Membrane method denitration treatment system

Abstract

The utility model relates to a membrane process denitration treatment system, which belongs to the technical field of water treatment and comprises a cooling system, a nanofiltration membrane filter and a reaction tank which are sequentially communicated along the flowing direction of saline water, a calcium chloride solution inflow pipeline is arranged on the reaction tank, and a hydrochloric acid solution inflow pipeline and a sodium sulfite solution inflow pipeline are communicated on the cooling system. The denitration device is simple in denitration process, low in one-time investment cost and free of heavy metal ion pollution.

Description

TECHNICAL FIELD

[0001] The utility model belongs to water treatment technical field relates to brine treatment technology, concretely is a kind of membrane method desulfurization treatment system. BACKGROUND

[0002] Brine is the raw material of chlor-alkali industry, and the removal of sulfate in brine mainly includes barium chloride method and membrane method at present. Referring to the patent document with application number CN201610996947.1, a method for preparing crude brine by reducing sulfate in brine is disclosed, which includes the following steps: (1) pretreating the brine to reduce the Ca 2+ ion concentration in the brine and remove floating impurities in the brine; (2) filtering the pretreated brine through a precision filter to remove suspended particles in the brine; and (3) passing the filtered brine through a nanofiltration membrane system, and the softened liquid passing through the nanofiltration membrane system is the crude brine. Meanwhile, the patent document also discloses a system for removing sulfate in brine. By using the method and system of the present application, sulfate, calcium and magnesium ions in the brine can be trapped, the concentrated water can be used to produce mirabilite, and the filtrate can directly enter the subsequent brine refining process, thereby effectively controlling the influence of sulfate on the subsequent production of caustic soda and reducing the production cost. The patent document uses membrane method to remove sulfate in brine. However, this method is complex and requires a large one-time investment.

[0003] In the prior art, there is also a barium chloride method for removing sulfate. Since barium chloride is a highly toxic chemical, the storage of barium chloride requires high standards. In addition, Ba 2+ ions belong to heavy metal ions, and the generated waste residue causes secondary pollution. If not handled properly, the concentration of Ba 2+ ions will exceed the standard, which will damage the ion-exchange membrane electrolytic cell. UTILITY MODEL CONTENTS

[0004] In view of the above problems of the existing membrane method for removing sulfate, such as large one-time investment, and the technical problem of heavy metal ion pollution in the barium chloride method for removing sulfate, the utility model provides a membrane method for removing sulfate.

[0005] The utility model discloses a membrane method for removing sulfate, which uses membrane method and calcium chloride method to remove sulfate, includes a nanofiltration membrane filter and a reaction tank. The nanofiltration membrane filter is used for membrane separation and filtration, and calcium chloride is added to the reaction tank. The sulfate calcium solution is dehydrated to generate CaSO4·2H2O precipitate (gypsum). The utility model has the advantages of simple desulfurization process, small one-time investment cost and no heavy metal ion pollution.

[0006] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0007] The utility model discloses a membrane method denitration treatment system, including the cooling system, nanofiltration membrane filter and reaction tank that communicate in proper order along the flowing direction of brine, be provided with calcium chloride solution inflow pipeline on the reaction tank, the cooling system is passed through sodium sulfite solution inflow pipeline and hydrochloric acid solution inflow pipeline and is communicated.

[0008] Further limit, the cooling system includes primary cooler and secondary cooler, and the primary cooler is communicated with nanofiltration membrane filter through secondary cooler, and the hydrochloric acid solution inflow pipeline and sodium sulfite solution inflow pipeline are all communicated with secondary cooler.

[0009] Further limit, the membrane method denitration treatment system still includes activated carbon filter, and the secondary cooler is communicated with nanofiltration membrane filter through activated carbon filter.

[0010] Further limit, the membrane method denitration treatment system still includes security filter, and the activated carbon filter is communicated with nanofiltration membrane filter through security filter.

[0011] Further limit, the membrane method denitration treatment system still includes the clarification bucket that is communicated with reaction tank.

[0012] Further limit, the clarification bucket is passed through salt mud pipeline and brine clear liquid pipeline and is communicated.

[0013] Further limit, the membrane method denitration treatment system still includes suspension separator, and the suspension separator is communicated with clarification bucket through salt mud pipeline.

[0014] Further limit, is provided with salt mud booster pump on the outlet pipe of suspension separator.

[0015] Further limit, is provided with flow pump on the import end of primary cooler.

[0016] Compared with prior art, the utility model has the beneficial effects that:

[0017] 1. The utility model relates to a membrane method denitration treatment system, including the cooling system, nanofiltration membrane filter and reaction tank that communicate in proper order along the flowing direction of brine, and the qualified dechlorination light brine is cooled in the cooling system, and the temperature of dechlorination light brine is controlled at 35 plus or minus 3 DEG C, and the hydrochloric acid solution and sodium sulfite solution are added in the cooling system and adjust the pH of qualified dechlorination light brine respectively ORP is less than 100mv 5~7 and 5~7, and the sulfate radical separation is carried out through nanofiltration membrane filter, and the rich nitrate (sulfate radical) brine is sent to the reaction tank, and the sulfate radical reacts with calcium chloride to generate calcium sulfate precipitate in the reaction tank, and carries out denitration (sulfate radical). The utility model discloses a membrane method - calcium chloride method denitration, and the sulfate radical separation is carried out through nanofiltration membrane filter, and the calcium sulfate solution is dehydrated, and CaSO4.2H2O precipitate (gypsum) is also used for the application of chemical raw materials. The denitration process of the utility model is simple, and the one-time investment cost is small, and there is no heavy metal ion pollution.

[0018] 2. The cooling system of the utility model includes primary cooler and secondary cooler, improves the cooling effect through two-stage cooler, carries out preliminary cooling in the primary cooler first with filtered brine, reduces the circulating water consumption in the secondary cooler.

[0019] 3. The utility model discloses a membrane method denitration treatment system also includes activated carbon filter and security filter, and the impurities in qualified dechlorination light brine are filtered out through activated carbon filter and security filter, avoid the membrane damage of nanofiltration membrane filter caused by impurities.

[0020] 4. The utility model discloses a membrane method denitration treatment system also includes booster pump, and the salt mud in suspension separator is pressurized through salt mud booster pump. ACCURACY

[0021] Figure 1 It is the schematic diagram of the utility model membrane method denitration treatment system;

[0022] Among them, 1-primary cooler, 2-secondary cooler, 3-activated carbon filter, 4-security filter, 5-nanofiltration membrane filter, 6-reaction tank, 7-clearing bucket, 8-suspension separator. SPECIFIC EMBODIMENT

[0023] The technical scheme of the utility model will be explained further in the following with the accompanying drawings and examples, but the utility model is not limited to the following described embodiment.

[0024] Example 1

[0025] Referring to Figure 1The cooling system, the nanofiltration membrane filter 5 and the reaction tank 6 are sequentially communicated along the flowing direction of the brine.

[0026] The working principle of the membrane method denitration treatment system is as follows: the qualified dechlorinated light brine is cooled in the cooling system, the temperature of the dechlorinated light brine is controlled at 35±3 DEG C (a suitable reaction temperature), the hydrochloric acid solution and the sodium sulfite solution are added in the cooling system to respectively adjust the pH value of the qualified dechlorinated light brine to 5-7 and the ORP to be less than 100 mv; the sulfate radical is separated through the nanofiltration membrane filter 5, the nitrate (sulfate radical) rich brine is sent to the reaction tank 6, the sulfate radical reacts with calcium chloride to generate calcium sulfate precipitate in the reaction tank 6, and the denitration (sulfate radical) is carried out.

[0027] Embodiment 2

[0028] The cooling system of the membrane method denitration treatment system of the embodiment comprises a first cooler 1 and a second cooler 2, the first cooler 1 is communicated with the nanofiltration membrane filter 5 through the second cooler 2; the hydrochloric acid solution inflow pipeline and the sodium sulfite solution inflow pipeline are both communicated with the second cooler 2.

[0029] Preferably, the membrane method denitration treatment system of the embodiment further comprises an activated carbon filter 3, the second cooler 2 is communicated with the nanofiltration membrane filter 5 through the activated carbon filter 3.

[0030] Preferably, the membrane method denitration treatment system of the embodiment further comprises a security filter 4, the activated carbon filter 3 is communicated with the nanofiltration membrane filter 5 through the security filter 4.

[0031] Specifically, the outlet of the first cooler 1 of the embodiment is communicated with the inlet of the second cooler 2, the outlet of the second cooler 2 is communicated with the inlet of the activated carbon filter 3, the outlet of the activated carbon filter 3 is communicated with the inlet of the security filter 4, and the outlet of the security filter 4 is communicated with the inlet of the nanofiltration membrane filter 5; the hydrochloric acid solution inflow pipeline and the sodium sulfite solution inflow pipeline are both communicated with the second cooler 2.

[0032] The working principle of the membrane method denitration treatment system of the embodiment is as follows: the pretreated qualified dechlorinated dilute brine (pH=5-7 and ORP<100mv) is filtered through the activated carbon filter 3 and the security filter 4 in sequence to remove impurities, and then filtered through the nanofiltration membrane filter 5, wherein the liquid phase on the permeation side of the first, second and third stages is the poor nitrate brine, which can be reused for salt making; the concentrated liquid of the third stage is the rich nitrate brine, which flows into the reaction tank 6, and the rich nitrate brine reacts with calcium chloride in the reaction tank 6 to generate calcium sulfate precipitate, and denitration (sulfate) is performed.

[0033] Embodiment 3

[0034] The membrane method denitration treatment system of the embodiment is based on the embodiment 2, and the clarification barrel 7 is connected with the salt mud pipeline and the brine clear liquid pipeline.

[0035] The membrane method denitration treatment system of the embodiment further comprises the suspension separator 8, which is connected with the clarification barrel 7 through the salt mud pipeline.

[0036] Preferably, the embodiment is provided with the salt mud lifting pump on the outlet pipe of the clarification barrel 7.

[0037] Preferably, the embodiment is provided with the flow pump between the security filter 4 and the nanofiltration membrane filter 5.

[0038] Preferably, the embodiment is provided with the flow pump on the inlet end of the first cooler 1.

[0039] The above embodiments are only used to illustrate the technical solutions of the present application, rather than limit them; although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that the technical solutions recorded in the foregoing embodiments can still be modified, or some technical features can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A membrane process desulfurization treatment system characterized by, The cooling system, the nanofiltration membrane filter (5) and the reaction tank (6) are sequentially communicated along the flowing direction of the brine, the reaction tank (6) is provided with a calcium chloride solution inflow pipe, and the cooling system is communicated with a hydrochloric acid solution inflow pipe and a sodium sulfite solution inflow pipe.

2. The membrane-based sulfur removal treatment system of claim 1, wherein, The cooling system comprises a primary cooler (1) and a secondary cooler (2), the primary cooler (1) is communicated with the nanofiltration membrane filter (5) through the secondary cooler (2), and the hydrochloric acid solution inflow pipe and the sodium sulfite solution inflow pipe are both communicated with the secondary cooler (2).

3. The membrane-based sulfur removal treatment system of claim 2, wherein, The membrane method denitration treatment system further comprises an activated carbon filter (3), the secondary cooler (2) is communicated with the nanofiltration membrane filter (5) through the activated carbon filter (3).

4. The membrane-based sulfur removal treatment system of claim 3, wherein, The membrane method denitration treatment system further comprises a security filter (4), the activated carbon filter (3) is communicated with the nanofiltration membrane filter (5) through the security filter (4).

5. The membrane-based sulfur removal treatment system according to any one of claims 1-4, wherein, The membrane method denitration treatment system further comprises a clarifying tank (7) communicated with the reaction tank (6).

6. The membrane-based sulfur removal treatment system of claim 5, wherein, The clarifying tank (7) is communicated with a salt mud pipe and a brine clear liquid pipe.

7. The membrane-based sulfur removal treatment system of claim 6, wherein, The membrane method denitration treatment system further comprises a suspension separator (8), the suspension separator (8) is communicated with the clarifying tank (7) through the salt mud pipe.

8. The membrane-based sulfur removal treatment system of claim 7, wherein, A salt mud lifting pump is arranged on the outlet pipe of the suspension separator (8).

9. The membrane desulfurization treatment system according to claim 4, wherein A flow pump is arranged between the security filter (4) and the nanofiltration membrane filter (5).

10. The membrane-based sulfur removal treatment system of claim 2, wherein, A flow pump is arranged on the inlet end of the primary cooler (1).

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