Efficient percolation and denitrification nitrogen removal treatment system for rare earth mine tail water

Abstract

The invention relates to an efficient percolation and denitrification nitrogen removal treatment system for rare earth mine tail water. The efficient percolation and denitrification nitrogen removal treatment system comprises a water inlet system, a denitrification percolation reaction system, a backwashing system, a dosing system and a drainage system, the water inlet system comprises a water inlet tank; the water inlet tank is connected with a water distribution pipe network through a pipeline I provided with a lifting pump; the denitrification percolation reaction system comprises a reaction box body for accommodating a water distribution pipe network, and a filter material is arranged in the reaction box body; the backwashing system comprises a multi-layer backwashing pipe network positioned in the reaction box body, and a pipeline II for mounting a backwashing pump is arranged on the backwashing pipe network; the dosing system comprises a carbon source dosing barrel connected with the reaction box body through a pipeline III; the drainage system comprises a water collecting pipe network positioned in the reaction box body, and a drainage electric valve is arranged on the water collecting pipe network. The system achieves the purpose of high-efficiency and low-cost denitrification treatment.

Description

Technical Field

[0001] The present invention relates to the field of sewage treatment, and in particular to a rare earth mine tail water high-efficiency infiltration and denitrification treatment system. Background Art

[0002] Rare earth resources are one of my country's important mineral resources. Their mining is to use ammonium sulfate immersion to replace ionic rare earth elements into the solution, and then use oxalic acid or ammonium carbonate to precipitate to obtain rare earth concentrate. This in-situ leaching method will form a large amount of rare earth tail water containing high ammonia nitrogen and high nitrate nitrogen during the production process. Improper treatment will cause the risk of excessive total nitrogen in surface water.

[0003] At present, the main methods for treating total nitrogen in basin-wide rare earth tail water include traditional biological denitrification, membrane method, ion exchange method, short-term nitrification and denitrification processes. Due to the low concentration of organic matter and poor biodegradability of rare earth tail water, the traditional biological denitrification method has a high residual sludge output and a large amount of carbon source addition, which makes it difficult to use. The membrane method has problems such as easy clogging and high cost. The ion exchange method has high energy consumption. The short-term nitrification and denitrification process has problems such as difficult to control operating conditions and unstable effects. Summary of the Invention

[0004] The purpose of the present invention is to provide a rare earth mine tail water high-efficiency infiltration denitrification treatment system.

[0005] The technical problems of the present invention are mainly solved by the following technical solutions:

[0006] A rare earth mine tail water high-efficiency filtration and denitrification treatment system, including a water inlet system, a denitrification filtration reaction system, a backwash system, a dosing system and a drainage system;

[0007] The water inlet system includes a water inlet tank, which is connected to the water distribution network through a pipe I equipped with a lift pump;

[0008] The denitrification filtration reaction system includes a reaction box for accommodating a water distribution network, wherein filter material is arranged in the reaction box;

[0009] The backwash system includes a multi-layer backwash pipe network located in the reaction box, and a pipe II for installing a backwash pump is provided on the backwash pipe network;

[0010] The dosing system includes a carbon source dosing barrel connected to the reaction box through a pipeline III;

[0011] The drainage system includes a water collection network located in the reaction box body, and a drainage electric valve is provided on the water collection network.

[0012] Preferably, the filter material consists of a water-absorbing layer and a fine material layer, wherein the water-absorbing layer is made of crushed stone, and the fine material layer is made of a mixture of ceramsite and slag.

[0013] Preferably, the water distribution network, backwash network and water collection network are all designed in a V-shaped structure.

[0014] Preferably, the pipeline 1 is provided with a water inlet flow meter.

[0015] Preferably, a carbon source dosing pump is provided on the pipeline III.

[0016] The beneficial effects of the present invention are:

[0017] (1) The filter material with a large specific surface area in the reaction box of the present invention provides a large amount of attachment surface for the denitrifying bacteria biofilm, which increases the amount of the denitrifying bacteria biofilm to a certain extent, thereby improving the treatment effect.

[0018] (2) In the present invention, sewage passes through the filter material layer from top to bottom. The filter material can not only block the entry of air, thereby ensuring that the interior of the filter material is always in an oxygen-deficient or even anaerobic environment; secondly, the interception effect of the filter material can also effectively reduce the loss of microbial membranes, ensuring the smooth progress of denitrification.

[0019] (3) The present invention requires fewer pieces of equipment when applied to a project, significantly reducing electricity costs and simplifying daily management and maintenance. Furthermore, compared to conventional denitrification processes, the present invention produces significantly less sludge, which reduces sludge disposal costs to a certain extent. Therefore, the present invention can reduce overall operating costs to a certain extent.

[0020] (4) Compared with the traditional denitrification denitrification process, the present invention does not require the addition of a sedimentation tank at the back end, which can greatly reduce the floor space and has a higher treatment efficiency. The present invention is suitable for the construction or upgrading of sewage treatment facilities of various sizes. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the present invention.

[0022] In the figure: 1-water inlet tank, 2-lifting pump, 3-water inlet flowmeter, 4-water distribution network, 5-reaction box, 6-backwash pump, 7-first layer backwash network, 8-second layer backwash network, 9-third layer backwash network, 10-water collection network, 11-drainage electric valve, 12-second layer backwash drain valve, 13-first layer backwash drain valve, 14-carbon source dosing barrel, 15-carbon source dosing pump, 16-filter material. DETAILED DESCRIPTION

[0023] The technical solution of the present invention will be further specifically described below through embodiments and in conjunction with the accompanying drawings.

[0024] An efficient infiltration denitrification nitrogen removal treatment system for rare earth mine tail water mainly includes an inlet water system, a denitrification infiltration reaction system, a backwashing system, a dosing system and a drainage system;

[0025] As Figure 1 shown, the inlet water system includes an inlet water tank 1, and the inlet water tank is connected to a water distribution network 4 through a pipeline I equipped with a lift pump 2, and an inlet water flowmeter 3 is arranged on the pipeline I;

[0026] As Figure 1 shown, the denitrification infiltration reaction system includes a reaction box body 5 for accommodating the water distribution network 4, and a filter material 16 is arranged in the reaction box body 5. The filter material consists of a water collection layer and a fine material layer. The material of the water collection layer is gravel, and the fine material layer is composed of a mixture of ceramsite and slag.

[0027] As Figure 1 shown, the backwashing system includes a first-layer backwashing pipe network 7, a second-layer backwashing pipe network 8 and a third-layer backwashing pipe network 9 located in the reaction box body 5. A pipeline II equipped with a backwashing pump 6 is arranged on each of the first-layer backwashing pipe network 7, the second-layer backwashing pipe network 8 and the third-layer backwashing pipe network 9. A first-layer backwashing sewage discharge valve 13 and a second-layer backwashing sewage discharge valve 12 are sequentially arranged on the reaction box body 5.

[0028] As Figure 1 shown, the dosing system includes a carbon source dosing barrel 14 connected to the reaction box body 5 through a pipeline III, and a carbon source dosing pump 15 is arranged on the pipeline III.

[0029] As Figure 1 shown, the drainage system includes a water collection pipe network 10 located in the reaction box body 5, and a drainage electric valve 11 is arranged on the water collection pipe network 10. In the drainage system of this embodiment, the height of the water outlet is adjustable, and it is ensured that the height of the submerged water layer at the bottom of the filter material is not less than 50 cm.

[0030] During the actual operation process, the rare earth tail water in the inlet water tank 1 is sent into the reaction box body 5 through the lift pump 2 after nitrification, and the inlet water volume is regulated by the inlet water flowmeter 3. When the wastewater enters the reaction box body 5, the "丰"-shaped water distribution network 4 arranged above the filter material 16 makes the wastewater evenly pass through the filter material 16 from top to bottom.

[0031] The carbon source required in the reaction box 5 is delivered to the reaction box 5 through the carbon source dosing pump 15 to dissolve the carbon source in the carbon source dosing barrel 14 through the water distribution network, wherein the dosing system and the water inlet system are intermittently operated at the same time to ensure that the carbon source and the sewage are evenly mixed when the water is distributed, and the carbon-nitrogen ratio of the inlet water is controlled at 2.5:1 to 4:1. The carbon source added to the inlet water is composed of one or more of sodium acetate, glucose, ethanol, and a composite carbon source. The wastewater is fully contacted with the microbial membrane system in the filter material 16 during the filtration process to convert the nitrate nitrogen in the rare earth tail water into nitrogen gas, thereby achieving the purpose of removing the total nitrogen in the wastewater through the denitrification action of the microbial membrane system.

[0032] The drainage system is opened and closed by the drainage electric valve 11 to discharge the wastewater after denitrification in the reaction box 5 through the water collection pipe network 10. The drainage electric valve 11 can control the residence reaction time of the wastewater in the reaction box 5 to ensure that the denitrification reaction is fully carried out.

[0033] Due to the addition of carbon source in the reaction box 5, a flocculent substance will be generated in the reaction box 5, and it will mainly remain on the surface of the filter material 16. Therefore, a backwash system is set up for cleaning. The backwash system is mainly composed of a first-layer backwash pipe network, while a second and third-layer backwash pipe network is reserved. By using pipeline II and backwash pump 6 and passing clean water into the reaction box 5 through the first-layer backwash pipe network 7, the second-layer backwash pipe network 8, and the third-layer backwash pipe network 9, the filter material 16 is cleaned to prevent blockage in the filter material layer. The three-layer backwash pipe network is set up to clean the filter material layers at different heights to achieve the purpose of comprehensive cleaning; the filter material sewage cleaned by backwashing is discharged through the first-layer backwash drain valve 13 and the second-layer backwash drain valve 12.

[0034] To ensure quick system startup:

[0035] Preferably, activated sludge that has been acclimated to denitrification is given priority for inoculation. If not available, the residual sludge from the secondary sedimentation tank of a nearby municipal sewage treatment plant can be selected as the source of inoculation sludge.

[0036] Preferably, the height of the flooded layer at the bottom of the filter material 16 in the reaction box 5 is not less than 50 cm.

[0037] Preferably, in order to ensure the normal operation of the system, the filter material 16 needs to be backwashed regularly to clear blockages, and the surface filter material 16 needs to be flushed mainly, and each backwashing time is not less than 30 minutes.

[0038] At the same time, the total nitrogen value of the influent should be gradually increased by increasing the influent pollution concentration in stages, and the effluent should be taken for water quality analysis at least twice a day until the system operates stably.

[0039] The present invention is described in detail below with reference to specific embodiments.

[0040] Example 1:

[0041] A pilot project for rare earth tailwater treatment in a rare earth basin in Longnan, with a daily water treatment volume of 8m 3 / d, with an influent total nitrogen concentration of 70-100 mg / L, a high-efficiency filtration and denitrification treatment system for rare earth mine tailwater was tested. A carbon source, primarily glucose, was added to supplement the denitrification process. A backwash system was regularly used to clear blockages in the surface filter media within the denitrification filtration reaction chamber 5. The test results are shown in the following table:

[0042]

[0043] As can be seen from the results in Table 1, the present invention adopts a rare earth mine tail water high-efficiency filtration denitrification denitrification treatment system that can meet the corresponding emission requirements in the national "Rare Earth Industry Pollutant Emission Standard" (GB26451-2011). For the total nitrogen in the influent of 70-100 mg / L, the effluent of this system is stable and the total nitrogen in the effluent is less than 15 mg / L, with an average of 4.88 mg / L; at the same time, from the perspective of the influent C / N, the influent C / N of the traditional denitrification denitrification process is greater than 5, and the influent C / N of the present invention is between 1.42-3.30, with an average of 2.2, which greatly reduces the cost of using the carbon source. At the same time, from the perspective of daily maintenance and management, the present invention has a small number of equipment, and daily maintenance and management are relatively simple and greatly reduce electricity consumption costs. Secondly, the system produces a small amount of sludge, which greatly reduces the cost of sludge disposal. It can be seen that this system has great advantages over traditional denitrification processes.

[0044] The present invention has been described in detail above, but the contents described are only preferred embodiments of the present invention and should not be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A rare earth mine tail water high-efficiency filtration and denitrification treatment system, characterized by: Including water inlet system, denitrification and filtration reaction system, backwash system, dosing system and drainage system; The water inlet system includes a water inlet tank, which is connected to the water distribution network through a pipe I equipped with a lift pump; The denitrification filtration reaction system includes a reaction box for accommodating a water distribution network, wherein filter material is arranged in the reaction box; The backwash system includes a multi-layer backwash pipe network located in the reaction box, and a pipe II for installing a backwash pump is provided on the backwash pipe network; The dosing system includes a carbon source dosing barrel connected to the reaction box through a pipeline III; The drainage system includes a water collection network located in the reaction box body, and a drainage electric valve is provided on the water collection network.

2. The rare earth mine tailwater high-efficiency filtration and denitrification treatment system according to claim 1, characterized in that: The filter material consists of crushed stone, ceramsite and slag.

3. The rare earth mine tailwater high-efficiency filtration and denitrification treatment system according to claim 1, characterized in that: The water distribution network, backwash network and water collection network are all designed in a "F"-shaped structure.

4. The rare earth mine tailwater high-efficiency filtration and denitrification treatment system according to claim 1, characterized in that: The pipeline 1 is provided with a water inlet flow meter.

5. The high-efficiency filtration and denitrification treatment system for rare earth mine tail water according to claim 1, characterized in that: The pipeline III is provided with a carbon source dosing pump.

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