CN104649515A - Treatment process method and device for high-salinity and high-ammonia-nitrogen rare-earth production wastewater - Google Patents

Abstract

A treatment process and device for high-salinity, high-ammonia-nitrogen rare earth production wastewater, specifically a wastewater treatment process for efficient desalination and denitrification that combines electrodialysis, three-effect concentration and crystallization processes, and integrated anaerobic ammonium oxidation processes ; Rare earth production wastewater enters the electrodialysis device after passing through pretreatment units such as grids, regulating tanks, and multi-media filters. After electrodialysis treatment, it is divided into concentrated liquid and desalinated liquid; liquid separation; the desalinated liquid and the effluent of the three-effect concentrated crystallizer enter the integrated anaerobic ammonium oxidation reactor for biochemical denitrification reaction. The invention has perfect technology, simple operation, flexible control, low operating cost, good sewage treatment effect and high efficiency.

Description

A treatment method and device for high-salinity, high-ammonia-nitrogen rare earth production wastewater

technical field

The invention relates to a processing method and device for high-salinity, high-ammonia-nitrogen rare earth production wastewater, and belongs to the technical field of sewage treatment.

Background technique

my country is a big country in rare earth mining and processing. After half a century of development, my country's rare earth industry has made great achievements. environmental problems. From October 1, 2011, the Ministry of Environmental Protection of my country began to implement the "Discharge Standard of Rare Earth Industrial Pollutants (GB 26451-2011)", which has stricter requirements on the quality of wastewater discharged from the rare earth industry. Rare earth wastewater contains extremely high concentrations of ammonia nitrogen, as well as high salinity and concentration of heavy metal elements. It is difficult for the current treatment processes of various enterprises to meet the latest industrial wastewater discharge requirements, which greatly restricts the development of the rare earth industry.

(1) Water quality characteristics of rare earth production wastewater

Taking the production process of mixed rare earth mine in Baotou as an example: use concentrated sulfuric acid to intensify roasting method to decompose rare earth concentrate, then undergo water immersion, ammonium bicarbonate precipitation or P204 extraction transformation to obtain mixed rare earth chloride solution, and then use saponification P507 extraction to separate single rare earth elements, and finally precipitated and calcined to prepare rare earth oxides. The amount of wastewater and the content of pollutants produced in the production process of Baotou Mixed Rare Earth Mine are listed in Table 1. Baotou City annually smelts more than 150,000 tons of Baotou rare earth concentrates, and discharges 8-10 million tons of rare earth production wastewater. The annual discharge of major pollutants in wastewater is: 1,780 tons of fluoride, 70,000 tons of ammonia nitrogen, 53,000 tons of sulfate radicals, chlorine Ion 95,000 t.

Table 1 Wastewater volume and pollutant content in mixed rare earth production process

To sum up, four types of wastewater are mainly discharged during the rare earth production and smelting process. The first is the fluorine-containing acidic wastewater produced by the spray purification of the tail gas of rare earth concentrate roasting; the second is the ammonium salt (ammonium sulfate) wastewater produced in the production process of rare earth carbonate; Separation of ammonium salt (ammonium chloride) waste water produced. Due to various reasons, many enterprises have not treated it and discharged it directly, causing serious environmental pollution problems. At present, the wastewater discharge standard stipulated in my country is 15mg/L for ammonia nitrogen and 10mg/L for F. Therefore, rare earth smelting wastewater has greatly exceeded the national discharge standard and must be comprehensively treated.

(2) Rare earth production wastewater treatment technology

Ammonia nitrogen wastewater is the largest and most serious source of pollution produced by rare earth separation plants. The methods for treating ammonia nitrogen wastewater mainly include evaporation concentration method, breakpoint chlorination method, membrane method, ammonia stripping method, ammonium magnesium phosphate method, etc.

The evaporation concentration method is suitable for high-concentration ammonium chloride wastewater with an ammonium concentration of more than 130g/L, and consumes a lot of energy. The produced ammonium chloride products are also difficult to sell in the market, so this method is only suitable for coal resources. And areas with better sales of ammonium chloride. Ammonium sulfate wastewater is produced during the impurity removal process of rare earth smelting. The content of impurity ions such as calcium and magnesium is relatively high. The nitrogen content of the ammonium sulfate product obtained after evaporation and crystallization is allowed to be up to 18%, which makes the product unqualified and is sold after extraction. difficulty. Therefore, ammonium sulfate wastewater is difficult to treat by concentration and evaporation.

The breakpoint chlorination method is suitable for low-concentration ammonia nitrogen wastewater, and the treatment effect is stable, not affected by water temperature, and the investment is small, but the amount of chlorine added is large and the cost is high. The treatment cost of wastewater with an ammonia nitrogen concentration of 100mg/L is 1 A kilogram of ammonia nitrogen is 37.6 yuan, and the treatment rate is over 96%. During the process, every mol of ammonia nitrogen oxidized will produce 4 mol of acid, which means that 1mg/L of alkalinity (calculated as CaCO ₃ ) is needed to neutralize the acid produced, thereby increasing The content of total dissolved solids is exceeded, and the by-products chloramines and chlorinated organics will cause secondary pollution.

The ammonia stripping method converts ammonia nitrogen into molecular ammonia by adjusting the pH value, and then aerates a large amount of water to promote the transfer of NH ₃ to the air, so as to achieve the purpose of removing the ammonia nitrogen content in the water body. The biggest expense in the operation of the ammonia stripping method is the alkali consumed to adjust the pH value to 11. The cost of lime is low, but the sediment is difficult to clean up; the price of soda ash or solid alkali is high. Using the ammonia stripping method, the removal rate of ammonia nitrogen is 60%-95%.

The magnesium ammonium phosphate method (MAP) removes ammonia ions from the aqueous solution by means of double salt precipitation, and is an effective method for recovering nitrogen, phosphorus, and magnesium. As a compound of water, its solubility product K _sp is only 2.5×10 ^-13 at 25°C. Therefore, the removal efficiency of nitrogen, phosphorus and magnesium by the ammonium magnesium phosphate method is high, and the obtained ammonium magnesium phosphate is a high-efficiency slow-release fertilizer with better economic value. Some R&D personnel mixed ammonia nitrogen wastewater produced in rare earth separation enterprises with magnesium-containing wastewater, added Na ₃ PO ₄ 12H ₂ O as a precipitant, adjusted the pH of the solution to 9.0, and the removal rate of ammonia nitrogen could reach 98.6%. It solves the salinity problem caused by magnesium-containing wastewater and solves the problem of ammonia nitrogen pollution. However, the precipitant phosphate used in the magnesium ammonium phosphate method has a high cost and has not been applied in industry at present.

To sum up, the cost of ammonia distillation and concentration method is high, low concentration wastewater needs to be concentrated first, and product sales are difficult; the break point chlorination method is effective in treating low concentration ammonia nitrogen wastewater, but secondary pollution must be prevented; the efficiency of ammonia stripping method The recovery of ammonia is difficult, so these methods are still in the research stage. The MAP method has large processing capacity, low operating cost, and the sediment can be recycled as fertilizer, which has great practical prospects. However, due to the high cost of phosphate, it is still difficult for enterprises to accept it. Although ammonia nitrogen can be treated by different methods, it is difficult to meet the emission standards by one method, and it will cause a lot of manpower, material and energy consumption, and the treatment cost is high.

Contents of the invention

In order to overcome the deficiencies of the prior art, the present invention provides a treatment method and device for high-salinity, high-ammonia-nitrogen rare earth production wastewater. Specifically, it is a process and method for jointly treating rare earth production wastewater by applying electrodialysis, three-effect concentration crystallization and integrated anaerobic ammonium oxidation process.

A treatment process device for high-salinity, high-ammonia-nitrogen rare earth production wastewater. The water inlet pump is connected to the artificial fine grid, the artificial fine grid is connected to the underground adjustment tank, the underground adjustment tank is connected to the lifting pump, and the outlet pipe of the lifting pump is connected to the multi-media filter. At the top, the lower part of the multi-media filter is connected to the first water inlet pump, the outlet pipe of the first water inlet pump is connected to the electrodialysis device, the upper part of the electrodialysis device is connected to the desalination liquid outlet pipe, and the lower part of the electrodialysis device is connected to the concentrate liquid outlet pipe, The desalinated liquid outlet pipeline is connected to the water storage tank, the concentrated liquid outlet pipeline is connected to the water inlet pump of the three-effect concentrator, the outlet pipe of the water inlet pump of the three-effect concentrator is connected to the three-effect concentration crystallizer, and the outlet pipe of the three-effect concentration crystallizer is connected to the water storage tank, The water storage tank is connected to the second water inlet pump, and the outlet pipe of the second water inlet pump is connected to the integrated anammox reactor. The top of the integrated anammox reactor is provided with a gas outlet and a gas return pipeline. The integrated anammox The inner cavity of the reactor is provided with a reaction zone and a top zone, and a microporous aeration head connected with an air compressor is provided at the bottom of the reaction zone; an overflow weir is set between the reaction zone and the top zone, and the outside of the overflow weir is connected to the outlet. The water pipes are connected.

A treatment process for rare earth production wastewater with high salinity and high ammonia nitrogen, comprising the following steps: the rare earth production wastewater enters an electrodialysis device after passing through pretreatment units such as a grid, a regulating tank, and a multi-media filter, and after being treated by electrodialysis, it is separated into It is concentrated liquid and desalinated liquid; the concentrated liquid enters the three-effect concentrated crystallizer for solid-liquid separation; the desalinated liquid and the effluent of the three-effect concentrated crystallizer enter the integrated anaerobic ammonium oxidation reactor for biochemical denitrification reaction.

The advantage of the present invention is that the anammox technology mainly uses anammox bacteria as the main body of the process, which has a unique metabolic pathway, and can use nitrite as an electron donor to directly oxidize ammonia nitrogen into nitrogen under anaerobic conditions , and this process does not require an organic carbon source. The introduction of anammox into the rare earth wastewater treatment process has obvious advantages over ordinary physical and chemical methods: anammox bacteria are chemoautotrophic bacteria that use inorganic carbon as a carbon source, and the C/N of rare earth production wastewater is very low. It is suitable for the growth of anammox bacteria; the nitrification process only needs to oxidize 50% of ammonia nitrogen to nitrite nitrogen, and the oxygen demand and oxygen supply energy consumption of the process are greatly reduced; the denitrification efficiency and removal load of anammox are relatively low High, but less sludge production. Therefore, after electrodialysis and three-effect concentrated crystallizer pretreatment, the salinity is reduced to the range suitable for the growth of anammox bacteria, and then the integrated anammox process is used for denitrification, which can produce significant economic benefits. Environmental benefits and overall benefits. The process conforms to the law of sustainable development and has a broad application market.

The electrodialysis process of the present invention divides the pretreated rare earth wastewater into concentrated water and desalinated liquid; the concentrated water enters the three-effect concentration crystallizer for evaporation and crystallization, and the salinity in the wastewater is greatly reduced while recovering materials; anaerobic ammonium oxidation SBR Ammonia oxidizing bacteria and anammox bacteria are enriched in the same time, through the synergistic effect of the two bacteria to achieve economical and efficient denitrification. The process is suitable for the treatment of rare earth production wastewater, and can effectively remove salinity and ammonia nitrogen in the wastewater; it also has a good treatment effect on other wastewater with high salinity and high ammonia nitrogen.

The invention effectively combines various sewage treatment processes, efficiently removes suspended solids in waste water through grids, adjustments and multi-media filters, and reduces the impact on subsequent processes; the combined application of electrodialysis process and three-effect concentration and crystallization industry can recycle materials At the same time, the salinity in the wastewater is greatly reduced; finally, the low-energy and high-efficiency anaerobic ammonium oxidation process is used for deep denitrification; the sewage water quality after this process can meet the "Rare Earth Industrial Pollutant Discharge Standard (GB 26451-2011)" requirements.

Description of drawings

A more complete and better understanding of the invention, and many of its attendant advantages, will readily be learned by reference to the following detailed description when considered in conjunction with the accompanying drawings, but the accompanying drawings illustrated herein are intended to provide a further understanding of the invention and constitute A part of the present invention, the exemplary embodiment of the present invention and its description are used to explain the present invention, and do not constitute an improper limitation of the present invention, as shown in the figure:

Fig. 1 is a structural schematic diagram of the device of the present invention.

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Detailed ways

Obviously, many modifications and changes made by those skilled in the art based on the gist of the present invention belong to the protection scope of the present invention.

Embodiment 1: As shown in Figure 1,

A treatment process device for high-salinity, high-ammonia-nitrogen, rare earth production wastewater. Inlet pump 1 is connected to artificial fine grid 2, artificial fine grid 2 is connected to underground regulating tank 3, underground regulating tank 3 is connected to lift pump 4, and the outlet of lift pump 4 The pipeline is connected to the top of the multimedia filter 5, the lower part of the multimedia filter 5 is connected to the first water inlet pump 6, the outlet pipe of the first water inlet pump 6 is connected to the electrodialysis device 7, and the upper part of the electrodialysis device 7 is connected to the desalination liquid outlet pipeline 8. The lower part of the electrodialysis device 7 is connected to the concentrated solution outlet pipeline 9, the desalinated solution outlet pipeline 8 is connected to the water storage tank 12, the concentrated solution outlet pipeline 9 is connected to the water inlet pump 10 of the three-effect concentrator, and the water inlet pump 10 of the three-effect concentrator The outlet pipe is connected to the three-effect concentrated crystallizer 11, the outlet pipe of the three-effect concentrated crystallizer 11 is connected to the water storage tank 12, the water storage tank 12 is connected to the second water inlet pump 13, and the outlet pipe of the second water inlet pump 13 is connected to the integrated anaerobic ammonium oxidation reaction device 14, the top of the integrated anammox reactor 14 is provided with a gas outlet and a gas return pipeline 18, the inner cavity of the integrated anammox reactor 14 is provided with a reaction zone 16, a top zone 17, and the bottom of the reaction zone 16 A microporous aeration head 15 communicating with an air compressor 20 is provided; an overflow weir is provided between the reaction zone 16 and the top zone 17 , and the outside of the overflow weir communicates with an outlet pipeline 19 .

The problems that need to be solved in high-salinity and high-ammonia nitrogen wastewater such as rare earth production wastewater include: how to achieve a high removal rate of ammonia nitrogen to meet the drainage standard; high salinity inhibits functional microorganisms in biochemical systems. The present invention solves the above-mentioned technical problems, and proposes a process of combining electrodialysis, a three-effect concentration crystallizer and anaerobic ammonium oxidation. The process first undergoes pretreatment processes such as grids, regulating tanks, and multimedia filters to greatly reduce the concentration of suspended solids in wastewater and reduce the impact on subsequent processes; then the wastewater is decomposed into desalinated liquid and concentrated by electrodialysis process The salinity of the liquid and desalinated liquid fully meets the requirements of the biochemical system; the concentrated liquid is evaporated and crystallized after entering the three-effect concentrator, and the material is recovered while reducing the salinity; the anaerobic ammonium oxidation reactor uses the packing carrier technology to effectively retain and enrich Collect anammox bacteria, through reasonable reactor structure and aeration method, make the sludge circulate inside the reactor, provide the best growth environment for ammonia oxidizing bacteria and anammox, through reasonable hydraulic retention time and The SBR operation cycle efficiently removes ammonia nitrogen in two stages, realizing the improvement of nitrogen removal efficiency and the stability of operation.

The purpose of the present invention is to provide a high-efficiency, low-cost process and method that can effectively remove salinity and ammonia nitrogen in rare earth production wastewater, and make it discharge up to the standard. In order to realize the foregoing invention object, the technical scheme provided by the invention may further comprise the steps:

A. The saponification, extraction, and carbon precipitation mixed wastewater generated in the rare earth production process first enters the artificial fine grid 2 through the water inlet pump 1, and mainly removes packaging and large debris abandoned during the production process;

B. The fine grid initially enters the underground regulating pool 3 to homogenize the water quality and adjust the pH to 7.0-9.0;

C. The effluent from the adjustment pool enters the multi-media filter 5 through the lift pump 4, and further removes suspended solids in the water through multi-layer filtration such as anthracite filter material and quartz sand filter material;

D, the outlet pipe of the multimedia filter communicates with the electrodialysis device 7 through the water inlet pump 6, and the electrodialysis main device is provided with a cathode chamber, an anode chamber, a desalination chamber, and a concentration chamber;

E. The electrodialysis effluent enters the integrated anaerobic ammonium oxidation reactor through the desalination liquid outlet pipeline 8, and the concentrated solution outlet pipeline 9 and the three-effect concentrator water inlet pump 10 enter the three-effect concentration crystallizer 11;

F. The water entering the three-effect concentrator passes through the first-stage separator and evaporator, the second-stage separator and evaporator, and the third-stage separator and evaporator for crystal precipitation, and the remaining concentrated solution is mixed with the desalination solution of electrodialysis water Enter the water storage tank 12, and be connected with the integrated anammox reactor 14 by the inlet pump 13 of the anammox reactor;

G. The integrated anaerobic ammonium oxidation reactor is provided with a reaction zone 16 and a top zone 17, and the bottom of the reaction zone is provided with a microporous aeration head 15 communicated with an air compressor; an overflow is provided between the reaction zone and the top zone The weir, the overflow weir is connected to the outlet pipeline 19, and the outlet water goes to the advanced treatment part; the top of the reaction zone is provided with a gas outlet and a gas return pipeline 18, which is aerated by an air compressor 20; the bottom of the reactor Equipped with sludge discharge pipeline.

In the step E, enter the electrodialysis treatment process, incoming water TDS30000mg/L, ammonia nitrogen 5000mg/L, after the electrodialysis treatment, concentrated water TDS is controlled at about 150000mg/L (i.e. concentrated 5 times, concentrated water volume 15% -20%), fresh water volume 80%-85%, control TDS below 5000mg/L, ammonia nitrogen 500-1000mg/L enter the anammox system;

In the step F, the electrodialysis fresh water and the three-effect concentrated distillate are mixed into the anammox system for treatment after heat exchange (can provide the anammox water temperature requirement), and play a certain dilution effect. Ammonia nitrogen and COD are discharged after reaching the standard after oxygen ammonium oxidation treatment;

In the step G, the start-up steps of the integrated anammox are as follows:

Step 1. Sludge inoculation: Take the fresh excess sludge from the sewage treatment plant, the filler sludge with better film-hanging condition in the integrated anaerobic ammonium oxidation reactor running stably; put the anaerobic ammonium oxidation filler sludge into In the integrated anaerobic ammonium oxidation reactor, the filling rate is about 30%, and then the remaining sludge from the sewage treatment plant in the floc state is added to the reactor, and the initial floc sludge concentration is kept at 1g/L;

Step 2. Start-up stage: Turn on the water pump to feed water intermittently from the water storage tank. The total nitrogen concentration in the water is 400-500mg/L, of which the ammonia nitrogen concentration is 350-450mg/L. If it is water distribution, you can control the dosage. It is actual wastewater, which can be diluted according to the concentration to meet the above requirements; check the air tightness of the system, open the aeration system; adjust the valve of the aeration pipeline, control the dissolved oxygen in the reaction zone below 1.0mg/L, and ensure that the filler pollution The mud is fully suspended in the reaction zone, without short flow and dead zone; if the dissolved oxygen cannot be kept below 1.0mg/L stably through aeration only, add an agitator for mixing to meet the requirements; control the hydraulic retention during the start-up phase The time is 48 hours, with 12 hours as a cycle, aeration for 10.5 hours and precipitation for 1.5 hours in each period, so that the concentration of nitrate nitrogen and nitrite nitrogen in the effluent is maintained below 15 mg/L. If nitrate nitrogen and nitrite If the nitrogen concentration is too high, increase the reactor temperature and reduce the dissolved oxygen to meet the requirements; when the nitrite nitrogen concentration in the effluent is lower than 5mg/L, reduce one cycle to reduce the hydraulic retention time and adjust the aeration system and agitator to ensure oxygenation and mixing effect; discharge the mixed sludge from the reaction zone at a fixed time every day, and the volume of the discharged mixed sludge accounts for 1/10-1/15 of the volume of the reaction zone; when operating under the above conditions, when The ammonia nitrogen removal load of the reactor, that is, the amount of pollutants that can be removed by a unit volume reactor per unit time, reaches 0.3kg N/(m ³ ·d), and when the total nitrogen removal rate exceeds 75%, it is determined that the start-up is over. Enter the stable operation period; if it is not reached, continue the above operation process until it enters the stable operation period;

Step 3. Continuous operation: In order to ensure the denitrification effect of the system and the stability of operation, the dissolved oxygen concentration in the reaction zone is continuously monitored, and the aeration system is adjusted in time to avoid over-aeration or insufficient oxygenation; by increasing or Reduce the total amount of mixed sludge discharge to maintain a reasonable sludge age; in the process of continuous operation, the amount of water inflow should be controlled to avoid large-scale fluctuations in water quality and water volume, and ensure that the reaction conditions: temperature and pH are basically constant , to ensure the stability of the system processing effect.

Embodiment 2: As shown in Figure 1, the process of electrodialysis, three-effect concentrated crystallization and integrated anammox process of the present invention to treat rare earth production wastewater consists of electrodialysis device, three-effect concentrated crystallizer, water storage tank and integrated Composition of anaerobic ammonium oxidation reactor. The volume of the water storage tanks is 20m ³ , and the volume of the integrated anaerobic ammonium oxidation reactor is 100m ³ . Use an air compressor for aeration.

The influent water used in the example is the carbon precipitation effluent in the rare earth production wastewater treatment process, which is taken from the production workshop in Inner Mongolia. Its water quality is: pH 7.11, ammonia nitrogen 4103mg/L, COD 1260mg/L, alkalinity 298mg/L (calculated as calcium carbonate), and TDS 32500mg/L.

Utilize the operation method step of above-mentioned device as follows:

Step 1. Inoculation sludge: The inoculation sludge is taken from an integrated anaerobic ammonium oxidation reactor that treats sludge digestion liquid in an urban sewage plant, and the filler sludge with stable operation and good film formation is taken, and the filling rate after being put into the reactor 30%. The sludge has good activity, the denitrification rate is about 80%, and the denitrification load is 0.3-0.4kg N/(m ³ ·d).

Step 2. Start-up stage: Turn on the water pump to intermittently feed water from the water storage tank. The water intake is the diluted carbon sediment effluent, and the volume of each water change is 1/4 of the total volume of the reactor. The total nitrogen concentration after each water intake is 300-400mg/L, of which the ammonia nitrogen concentration is 250-350mg/L, adding sodium bicarbonate to increase the pH of the reactor to 7.8-8.0; check the air tightness of the system and start the aeration system; Adjust the valve of the aeration pipeline, control the dissolved oxygen in the reaction zone below 1.0mg/L, and at the same time ensure that the filler sludge is fully suspended in the reaction zone without short flow and dead zone; control the hydraulic retention time at the start-up stage to 48h, to 12 hours is a cycle, aeration is 10.5 hours per cycle, sedimentation is 1.5 hours, and after one week of cultivation, the concentration of nitrite nitrogen in the effluent is reduced to below 5 mg/L, and the concentration of ammonia nitrogen is reduced to below 10 mg/L, gradually reducing hydraulic retention Time to increase the load, and adjust the aeration system and agitator to ensure the oxygenation and mixing effect; when changing the water in each cycle, fix 1/15-1/10 of the total amount of mud discharged from the mud outlet; operate under the above conditions, When the ammonia nitrogen removal load of the reactor reaches 0.3kg N/(m ³ ·d), and the total nitrogen removal rate exceeds 75%, it is determined that the integrated anammox reactor enters a stable operation period.

Step 3. Continuous operation: In order to ensure the denitrification effect of the system and the stability of operation, the dissolved oxygen concentration in the reaction zone of the two reactors is continuously monitored to ensure that the dissolved oxygen in the integrated anammox reactor is lower than 1.0mg/L . At the same time, regularly monitor the concentration of COD, ammonia nitrogen, nitrite and nitrate in the effluent, and judge the relationship between ammonia oxidizing bacteria, nitrite oxidizing bacteria and anammox bacteria in the system based on this, and adjust the mixed sludge appropriately. The total amount of discharge and maintain a reasonable sludge age. In the process of continuous operation, large-scale fluctuations in influent water quality and water volume should be avoided, and the reaction conditions such as temperature and pH value should be kept basically constant, so as to prevent the decline of system treatment effect and the loss of sludge.

The continuous test results show that the temperature of the integrated anammox reactor is kept at 30°C through the temperature control system, the hydraulic retention time is 24h, and the test results of stable operation for one month show that the final total nitrogen removal rate is stable above 80% , the concentration of ammonia nitrogen and nitrite nitrogen in the effluent is lower than 10mg/L, the concentration of total nitrogen is lower than 50mg/L, the concentration of COD is lower than 100mg/L, and the denitrification load reaches 0.47kgN/(m ³ ·d), which has good denitrification As a result, the effluent water quality meets the requirements of the Discharge Standard of Rare Earth Industrial Pollutants (GB 26451-2011).

As mentioned above, although the Example of this invention was demonstrated in detail, it is obvious to those skilled in the art that many modifications can be made as long as the inventive point and effect of this invention are not substantially deviated. Therefore, all such modified examples are also included in the protection scope of the present invention.

Claims (6)

1. A treatment process for high-salinity, high-ammonia-nitrogen rare-earth production wastewater, characterized in that the rare-earth production wastewater enters the electrodialysis unit after pretreatment units such as grids, regulating tanks, and multimedia filters, and after electrodialysis treatment, It is divided into concentrated liquid and desalinated liquid; the concentrated liquid enters the three-effect concentrated crystallizer for solid-liquid separation; the desalinated liquid and the effluent of the three-effect concentrated crystallizer enter the integrated anaerobic ammonium oxidation reactor for biochemical denitrification reaction. 2. the processing method of a kind of high salinity high ammonia nitrogen rare earth production waste water according to claim 1, comprises the following steps: Step A) The saponification, extraction and carbon precipitation mixed wastewater generated in the rare earth production process first enters the artificial fine grid through the water inlet pump, mainly to remove the packaging and large sundries abandoned during the production process; Step B) The fine grid initially enters the underground adjustment pool, and the water quality is homogenized to adjust the pH to 7.0-9.0; Step C) The effluent from the adjustment pool enters the multi-media filter through the lifting pump, and further removes suspended matter in the water through multi-layer filtration such as anthracite filter material and quartz sand filter material; Step D) The outlet pipe of the multi-media filter communicates with the electrodialysis device through the water inlet pump, and the electrodialysis main device is provided with a cathode chamber, an anode chamber, a desalination chamber, and a concentration chamber; Step E) The electrodialysis effluent enters the integrated anaerobic ammonium oxidation reactor through the desalination solution outlet pipeline, and the concentrated solution outlet pipeline and the three-effect concentrator water inlet pump enter the three-effect concentration crystallizer; Step F) The feed water of the three-effect concentrator passes through the first-stage separator and evaporator, the second-stage separator and evaporator, the third-stage separator and the evaporator to carry out crystal precipitation, and the remaining concentrated solution is mixed with the desalination solution of electrodialysis water After entering the water storage tank, it is connected with the integrated anaerobic ammonium oxidation reactor through the inlet pump of the anaerobic ammonium oxidation reactor; Step G) Wastewater enters the integrated anaerobic ammonium oxidation reactor for biochemical denitrification, the reactor is provided with a reaction zone, a top zone, and the bottom of the reaction zone is provided with a microporous aeration head connected to an air compressor; in the reaction zone There is an overflow weir between the top area and the top area, and the outside of the overflow weir is connected to the outlet pipeline, and the outlet water leads to the subsequent advanced treatment part; there is an air outlet and a gas return pipeline on the top of the reaction zone, and aeration is performed through an air compressor; A sludge discharge pipeline is provided at the bottom of the reactor. 3. the processing method of a kind of high salinity high ammonia nitrogen rare earth production waste water according to claim 2, it is characterized in that, in described step E), waste water enters electrodialysis treatment process, after electrodialysis treatment, effluent It is divided into concentrated liquid (5 times concentrated, about 15%-20% of water inflow), and desalinated liquid (about 80%-85% of water inflow), control TDS below 5000mg/l, ammonia nitrogen 500-1000mg/l or so into the anammox system. 4. the processing method of a kind of high salinity high ammonia nitrogen rare earth production waste water according to claim 2, it is characterized in that, in described step F), electrodialysis fresh water and three-effect concentrated distillate are after heat exchange ( Anaerobic ammonium oxidation water temperature requirements) can be mixed into the anaerobic ammonium oxidation system for treatment, and play a certain dilution role. 5. the processing method of a kind of high salinity high ammonia nitrogen rare earth production waste water according to claim 2, it is characterized in that, in described step G, the start-up step of integrated anammox is as follows: Step 1), inoculation sludge: take the fresh excess sludge from the sewage treatment plant, the filler sludge with better film-hanging condition in the integrated anaerobic ammonium oxidation reactor in stable operation; put the anaerobic ammonium oxidation filler sludge into the integrated anaerobic ammonium oxidation reactor, the filling rate is about 30%, and then the remaining sludge of the sewage treatment plant in the floc state is added to the reactor, and the initial floc sludge concentration is kept at 1g/L; Step 2), start-up stage: turn on the water pump to feed water intermittently from the water storage tank, the total nitrogen concentration in the water is 400-500mg/L, and the ammonia nitrogen concentration is 350-450mg/L. If it is actual wastewater, it can be diluted according to the concentration to meet the above requirements; check the air tightness of the system, open the aeration system; adjust the valve of the aeration pipeline, control the dissolved oxygen in the reaction zone below 1.0mg/L, and ensure that the filler The sludge is fully suspended in the reaction zone without short flow and dead zone; if the dissolved oxygen cannot be kept below 1.0mg/L stably through aeration only, add an agitator for mixing to meet the requirements; control the hydraulic pressure during the start-up phase The residence time is 48 hours, with 12 hours as a cycle, aeration for 10.5 hours and precipitation for 1.5 hours in each cycle, so that the concentration of nitrate nitrogen and nitrite nitrogen in the effluent is maintained below 15mg/L. If the concentration of nitrate nitrogen is too high, increase the temperature of the reactor and reduce the dissolved oxygen to meet the requirements; when the concentration of nitrite nitrogen in the effluent is lower than 5mg/L, reduce one cycle to reduce the hydraulic retention time Gas system and agitator to ensure oxygenation and mixing effect; discharge mixed sludge from the reaction zone at a fixed time every day, and the volume of the discharged mixed sludge accounts for 1/10-1/15 of the volume of the reaction zone; operating under the above conditions, When the ammonia nitrogen removal load of the reactor, that is, the amount of pollutants that can be removed by a unit volume reactor per unit time, reaches 0.3kg N/(m ³ ·d), and the total nitrogen removal rate exceeds 75%, it is determined that the start-up is over , to enter the stable operation period; if it is not reached, continue the above operation process until it enters the stable operation period; Step 3), continuous operation: in order to ensure the denitrification effect of the system and the stability of operation, the dissolved oxygen concentration in the reaction zone is continuously monitored, and the aeration system is adjusted in time to avoid the phenomenon of over-aeration or insufficient oxygenation; by increasing Or reduce the total amount of mixed sludge discharge to maintain a reasonable sludge age; in the process of continuous operation, control the amount of water inflow, avoid large-scale fluctuations in water quality and water volume, and ensure the reaction conditions: basic temperature, pH value Constant to ensure the stability of the system processing effect. 6. A treatment process device for high-salinity, high-ammonia-nitrogen rare earth production wastewater, characterized in that the water inlet pump is connected to an artificial fine grid, the artificial fine grid is connected to an underground regulating tank, the underground regulating tank is connected to a lift pump, and the outlet pipe of the lift pump Connect the top of the multi-media filter, the lower part of the multi-media filter is connected to the first water inlet pump, the outlet pipe of the first water inlet pump is connected to the electrodialysis device, the upper part of the electrodialysis device is connected to the desalination liquid outlet pipeline, and the lower part of the electrodialysis device is connected to The concentrated solution outlet pipeline, the desalinated solution outlet pipeline are connected to the water storage tank, the concentrated solution outlet pipeline is connected to the three-effect concentrator inlet pump, the outlet pipe of the three-effect concentrator inlet pump is connected to the three-effect concentration crystallizer, and the three-effect concentration crystallizer The outlet pipe is connected to the water storage tank, the water storage tank is connected to the second water inlet pump, the outlet pipe of the second water inlet pump is connected to the integrated anaerobic ammonium oxidation reactor, and the top of the integrated anaerobic ammonium oxidation reactor is provided with a gas outlet and a gas return pipeline, The inner cavity of the integrated anaerobic ammonium oxidation reactor is provided with a reaction zone and a top zone, and the bottom of the reaction zone is provided with a microporous aeration head connected to an air compressor; an overflow weir is provided between the reaction zone and the top zone, The outside of the overflow weir communicates with the outlet pipeline.