A system and method for treating black liquor wastewater by separating anions

Abstract

The present invention discloses a system for treating black liquor wastewater by using separated anions, comprising an electrodialysis device, a black liquor wastewater tank, a concentrated water tank, and a fresh water tank, wherein the electrodialysis device is connected to a pipeline of the black liquor wastewater tank, the black liquor wastewater tank is connected to a pipeline of the concentrated water tank, the electrodialysis device is connected to a pipeline of the fresh water tank, an evaporation device is arranged on one side of the concentrated water tank, and the concentrated water tank is connected to a pipeline of the evaporation device; and a method for treating black liquor wastewater by using separated anions is also disclosed. The present invention adopts a monovalent anion membrane to migrate and separate the chloride ions in the black liquor wastewater and remove them, thereby avoiding the corrosion problem caused by the enrichment of chloride ions in the subsequent alkali recovery process.

Description

Technical Field

[0001] The invention relates to a system and a method for treating black liquor wastewater by utilizing separated anions, belonging to the technical field of wastewater treatment. Background Art

[0002] In the kraft pulping process of papermaking industry, 10m 3 The black liquor is about 10000 square meters. The main components of black liquor are sodium sulfate, sodium carbonate, sodium chloride, etc. In order to reduce water pollution, alkali recovery is needed to convert the sodium salt in the black liquor into sodium hydroxide, which is reused for cooking and continuously recycled. This can reduce the consumption of alkali and reduce water pollution. However, in the process of alkali recovery, as the black liquor continues to concentrate, the chloride ions in the black liquor are also continuously enriched. To a certain extent, the chloride ions will corrode the process equipment and pipelines, so the black liquor needs to be pretreated before alkali recovery. Summary of the invention

[0003] The purpose of the present invention is to provide a system for treating black liquor wastewater by using separated anions, and also to provide a method for treating black liquor wastewater by using separated anions. The present invention adopts a monovalent anion membrane to migrate, separate and remove chloride ions in the black liquor wastewater, thereby avoiding corrosion problems caused by chloride ion enrichment in the subsequent alkali recovery process.

[0004] In order to solve the above technical problems, the present invention adopts the following technical scheme: a system for treating black liquor wastewater by separating anions, comprising an electrodialysis device, a black liquor wastewater tank, a concentrated water tank, and a fresh water tank, wherein the electrodialysis device is connected to a black liquor wastewater tank pipeline, the black liquor wastewater tank is connected to a concentrated water tank pipeline, the electrodialysis device is connected to a fresh water tank pipeline, an evaporation device is arranged on one side of the concentrated water tank, and the concentrated water tank is connected to the evaporation device pipeline; a monovalent anion membrane is used to migrate, separate and remove chloride ions in the black liquor wastewater, thereby avoiding corrosion problems caused by chloride ion enrichment in the subsequent alkali recovery process.

[0005] The aforementioned system for treating black liquor wastewater by separating anions, wherein an anode, two groups of electrode plates and a cathode are sequentially arranged in the electrodialysis device, a plurality of dilute chambers are arranged between the two groups of electrode plates, the plurality of dilute chambers are equidistantly arranged between the two groups of electrode plates, a concentrated chamber is arranged between two adjacent dilute chambers, the dilute chamber includes a monovalent anion membrane and a cation membrane, the monovalent anion membrane is arranged on the side close to the anode, and the cation membrane is arranged on the side close to the cathode.

[0006] In the aforementioned system for treating black liquor wastewater by separating anions, an anode liquid circulation area is provided between the electrode plate and the monovalent anion membrane, and a cathode liquid circulation area is provided between the electrode plate and the cation membrane.

[0007] The above-mentioned system for treating black liquor wastewater by separating anions, the black liquor wastewater tank is provided with a first wastewater outlet pipe, a second wastewater outlet pipe and a concentrate inlet pipe, one end of the first wastewater outlet pipe is connected to the outlet of the black liquor wastewater tank, the other end of the first wastewater outlet pipe is connected to the inlet of the dilute chamber, one end of the second wastewater outlet pipe is connected to the first wastewater outlet pipe, the other end of the second wastewater outlet pipe is connected to the inlet of the dilute chamber, one end of the concentrate inlet pipe is connected to the outlet of the concentrate chamber, and the other end of the concentrate inlet pipe is connected to the inlet of the black liquor wastewater tank; the number of wastewater outlet pipes changes according to the number of dilute chambers.

[0008] The aforementioned system for treating black liquor wastewater by separating anions, the concentrate water tank is provided with a concentrate water inlet pipe and a concentrate water outlet pipe, one end of the concentrate water inlet pipe is connected to the outlet of the black liquor wastewater tank, the other end of the concentrate water inlet pipe is connected to the inlet of the concentrate water tank, one end of the concentrate water outlet pipe is connected to the outlet of the concentrate water tank, and the other end of the concentrate water outlet pipe is connected to the inlet of the evaporation device.

[0009] The aforementioned system for treating black liquor wastewater by separating anions, wherein the fresh water tank is provided with a fresh water pipe and a fresh water outlet pipe, one end of the fresh water pipe is connected to the water inlet of the fresh water tank, the other end of the fresh water pipe is connected to the water outlet of the concentration chamber, one end of the fresh water outlet pipe is connected to the water outlet of the fresh water tank, and the other end of the fresh water outlet pipe is connected to an alkali recovery device.

[0010] The aforementioned system for treating black liquor wastewater by separating anions, wherein a clean water tank is provided on the fresh water pipe, and a first clean water pipe and a second clean water pipe are provided on the clean water tank, one end of the first clean water pipe is connected to the water outlet of the fresh water chamber, and the other end of the first clean water pipe is connected to the clean water tank, one end of the second clean water pipe is connected to the water outlet of the fresh water chamber, and the other end of the second clean water pipe is connected to the first clean water pipe; the number of clean water pipes changes according to the change in the number of fresh water chambers.

[0011] In the aforementioned system for treating black liquor wastewater by separating anions, at least two dilution chambers are provided.

[0012] A method for treating black liquor wastewater by separating anions comprises the following steps:

[0013] S1, the electrodialysis device starts to operate, the black liquor raw water in the black liquor wastewater tank enters the dilute chamber through the first wastewater outlet pipe, the black liquor raw water in the black liquor wastewater tank enters the dilute chamber through the second wastewater outlet pipe, and the clean water in the clean water tank enters the concentrate chamber through the pipeline. Under the action of the DC electric field of the electrodialysis device, the cations in the black liquor raw water migrate to the cathode in the dilute chamber, the monovalent anions in the black liquor raw water migrate into the concentrate chamber to form concentrated water, and the divalent anions in the black liquor raw water remain in the dilute chamber to form fresh water. The dilute chamber and the concentrate chamber are both equipped with pumps, and the fresh water in the clean water tank circulates back after passing through the electrodialysis device. When the sodium sulfate content in the fresh water in the clean water tank reaches 0.8-1.2%, it enters the fresh water tank through the fresh water pipe, and the clean water in the clean water tank enters the concentrate chamber through the pipeline. Under the action of the DC electric field of the electrodialysis device, the cations in the black liquor raw water migrate to the cathode in the dilute chamber, the monovalent anions in the black liquor raw water migrate into the concentrate chamber to form concentrated water, and the divalent anions in the black liquor raw water remain in the dilute chamber to form fresh water;

[0014] S2, the concentrated water in the concentrated chamber enters the black liquor wastewater tank through the concentrated water inlet pipe to obtain a mixture of concentrated water and black liquor raw water, which is circulated and refluxed by a pump. When the sodium sulfate content in the mixture of concentrated water in the black liquor wastewater tank and black liquor raw water reaches 10%-15%, it enters the concentrated water tank through the concentrated water inlet pipe, and the fresh water in the dilute chamber enters the clean water tank through the first clean water pipe and the second clean water pipe;

[0015] S3, the mixture of concentrated water in the black liquor waste water tank and black liquor raw water enters the concentrated water tank through the concentrated water inlet pipe, and the mixture of concentrated water in the concentrated water tank and black liquor raw water enters the evaporation device through the concentrated water outlet pipe; the fresh water in the fresh water tank enters the alkali recovery device through the fresh water outlet pipe for alkali recovery treatment.

[0016] Compared with the prior art, the present invention comprises an electrodialysis device, a black liquor wastewater tank, a concentrated water tank and a fresh water tank, wherein the electrodialysis device is connected to the black liquor wastewater tank pipeline, the black liquor wastewater tank is connected to the concentrated water tank pipeline, the electrodialysis device is connected to the fresh water tank pipeline, an evaporation device is arranged on one side of the concentrated water tank, and the concentrated water tank is connected to the evaporation device pipeline; an anode, two groups of electrode plates and a cathode are arranged in the electrodialysis device, a plurality of dilute chambers are arranged between the two groups of electrode plates, the plurality of dilute chambers are arranged at equal intervals between the two groups of electrode plates, a concentrated chamber is arranged between two adjacent dilute chambers, the dilute chamber comprises a monovalent anion membrane and a cation membrane, the monovalent anion membrane is arranged on the side close to the anode, and the cation membrane is arranged on the side close to the cathode, the present invention adopts a monovalent anion membrane to migrate, separate and remove chloride ions in the black liquor wastewater, solves the problem of chloride ion enrichment and corrosion of pipelines and process equipment in the black liquor wastewater alkali recovery process, and reduces maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a structural schematic diagram of the present invention.

[0018] Figure numerals: 1-electrodialysis device, 2-black liquor wastewater tank, 3-concentrate water tank, 4-fresh water tank, 5-evaporation device, 6-anode, 7-plate, 8-cathode, 9-fresh chamber, 10-concentrate chamber, 11-monovalent anion membrane, 12-cation membrane, 13-anolyte circulation area, 14-cathode liquid circulation area, 15-first wastewater outlet pipe, 16-second wastewater outlet pipe, 17-concentrate inlet pipe, 18-concentrate water inlet pipe, 19-concentrate water outlet pipe, 20-fresh water pipe, 21-fresh water outlet pipe, 22-alkali recovery device, 23-clean water tank, 24-first clean water pipe, 25-second clean water pipe.

[0019] The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments. DETAILED DESCRIPTION

[0020] Embodiment 1 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate, separate, and remove chloride ions in the black liquor wastewater, thereby avoiding corrosion problems caused by chloride ion enrichment in the subsequent alkali recovery process.

[0021] Embodiment 2 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate and separate chloride ions in the black liquor wastewater. Removal to avoid corrosion problems caused by chloride ion enrichment in the subsequent alkali recovery process; an anode 6, two groups of electrode plates 7 and a cathode 8 are arranged in sequence in the electrodialysis device 1, a plurality of dilute chambers 9 are arranged between the two groups of electrode plates 7, and the plurality of dilute chambers 9 are arranged at equal intervals between the two groups of electrode plates 7, and a concentrated chamber 10 is arranged between two adjacent dilute chambers 9, the dilute chamber 9 includes a monovalent anion membrane 11 and a cation membrane 12, the monovalent anion membrane 11 is arranged on the side close to the anode 6, and the cation membrane 12 is arranged on the side close to the cathode 8.

[0022] Embodiment 3 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate, separate, and remove chloride ions in the black liquor wastewater, thereby avoiding corrosion caused by chloride ion enrichment during the subsequent alkali recovery process Problem: An anode 6, two groups of electrode plates 7 and a cathode 8 are sequentially arranged in the electrodialysis device 1, a plurality of dilute chambers 9 are arranged between the two groups of electrode plates 7, the plurality of dilute chambers 9 are equidistantly arranged between the two groups of electrode plates 7, a concentrated chamber 10 is arranged between two adjacent dilute chambers 9, the dilute chamber 9 comprises a monovalent anion membrane 11 and a cation membrane 12, the monovalent anion membrane 11 is arranged on the side close to the anode 6, the cation membrane 12 is arranged on the side close to the cathode 8; an anode liquid circulation area 13 is arranged between the electrode plate 7 and the monovalent anion membrane 11, a cathode liquid circulation area 14 is arranged between the electrode plate 7 and the cation membrane 12.

[0023] Embodiment 4 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is arranged on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate, separate and remove chloride ions in the black liquor wastewater, thereby avoiding corrosion problems caused by chloride ion enrichment in the subsequent alkali recovery process; an anode 6, two sets of electrode plates 7 and a cathode 8 are sequentially arranged in the electrodialysis device 1, a plurality of fresh water chambers 9 are arranged between the two sets of electrode plates 7, the plurality of fresh water chambers 9 are equidistantly arranged between the two sets of electrode plates 7, a concentrated water chamber 10 is arranged between two adjacent fresh water chambers 9, the fresh water chamber 9 comprises a monovalent anion membrane 11 and a cation membrane 12, the monovalent anion membrane 13 and the cathode 8 are arranged in sequence in the electrodialysis device 1, a plurality of fresh water chambers 9 are ... The monovalent anion membrane 11 is arranged on a side close to the anode 6, and the cation membrane 12 is arranged on a side close to the cathode 8; an anode liquid circulation area 13 is arranged between the electrode plate 7 and the monovalent anion membrane 11, and a cathode liquid circulation area 14 is arranged between the electrode plate 7 and the cation membrane 12; the black liquor wastewater tank 2 is provided with a first wastewater outlet pipe 15, a second wastewater outlet pipe 16 and a concentrated liquid inlet pipe 17, one end of the first wastewater outlet pipe 15 is connected to the outlet of the black liquor wastewater tank 2, the other end of the first wastewater outlet pipe 15 is connected to the inlet of the dilute chamber 9, one end of the second wastewater outlet pipe 16 is connected to the first wastewater outlet pipe 15, the other end of the second wastewater outlet pipe 16 is connected to the inlet of the dilute chamber 9, one end of the concentrated liquid inlet pipe 17 is connected to the outlet of the concentrated chamber 10, and the other end of the concentrated liquid inlet pipe 17 is connected to the inlet of the black liquor wastewater tank 2; the number of wastewater outlet pipes changes according to the number of dilute chambers.

[0024] Embodiment 5 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to separate and remove chloride ions in the black liquor wastewater, thereby avoiding the following alkali recovery process. Chloride ion enrichment in the electrolyte causes corrosion problems; an anode 6, two sets of electrode plates 7 and a cathode 8 are sequentially arranged in the electrodialysis device 1, a plurality of dilute chambers 9 are arranged between the two sets of electrode plates 7, a plurality of dilute chambers 9 are arranged at equal intervals between the two sets of electrode plates 7, a concentrated chamber 10 is arranged between two adjacent dilute chambers 9, the dilute chamber 9 includes a monovalent anion membrane 11 and a cation membrane 12, the monovalent anion membrane 11 is arranged on the side close to the anode 6, and the cation membrane 12 is arranged on the side close to the cathode 8; an anolyte circulation area 13 is arranged between the electrode plate 7 and the monovalent anion membrane 11, A cathode liquid circulation area 14 is arranged between the plate 7 and the cation membrane 12; a first wastewater outlet pipe 15, a second wastewater outlet pipe 16 and a concentrated solution inlet pipe 17 are arranged on the black liquor wastewater tank 2, one end of the first wastewater outlet pipe 15 is connected to the outlet of the black liquor wastewater tank 2, the other end of the first wastewater outlet pipe 15 is connected to the inlet of the dilute chamber 9, one end of the second wastewater outlet pipe 16 is connected to the first wastewater outlet pipe 15, the other end of the second wastewater outlet pipe 16 is connected to the inlet of the dilute chamber 9, and one end of the concentrated solution inlet pipe 17 is connected to the concentrated chamber 10 is connected with the water outlet of the black liquor wastewater tank 2, and the other end of the concentrate inlet pipe 17 is connected with the water inlet of the black liquor wastewater tank 2; the number of wastewater outlet pipes changes according to the number of dilute chambers; a concentrate inlet pipe 18 and a concentrate outlet pipe 19 are provided on the concentrate water tank 3, one end of the concentrate inlet pipe 18 is connected with the water outlet of the black liquor wastewater tank 2, the other end of the concentrate inlet pipe 18 is connected with the water inlet of the concentrate water tank 3, one end of the concentrate outlet pipe 19 is connected with the water outlet of the concentrate water tank 3, and the other end of the concentrate outlet pipe 19 is connected with the water inlet of the evaporation device 5.

[0025] Embodiment 6 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate and separate the chloride ions in the black liquor wastewater and remove them, thereby avoiding the corrosion problem caused by the accumulation of chloride ions in the subsequent alkali recovery process; an anode 6, two groups of electrodes are sequentially provided in the electrodialysis device 1; Plates 7 and cathodes 8, a plurality of dilute chambers 9 are arranged between the two sets of plates 7, the plurality of dilute chambers 9 are arranged at equal intervals between the two sets of plates 7, a concentrated chamber 10 is arranged between two adjacent dilute chambers 9, the dilute chamber 9 comprises a monovalent anion membrane 11 and a cation membrane 12, the monovalent anion membrane 11 is arranged on the side close to the anode 6, the cation membrane 12 is arranged on the side close to the cathode 8; an anode liquid circulation area 13 is arranged between the plate 7 and the monovalent anion membrane 11, a cathode liquid circulation area 14 is arranged between the plate 7 and the cation membrane 12; a first wastewater outlet pipe 15, a second wastewater outlet pipe 16 and a concentrated liquid inlet pipe 17 are arranged on the black liquor wastewater tank 2, the first wastewater outlet pipe 16 and the concentrated liquid inlet pipe 17 are arranged on the black liquor wastewater tank 2, One end of the water pipe 15 is connected to the outlet of the black liquor wastewater tank 2, the other end of the first wastewater outlet pipe 15 is connected to the water inlet of the dilute chamber 9, one end of the second wastewater outlet pipe 16 is connected to the first wastewater outlet pipe 15, the other end of the second wastewater outlet pipe 16 is connected to the water inlet of the dilute chamber 9, one end of the concentrated liquid inlet pipe 17 is connected to the outlet of the concentrated chamber 10, and the other end of the concentrated liquid inlet pipe 17 is connected to the water inlet of the black liquor wastewater tank 2; the number of wastewater outlet pipes changes according to the number of dilute chambers; the number of wastewater outlet pipes changes according to the number of dilute chambers; the concentrated water tank 3 is provided with a concentrated water inlet pipe 18 and a concentrated water outlet pipe 19, One end of the concentrated water inlet pipe 18 is connected to the water outlet of the black liquor wastewater tank 2, and the other end of the concentrated water inlet pipe 18 is connected to the water inlet of the concentrated water tank 3, one end of the concentrated water outlet pipe 19 is connected to the water outlet of the concentrated water tank 3, and the other end of the concentrated water outlet pipe 19 is connected to the water inlet of the evaporation device 5; a fresh water pipe 20 and a fresh water outlet pipe 21 are provided on the fresh water tank 4, one end of the fresh water pipe 20 is connected to the water inlet of the fresh water tank 4, and the other end of the fresh water pipe 20 is connected to the water outlet of the concentrate chamber 10, one end of the fresh water outlet pipe 21 is connected to the water outlet of the fresh water tank 4, and the other end of the fresh water outlet pipe 21 is connected to the alkali recovery device 22.

[0026] Embodiment 7 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate and separate the chloride ions in the black liquor wastewater and remove them, thereby avoiding the corrosion problem caused by the enrichment of chloride ions in the subsequent alkali recovery process; an anode 6, two sets of electrode plates 7, and a cathode 8 are sequentially arranged in the electrodialysis device 1, and the two sets of electrode plates 7 and cathode 8 are sequentially arranged in the electrodialysis device 1, wherein ... A plurality of dilute chambers 9 are arranged between the plates 7, and the plurality of dilute chambers 9 are arranged at equal intervals between the two groups of plates 7. A concentrated chamber 10 is arranged between two adjacent dilute chambers 9, and the dilute chamber 9 includes a monovalent anion membrane 11 and a cation membrane 12, wherein the monovalent anion membrane 11 is arranged on a side close to the anode 6, and the cation membrane 12 is arranged on a side close to the cathode 8; an anode liquid circulation area 13 is arranged between the plate 7 and the monovalent anion membrane 11, and a cathode liquid circulation area 14 is arranged between the plate 7 and the cation membrane 12; a first wastewater outlet pipe 15, a second wastewater outlet pipe 16 and a concentrated liquid inlet pipe 17 are arranged on the black liquor wastewater tank 2, one end of the first wastewater outlet pipe 15 is connected to the outlet of the black liquor wastewater tank 2, and the first wastewater outlet pipe 16 is connected to the outlet of the black liquor wastewater tank 2. The other end of the water outlet pipe 15 is connected to the water inlet of the dilute chamber 9, one end of the second wastewater outlet pipe 16 is connected to the first wastewater outlet pipe 15, the other end of the second wastewater outlet pipe 16 is connected to the water inlet of the dilute chamber 9, one end of the concentrate inlet pipe 17 is connected to the water outlet of the concentrate chamber 10, and the other end of the concentrate inlet pipe 17 is connected to the water inlet of the black liquor wastewater tank 2; the number of wastewater outlet pipes changes according to the number of dilute chambers; the concentrate tank 3 is provided with a concentrate inlet pipe 18 and a concentrate outlet pipe 19, one end of the concentrate inlet pipe 18 is connected to the water outlet of the black liquor wastewater tank 2, the other end of the concentrate inlet pipe 18 is connected to the water inlet of the concentrate tank 3, and the concentrate outlet pipe 19 One end of the concentrated water outlet pipe 19 is connected to the water outlet of the concentrated water tank 3, and the other end of the concentrated water outlet pipe 19 is connected to the water inlet of the evaporation device 5; the fresh water tank 4 is provided with a first fresh water inlet pipe 19, a second fresh water inlet pipe 20 and a fresh water outlet pipe 21, one end of the first fresh water inlet pipe 19 is connected to the water inlet of the fresh water tank 4, the other end of the first fresh water inlet pipe 19 is connected to the water outlet of the dilute chamber 9, one end of the second fresh water inlet pipe 20 is connected to the first fresh water inlet pipe 19, the other end of the second fresh water inlet pipe 20 is connected to the water outlet of the dilute chamber 9, one end of the fresh water outlet pipe 21 is connected to the water outlet of the fresh water tank 4, and the other end of the fresh water outlet pipe 21 is connected to the alkali recovery device 22;The fresh water pipe 20 is provided with a clean water tank 23, and the clean water tank 23 is provided with a first clean water pipe 24 and a second clean water pipe 25, one end of the first clean water pipe 24 is connected to the water outlet of the fresh water chamber 9, and the other end of the first clean water pipe 24 is connected to the clean water tank 23, one end of the second clean water pipe 25 is connected to the water outlet of the fresh water chamber 9, and the other end of the second clean water pipe 25 is connected to the first clean water pipe 24; the number of clean water pipes varies according to the number of fresh water chambers 9. ;

[0027] Embodiment 8 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate and separate the chloride ions in the black liquor wastewater and remove them, thereby avoiding the corrosion problem caused by the enrichment of chloride ions in the subsequent alkali recovery process; an anode 6, two sets of electrode plates 7, and a cathode 8 are sequentially arranged in the electrodialysis device 1, and the two sets of electrode plates 7 and a cathode 8 are sequentially arranged in the electrodialysis device 1; A plurality of dilute chambers 9 are arranged between the plates 7, and the plurality of dilute chambers 9 are arranged at equal intervals between the two groups of plates 7. A concentrated chamber 10 is arranged between two adjacent dilute chambers 9, and the dilute chamber 9 includes a monovalent anion membrane 11 and a cation membrane 12, wherein the monovalent anion membrane 11 is arranged on a side close to the anode 6, and the cation membrane 12 is arranged on a side close to the cathode 8; an anode liquid circulation area 13 is arranged between the plate 7 and the monovalent anion membrane 11, and a cathode liquid circulation area 14 is arranged between the plate 7 and the cation membrane 12; a first wastewater outlet pipe 15, a second wastewater outlet pipe 16 and a concentrated liquid inlet pipe 17 are arranged on the black liquor wastewater tank 2, one end of the first wastewater outlet pipe 15 is connected to the outlet of the black liquor wastewater tank 2, and the first wastewater outlet pipe 16 is connected to the outlet of the black liquor wastewater tank 2. The other end of the water outlet pipe 15 is connected to the water inlet of the dilute chamber 9, one end of the second wastewater outlet pipe 16 is connected to the first wastewater outlet pipe 15, the other end of the second wastewater outlet pipe 16 is connected to the water inlet of the dilute chamber 9, one end of the concentrate inlet pipe 17 is connected to the water outlet of the concentrate chamber 10, and the other end of the concentrate inlet pipe 17 is connected to the water inlet of the black liquor wastewater tank 2; the number of wastewater outlet pipes changes according to the number of dilute chambers; the concentrate tank 3 is provided with a concentrate inlet pipe 18 and a concentrate outlet pipe 19, one end of the concentrate inlet pipe 18 is connected to the water outlet of the black liquor wastewater tank 2, the other end of the concentrate inlet pipe 18 is connected to the water inlet of the concentrate tank 3, and the concentrate outlet pipe 19 One end of the concentrated water outlet pipe 19 is connected to the water outlet of the concentrated water tank 3, and the other end of the concentrated water outlet pipe 19 is connected to the water inlet of the evaporation device 5; the fresh water tank 4 is provided with a first fresh water inlet pipe 19, a second fresh water inlet pipe 20 and a fresh water outlet pipe 21, one end of the first fresh water inlet pipe 19 is connected to the water inlet of the fresh water tank 4, the other end of the first fresh water inlet pipe 19 is connected to the water outlet of the dilute chamber 9, one end of the second fresh water inlet pipe 20 is connected to the first fresh water inlet pipe 19, the other end of the second fresh water inlet pipe 20 is connected to the water outlet of the dilute chamber 9, one end of the fresh water outlet pipe 21 is connected to the water outlet of the fresh water tank 4, and the other end of the fresh water outlet pipe 21 is connected to the alkali recovery device 22;The fresh water pipe 20 is provided with a clean water tank 23, and the clean water tank 23 is provided with a first clean water pipe 24 and a second clean water pipe 25, one end of the first clean water pipe 24 is connected to the water outlet of the fresh water chamber 9, and the other end of the first clean water pipe 24 is connected to the clean water tank 23, one end of the second clean water pipe 25 is connected to the water outlet of the fresh water chamber 9, and the other end of the second clean water pipe 25 is connected to the first clean water pipe 24; the number of clean water pipes varies according to the number of fresh water chambers 9; the fresh water chambers 9 are provided with at least two.;

[0028] A method for treating black liquor wastewater by separating anions comprises the following steps:

[0029] S1, the electrodialysis device 1 starts to operate, the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the first wastewater outlet pipe 15, and the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the second wastewater outlet pipe 16. After passing through the electrodialysis device 1, the fresh water enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25, and circulates back through the pump. When the sodium sulfate content in the fresh water in the clean water tank 23 reaches 0.8-1.2%, it enters the fresh water tank 4 through the fresh water pipe 20, and the clean water in the clean water tank 23 enters the concentrate chamber 10 through the pipeline. Under the action of the DC electric field of the electrodialysis device 1, the cations in the raw black liquor water migrate to the cathode in the dilute chamber 9, the monovalent anions in the raw black liquor water migrate into the concentrate chamber 10 to form concentrated water, and the divalent anions in the raw black liquor water remain in the dilute chamber 9 to form fresh water;

[0030] S2, the concentrated water in the concentrated chamber 10 enters the black liquor waste water tank 2 through the concentrated water inlet pipe 17, and a mixture of concentrated water and black liquor raw water is obtained, which is circulated and refluxed by a pump. When the sodium sulfate content in the mixture of concentrated water in the black liquor waste water tank 2 and black liquor raw water reaches 10%-15%, it enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the fresh water in the dilute chamber 9 enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25;

[0031] S3, the mixture of concentrated water and black liquor raw water in the black liquor waste water tank 2 enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the mixture of concentrated water and black liquor raw water in the concentrated water tank 3 enters the evaporation device 5 through the concentrated water outlet pipe 19; the fresh water in the fresh water tank 4 enters the alkali recovery device 22 through the fresh water outlet pipe 21 for alkali recovery treatment.

[0032] Embodiment 9 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is arranged on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate and separate the chloride ions in the black liquor wastewater and remove them, thereby avoiding the corrosion problem caused by the enrichment of chloride ions in the subsequent alkali recovery process; an anode 6, two sets of electrode plates 7, and a cathode 8 are arranged in sequence in the electrodialysis device 1, and the two sets of electrode plates 7 and a cathode 8 are arranged in sequence; A plurality of dilute chambers 9 are arranged between the plates 7, and the plurality of dilute chambers 9 are arranged at equal intervals between the two groups of plates 7. A concentrated chamber 10 is arranged between two adjacent dilute chambers 9, and the dilute chamber 9 includes a monovalent anion membrane 11 and a cation membrane 12, wherein the monovalent anion membrane 11 is arranged on a side close to the anode 6, and the cation membrane 12 is arranged on a side close to the cathode 8; an anode liquid circulation area 13 is arranged between the plate 7 and the monovalent anion membrane 11, and a cathode liquid circulation area 14 is arranged between the plate 7 and the cation membrane 12; a first wastewater outlet pipe 15, a second wastewater outlet pipe 16 and a concentrated liquid inlet pipe 17 are arranged on the black liquor wastewater tank 2, one end of the first wastewater outlet pipe 15 is connected to the outlet of the black liquor wastewater tank 2, and the first wastewater outlet pipe 16 is connected to the outlet of the black liquor wastewater tank 2. The other end of the water outlet pipe 15 is connected to the water inlet of the dilute chamber 9, one end of the second wastewater outlet pipe 16 is connected to the first wastewater outlet pipe 15, the other end of the second wastewater outlet pipe 16 is connected to the water inlet of the dilute chamber 9, one end of the concentrate inlet pipe 17 is connected to the water outlet of the concentrate chamber 10, and the other end of the concentrate inlet pipe 17 is connected to the water inlet of the black liquor wastewater tank 2; the number of wastewater outlet pipes changes according to the number of dilute chambers; the concentrate tank 3 is provided with a concentrate inlet pipe 18 and a concentrate outlet pipe 19, one end of the concentrate inlet pipe 18 is connected to the water outlet of the black liquor wastewater tank 2, the other end of the concentrate inlet pipe 18 is connected to the water inlet of the concentrate tank 3, and the concentrate outlet pipe 19 One end of the concentrated water outlet pipe 19 is connected to the water outlet of the concentrated water tank 3, and the other end of the concentrated water outlet pipe 19 is connected to the water inlet of the evaporation device 5; the fresh water tank 4 is provided with a first fresh water inlet pipe 19, a second fresh water inlet pipe 20 and a fresh water outlet pipe 21, one end of the first fresh water inlet pipe 19 is connected to the water inlet of the fresh water tank 4, the other end of the first fresh water inlet pipe 19 is connected to the water outlet of the dilute chamber 9, one end of the second fresh water inlet pipe 20 is connected to the first fresh water inlet pipe 19, the other end of the second fresh water inlet pipe 20 is connected to the water outlet of the dilute chamber 9, one end of the fresh water outlet pipe 21 is connected to the water outlet of the fresh water tank 4, and the other end of the fresh water outlet pipe 21 is connected to the alkali recovery device 22;The fresh water pipe 20 is provided with a clean water tank 23, and the clean water tank 23 is provided with a first clean water pipe 24 and a second clean water pipe 25, one end of the first clean water pipe 24 is connected to the water outlet of the fresh water chamber 9, and the other end of the first clean water pipe 24 is connected to the clean water tank 23, one end of the second clean water pipe 25 is connected to the water outlet of the fresh water chamber 9, and the other end of the second clean water pipe 25 is connected to the first clean water pipe 24; the number of clean water pipes varies according to the number of fresh water chambers 9; the fresh water chambers 9 are provided with two.;

[0033] A method for treating black liquor wastewater by separating anions comprises the following steps:

[0034] S1, the electrodialysis device 1 starts to operate, the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the first wastewater outlet pipe 15, and the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the second wastewater outlet pipe 16. After passing through the electrodialysis device 1, the fresh water enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25, and circulates back through the pump. When the sodium sulfate content in the fresh water in the clean water tank 23 reaches 0.8-1.2%, it enters the fresh water tank 4 through the fresh water pipe 20, and the clean water in the clean water tank 23 enters the concentrate chamber 10 through the pipeline. Under the action of the DC electric field of the electrodialysis device 1, the cations in the raw black liquor water migrate to the cathode in the dilute chamber 9, the monovalent anions in the raw black liquor water migrate into the concentrate chamber 10 to form concentrated water, and the divalent anions in the raw black liquor water remain in the dilute chamber 9 to form fresh water;

[0035] S2, the concentrated water in the concentrated chamber 10 enters the black liquor waste water tank 2 through the concentrated water inlet pipe 17, and a mixture of concentrated water and black liquor raw water is obtained, which is circulated and refluxed by a pump. When the sodium sulfate content in the mixture of concentrated water in the black liquor waste water tank 2 and black liquor raw water reaches 10%-15%, it enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the fresh water in the dilute chamber 9 enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25;

[0036] S3, the mixture of concentrated water and black liquor raw water in the black liquor waste water tank 2 enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the mixture of concentrated water and black liquor raw water in the concentrated water tank 3 enters the evaporation device 5 through the concentrated water outlet pipe 19; the fresh water in the fresh water tank 4 enters the alkali recovery device 22 through the fresh water outlet pipe 21 for alkali recovery treatment.

[0037] Embodiment 10 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate, separate, and remove chloride ions in the black liquor wastewater, thereby avoiding corrosion problems caused by chloride ion enrichment in the subsequent alkali recovery process; an anode 6, two sets of electrode plates 7, and a cathode 8 are sequentially arranged in the electrodialysis device 1, and the two sets of electrode plates 7 and a cathode 8 are sequentially arranged in the electrodialysis device 1; A plurality of dilute chambers 9 are arranged between the plates 7, and the plurality of dilute chambers 9 are arranged at equal intervals between the two groups of plates 7. A concentrated chamber 10 is arranged between two adjacent dilute chambers 9, and the dilute chamber 9 includes a monovalent anion membrane 11 and a cation membrane 12, wherein the monovalent anion membrane 11 is arranged on a side close to the anode 6, and the cation membrane 12 is arranged on a side close to the cathode 8; an anode liquid circulation area 13 is arranged between the plate 7 and the monovalent anion membrane 11, and a cathode liquid circulation area 14 is arranged between the plate 7 and the cation membrane 12; a first wastewater outlet pipe 15, a second wastewater outlet pipe 16 and a concentrated liquid inlet pipe 17 are arranged on the black liquor wastewater tank 2, one end of the first wastewater outlet pipe 15 is connected to the outlet of the black liquor wastewater tank 2, and the first wastewater outlet pipe 16 is connected to the outlet of the black liquor wastewater tank 2. The other end of the water outlet pipe 15 is connected to the water inlet of the dilute chamber 9, one end of the second wastewater outlet pipe 16 is connected to the first wastewater outlet pipe 15, the other end of the second wastewater outlet pipe 16 is connected to the water inlet of the dilute chamber 9, one end of the concentrate inlet pipe 17 is connected to the water outlet of the concentrate chamber 10, and the other end of the concentrate inlet pipe 17 is connected to the water inlet of the black liquor wastewater tank 2; the number of wastewater outlet pipes changes according to the number of dilute chambers; the concentrate tank 3 is provided with a concentrate inlet pipe 18 and a concentrate outlet pipe 19, one end of the concentrate inlet pipe 18 is connected to the water outlet of the black liquor wastewater tank 2, the other end of the concentrate inlet pipe 18 is connected to the water inlet of the concentrate tank 3, and the concentrate outlet pipe 19 One end of the concentrated water outlet pipe 19 is connected to the water outlet of the concentrated water tank 3, and the other end of the concentrated water outlet pipe 19 is connected to the water inlet of the evaporation device 5; the fresh water tank 4 is provided with a first fresh water inlet pipe 19, a second fresh water inlet pipe 20 and a fresh water outlet pipe 21, one end of the first fresh water inlet pipe 19 is connected to the water inlet of the fresh water tank 4, the other end of the first fresh water inlet pipe 19 is connected to the water outlet of the dilute chamber 9, one end of the second fresh water inlet pipe 20 is connected to the first fresh water inlet pipe 19, the other end of the second fresh water inlet pipe 20 is connected to the water outlet of the dilute chamber 9, one end of the fresh water outlet pipe 21 is connected to the water outlet of the fresh water tank 4, and the other end of the fresh water outlet pipe 21 is connected to the alkali recovery device 22;The fresh water pipe 20 is provided with a clean water tank 23, and the clean water tank 23 is provided with a first clean water pipe 24 and a second clean water pipe 25, one end of the first clean water pipe 24 is connected to the water outlet of the fresh water chamber 9, and the other end of the first clean water pipe 24 is connected to the clean water tank 23, one end of the second clean water pipe 25 is connected to the water outlet of the fresh water chamber 9, and the other end of the second clean water pipe 25 is connected to the first clean water pipe 24; the number of clean water pipes varies according to the number of fresh water chambers 9; the fresh water chambers 9 are provided with three.;

[0038] A method for treating black liquor wastewater by separating anions comprises the following steps:

[0039] S1, the electrodialysis device 1 starts to operate, the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the first wastewater outlet pipe 15, and the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the second wastewater outlet pipe 16. After passing through the electrodialysis device 1, the fresh water enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25, and circulates back through the pump. When the sodium sulfate content in the fresh water in the clean water tank 23 reaches 0.8-1.2%, it enters the fresh water tank 4 through the fresh water pipe 20, and the clean water in the clean water tank 23 enters the concentrate chamber 10 through the pipeline. Under the action of the DC electric field of the electrodialysis device 1, the cations in the raw black liquor water migrate to the cathode in the dilute chamber 9, the monovalent anions in the raw black liquor water migrate into the concentrate chamber 10 to form concentrated water, and the divalent anions in the raw black liquor water remain in the dilute chamber 9 to form fresh water;

[0040] S2, the concentrated water in the concentrated chamber 10 enters the black liquor waste water tank 2 through the concentrated water inlet pipe 17, and a mixture of concentrated water and black liquor raw water is obtained, which is circulated and refluxed by a pump. When the sodium sulfate content in the mixture of concentrated water in the black liquor waste water tank 2 and black liquor raw water reaches 10%-15%, it enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the fresh water in the dilute chamber 9 enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25;

[0041] S3, the mixture of concentrated water and black liquor raw water in the black liquor waste water tank 2 enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the mixture of concentrated water and black liquor raw water in the concentrated water tank 3 enters the evaporation device 5 through the concentrated water outlet pipe 19; the fresh water in the fresh water tank 4 enters the alkali recovery device 22 through the fresh water outlet pipe 21 for alkali recovery treatment.

[0042] Embodiment 11 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate, separate, and remove chloride ions in the black liquor wastewater, thereby avoiding corrosion problems caused by chloride ion enrichment in the subsequent alkali recovery process; an anode 6, two sets of electrode plates 7, and a cathode 8 are sequentially arranged in the electrodialysis device 1, and the two sets of electrode plates 7 and a cathode 8 are sequentially arranged in the electrodialysis device 1, wherein ... A plurality of dilute chambers 9 are arranged between the plates 7, and the plurality of dilute chambers 9 are arranged at equal intervals between the two groups of plates 7. A concentrated chamber 10 is arranged between two adjacent dilute chambers 9, and the dilute chamber 9 includes a monovalent anion membrane 11 and a cation membrane 12, wherein the monovalent anion membrane 11 is arranged on a side close to the anode 6, and the cation membrane 12 is arranged on a side close to the cathode 8; an anode liquid circulation area 13 is arranged between the plate 7 and the monovalent anion membrane 11, and a cathode liquid circulation area 14 is arranged between the plate 7 and the cation membrane 12; a first wastewater outlet pipe 15, a second wastewater outlet pipe 16 and a concentrated liquid inlet pipe 17 are arranged on the black liquor wastewater tank 2, one end of the first wastewater outlet pipe 15 is connected to the outlet of the black liquor wastewater tank 2, and the first wastewater outlet pipe 16 is connected to the outlet of the black liquor wastewater tank 2. The other end of the water outlet pipe 15 is connected to the water inlet of the dilute chamber 9, one end of the second wastewater outlet pipe 16 is connected to the first wastewater outlet pipe 15, the other end of the second wastewater outlet pipe 16 is connected to the water inlet of the dilute chamber 9, one end of the concentrate inlet pipe 17 is connected to the water outlet of the concentrate chamber 10, and the other end of the concentrate inlet pipe 17 is connected to the water inlet of the black liquor wastewater tank 2; the number of wastewater outlet pipes changes according to the number of dilute chambers; the concentrate tank 3 is provided with a concentrate inlet pipe 18 and a concentrate outlet pipe 19, one end of the concentrate inlet pipe 18 is connected to the water outlet of the black liquor wastewater tank 2, the other end of the concentrate inlet pipe 18 is connected to the water inlet of the concentrate tank 3, and the concentrate outlet pipe 19 One end of the concentrated water outlet pipe 19 is connected to the water outlet of the concentrated water tank 3, and the other end of the concentrated water outlet pipe 19 is connected to the water inlet of the evaporation device 5; the fresh water tank 4 is provided with a first fresh water inlet pipe 19, a second fresh water inlet pipe 20 and a fresh water outlet pipe 21, one end of the first fresh water inlet pipe 19 is connected to the water inlet of the fresh water tank 4, the other end of the first fresh water inlet pipe 19 is connected to the water outlet of the dilute chamber 9, one end of the second fresh water inlet pipe 20 is connected to the first fresh water inlet pipe 19, the other end of the second fresh water inlet pipe 20 is connected to the water outlet of the dilute chamber 9, one end of the fresh water outlet pipe 21 is connected to the water outlet of the fresh water tank 4, and the other end of the fresh water outlet pipe 21 is connected to the alkali recovery device 22;The fresh water pipe 20 is provided with a clean water tank 23, and the clean water tank 23 is provided with a first clean water pipe 24 and a second clean water pipe 25, one end of the first clean water pipe 24 is connected to the water outlet of the fresh water chamber 9, and the other end of the first clean water pipe 24 is connected to the clean water tank 23, one end of the second clean water pipe 25 is connected to the water outlet of the fresh water chamber 9, and the other end of the second clean water pipe 25 is connected to the first clean water pipe 24; the number of clean water pipes varies according to the number of fresh water chambers 9; the fresh water chambers 9 are provided with at least two.;

[0043] A method for treating black liquor wastewater by separating anions comprises the following steps:

[0044] S1, the electrodialysis device 1 starts to operate, the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the first wastewater outlet pipe 15, and the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the second wastewater outlet pipe 16. After passing through the electrodialysis device 1, the fresh water enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25, and circulates back through the pump. When the sodium sulfate content in the fresh water in the clean water tank 23 reaches 0.8%, it enters the fresh water tank 4 through the fresh water pipe 20, and the clean water in the clean water tank 23 enters the concentration chamber 10 through the pipeline. Under the action of the DC electric field of the electrodialysis device 1, the cations in the raw black liquor water migrate to the cathode in the dilute chamber 9, the monovalent anions in the raw black liquor water migrate into the concentration chamber 10 to form concentrated water, and the divalent anions in the raw black liquor water remain in the dilute chamber 9 to form fresh water;

[0045] S2, the concentrated water in the concentrated chamber 10 enters the black liquor waste water tank 2 through the concentrated water inlet pipe 17 to obtain a mixture of concentrated water and black liquor raw water, which is circulated back through the pump. When the sodium sulfate content in the mixture of concentrated water in the black liquor waste water tank 2 and black liquor raw water reaches 10%, it enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the fresh water in the dilute chamber 9 enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25;

[0046] S3, the mixture of concentrated water and black liquor raw water in the black liquor waste water tank 2 enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the mixture of concentrated water and black liquor raw water in the concentrated water tank 3 enters the evaporation device 5 through the concentrated water outlet pipe 19; the fresh water in the fresh water tank 4 enters the alkali recovery device 22 through the fresh water outlet pipe 21 for alkali recovery treatment.

[0047] Embodiment 12 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate, separate, and remove chloride ions in the black liquor wastewater, thereby avoiding corrosion problems caused by chloride ion enrichment in the subsequent alkali recovery process; an anode 6, two sets of electrode plates 7, and a cathode 8 are sequentially arranged in the electrodialysis device 1, and the two sets of electrode plates 7 and a cathode 8 are sequentially arranged in the electrodialysis device 1, wherein ... A plurality of dilute chambers 9 are arranged between the plates 7, and the plurality of dilute chambers 9 are arranged at equal intervals between the two groups of plates 7. A concentrated chamber 10 is arranged between two adjacent dilute chambers 9, and the dilute chamber 9 includes a monovalent anion membrane 11 and a cation membrane 12, wherein the monovalent anion membrane 11 is arranged on a side close to the anode 6, and the cation membrane 12 is arranged on a side close to the cathode 8; an anode liquid circulation area 13 is arranged between the plate 7 and the monovalent anion membrane 11, and a cathode liquid circulation area 14 is arranged between the plate 7 and the cation membrane 12; a first wastewater outlet pipe 15, a second wastewater outlet pipe 16 and a concentrated liquid inlet pipe 17 are arranged on the black liquor wastewater tank 2, one end of the first wastewater outlet pipe 15 is connected to the outlet of the black liquor wastewater tank 2, and the first wastewater outlet pipe 16 is connected to the outlet of the black liquor wastewater tank 2. The other end of the water outlet pipe 15 is connected to the water inlet of the dilute chamber 9, one end of the second wastewater outlet pipe 16 is connected to the first wastewater outlet pipe 15, the other end of the second wastewater outlet pipe 16 is connected to the water inlet of the dilute chamber 9, one end of the concentrate inlet pipe 17 is connected to the water outlet of the concentrate chamber 10, and the other end of the concentrate inlet pipe 17 is connected to the water inlet of the black liquor wastewater tank 2; the number of wastewater outlet pipes changes according to the number of dilute chambers; the concentrate tank 3 is provided with a concentrate inlet pipe 18 and a concentrate outlet pipe 19, one end of the concentrate inlet pipe 18 is connected to the water outlet of the black liquor wastewater tank 2, the other end of the concentrate inlet pipe 18 is connected to the water inlet of the concentrate tank 3, and the concentrate outlet pipe 19 One end of the concentrated water outlet pipe 19 is connected to the water outlet of the concentrated water tank 3, and the other end of the concentrated water outlet pipe 19 is connected to the water inlet of the evaporation device 5; the fresh water tank 4 is provided with a first fresh water inlet pipe 19, a second fresh water inlet pipe 20 and a fresh water outlet pipe 21, one end of the first fresh water inlet pipe 19 is connected to the water inlet of the fresh water tank 4, the other end of the first fresh water inlet pipe 19 is connected to the water outlet of the dilute chamber 9, one end of the second fresh water inlet pipe 20 is connected to the first fresh water inlet pipe 19, the other end of the second fresh water inlet pipe 20 is connected to the water outlet of the dilute chamber 9, one end of the fresh water outlet pipe 21 is connected to the water outlet of the fresh water tank 4, and the other end of the fresh water outlet pipe 21 is connected to the alkali recovery device 22;The fresh water pipe 20 is provided with a clean water tank 23, and the clean water tank 23 is provided with a first clean water pipe 24 and a second clean water pipe 25, one end of the first clean water pipe 24 is connected to the water outlet of the fresh water chamber 9, and the other end of the first clean water pipe 24 is connected to the clean water tank 23, one end of the second clean water pipe 25 is connected to the water outlet of the fresh water chamber 9, and the other end of the second clean water pipe 25 is connected to the first clean water pipe 24; the number of clean water pipes varies according to the number of fresh water chambers 9; the fresh water chambers 9 are provided with at least two.;

[0048] A method for treating black liquor wastewater by separating anions comprises the following steps:

[0049] S1, the electrodialysis device 1 starts to operate, the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the first wastewater outlet pipe 15, and the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the second wastewater outlet pipe 16. After passing through the electrodialysis device 1, the fresh water enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25, and circulates back through the pump. When the sodium sulfate content in the fresh water in the clean water tank 23 reaches 1%, it enters the fresh water tank 4 through the fresh water pipe 20, and the clean water in the clean water tank 23 enters the concentration chamber 10 through the pipeline. Under the action of the DC electric field of the electrodialysis device 1, the cations in the raw black liquor water migrate to the cathode in the dilute chamber 9, the monovalent anions in the raw black liquor water migrate into the concentration chamber 10 to form concentrated water, and the divalent anions in the raw black liquor water remain in the dilute chamber 9 to form fresh water;

[0050] S2, the concentrated water in the concentrated chamber 10 enters the black liquor waste water tank 2 through the concentrated water inlet pipe 17, and a mixture of concentrated water and black liquor raw water is obtained, which is circulated and refluxed by a pump. When the sodium sulfate content in the mixture of concentrated water in the black liquor waste water tank 2 and black liquor raw water reaches 12.5%, it enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the fresh water in the dilute chamber 9 enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25;

[0051] S3, the mixture of concentrated water and black liquor raw water in the black liquor waste water tank 2 enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the mixture of concentrated water and black liquor raw water in the concentrated water tank 3 enters the evaporation device 5 through the concentrated water outlet pipe 19; the fresh water in the fresh water tank 4 enters the alkali recovery device 22 through the fresh water outlet pipe 21 for alkali recovery treatment.

[0052] Embodiment 13 of the present invention: A system for treating black liquor wastewater by separating anions, comprising an electrodialysis device 1, a black liquor wastewater tank 2, a concentrated water tank 3, and a fresh water tank 4, wherein the electrodialysis device 1 is connected to the black liquor wastewater tank 2 through a pipeline, the black liquor wastewater tank 2 is connected to the concentrated water tank 3 through a pipeline, the electrodialysis device 1 is connected to the fresh water tank 4 through a pipeline, an evaporation device 5 is provided on one side of the concentrated water tank 3, and the concentrated water tank 3 is connected to the evaporation device 5 through a pipeline; a monovalent anion membrane is used to migrate and separate the chloride ions in the black liquor wastewater and remove them, thereby avoiding corrosion problems caused by chloride ion enrichment in the subsequent alkali recovery process; an anode 6, two sets of electrode plates 7, and a cathode 8 are sequentially arranged in the electrodialysis device 1, and the two sets of electrode plates 7 and a cathode 8 are sequentially arranged in the electrodialysis device 1, wherein ... A plurality of dilute chambers 9 are arranged between the plates 7, and the plurality of dilute chambers 9 are arranged at equal intervals between the two groups of plates 7. A concentrated chamber 10 is arranged between two adjacent dilute chambers 9, and the dilute chamber 9 includes a monovalent anion membrane 11 and a cation membrane 12, wherein the monovalent anion membrane 11 is arranged on a side close to the anode 6, and the cation membrane 12 is arranged on a side close to the cathode 8; an anode liquid circulation area 13 is arranged between the plate 7 and the monovalent anion membrane 11, and a cathode liquid circulation area 14 is arranged between the plate 7 and the cation membrane 12; a first wastewater outlet pipe 15, a second wastewater outlet pipe 16 and a concentrated liquid inlet pipe 17 are arranged on the black liquor wastewater tank 2, one end of the first wastewater outlet pipe 15 is connected to the outlet of the black liquor wastewater tank 2, and the first wastewater outlet pipe 16 is connected to the outlet of the black liquor wastewater tank 2. The other end of the water outlet pipe 15 is connected to the water inlet of the dilute chamber 9, one end of the second wastewater outlet pipe 16 is connected to the first wastewater outlet pipe 15, the other end of the second wastewater outlet pipe 16 is connected to the water inlet of the dilute chamber 9, one end of the concentrate inlet pipe 17 is connected to the water outlet of the concentrate chamber 10, and the other end of the concentrate inlet pipe 17 is connected to the water inlet of the black liquor wastewater tank 2; the number of wastewater outlet pipes changes according to the number of dilute chambers; the concentrate tank 3 is provided with a concentrate inlet pipe 18 and a concentrate outlet pipe 19, one end of the concentrate inlet pipe 18 is connected to the water outlet of the black liquor wastewater tank 2, the other end of the concentrate inlet pipe 18 is connected to the water inlet of the concentrate tank 3, and the concentrate outlet pipe 19 One end of the concentrated water outlet pipe 19 is connected to the water outlet of the concentrated water tank 3, and the other end of the concentrated water outlet pipe 19 is connected to the water inlet of the evaporation device 5; the fresh water tank 4 is provided with a first fresh water inlet pipe 19, a second fresh water inlet pipe 20 and a fresh water outlet pipe 21, one end of the first fresh water inlet pipe 19 is connected to the water inlet of the fresh water tank 4, the other end of the first fresh water inlet pipe 19 is connected to the water outlet of the dilute chamber 9, one end of the second fresh water inlet pipe 20 is connected to the first fresh water inlet pipe 19, the other end of the second fresh water inlet pipe 20 is connected to the water outlet of the dilute chamber 9, one end of the fresh water outlet pipe 21 is connected to the water outlet of the fresh water tank 4, and the other end of the fresh water outlet pipe 21 is connected to the alkali recovery device 22;The fresh water pipe 20 is provided with a clean water tank 23, and the clean water tank 23 is provided with a first clean water pipe 24 and a second clean water pipe 25, one end of the first clean water pipe 24 is connected to the water outlet of the fresh water chamber 9, and the other end of the first clean water pipe 24 is connected to the clean water tank 23, one end of the second clean water pipe 25 is connected to the water outlet of the fresh water chamber 9, and the other end of the second clean water pipe 25 is connected to the first clean water pipe 24; the number of clean water pipes varies according to the number of fresh water chambers 9; the fresh water chambers 9 are provided with at least two.;

[0053] A method for treating black liquor wastewater by separating anions comprises the following steps:

[0054] S1, the electrodialysis device 1 starts to operate, the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the first wastewater outlet pipe 15, and the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 through the second wastewater outlet pipe 16. After passing through the electrodialysis device 1, the fresh water enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25, and is circulated back through the pump. When the sodium sulfate content in the fresh water in the clean water tank 23 reaches 1.2%, it enters the fresh water tank 4 through the fresh water pipe 20, and the clean water in the clean water tank 23 enters the concentration chamber 10 through the pipeline. Under the action of the DC electric field of the electrodialysis device 1, the cations in the raw black liquor water migrate to the cathode in the dilute chamber 9, the monovalent anions in the raw black liquor water migrate into the concentration chamber 10 to form concentrated water, and the divalent anions in the raw black liquor water remain in the dilute chamber 9 to form fresh water;

[0055] S2, the concentrated water in the concentrated chamber 10 enters the black liquor waste water tank 2 through the concentrated water inlet pipe 17, and a mixture of concentrated water and black liquor raw water is obtained, which is circulated back through the pump. When the sodium sulfate content in the mixture of concentrated water in the black liquor waste water tank 2 and black liquor raw water reaches 15%, it enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the fresh water in the dilute chamber 9 enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25;

[0056] S3, the mixture of concentrated water and black liquor raw water in the black liquor waste water tank 2 enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the mixture of concentrated water and black liquor raw water in the concentrated water tank 3 enters the evaporation device 5 through the concentrated water outlet pipe 19; the fresh water in the fresh water tank 4 enters the alkali recovery device 22 through the fresh water outlet pipe 21 for alkali recovery treatment.

[0057] The working principle of an embodiment of the present invention is as follows: when the present invention is working, the electrodialysis device 1 starts to operate, the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 via the first wastewater outlet pipe 15, and the raw black liquor water in the black liquor wastewater tank 2 enters the dilute chamber 9 via the second wastewater outlet pipe 16. After passing through the electrodialysis device 1, the fresh water enters the clean water tank 23 via the first clean water pipe 24 and the second clean water pipe 25, and circulates back through the pump. When the sodium sulfate content in the fresh water in the clean water tank 23 reaches 0.8-1.2%, it enters the fresh water tank 4 via the fresh water pipe 20, and the clean water in the clean water tank 23 enters the concentration chamber 10 via the pipeline. Under the action of the DC electric field of the electrodialysis device 1, the cations in the raw black liquor water migrate to the cathode in the dilute chamber 9, and the monovalent anions in the raw black liquor water migrate into the concentration chamber 10 to form concentrated water. The divalent anions of the raw black liquor water are retained in the dilute chamber 9 to form fresh water; the concentrated water in the concentrated chamber 10 enters the black liquor wastewater tank 2 through the concentrated liquid inlet pipe 17 to obtain a mixture of concentrated water and black liquor raw water, which is circulated back through the pump. When the sodium sulfate content in the mixture of concentrated water and black liquor raw water in the black liquor wastewater tank 2 reaches 10%-15%, it enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the fresh water in the dilute chamber 9 enters the clean water tank 23 through the first clean water pipe 24 and the second clean water pipe 25; the mixture of concentrated water and black liquor raw water in the black liquor wastewater tank 2 enters the concentrated water tank 3 through the concentrated water inlet pipe 18, and the mixture of concentrated water and black liquor raw water in the concentrated water tank 3 enters the evaporation device 5 through the concentrated water outlet pipe 19; the fresh water in the fresh water tank 4 enters the alkali recovery device 22 through the fresh water outlet pipe 21 for alkali recovery treatment.

Claims

1. A method for treating black liquor wastewater by separating anions, characterized in that: A device for treating black liquor wastewater by separating anions is used, comprising an electrodialysis device (1), a black liquor wastewater tank (2), a concentrated water tank (3), and a fresh water tank (4); the electrodialysis device (1) is connected to the black liquor wastewater tank (2) via a pipeline, the black liquor wastewater tank (2) is connected to the concentrated water tank (3) via a pipeline, the electrodialysis device (1) is connected to the fresh water tank (4) via a pipeline, an evaporation device (5) is provided on one side of the concentrated water tank (3), and the concentrated water tank (3) is connected to the evaporation device (5) via a pipeline; a first fresh water chamber, a concentrated water chamber (10), and a second fresh water chamber are sequentially provided in the electrodialysis device (1); The black liquor wastewater tank (2) is provided with a first wastewater outlet pipe (15), a second wastewater outlet pipe (16) and a concentrated liquid inlet pipe (17); one end of the first wastewater outlet pipe (15) is connected to the outlet of the black liquor wastewater tank (2); the other end of the first wastewater outlet pipe (15) is connected to the inlet of the first dilute chamber; one end of the second wastewater outlet pipe (16) is connected to the first wastewater outlet pipe (15); the other end of the second wastewater outlet pipe (16) is connected to the inlet of the second dilute chamber; one end of the concentrated liquid inlet pipe (17) is connected to the outlet of the concentrated chamber (10); the other end of the concentrated liquid inlet pipe (17) is connected to the inlet of the black liquor wastewater tank (2); The concentrated water tank (3) is provided with a concentrated water inlet pipe (18) and a concentrated water outlet pipe (19), one end of the concentrated water inlet pipe (18) is connected to the water outlet of the black liquor wastewater tank (2), the other end of the concentrated water inlet pipe (18) is connected to the water inlet of the concentrated water tank (3), one end of the concentrated water outlet pipe (19) is connected to the water outlet of the concentrated water tank (3), and the other end of the concentrated water outlet pipe (19) is connected to the water inlet of the evaporation device (5); The fresh water tank (4) is provided with a fresh water pipe (20) and a fresh water outlet pipe (21); the fresh water pipe (20) is provided with a clean water tank (23); one end of the fresh water pipe (20) is connected to the water inlet of the fresh water tank (4); the other end of the fresh water pipe (20) is connected to the water outlet of the clean water tank (23); one end of the fresh water outlet pipe (21) is connected to the water outlet of the fresh water tank (4); the other end of the fresh water outlet pipe (21) is connected to the water outlet of the fresh water tank (4); One end is connected to an alkali recovery device (22); a first clean water pipe (24) and a second clean water pipe (25) are arranged on the clean water tank (23); one end of the first clean water pipe (24) is connected to the water outlet of the second dilute chamber, the other end of the first clean water pipe (24) is connected to the clean water tank (23), one end of the second clean water pipe (25) is connected to the water outlet of the first dilute chamber, and the other end of the second clean water pipe (25) is connected to the first clean water pipe (24); The method comprises the following steps: S1, the electrodialysis device (1) starts to operate, the raw black liquor water in the black liquor wastewater tank (2) enters the first dilute chamber through the first wastewater outlet pipe (15), the raw black liquor water in the black liquor wastewater tank (2) enters the second dilute chamber through the second wastewater outlet pipe (16), after passing through the electrodialysis device (1), the fresh water enters the clean water tank (23) through the first clean water pipe (24) and the second clean water pipe (25), and is circulated back through the pump. When the sodium sulfate content in the fresh water in the clean water tank (23) reaches 0.8-1.2%, it enters the fresh water tank (4) through the fresh water pipe (20), and the clean water in the clean water tank (23) enters the concentration chamber (10) through the pipeline. Under the action of the direct current electric field of the electrodialysis device (1), the cations in the raw black liquor water migrate to the cathode in the first dilute chamber and the second dilute chamber, the monovalent anions in the raw black liquor water migrate into the concentration chamber (10) to form concentrated water, and the divalent anions in the raw black liquor water remain in the first dilute chamber and the second dilute chamber to form fresh water; S2, the concentrated water in the concentrated chamber (10) enters the black liquor waste water tank (2) through the concentrated water inlet pipe (17), and a mixture of concentrated water and black liquor raw water is obtained, which is circulated back through a pump. When the sodium sulfate content in the mixture of concentrated water in the black liquor waste water tank (2) and black liquor raw water reaches 10%-15%, it enters the concentrated water tank (3) through the concentrated water inlet pipe (18), and the fresh water in the second dilute chamber and the first dilute chamber enters the clean water tank (23) through the first clean water pipe (24) and the second clean water pipe (25); S3, the mixed liquid of the concentrated water in the black liquor waste water tank (2) and the black liquor raw water enters the concentrated water tank (3) through the concentrated water inlet pipe (18), and the mixed liquid of the concentrated water in the concentrated water tank (3) and the black liquor raw water enters the evaporation device (5) through the concentrated water outlet pipe (19); the fresh water in the fresh water tank (4) enters the alkali recovery device (22) through the fresh water outlet pipe (21) for alkali recovery treatment.

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