reaction kettle and a first crystallizer, the second double decomposition reaction device 6 comprises a second reaction kettle and a second crystallizer, and the material outlet of the first reaction kettle is connected with the inlet end of the sodium chloride water preparation tank 6 through a pipeline.

When the embodiment is used, the high-salt wastewater enters the RO pre-concentration unit 2 after being subjected to the hard removal and impurity removal and COD reduction by the wastewater pretreatment unit 1, the produced water is recycled, the concentrated water passes through the low-pressure nanofiltration membrane salt separation unit 3, the produced water is sodium chloride concentrated solution, and the concentrated water is sodium sulfate concentrated solution. The subsequent process is divided into two production sections, namely a section I: the nanofiltration produced water is sodium chloride concentrated brine, enters a sodium chloride salt water blending tank 6 to be blended and is used as a production raw material, ammonium bicarbonate is added through an ammonium bicarbonate input pipe, sodium bicarbonate (sodium bicarbonate) precipitation crystallization is generated through a second reaction kettle, filtrate is evaporated, salt is separated out, ammonium chloride is separated out by cooling, and evaporated condensate water is recycled. Section II: the nanofiltration concentrated water is sodium sulfate concentrated brine, the sodium sulfate concentrated brine enters a sodium sulfate brine mixing tank 4 to be mixed and then is used as a production raw material, potassium chloride is added through a potassium chloride input pipe, filtrate is evaporated and salted out through a first reaction kettle, the potassium sulfate is cooled and separated out, evaporated condensate water is recycled, and a byproduct sodium chloride saturated solution enters a brine mixing tank 6 as a raw material of a production section I.

The above embodiments are only for illustrating the technical solution of the present utility model, and not for limiting the same; although the utility model has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the utility model, and are intended to be included within the scope of the appended claims and description.

Claims

1. The zero discharge device for the high-salinity wastewater comprises a wastewater pretreatment unit, an RO pre-concentration unit and a low-pressure nanofiltration salt separation unit which are sequentially connected, and is characterized in that the water producing end of the low-pressure nanofiltration salt separation unit is connected with the inlet end of a sodium sulfate water preparation tank through a pipeline, the outlet end of the sodium sulfate water preparation tank is connected with the inlet end of a first double decomposition reaction device through a pipeline, the concentrated water end of the low-pressure nanofiltration salt separation unit is connected with the inlet end of a sodium chloride water preparation tank through a pipeline, the outlet end of the sodium chloride water preparation tank is connected with a second double decomposition reaction device through a pipeline, the first double decomposition reaction device comprises a first reaction kettle and a first crystallizer, and the second double decomposition reaction device comprises a second reaction kettle and a second crystallizer.

2. The high-salt wastewater zero-discharge device according to claim 1, wherein the inlet ends of the first reaction kettle and the second reaction kettle are respectively connected with an ammonium bicarbonate input pipe.

3. The zero-emission device for high-salt wastewater according to claim 1, wherein the inlet end of the first reaction kettle is connected with a potassium chloride input pipe, the inlet end of the second reaction kettle is connected with an ammonium bicarbonate input pipe, and the outlet end of the first reaction kettle is connected with the inlet end of a sodium chloride water blending tank through a pipeline.