Hardness and silicon removal system for high-salt concentrated water
By using polymeric ferric chloride, calcium carbide slag, sodium hydroxide and other agents in high-salt concentrated water treatment systems, and combining polyacrylamide and magnesium oxide agents to remove silicon, the problems of high-salt concentrated water hardness and high silicon content are solved, and the stable operation and environmentally friendly treatment effect of the secondary membrane system are achieved.
Patent Information
- Application Number
- CN202421967085.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-14
- Publication Date
- 2025-09-05
- Estimated Expiration
- 2034-08-14
AI Technical Summary
The prior art is difficult to effectively reduce the hardness and silicon content of high-salt concentrated water of primary membranes, resulting in the inability to operate normally in the subsequent secondary membrane system, especially the stability of the nanofiltration system is affected.
Polyferrous ferric chloride, calcium carbide slag, sodium hydroxide and other agents are used to remove hardness in the reaction tank, and silicon is removed in the nanofiltration high-density pool through polyacrylamide and magnesium oxide agents, combined with equipment such as inclined plate precipitation tank and multi-media filter to form a high-salt and concentrated water hardness and silicon removal system.
It effectively reduces the hardness and silicon content of the primary high-salt concentrated water, so that it meets the water inlet conditions of the secondary membrane of inorganic water treatment, ensures the stable operation of the nanofiltration system, and reduces the use of chemical agents and environmental pollution.
Smart Images
Figure CN223304273U_ABST
Abstract
Description
Technical Field
[0001] The utility model belongs to the technical field of wastewater treatment, and relates to a high-salt concentrated water hardness and silicon removal system, which is used for removing hardness and silicon from high-salt concentrated water using a single membrane in inorganic wastewater treatment. Background Art
[0002] In the dual-membrane process for treating inorganic wastewater, impurities are typically removed from the inorganic wastewater, followed by two-stage membrane concentration and nanofiltration. However, the primary brine produced by the first membrane concentration step has a 2-3 times higher hardness and alkalinity. Without desalination to reduce the hardness of the primary brine, subsequent treatment processes will not function properly.
[0003] Currently, chemical and ion exchange methods are commonly used to reduce the hardness of high-concentration saline wastewater. The chemical method involves adding chemicals to cause calcium and magnesium ions to form insoluble salts, which are then precipitated or flocculated for removal. However, the use of chemicals increases the hardness and volume of high-salinity wastewater, requiring a relatively large amount of chemicals for chemical treatment, resulting in high costs. Furthermore, chemical methods often produce large amounts of sludge, causing secondary environmental pollution. While ion exchange can effectively remove calcium and magnesium ions, it can also lead to issues with resin and carrier regeneration during use. Regeneration agents are generally expensive and can cause secondary environmental pollution, making them unsuitable for softening high-hardness wastewater.
[0004] The patent document with announcement number CN218951194U discloses a zero-discharge treatment system for high-salt wastewater, including: a sedimentation tank, an activated carbon adsorption tank, a biochemical degradation tank, an ultrafiltration membrane device, a nanofiltration membrane device, a reverse osmosis device and a concentrate evaporation device; by allowing the high-salt wastewater to stand, using activated carbon to preliminarily adsorb various pollutants in the high-salt wastewater, and then using anaerobic bacteria, facultative anaerobic bacteria and aerobic bacteria to biochemically degrade the high-salt wastewater, most of the pollutants in the high-salt wastewater are removed, and the high-salt wastewater is then precision-filtered in the ultrafiltration membrane device, the nanofiltration membrane device, and the reverse osmosis device in sequence, and the obtained reclaimed water can be recycled, and the obtained concentrate can be evaporated using an evaporation device, and the obtained crystalline salt is subjected to source treatment.
[0005] However, since the hardness and alkalinity of the primary high-salt concentrate produced by the primary membrane concentration increase by 2-3 times, the hardness of the concentrate is still high after treatment using the existing method, resulting in the secondary membrane system being unable to operate normally; in addition, since the primary high-salt concentrate contains silicon, the existing desalination system cannot remove the silicon well, resulting in the silicon content in the secondary membrane concentrate increasing by 5-6 times after the primary high-salt concentrate undergoes secondary membrane treatment, affecting the stable operation of the subsequent nanofiltration system. Utility Model Content
[0006] Aiming at the technical problems of high hardness and high silicon content in the existing single-membrane high-salt concentrated water treatment, the utility model provides a high-salt concentrated water hardness and silicon removal system.
[0007] The utility model adds corresponding reagents to the primary high-salt concentrated water through the first dosing pipe and the fourth dosing pipe to remove hardness and silicon, which can effectively reduce the hardness and silicon content of the primary concentrated water, so that the primary high-salt concentrated water meets the water inlet conditions of the secondary membrane of inorganic water treatment, and ensures the stable operation of the subsequent nanofiltration system.
[0008] In order to achieve the above purpose, the technical solution adopted by the utility model is:
[0009] A high-salt concentrated water hardness and silicon removal system comprises a reaction tank, a secondary reverse osmosis device and a nanofiltration high-density tank connected in sequence; a first dosing pipe is arranged outside the reaction tank, the first dosing pipe is connected to the interior of the reaction tank, and a fourth dosing pipe is arranged outside the nanofiltration high-density tank, the fourth dosing pipe is connected to the interior of the nanofiltration high-density tank.
[0010] It is further defined that the first dosing pipe includes a polyferric chloride agent pipe, a carbide slag pipe and a sodium hydroxide agent pipe respectively connected to the interior of the reaction tank.
[0011] It is further defined that the fourth dosing tube includes a polyacrylamide dosing tube and a magnesium oxide dosing tube, and the polyacrylamide dosing tube and the magnesium oxide dosing tube are both connected to the interior of the nanofiltration high-density tank.
[0012] It is further defined that the reaction tank includes a first reaction tank and a second reaction tank connected to the first reaction tank; the second reaction tank is connected to a secondary reverse osmosis device; the first dosing pipe is located outside the first reaction tank and connected to the inside of the first reaction tank.
[0013] It is further defined that the reaction tank further includes a second dosing pipe disposed outside the second reaction tank and communicating with the interior of the second reaction tank.
[0014] It is further defined that the second dosing tube includes a polyacrylamide dosing tube and a sodium carbonate dosing tube respectively placed outside the second reaction tank, and the polyacrylamide dosing tube and the sodium carbonate dosing tube are both connected to the interior of the second reaction tank.
[0015] It is further defined that a third dosing pipe is provided outside the nanofiltration high-density tank, and the third dosing pipe includes a polyferric chloride agent pipe, a sodium hypochlorite agent pipe and a sodium hydroxide agent pipe, which are respectively located outside the nanofiltration high-density tank and are connected to the inside of the nanofiltration high-density tank.
[0016] It is further defined that the high-salt concentrated water hardness and silicon removal system also includes an inclined plate sedimentation tank placed between the second reaction tank and the secondary reverse osmosis device.
[0017] It is further defined that the high-salt concentrated water hardness and silicon removal system also includes a multi-media filter placed between the inclined plate sedimentation tank and the secondary reverse osmosis device.
[0018] It is further defined that the high-salt concentrated water hardness and silicon removal system also includes an ultrafiltration device placed between the multi-media filter and the secondary reverse osmosis device.
[0019] The beneficial effects of the utility model are:
[0020] 1. The utility model includes a reaction pool, a secondary reverse osmosis device and a nanofiltration high-density pool which are connected in sequence; a first dosing pipe is arranged outside the reaction pool and is connected to the inside of the reaction pool, and a corresponding agent is added to the primary high-salt concentrated water through the first dosing pipe to remove hardness; a fourth dosing pipe is arranged outside the nanofiltration high-density pool and is connected to the inside of the nanofiltration high-density pool, and a corresponding agent is added to the wastewater through the fourth dosing pipe to remove silicon, which can well reduce the hardness and silicon content of the primary concentrated water, so that the primary high-salt concentrated water meets the water inlet conditions of the secondary membrane of inorganic water treatment, thereby ensuring the stable operation of the subsequent nanofiltration system.
[0021] 2. In the present invention, by setting a polyferric chloride agent pipe, a carbide slag pipe and a sodium hydroxide agent pipe, corresponding agents are added to the primary concentrated water to remove hardness, and the hardness removal effect can meet the secondary membrane water inlet conditions at a higher pH.
[0022] 3. In the present invention, corresponding reagents are added to the wastewater through polyacrylamide reagent tubes and magnesium oxide reagent tubes to remove silicon, which has a good removal effect on silicon in the system at a higher pH, making the subsequent nanofiltration device operate stably.
[0023] 4. In the present invention, a second dosing pipe is provided outside the second reaction tank. The second dosing pipe includes a polyacrylamide agent pipe and a sodium carbonate agent pipe. The second dosing pipe is used as a backup hardness removal facility to improve the hardness removal effect of the primary concentrated water. It can be adjusted in time according to the water quality during the treatment.
[0024] 5. In the present invention, the reaction tank and the inclined plate sedimentation tank are designed separately to replace the ordinary high-density tank, which is convenient for daily maintenance and tank cleaning. BRIEF DESCRIPTION OF THE DRAWINGS
[0025] Figure 1 This is a schematic diagram of a high-salt concentrated water hardness and silicon removal system;
[0026] in:
[0027] 1—reaction tank; 110—first reaction tank; 120—second reaction tank; 130—first dosing pipe; 140—second dosing pipe; 2—inclined plate sedimentation tank; 3—multi-media filter; 4—ultrafilter; 5—secondary reverse osmosis device; 6—nanofiltration high-density tank; 601—third dosing pipe; 602—fourth dosing pipe; 7—nanofiltration device. DETAILED DESCRIPTION
[0028] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.
[0029] The preferred embodiments of the present invention are described in detail below in conjunction with the accompanying drawings so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby making a clearer and more precise definition of the protection scope of the present invention.
[0030] Example 1
[0031] See also Figure 1 A high-salt concentrated water hardness and silicon removal system includes a reaction tank 1, a secondary reverse osmosis device 5 and a nanofiltration high-density tank 6 connected in sequence; a first dosing pipe 130 is arranged outside the reaction tank 1, and the first dosing pipe 130 is connected to the inside of the reaction tank 1; a fourth dosing pipe 602 is arranged outside the nanofiltration high-density tank 6, and the fourth dosing pipe 602 is connected to the inside of the nanofiltration high-density tank 6.
[0032] In this embodiment, the first dosing pipe 130 includes a polyferric chloride agent pipe, a carbide slag pipe, and a sodium hydroxide agent pipe, each of which is connected to the interior of the reaction tank 1. By providing the polyferric chloride agent pipe, the carbide slag pipe, and the sodium hydroxide agent pipe, the corresponding agents are added to the primary concentrated water (i.e., the primary high-salt concentrated water) to remove hardness. At a higher pH, the hardness removal effect can meet the secondary membrane water inlet conditions.
[0033] In this embodiment, the fourth dosing pipe 602 includes a polyacrylamide reagent pipe and a magnesium oxide reagent pipe, both of which are connected to the interior of the nanofiltration high-density tank 6. The polyacrylamide reagent pipe and the magnesium oxide reagent pipe are used to add corresponding reagents to the primary concentrated water (i.e., the primary high-salt concentrated water) to remove silicon. At a higher pH, the silicon in the system is effectively removed, making the subsequent nanofiltration device operate stably.
[0034] In this embodiment, the reaction tank 1 includes a first reaction tank 110 and a second reaction tank 120 connected to the first reaction tank 110; the second reaction tank 120 is connected to the secondary reverse osmosis device 5; the first dosing pipe 130 is located outside the first reaction tank 110 and connected to the inside of the first reaction tank 110.
[0035] In this embodiment, the reaction tank 1 also includes a second dosing pipe 140 placed outside the second reaction tank 120 and connected to the interior of the second reaction tank 120. Using the second dosing pipe 140 as a backup hardness removal facility can further improve the hardness removal effect of the primary concentrated water (i.e., the primary high-salt concentrated water). During the treatment, the amount of the added agent can be adjusted in time according to the water quality.
[0036] In this embodiment, the second dosing tube 140 includes a polyacrylamide dosing tube and a sodium carbonate dosing tube respectively placed outside the second reaction tank 120 , and both the polyacrylamide dosing tube and the sodium carbonate dosing tube are connected to the interior of the second reaction tank 120 .
[0037] In this embodiment, a third dosing pipe 601 is set outside the nanofiltration high-density tank 6, and the third dosing pipe 601 includes a polyferric chloride agent pipe, a sodium hypochlorite agent pipe and a sodium hydroxide agent pipe, which are respectively located outside the nanofiltration high-density tank 6 and are connected to the inside of the nanofiltration high-density tank 6.
[0038] Example 2
[0039] On the basis of Example 1, the high-salt concentrated water hardness and silicon removal system provided in this embodiment further includes an inclined plate sedimentation tank 2 disposed between the second reaction tank 120 and the secondary reverse osmosis device 5 .
[0040] The purpose of providing the inclined plate sedimentation tank 2 in this embodiment is to remove the precipitated flocs produced by adding chemicals into the reaction tank 1 .
[0041] Furthermore, the high-salt concentrated water hardness and silicon removal system provided in this embodiment further includes a multi-media filter 3 placed between the inclined plate sedimentation tank 2 and the secondary reverse osmosis device 5 .
[0042] In this embodiment, the purpose of the multi-media filter 3 is to further remove a small amount of suspended solids in the supernatant of the inclined plate sedimentation tank to meet the ultrafiltration requirement and the turbidity is less than 3NTU.
[0043] Furthermore, the high-salt concentrated water hardness and silicon removal system provided in this embodiment further includes an ultrafilter 4 placed between the multi-media filter 3 and the secondary reverse osmosis device 5 .
[0044] In this embodiment, the purpose of the ultrafilter 4 is to further remove suspended matter, colloids, macromolecular substances and part of COD in the water. The turbidity of the produced water is less than 0.3 NTU and the SDI is less than 3, which meets the secondary reverse osmosis water inlet requirements.
[0045] The high-salt concentrated water hardness and silicon removal system provided by the present invention has the following main working process: in the treatment of inorganic wastewater, the high-salt concentrated water (water quality conditions: TDS is 5000mg / L-7000mg / L, hardness is 500mg / L-700mg / L, alkalinity is 400mg / L-600mg / L, silica content is 20mg / L-30mg / L) after the first membrane treatment enters the first reaction tank 110, and the polyferric chloride agent is added to the first reaction tank 110 through the first dosing pipe 130. Carbide slag and sodium hydroxide are used to remove calcium, magnesium and other substances in the primary high-salt concentrated water, thereby reducing the hardness of the primary high-salt concentrated water. The primary high-salt concentrated water after hardness removal continues to enter the second reaction tank 120. After the water quality is tested, if the hardness meets the conditions for secondary membrane concentration (conditions: hardness is 80mg / L-120mg / L, alkalinity is 100mg / L-200mg / L, and silica content is less than 20mg / L), the primary high-salt concentrated water after hardness removal enters the inclined plate sedimentation tank 2. If it is unqualified, the secondary membrane concentration water is added through the second dosing pipe 140. The corresponding reagents are further de-hardened until they meet the conditions for secondary membrane concentration and then enter the inclined plate sedimentation tank 2; after sedimentation and separation in the inclined plate sedimentation tank 2, supernatant and sediment are obtained, the sediment is collected and centrally processed, and the supernatant passes through the multi-media filter 3 and the ultrafilter 4 and enters the secondary reverse osmosis device 5 to complete the secondary membrane concentration treatment to obtain secondary concentrated water and clear water. The water quality of the clear water meets the requirements and can be reused in the production system; the secondary concentrated water (water quality conditions: total dissolved solids TDS is 20000mg / L-28000mg / L, hardness is 300mg / L) L-480mg / L, alkalinity is 400mg / L-800mg / L, silica content is 80mg / L-120mg / L) enters the nanofiltration high-density tank 6, and polyacrylamide agent and magnesium oxide are added to the secondary concentrated water through the fourth dosing pipe 602 to remove silicon. The secondary concentrated water after silicon removal (water quality conditions: hardness is 100mg / L-200mg / L, alkalinity is 100mg / L-200mg / L, silica content is less than 30mg / L) enters the subsequent nanofiltration device 7 for subsequent treatment.
[0046] In summary, the utility model uses calcium carbide slag for hardness removal. At a higher pH, the hardness removal effect meets the secondary membrane water inlet conditions. In order to ensure the hardness removal effect, sodium carbonate is selected as a backup hardness removal facility. It can be adjusted in time according to the water quality to ensure that the pH of the concentrated water after hardness removal is neutral before entering the secondary reverse osmosis device 5. Magnesium oxide is used to remove silicon in the secondary concentrated water at a higher pH to ensure the stable operation of the nanofiltration device.
[0047] The above description is merely an embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made by using the contents of the description and drawings of the present invention, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A high-salt concentrated water hardness and silicon removal system, characterized in that: The invention comprises a reaction pool (1), a secondary reverse osmosis device (5) and a nanofiltration high-density pool (6) which are connected in sequence; a first dosing pipe (130) is arranged outside the reaction pool (1), and the first dosing pipe (130) is connected to the inside of the reaction pool (1); a fourth dosing pipe (602) is arranged outside the nanofiltration high-density pool (6), and the fourth dosing pipe (602) is connected to the inside of the nanofiltration high-density pool (6).
2. The high-salt concentrated water hardness and silicon removal system according to claim 1 is characterized in that: The first dosing pipe (130) comprises a polyferric chloride dosing pipe, a carbide slag pipe and a sodium hydroxide dosing pipe respectively connected to the interior of the reaction tank (1).
3. The high-salt concentrated water hardness and silicon removal system according to claim 2 is characterized in that: The fourth dosing tube (602) includes a polyacrylamide dosing tube and a magnesium oxide dosing tube, and both the polyacrylamide dosing tube and the magnesium oxide dosing tube are connected to the interior of the nanofiltration high-density tank (6).
4. The high-salt concentrated water hardness and silicon removal system according to any one of claims 1 to 3, characterized in that: The reaction tank (1) comprises a first reaction tank (110) and a second reaction tank (120) connected to the first reaction tank (110); the second reaction tank (120) is connected to the secondary reverse osmosis device (5); and the first dosing pipe (130) is located outside the first reaction tank (110) and is connected to the inside of the first reaction tank (110).
5. The high-salt concentrated water hardness and silicon removal system according to claim 4 is characterized in that: The reaction tank (1) further comprises a second dosing pipe (140) disposed outside the second reaction tank (120) and communicating with the interior of the second reaction tank (120).
6. The high-salt concentrated water hardness and silicon removal system according to claim 5, characterized in that: The second dosing pipe (140) includes a polyacrylamide dosing pipe and a sodium carbonate dosing pipe respectively placed outside the second reaction tank (120), and the polyacrylamide dosing pipe and the sodium carbonate dosing pipe are both connected to the interior of the second reaction tank (120).
7. The high-salt concentrated water hardness and silicon removal system according to claim 6, characterized in that: A third dosing pipe (601) is provided outside the nanofiltration high-density tank (6), and the third dosing pipe (601) includes a polyferric chloride drug pipe, a sodium hypochlorite drug pipe, and a sodium hydroxide drug pipe, which are respectively located outside the nanofiltration high-density tank (6) and are all connected to the inside of the nanofiltration high-density tank (6).
8. The high-salt concentrated water hardness and silicon removal system according to claim 7, characterized in that: The high-salt concentrated water hardness and silicon removal system further comprises an inclined plate sedimentation tank (2) disposed between the second reaction tank (120) and the secondary reverse osmosis device (5).
9. The high-salt concentrated water hardness and silicon removal system according to claim 8, characterized in that: The high-salt concentrated water hardness and silicon removal system further comprises a multi-media filter (3) disposed between the inclined plate sedimentation tank (2) and the secondary reverse osmosis device (5).
10. The high-salt concentrated water hardness and silicon removal system according to claim 9, characterized in that: The high-salt concentrated water hardness and silicon removal system further comprises an ultrafilter (4) disposed between the multi-media filter (3) and the secondary reverse osmosis device (5).