A high-hardness groundwater resource treatment system suitable for low ammonia-nitrogen pollution

Abstract

The utility model discloses a kind of high hardness groundwater resource processing system suitable for low ammonia nitrogen pollution, including filtration system, ion exchange system, calcium ion removal system, nanofiltration system and recovery system, wherein: ion exchange system is communicated with the outlet of filtration system, including series' softening ion exchanger and strong acid type ion exchanger, and first regenerant storage tank, second regenerant storage tank communicated with both respectively;Softening ion exchanger and strong acid type ion exchanger are respectively provided with regenerative liquid outlet;Calcium ion removal system is communicated with the regenerative liquid outlet of softening ion exchanger, nanofiltration system is communicated with the liquid phase outlet of sedimentation separation tank, including nanofiltration membrane assembly;The water outlet of nanofiltration membrane assembly is communicated with first regenerant storage tank;The concentrated liquid outlet of nanofiltration membrane assembly is communicated with the regenerative liquid outlet of strong acid type ion exchanger to recovery system. The processing system is low in cost, easy to operate, avoid or alleviate secondary pollution problem, realize resource utilization.

Description

Technical Field

[0001] This utility model belongs to the field of groundwater treatment technology, specifically relating to a resource-based treatment system for high-hardness groundwater with low ammonia nitrogen pollution. Background Technology

[0002] In some parts of my country, groundwater is contaminated with ammonia nitrogen and has high hardness. Ammonia nitrogen pollution not only causes eutrophication but may also generate harmful substances such as nitrites, threatening human health. High-hardness groundwater leads to pipe scaling, severely affecting the quality of industrial and residential water. Currently, traditional treatment technologies include membrane methods, biological methods, chemical methods, and ion exchange methods, but all have significant drawbacks in practical applications.

[0003] 1) Membrane-based (such as nanofiltration / reverse osmosis) full-volume water treatment equipment has high investment, high energy consumption, complex operation, and difficulty in treating the concentrate;

[0004] 2) Biological methods rely on microbial communities to degrade ammonia nitrogen, but this method requires strain domestication, has a long start-up period, and requires a large area, making it difficult to meet the needs of rapid processing.

[0005] 3) Chemical methods reduce the hardness and ammonia nitrogen content of groundwater by adding softening agents such as lime and soda ash. Although the water softening and ammonia nitrogen removal effects are good, the cost is high and it is easy to cause secondary pollution.

[0006] 4) Conventional ion exchange methods utilize ion exchange resins to adsorb ammonia nitrogen and hardness ions, but the resin regeneration waste liquid contains high concentrations of salt and pollutants, resulting in high disposal costs and limiting the application of ion exchange methods. Utility Model Content

[0007] This invention addresses the aforementioned problems in the prior art by proposing a resource-based treatment system for high-hardness groundwater with low ammonia nitrogen pollution. It is particularly suitable for groundwater treatment scenarios where calcium and magnesium ion concentrations are ≤800 mg / L and ammonia nitrogen concentrations are ≤50 mg / L, and rapid treatment is required. This treatment system is low in cost, simple to operate, can avoid or mitigate secondary pollution problems, and realizes resource utilization.

[0008] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0009] A resource recovery system for high-hardness groundwater with low ammonia nitrogen pollution is proposed. The system includes a filtration system, an ion exchange system, a calcium ion removal system, a nanofiltration system, and a recovery system, wherein:

[0010] The filtration system includes a sand filter and a security filter connected in series;

[0011] The ion exchange system is connected to the outlet of the filtration system, including a softening ion exchanger and a strong acid ion exchanger connected in series, and a first regenerant storage tank and a second regenerant storage tank respectively connected to the softening ion exchanger and the strong acid ion exchanger; the softening ion exchanger and the strong acid ion exchanger are respectively provided with regenerant outlets.

[0012] The calcium ion removal system is connected to the regenerated liquid outlet of the softened ion exchanger and includes a precipitation separation tank and a pH adjustment agent storage tank connected to the precipitation separation tank.

[0013] The nanofiltration system is connected to the liquid phase outlet of the sedimentation separation tank and includes a nanofiltration membrane module; the product water outlet of the nanofiltration membrane module is connected to the first regenerant storage tank; the concentrate outlet of the nanofiltration membrane module is connected to the regenerant outlet of the strong acid ion exchanger and then to the recovery system.

[0014] In some embodiments, the particle size of the packing material in the sand filter is 0.5 mm to 2 mm; the packing material is quartz sand or manganese sand.

[0015] In some embodiments, the precision of the security filter described above is 30μm-100μm.

[0016] In some embodiments, the softening ion exchanger described above incorporates a sodium ion exchange resin.

[0017] In some embodiments, the above-described strong acid type ion exchanger incorporates a special ion exchange resin.

[0018] In some embodiments, the sedimentation separation tank is further provided with a stirring device.

[0019] In some embodiments, the calcium ion removal system described above further includes an online pH monitoring device and a level gauge.

[0020] In some embodiments, the nanofiltration system further includes a security filter in communication with the inlet of the nanofiltration membrane module.

[0021] In some embodiments, the nanofiltration system further includes a nanofiltration concentrate storage tank connected to the concentrate outlet of the nanofiltration membrane module.

[0022] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0023] (1) The system has good treatment effect: it can reduce the total concentration of calcium and magnesium ions in water to below 100 mg / L and the concentration of ammonia nitrogen to below 0.5 mg / L. The amount of water transported out of the system is 5%-15% of the treated water volume, which effectively reduces the cost of transporting out of the system.

[0024] (2) Resource utilization: The nanofiltration concentrate and the second regenerated liquid can be mixed and used as raw materials for struvite, which greatly reduces the synthesis cost of struvite (when struvite is synthesized using phosphorus-containing wastewater, magnesium salts account for about 30-40% of the cost). The nanofiltration permeate can be used as a supplement to the saturated sodium chloride solution of the first regenerated liquid, which can reduce the amount of sodium chloride used by about 30%.

[0025] (3) Good economic performance: The system occupies a small area and can be flexibly assembled according to the amount of water to be treated. The investment cost is reduced by 40%-60% compared with the full treatment of membrane method, the operating energy consumption is reduced by more than 30%, and the treatment speed is fast. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the main process for a resource-based treatment system for high-hardness groundwater with low ammonia nitrogen pollution.

[0027] Figure 2 This is a schematic diagram of a specific process for the resource-based treatment system of high-hardness groundwater with low ammonia nitrogen pollution.

[0028] In the picture:

[0029] 10-Filtration system; 11-Sand filter; 12-Security filter; 20-Ion exchange system; 21-Softening ion exchanger; 22-Strong acid ion exchanger; 30-Calcium ion removal system; 31-Precipitation separation tank; 32-pH adjuster storage tank; 40-Nanofiltration system; 50-Recovery system. Detailed Implementation

[0030] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0031] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as known to those skilled in the art. The equipment involved in the following examples is all common equipment already used in water treatment.

[0032] Unless otherwise specified in the examples, the conditions shall be performed in accordance with conventional conditions or the conditions recommended by the manufacturer. Unless otherwise specified, the manufacturers or models of the materials or equipment used shall be conventional products that can be purchased through commercial channels.

[0033] Example 1

[0034] like Figure 1 and Figure 2As shown, this utility model discloses a resource-based treatment system for high-hardness groundwater with low ammonia nitrogen pollution. The system includes a filtration system 10, an ion exchange system 20, a calcium ion removal system 30, a nanofiltration system 40, and a recovery system 50, wherein:

[0035] Filtration system 10 includes a sand filter 11 and a security filter 12 connected in series;

[0036] The ion exchange system 20 is connected to the outlet of the filtration system 10, and includes a softening ion exchanger 21 and a strong acid ion exchanger 22 connected in series, as well as a first regenerant storage tank 23 and a second regenerant storage tank 24 respectively connected to the softening ion exchanger 21 and the strong acid ion exchanger 22; the softening ion exchanger 21 and the strong acid ion exchanger 22 are respectively provided with regenerant outlets.

[0037] The calcium ion removal system 30 is connected to the regenerated liquid outlet of the softened ion exchanger 21, and includes a precipitation separation tank 31 and a pH adjustment agent storage tank 32 connected to the precipitation separation tank 31.

[0038] The nanofiltration system 40 is connected to the liquid phase outlet of the sedimentation separation tank 31 and includes a nanofiltration membrane module; the product water outlet of the nanofiltration membrane module is connected to the first regenerator storage tank 23; the concentrate outlet of the nanofiltration membrane module is connected to the regenerator outlet of the strong acid ion exchanger 22 and then to the recovery system 50.

[0039] The aforementioned filtration system 10 is used to remove particulate matter, colloids and some organic matter from groundwater. The sand filter 11 uses quartz sand or manganese sand as filler, and the filler particle size is preferably 0.5 mm to 2 mm. The security filter has an accuracy of 30 μm to 100 μm.

[0040] The softening ion exchanger 21 in the aforementioned ion exchange system 20 contains sodium ion exchange resin, which is used to remove calcium and magnesium ions from groundwater and reduce groundwater hardness. The first regenerant in the first regenerant storage tank 23 is a saturated sodium chloride solution. After the sodium ion exchange resin is saturated, the first regenerant is introduced for regeneration to produce regenerated liquid A, which contains calcium and magnesium ions and sodium chloride.

[0041] The strong acid type ion exchanger 22 in the aforementioned ion exchange system 20 contains a special ion exchange resin for removing ammonia nitrogen from groundwater. The second regenerant in the second regenerant storage tank 24 is a 5% hydrochloric acid solution. After the special ion exchange resin is saturated with adsorption, the second regenerant is introduced for regeneration to produce regenerated solution B.

[0042] The precipitation separation tank 31 of the calcium ion removal system 30 is also equipped with a stirring device to ensure that the regenerated solution A and the pH adjuster are fully mixed and completely precipitated, thereby removing calcium ions from the regenerated solution A; the pH adjuster is a sodium carbonate solution. The calcium ion removal system 30 also includes an online pH monitoring device and a level gauge.

[0043] The nanofiltration system 40 concentrates the regenerated liquid A after calcium ion removal. The nanofiltration permeate can be used as a supplement to the first regenerator, reducing the amount of sodium chloride used in the first regenerator. The nanofiltration concentrate has a high concentration of magnesium ions, which can be mixed with the regenerated liquid B and used as raw material for struvite for resource utilization.

[0044] The nanofiltration system 40 also includes a security filter connected to the inlet of the nanofiltration membrane module to further remove particulate impurities, and a nanofiltration concentrate storage tank connected to the concentrate outlet of the nanofiltration membrane module.

[0045] Example 2

[0046] The treatment process for the high-hardness groundwater resource utilization system suitable for low ammonia nitrogen pollution is as follows:

[0047] S1: Groundwater is pumped to the filtration system 10. After the sand filter 11 removes the suspended particles, colloids and some organic matter in the water, it is transported to the security filter 12 to further remove fine particles and other impurities in the water. The filtered impurities are transported off-site for disposal.

[0048] S2: Groundwater treated by filtration system 10 is transported to ion exchange system 20. It first passes through softening ion exchanger 21, where its built-in sodium ion exchange resin removes calcium and magnesium ions from the groundwater, reducing water hardness. Then it is transported to strong acid ion exchanger 22, where its built-in special ion exchange resin removes ammonia nitrogen from the water. The water treated by ion exchange system 20 can be used for subsequent purposes, such as for producing drinking water or for use as circulating water.

[0049] S3: After the sodium ion exchange resin in the softening ion exchanger 21 is saturated with adsorption, the first regenerator is added for regeneration to produce regenerated liquid A; after the special ion exchange resin in the strong acid type ion exchanger 22 is saturated with adsorption, the second regenerator is added for regeneration to produce regenerated liquid B.

[0050] S4: Regenerated liquid A is sent to calcium ion removal system 30 to remove calcium ions, and the resulting calcium slag is transported off-site for disposal; after calcium ion removal, regenerated liquid A is sent to nanofiltration system 40 for concentration to produce nanofiltration permeate and nanofiltration concentrate.

[0051] S5: Nanofiltration permeate is recycled as a supplement to the first regenerator, which can reduce the amount of the first regenerator used; the nanofiltration concentrate is mixed with the regenerated liquid B from step S3 and used as raw material for struvite for resource utilization.

[0052] Application Examples

[0053] The high-hardness groundwater resource utilization treatment system suitable for low ammonia nitrogen pollution described in Example 1 above was used for water purification. The properties of the groundwater before treatment and the treatment volume were as follows: calcium and magnesium ion concentration 748.7 mg / L, ammonia nitrogen 36.6 mg / L, pH 7.3, and the treatment volume was 10 m³. 3 / h;

[0054] After treatment, the effluent had the following characteristics: calcium and magnesium ion concentration of 85.4 mg / L, ammonia nitrogen of 0.4 mg / L, and pH of 6.4.

[0055] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

Claims

1. A resource-based treatment system for high-hardness groundwater with low ammonia nitrogen pollution, characterized in that, The system includes a filtration system, an ion exchange system, a calcium ion removal system, a nanofiltration system, and a recovery system, wherein: The filtration system includes a sand filter and a security filter connected in series; The ion exchange system is connected to the outlet of the filtration system and includes a softening ion exchanger and a strong acid ion exchanger connected in series, as well as a first regenerant storage tank and a second regenerant storage tank respectively connected to the softening ion exchanger and the strong acid ion exchanger; the softening ion exchanger and the strong acid ion exchanger are respectively provided with regenerant outlets. The calcium ion removal system is connected to the regenerated liquid outlet of the softened ion exchanger and includes a precipitation separation tank and a pH adjustment agent storage tank connected to the precipitation separation tank. The nanofiltration system is connected to the liquid phase outlet of the sedimentation separation tank and includes a nanofiltration membrane module; the product water outlet of the nanofiltration membrane module is connected to the first regenerant storage tank; the concentrate outlet of the nanofiltration membrane module is connected to the regenerant outlet of the strong acid ion exchanger and then to the recovery system.

2. The resource utilization system for high-hardness groundwater with low ammonia nitrogen pollution according to claim 1, characterized in that, The particle size of the packing material in the sand filter is 0.5mm to 2mm.

3. The resource utilization system for high-hardness groundwater with low ammonia nitrogen pollution according to claim 1 or 2, characterized in that, The precision of the security filter is 30μm-100μm.

4. The resource-based treatment system for high-hardness groundwater with low ammonia nitrogen pollution according to claim 1, characterized in that, The softening ion exchanger contains sodium ion exchange resin for removing calcium and magnesium ions from groundwater.

5. The resource-based treatment system for high-hardness groundwater with low ammonia nitrogen pollution according to claim 1 or 4, characterized in that, The strong acid type ion exchanger has a built-in special ion exchange resin for removing ammonia nitrogen from groundwater.

6. The resource utilization system for high-hardness groundwater with low ammonia nitrogen pollution according to claim 1, characterized in that, The sedimentation separation tank is also equipped with a stirring device.

7. The resource utilization system for high-hardness groundwater with low ammonia nitrogen pollution according to claim 1 or 6, characterized in that, The calcium ion removal system also includes an online pH monitoring device and a level gauge.

8. The resource-based treatment system for high-hardness groundwater with low ammonia nitrogen pollution according to claim 1, characterized in that, The nanofiltration system also includes a security filter connected to the inlet of the nanofiltration membrane module.

9. The resource-based treatment system for high-hardness groundwater with low ammonia nitrogen pollution according to claim 1, characterized in that, The nanofiltration system also includes a nanofiltration concentrate storage tank connected to the concentrate outlet of the nanofiltration membrane module.

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