A multi-stage roadway wastewater heavy metal blocking and controlling device and a wastewater treatment method

Abstract

The application discloses a kind of roadway inside wastewater heavy metal multistage type blocking and controlling device and wastewater treatment method, including reactor and reaction pool, reactor and reaction pool are set in the water outlet roadway of flat adit mining, one end of reactor is communicated with mine wastewater through pipeline, one end of reaction pool and the other end of reactor are connected through pipeline, and the artificial wetland is connected into adit mouth after water outlet of reaction pool.The device effectively treats iron and other pollutants in the wastewater migration roadway, reduces the burden of downstream treatment, avoids system blockage and paralysis caused by high metal concentration in traditional treatment device, thereby reducing the difficulty of mine wastewater treatment, and the reasonable device filler sequence reduces the filling of organic nutrients, effectively reduces the wastewater treatment cost.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, specifically to a multi-stage heavy metal control device for wastewater in tunnels, and also to a method for treating wastewater in tunnels. Background Technology

[0002] Currently, most acidic mine wastewater treatment in China adopts end-of-pipe treatment methods, constructing relevant treatment facilities at the point of wastewater discharge. However, karst mining areas have high rainfall, numerous surface karst fissures, and favorable groundwater recharge conditions, resulting in large wastewater volumes and high treatment costs. Furthermore, the dispersed and disorganized nature of closed mines, along with the presence of large amounts of sulfur-containing slag deposits on the surface, makes wastewater treatment extremely difficult.

[0003] In addition, acidic mine wastewater generated by mining activities is mainly formed by metal sulfide minerals (pyrite, chalcopyrite, arsenopyrite, sphalerite, galena, etc.) through complex physicochemical processes. Taking pyrite as an example, its reaction process mainly includes the following aspects: (1) In the initial stage, pyrite reacts with water and air to produce acid and generate sulfuric acid and ferrous sulfate; (2) As the oxidation reaction proceeds, ferrous iron is oxidized to ferric iron; (3) The ferric iron formed is further hydrolyzed to form Fe(OH)3, which at the same time lowers the pH of the water; (4) Under acidic conditions, Fe 3+ FeS2 becomes the main oxidizing agent, and is converted by Fe 3+ Oxidation, the reaction produces a large amount of Fe 2+ and H + Therefore, the iron element in freshly leached mine wastewater is mainly in the form of Fe. 2+ Fe ions exist in ionic form, but common neutralization reactions can only raise the pH of mine wastewater to neutral, and cannot quickly and effectively precipitate Fe ions. Therefore, complex, floor-sized equipment is required to precipitate Fe ions. 2+ Ions are removed. Due to the size limitations of the equipment, a wastewater treatment plant can only be installed outside the mine shaft. Therefore, the mine wastewater generated inside the mine shaft must first be diverted outside for treatment. During the diversion process, the mine wastewater comes into contact with oxygen in the air and produces precipitates, causing problems with the pipes diverting the wastewater and the Fe... 2+ The equipment used for ion removal will gradually become clogged, requiring time and manpower for cleaning. The resulting precipitates will adhere firmly to the pipes, making cleaning difficult. Improper operation during the cleaning process can also easily damage the tunnels and equipment. Summary of the Invention

[0004] Therefore, the present invention provides a multi-stage heavy metal control device for wastewater in tunnels to solve the above-mentioned problems in the prior art.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] According to a first aspect of the present invention, a multi-stage heavy metal control device for wastewater in a tunnel includes a reactor and a reaction tank. The reactor and the reaction tank are disposed in the water outlet tunnel of an adit. One end of the reactor is connected to the mine wastewater through a pipeline, and one end of the reaction tank and the other end of the reactor are connected through a pipeline. The other end of the reaction tank is connected to an artificial wetland at the entrance of the tunnel.

[0007] Furthermore, the reactor includes a reaction shell, and multiple partition plates are provided inside the reaction shell to divide the chambers inside the reaction shell into an anaerobic chamber, a culture chamber, and a microbial chamber;

[0008] Each partition has a water passage hole;

[0009] The anaerobic chamber is connected to the mine wastewater through a water passage, the culture chamber is connected to the anaerobic chamber through a water passage, the microbial chamber is connected to the culture chamber through a water passage, and the reaction tank is connected to the microbial chamber through a water passage.

[0010] Furthermore, the reactor also includes multiple settling frames and multiple settling racks, with the multiple settling racks slidingly connected to the multiple settling frames in a one-to-one correspondence;

[0011] The lower surface of the reaction shell has multiple lower openings, which correspond one-to-one with the anaerobic chamber, the culture chamber and the microbial chamber. Multiple sedimentation racks are detachably connected to the lower openings of the reaction shell.

[0012] Furthermore, the reaction tank includes a mine wastewater inlet, a primary sedimentation tank, a carbon tank, a calcium carbonate tank, a secondary sedimentation tank, a mine wastewater outlet, and a filter, which are connected in sequence. The microbial chamber is connected to the mine wastewater inlet through a water passage, and the mine wastewater outlet is connected to the constructed wetland through the filter.

[0013] Furthermore, the reaction tank also includes a residue tank, a primary sedimentation tank connected to a residue tank via a pipeline, a carbon tank connected to a residue tank via a pipeline, a calcium carbonate tank connected to a residue tank via a pipeline, and a secondary sedimentation tank connected to a residue tank via a pipeline.

[0014] Furthermore, the anaerobic chamber is equipped with acidophilic iron-oxidizing bacteria.

[0015] The first aspect of this invention provides a multi-stage heavy metal control device for wastewater in roadways, which has the following advantages: The device effectively treats pollutants such as iron in wastewater migration roadways, reducing the burden on downstream treatment. It also avoids system blockage and paralysis caused by excessively high metal concentrations in traditional treatment devices, thereby reducing the difficulty of treating mine wastewater. The reasonable packing sequence reduces the amount of organic nutrients required, effectively lowering wastewater treatment costs. The reactor and reaction tank are located in the wastewater overflow roadway of the adit mining, allowing the mine wastewater generated in the mine to be directly introduced into the reactor and reaction tank for treatment within the roadway, eliminating the need for surface-mounted reaction equipment. This effectively shortens the wastewater transport time and prevents the formation of large amounts of sediment due to prolonged contact with oxygen in the air, thus avoiding pipe blockage and further reducing the difficulty of mine wastewater treatment.

[0016] According to a second aspect of the present invention, a method for treating wastewater in a tunnel utilizes all the technical features of a multi-stage heavy metal control device for wastewater in a tunnel according to the first aspect of the present invention, and further includes the following steps:

[0017] Step S100: Place the reactor and reaction tank in the wastewater tunnel of the adit mining. The mine wastewater in the mine flows into the anaerobic chamber of the reactor, so that the acidophilic iron oxidizing bacteria come into contact with the mine wastewater. After the reaction, separate the supernatant to obtain the filtrate.

[0018] Step S200: The filtrate flows into the anaerobic chamber through the water passage, and the pH value of the filtrate is neutralized to 6-8 by the carbonate rocks in the anaerobic chamber, resulting in neutral wastewater;

[0019] Step S300: Neutral wastewater flows into the culture chamber of the reactor, and the bacteria are cultured by the organic matter in the culture chamber to obtain organic liquid;

[0020] Step S400: The organic liquid flows into the microbial chamber of the reactor through the water passage, and the sulfate-reducing bacteria in the microbial chamber react with the heavy metals in the organic liquid to form heavy metal sulfide precipitates.

[0021] Step S500: The settled liquid flows into the primary sedimentation tank, yielding residue and primary sedimentation wastewater;

[0022] Step S600: The primary sedimentation wastewater flows sequentially into the carbon tank and the calcium carbonate tank for filtration, resulting in residue and primary filtration wastewater;

[0023] Step S700: The primary filtration wastewater flows into the secondary sedimentation tank for sedimentation, resulting in residue and secondary sedimentation wastewater;

[0024] Step S800: The secondary sedimentation wastewater flows out after being filtered by a filter to obtain clean water; after being adsorbed by iron powder and processed by an artificial wetland, the effluent is discharged into rivers.

[0025] Furthermore, the acidophilic iron-oxidizing bacteria in step S100 are *Thiobacillus ferrooxidans*.

[0026] Furthermore, the grain size of the carbonate rock in step S200 is 10 mm to 20 mm.

[0027] Furthermore, the organic matter in step S300 is crushed straw.

[0028] The wastewater treatment method in a tunnel according to the second aspect of the present invention has the following advantages:

[0029] First, the device of this invention effectively treats pollutants such as iron in wastewater migration tunnels, reducing the burden on downstream treatment. It also avoids system blockage and paralysis caused by excessively high metal concentrations in traditional treatment devices, thereby reducing the difficulty of treating mine wastewater. The reasonable packing sequence of the device reduces the amount of organic nutrients required, effectively lowering wastewater treatment costs. The reactor in this invention is placed in the wastewater overflow tunnel of an adit. Mine wastewater generated in the adit can be directly introduced into the reactor and reaction tank for treatment within the tunnel, eliminating the need for surface-mounted reaction equipment. This effectively shortens the transportation time of mine wastewater and prevents the formation of large amounts of sediment due to prolonged contact with oxygen in the air, thus avoiding pipe blockage.

[0030] Second, Fe is oxidized by acidophilic iron-oxidizing bacteria. 2+ Oxidation of ions to Fe 3+ In addition to ionization, acidophilic iron-oxidizing bacteria also consume oxygen in the mine wastewater during the reaction process, further preventing Fe from oxidizing in the mine wastewater. 2+ Oxidation and precipitation clog the reactor.

[0031] Third, in step S400 of the present invention, the bacteria are first cultured in organic matter to rapidly increase the total amount of bacteria, thereby increasing the reaction rate during subsequent reactions and thus improving the overall treatment efficiency of mine wastewater.

[0032] Fourth, the carbonate rock added in this invention neutralizes the acid in the wastewater in the tunnel, increasing the pH value. Simultaneously, it generates CO2 during the reaction. The CO2, when dissolved in water, provides carbon for the growth of acidophilic iron-oxidizing bacteria. Therefore, steps S100 and S200 do not require the addition of excessive organic nutrients to allow the acidophilic iron-oxidizing bacteria to multiply rapidly, thereby improving their ability to absorb Fe. 2+ While improving ion treatment efficiency, this approach also avoids excessive nutrient residue in wastewater, preventing secondary pollution. Furthermore, the carbonate rock used in this solution is more cost-effective, and the optimized packing sequence reduces the amount of organic nutrients required, effectively lowering wastewater treatment costs. Attached Figure Description

[0033] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0034] The structures, proportions, sizes, etc. illustrated in this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed herein, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportions, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should still fall within the scope of the technical content disclosed in the present invention.

[0035] Figure 1 The flowchart illustrates a method for treating heavy metals in wastewater in a roadway using a multi-stage barrier control device, as provided in some embodiments of the present invention.

[0036] Figure 2 The present invention provides a process flow diagram of the reaction tank of a multi-stage heavy metal control device for wastewater in a roadway, which is provided for some embodiments of the present invention.

[0037] Figure 3 This is a schematic diagram of an artificial wetland 42 for a multi-stage heavy metal control device for wastewater in a roadway, provided in some embodiments of the present invention.

[0038] Figure 4 This is a perspective view of the reaction tank of a multi-stage heavy metal control device for wastewater in a roadway, provided for some embodiments of the present invention.

[0039] Figure 5 This is a schematic diagram of the primary sedimentation tank structure of a multi-stage heavy metal control device for wastewater in a roadway, provided for some embodiments of the present invention.

[0040] Figure 6 This is a schematic diagram of the carbon pool structure of a multi-stage heavy metal control device for wastewater in a roadway, provided in some embodiments of the present invention.

[0041] Figure 7 This is a schematic diagram of the calcium carbonate tank in a multi-stage heavy metal control device for wastewater in a roadway, provided for some embodiments of the present invention.

[0042] Figure 8 This is a schematic diagram of the structure of a two-stage sedimentation tank in a multi-stage heavy metal control device for wastewater in a roadway, provided for some embodiments of the present invention.

[0043] Figure 9This is a schematic diagram of the filter structure of a multi-stage heavy metal control device for wastewater in a tunnel, provided in some embodiments of the present invention.

[0044] Figure 10 The diagram shows the structure of the residue pool in a multi-stage heavy metal control device for wastewater in a tunnel, as provided in some embodiments of the present invention.

[0045] Figure 11 This is a reactor assembly diagram of a multi-stage heavy metal control device for wastewater in a tunnel, provided for some embodiments of the present invention.

[0046] Figure 12 This is a perspective view of a reactor without a side cover in a multi-stage heavy metal control device for wastewater in a tunnel, provided for some embodiments of the present invention.

[0047] Figure 13 This is a structural diagram of the reaction shell of a multi-stage heavy metal control device for wastewater in a tunnel, provided in some embodiments of the present invention.

[0048] Figure 14 The diagram shows the sedimentation frame structure of a multi-stage heavy metal control device for wastewater in a tunnel, provided in some embodiments of the present invention.

[0049] Figure 15 This is a perspective view of a sedimentation rack for a multi-stage heavy metal control device for wastewater in a tunnel, provided for some embodiments of the present invention.

[0050] Figure 16 This is a side cover structure diagram of a reactor for a multi-stage heavy metal control device for wastewater in a roadway, provided for some embodiments of the present invention.

[0051] Figure 17 This is a diagram showing the pore plug structure of the reactor in a sedimentation rack of a multi-stage heavy metal control device for wastewater in a tunnel, provided for some embodiments of the present invention.

[0052] In the diagram: 1. Mine wastewater; 2. Reactor; 21. Reaction shell; 211. Partition plate; 212. Water passage hole; 213. Anaerobic chamber; 214. Culture chamber; 215. Microbial chamber; 216. Lower opening; 217. First groove; 22. Side cover; 221. Feed hole; 231. Sedimentation frame; 2311. Frame body; 2312. Slide chamber; 2313. Top cover plate; 2314. Second groove; 2315. First protrusion; 231 6. Sedimentation hole; 232. Sedimentation rack; 2321. Drawer; 2322. Drawer lid; 2323. Handle; 25. Hole plug; 3. Reaction tank; 30. Mine wastewater inlet; 31. Primary sedimentation tank; 311. First inlet channel; 312. Sludge discharge pipe; 313. Drainage channel; 32. Carbon tank; 321. First inlet; 322. Charcoal layer; 323. Carbon tank body; 324. First cement slab; 325. First outlet; 326. White water layer. 33. Calcium carbonate tank; 330. Calcium carbonate tank body; 331. Second inlet; 332. Overflow weir; 333. Calcium carbonate filter media layer; 334. Second cement slab; 335. Water gate; 336. Vent; 337. Second outlet; 338. Baffle wall; 34. Secondary sedimentation tank; 341. Second inlet channel; 342. Filter media layer; 343. Outlet channel; 35. Filter; 3502. First inlet / outlet pipe; 3504. Fiber ball filter media; 3 505. First water distribution pipe; 3506. Support leg; 3507. Second inlet / outlet pipe; 3508. Discharge port; 3509. Manhole; 3510. Second water distribution pipe; 3511. Exhaust port; 3512. Filter tank; 36. Residue tank; 361. First residue tank; 362. Second residue tank; 363. Vent hole; 364. Sedimentation baffle; 37. Mine wastewater outlet hole; 4. Wetland treatment; 41. Iron powder layer; 42. Constructed wetland; 5. Effluent. Detailed Implementation

[0053] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0054] like Figures 1 to 17 As shown, a multi-stage heavy metal control device for wastewater in a roadway according to a first aspect embodiment of the present invention includes a reactor 2 and a reaction tank 3. The reactor 2 is placed in the goaf of the mine. One end of the reactor 2 is connected to the mine wastewater 1 through a pipeline. One end of the reaction tank 3 is connected to the other end of the reactor 2 through a pipeline. The other end of the reaction tank 3 is connected to an artificial wetland 42.

[0055] In the above embodiments, it should be noted that the working principle of this device is as follows: the mine wastewater 1 is guided to the reactor 2, the reactor 2 is used to neutralize the mine wastewater 1 to obtain neutral wastewater, and then the neutral wastewater is precipitated and filtered in the reaction tank 3. After being treated by adsorption of iron powder layer 41 in the wetland treatment 4, it passes through the artificial wetland 42 and is discharged into the river through the effluent 5, and the treatment is completed.

[0056] Specifically, a retaining wall can be installed at the end of the exit away from the roadway to raise the level of the mine wastewater. The pipe is then installed through the thickness of the retaining wall, with one end connected to the mine wastewater and the other end connected to reactor 2. The mine wastewater in the roadway is then introduced into reactor 2 by gravity for a series of wastewater treatment processes.

[0057] The technical effects achieved by the above embodiments are as follows: Reactor 2 and reaction tank 3 are set in the wastewater overflow roadway of the adit mining. The mine wastewater 1 generated in the mine can be directly introduced into the reactor and reaction tank for treatment in sequence within the roadway, eliminating the need for surface-mounted reaction equipment. This effectively shortens the transportation time of mine wastewater and avoids the formation of large amounts of sediment due to prolonged contact with oxygen in the air, thus preventing pipe blockage and reducing the difficulty of mine wastewater treatment. In addition, the multi-stage heavy metal control device in the roadway can effectively treat pollutants such as iron directly within the roadway, reducing the burden on downstream treatment. This device effectively treats pollutants such as iron in the wastewater migration roadway, reducing the burden on downstream treatment, while avoiding system blockage and paralysis caused by excessively high metal concentrations in traditional treatment devices. This further reduces the difficulty of mine wastewater treatment. The reasonable packing sequence of the device reduces the amount of organic nutrients required, effectively lowering the cost of wastewater treatment.

[0058] It should be noted that casters can be installed at the bottom of reactor 2 and reaction tank 3, which makes it easy to place reactor 2 and reaction tank 3 in the tunnel and lock them.

[0059] Optional, such as Figures 1 to 17 As shown, in some embodiments, the reactor 2 includes a reaction shell 21, and a plurality of partition plates 211 are provided inside the reaction shell 21. The partition plates 211 divide the chambers inside the reaction shell 21 into an anaerobic chamber 213, a culture chamber 214, and a microbial chamber 215.

[0060] Each partition 211 has a water passage hole 212.

[0061] Anaerobic chamber 213 is connected to mine wastewater 1 through water passage 212, culture chamber 214 is connected to anaerobic chamber 213 through water passage 212, microbial chamber 215 is connected to culture chamber 214 through water passage 212, and reaction tank 3 is connected to microbial chamber 215 through water passage 212.

[0062] In the above optional embodiments, it should be noted that pH meters are installed in both the anaerobic chamber 213 and the culture chamber 214.

[0063] The beneficial effects of the above optional embodiments are as follows: by setting up water passage holes 212 on each partition plate 211, the gravity and flow of water can be used to guide the flow of each mine wastewater 1 in each chamber. In addition, the anaerobic chamber 213 creates an anaerobic environment to inhibit the release of oxidizing acids from primary minerals; the microbial chamber 215 promotes the growth of microorganisms, and the sulfides generated react with dissolved metals to produce precipitation; the culture chamber 214 increases the water flow path and water-rock reaction time, thus promoting water purification.

[0064] Optional, such as Figures 1 to 17 As shown, in some embodiments, the reactor 2 further includes a plurality of sedimentation frames 231 and a plurality of sedimentation racks 232, with the plurality of sedimentation racks 232 and the plurality of sedimentation frames 231 being slidably connected in a one-to-one correspondence.

[0065] The lower surface of the reaction shell 21 has multiple lower openings 216, which are respectively connected to the anaerobic chamber 213, the culture chamber 214 and the microbial chamber 215. Multiple sedimentation racks 232 are detachably connected to the lower openings 216 of the reaction shell 21.

[0066] In the above optional embodiments, it should be noted that the reactor 2 also includes a side cover 22. The side cover 22 is connected to the reaction shell 21 by means of bolt connection or welding connection. When the side cover 22 is connected to the reaction shell 21 by bolt connection, a sealing strip is provided between the side cover 22 and the reaction shell 21. The side cover 22 is provided with a feed hole 221, which is blocked by a plug 25.

[0067] The reaction shell 21 has a first groove 217 on the side wall of the lower opening 216. The sedimentation frame 231 includes a frame body 2311. A top cover plate 2313 is provided on the top of the frame body 2311. A first protrusion 2315 is provided on the surface of the top cover plate 2313 away from the frame body 2311. A sliding groove cavity 2312 is provided in the frame body 2311. A plurality of sedimentation holes 2316 are provided on the top cover plate 2313. The first protrusion 2315 is inserted into the first groove 217. A sealing strip is provided between the first protrusion 2315 and the side wall of the first groove 217.

[0068] The sedimentation rack 232 includes a drawer 2321, a drawer cover 2322, and a handle 2323. The drawer cover 2322 is located on one side of the drawer 2321. The drawer 2321 is slidably connected to the slide cavity 2312 of the sedimentation frame 231. The drawer cover 2322 is provided with a handle 2323 on the side facing away from the drawer 2321. A sealing strip is provided between the drawer 2321 and the sedimentation frame 231.

[0069] The advantages of the above optional embodiments are as follows: by setting up the sedimentation rack 232 and sedimentation frame 231, the residue after the wastewater is discharged from the anaerobic chamber 213, the culture chamber 214 and the microbial chamber 215 can be stored in the drawer 2321 of the sedimentation rack 232. The residue can be quickly poured out by pulling out the drawer 2321, which is very convenient.

[0070] Optional, such as Figures 1 to 17 As shown, in some embodiments, the reaction tank 3 includes a mine wastewater inlet 30, a primary sedimentation tank 31, a carbon tank 32, a calcium carbonate tank 33, a secondary sedimentation tank 34, a mine wastewater outlet 37, and a filter 35 connected in sequence. The microbial chamber 215 is connected to the mine wastewater inlet 30 through a water passage 212, and the mine wastewater outlet 37 is connected to the constructed wetland 42 through the filter 35.

[0071] In the above optional embodiments, it should be noted that the specific reaction tank 3 consists of two primary sedimentation tanks 31, three carbon tanks 32, three calcium carbonate tanks 33, and two secondary sedimentation tanks 34. The carbon tanks 32 are charcoal filters, and the calcium carbonate tanks 33 are calcium carbonate filters. The two primary sedimentation tanks 31 are connected in parallel, one in use and one on standby; the three carbon tanks 32 are all in parallel and all in use; the three calcium carbonate tanks 33 are all in parallel and all in use; and the two secondary sedimentation tanks 34 are connected in parallel, one in use and one on standby. Mine water enters through the primary sedimentation tank 31, and after sedimentation in the primary sedimentation tank 31, most of the antimony-containing particles, approximately 20%, are removed. Then, the water enters the carbon tank 32 through the channel connecting the primary sedimentation tank 31 and the carbon tank 32, then enters the calcium carbonate tank 33, and finally enters the secondary sedimentation tank 34 through the channel connecting the calcium carbonate tank 33 and the secondary sedimentation tank 34. After further sedimentation in the secondary sedimentation tank 34, it enters the filter 35, and then enters the fiber filter 35 through the outlet pipe. After being filtered by the disc filter and the fiber filter, the mine water can be discharged in compliance with standards.

[0072] There are two disc filters 35 and two fiber filters 35, one for backup and one for use.

[0073] In addition, the reaction tank 3 also includes a residue tank 36, the primary sedimentation tank 31 is connected to a residue tank 36 via a pipeline, the carbon tank 32 is connected to a residue tank 36 via a pipeline, the calcium carbonate tank 33 is connected to a residue tank 36 via a pipeline, and the secondary sedimentation tank 34 is connected to a residue tank 36 via a pipeline.

[0074] The primary sedimentation tank 31 includes a first inlet channel 311, a sludge discharge pipe 312, and a drainage channel 313. The bottom of the primary sedimentation tank 31 is square-shaped, with the angle between the corner of the bucket and the horizontal plane less than or equal to 45 degrees. The first inlet channel 311 and the drainage channel 313 are respectively set at both ends of the primary sedimentation tank 31. The first inlet channel 311 is connected to the mine wastewater inlet 30, and the drainage channel 313 is connected to the carbon pool 32. The bottom of the primary sedimentation tank 31 is equipped with a sludge discharge pipe 312. Sludge is discharged at regular intervals through the sludge discharge pipe 312. The sludge discharge cycle is generally 3 to 5 days. After filtration, the filtrate enters the residue pool 36, and the filter cake is collected in plastic buckets and transported away for disposal.

[0075] The carbon pool 32 includes a first inlet 321, a charcoal layer 322, a carbon pool body 323, a first cement slab 324, a first outlet 325, and a white water layer 326. The white water layer 326, the charcoal layer 322, and the first cement slab 324 are arranged sequentially from top to bottom inside the carbon pool body 323. The first cement slab 324 has multiple holes. The first inlet 321 is opened on one side wall of the carbon pool body 323, and the first outlet 325 is opened on the other side wall of the carbon pool body 323. The first inlet 321 is connected to the drainage ditch 313, and the first outlet 325 is connected to the calcium carbonate pool 33.

[0076] The calcium carbonate tank 33 includes a calcium carbonate tank body 330, a second inlet 331, an overflow weir 332, a calcium carbonate filter media layer 333, a second cement slab 334, a sluice gate 335, a vent 336, a second outlet 337, and a baffle wall 338. The baffle wall 338 is disposed within the calcium carbonate tank body 330. Between the baffle wall 338 and the inner side wall of one side of the calcium carbonate tank body 330, the overflow weir 332, the calcium carbonate filter media layer 333, and the second cement slab 334 are arranged sequentially from top to bottom. The cement slab 334 has multiple holes. An overflow weir 332 is installed on the inner side wall of the calcium carbonate tank 330. The side wall of the calcium carbonate tank 330 where the overflow weir 332 is installed has a second inlet 331. The other side wall of the calcium carbonate tank 330 has a second outlet 337 and a vent 336. A water gate 338 is provided on the partition wall 338. The second inlet 331 is connected to the first outlet 325 through a pipe. The second outlet 337 is connected to the secondary sedimentation tank 34.

[0077] The secondary sedimentation tank 34 includes a second inlet channel 341, a filter media layer 342, and an outlet channel 343. The two ends of the secondary sedimentation tank 34 are respectively provided with a second inlet channel 341 and an outlet channel 343. The filter media layer 342 is provided inside the secondary sedimentation tank 34. The filter media layer 342 is a charcoal / calcium carbonate layer. The second inlet channel 341 is connected to the second outlet 337 through a pipe. The outlet channel 343 is connected to the mine wastewater outlet 37.

[0078] Filter 35 includes a first inlet / outlet pipe 3502, fiber ball filter media 3504, a first water distribution pipe 3505, support legs 3506, a second inlet / outlet pipe 3507, a discharge port 3508, an inlet 3509, a second water distribution pipe 3510, an exhaust port 3511, and a filter tank 3512. The first inlet / outlet pipe 3502 is a common port for the filtrate inlet and the backwash water outlet. The second inlet / outlet pipe 3507 is a common port for the filtered water outlet, the backwash water inlet, and the sewage outlet. The filter tank 3512 is equipped with the first water distribution pipe 3505 and the second water distribution pipe. 3510, the second water distribution pipe 3510 is located above the first water distribution pipe 3505, the bottom wall of the filter tank 3512 is connected to the second inlet / outlet pipe 3507, the side wall of the filter tank 3512 is connected to the first inlet / outlet pipe 3502, the first water distribution pipe 3505 is connected to the second inlet / outlet pipe 3507, the second water distribution pipe 3510 is connected to the first inlet / outlet pipe 3502, the other side wall of the filter tank 3512 is provided with an outlet 3508, an inlet 3509 and an exhaust port 3511, and the bottom of the filter tank 3512 is provided with a support leg 3506.

[0079] Disc filters and fiber filters provide the final stage of treatment for mine water, removing approximately 70% of the antimony content. Disc filters and fiber filters are arranged in series, with two of each type connected in parallel—one in operation and one on standby. The inner wall of the 3512 filter tank must be made of corrosion-resistant materials such as ceramic, stainless steel, or PTFE plastic. The interior of the filter tank is filled with fiber balls or fiber bundles to filter out antimony-containing particles.

[0080] The residue tank 36 includes a first residue tank 361, a second residue tank 362, a vent hole 363, and a sedimentation baffle 364. The residue tank 36 is divided into the first residue tank 361 and the second residue tank 362 by the sedimentation baffle 364. Vent holes 363 are provided on the side walls of the first residue tank 361 and the side walls of the second residue tank 362. The vent holes 363 are connected to the primary sedimentation tank 31 through pipes.

[0081] The advantages of the above optional embodiments are as follows: the wastewater treated by reactor 2 is further filtered and settled through primary sedimentation tank 31, carbon tank 32, calcium carbonate tank 33, secondary sedimentation tank 34 and filter 35, ensuring the effect of wastewater treatment; in addition, pollutants such as iron and manganese dissolved in the water are adsorbed through adsorption.

[0082] Optional, such as Figures 1 to 17 As shown, in some embodiments, the anaerobic chamber 213 is provided with acidophilic iron-oxidizing bacteria.

[0083] like Figures 1 to 17 As shown, a method for treating wastewater in a tunnel according to a second aspect embodiment of the present invention uses all the technical features of a multi-stage heavy metal control device for wastewater in a tunnel according to a first aspect embodiment of the present invention, and further includes the following steps:

[0084] Step S100: Place reactor 2 and reaction tank 3 in the water outlet tunnel of the adit. Mine wastewater 1 in the mine flows into the anaerobic chamber 213 of reactor 2, so that acidophilic iron oxidizing bacteria come into contact with the mine wastewater 1. After the reaction, the supernatant is separated to obtain filtrate.

[0085] Step S200: The filtrate flows into the anaerobic chamber 213 through the water passage 212. The pH value of the filtrate is neutralized to 6-8 by the carbonate rocks in the anaerobic chamber 213, resulting in neutral wastewater.

[0086] Step S300: Neutral wastewater flows into the culture chamber 214 of reactor 2, and the bacteria are cultured by the organic matter in the culture chamber 214 to obtain organic liquid.

[0087] Step S400: The organic liquid flows into the microbial chamber 215 of the reactor 2 through the water passage 212. The sulfate-reducing bacteria in the microbial chamber 215 react the heavy metals in the organic liquid to form heavy metal sulfide precipitates.

[0088] Step S500: The settled liquid flows into the primary sedimentation tank 31, yielding residue and primary sedimentation wastewater.

[0089] Step S600: The primary sedimentation wastewater flows sequentially into the carbon tank 32 and the calcium carbonate tank 33 for filtration, resulting in residue and primary filtration wastewater.

[0090] Step S700: The primary filtered wastewater flows into the secondary sedimentation tank 34 for sedimentation, resulting in residue and secondary sedimented wastewater.

[0091] Step S800: The secondary sedimentation wastewater flows out after being filtered by filter 35 to obtain clean water; after passing through iron powder adsorption and artificial wetland 42, the effluent 5 is discharged into the river.

[0092] In the above optional embodiments, it should be noted that after the acidophilic iron-oxidizing bacteria react with the mine wastewater 1 in step S100, the mine wastewater is filtered using carbonate rocks with a particle size of 40mm to 60mm to obtain filtrate. The 40mm to 60mm carbonate rocks can react better with the mine wastewater 1 and filter the mine wastewater 1 at the same time. The volume of the sulfate-reducing bacteria in step S400 is 1 / 6 to 1 / 4 of the volume of the mine wastewater 1.

[0093] The advantages of the above-mentioned optional embodiments are as follows: First, the reactor 2 and reaction tank 3 in this invention are placed in the wastewater overflow roadway of the adit mining. The mine wastewater 1 generated in the mine can be directly introduced into the reactor and reaction tank for treatment in sequence in the roadway, without the need to construct a reaction device on the ground. This effectively shortens the transportation time of the mine wastewater and avoids the formation of a large amount of sediment due to prolonged contact with oxygen in the air, thereby preventing the pipeline from being blocked. Second, the Fe is oxidized by acidophilic iron-oxidizing bacteria. 2+ Oxidation of ions to Fe 3+ In addition to ionization, acidophilic iron-oxidizing bacteria also consume oxygen in the mine wastewater during the reaction process, further preventing Fe from oxidizing in the mine wastewater. 2+ Oxidation precipitation clogs the reactor; Third, in step S400 of this invention, the bacteria are first cultured with organic matter to rapidly increase the total number of bacteria, thereby increasing the reaction rate during subsequent reactions and thus improving the overall treatment efficiency of mine wastewater; Fourth, the carbonate rock added in this invention neutralizes the acid in the wastewater 1 in the tunnel, increasing the pH value, and generates CO2 during the reaction. CO2, after dissolving in water, can provide carbon for the growth of acidophilic iron-oxidizing bacteria. Therefore, steps S100 and S200 do not require the addition of excessive organic nutrients to allow the acidophilic iron-oxidizing bacteria to multiply rapidly, improving their ability to absorb Fe. 2+ While improving ion treatment efficiency, this approach also avoids excessive nutrient residue in wastewater, preventing secondary pollution. Furthermore, the carbonate rock used in this solution is more cost-effective, and the optimized packing sequence reduces the amount of organic nutrients required, effectively lowering wastewater treatment costs.

[0094] Optional, such as Figures 1 to 17 As shown, in some embodiments, the acidophilic iron-oxidizing bacteria in step S100 are ferrooxidizing thiobacilli.

[0095] The beneficial effects of the above-mentioned optional embodiments are as follows: *Thiobacillus ferrooxidans* thrives in acidic environments and can grow normally or even better in wastewater 1 within the tunnel. Furthermore, *Thiobacillus ferrooxidans* is easy to cultivate and does not require large amounts of nutrients during its growth. Therefore, it is unnecessary to add excessive nutrients to the mine wastewater, thus preventing the growth of other bacteria in the wastewater 1 and avoiding further deterioration of water quality due to excessive nutrients leading to putrefaction and making it difficult to treat. Finally, *Thiobacillus ferrooxidans* uses ferrous iron as an acceptor, enabling rapid precipitation of iron and facilitating iron separation.

[0096] Optional, such as Figures 1 to 17 As shown, in some embodiments, the grain size of the carbonate rock in step S200 is 10 mm to 20 mm.

[0097] The beneficial effects of the above optional embodiments are as follows: the alkali-releasing capacity and carbon source released by the carbonate rocks in the above optional embodiments are more conducive to bacterial activity, and a large amount of iron is precipitated by acidophilic iron-oxidizing bacteria at the front end, reducing the blockage pressure of small-particle-size carbonate rocks at the rear end. Small particle size is more conducive to pH increase, which helps the survival of sulfate-reducing bacteria at the rear end, and it is inexpensive, readily available, and low in cost.

[0098] Optional, such as Figures 1 to 17 As shown, in some embodiments, the organic matter in step S300 is crushed straw.

[0099] The advantages of the above optional embodiments are that the organic matter in the above optional embodiments is low in cost and easy to obtain, making it more suitable for treating large quantities of mine wastewater.

[0100] The experimental data on the ratio of various bacterial solutions to mine wastewater 11 in a method for treating wastewater 1 in a tunnel according to a second aspect embodiment of the present invention are as follows:

[0101] The amounts of *Thiobacillus ferrooxidans* solution and sulfate-reducing bacteria solution added to 100 ml of wastewater vary, as shown in Table 1:

[0102] Table 1

[0103]

[0104] Comparative experiments: Comparative Examples 1-6 are disclosed. The operating steps of Comparative Examples 1-6 are the same as those of Examples 1-3, except that the pH of the filtrate after neutralization, the amount of *Thiobacillus ferrooxidans* solution, and the amount of sulfate-reducing bacterial solution in Step 1 are specifically shown in Table 2.

[0105] Table 2

[0106]

[0107] Wastewater sample 1 from the same source in the alleyway was tested for Fe. 2+ Concentration of 600 mg / L, SO4 2- With a concentration >1799.78 mg / L and a pH of 2.5, the mine wastewater 1 in the tunnel was divided into 9 groups, with 10 portions in each group and 135 mL in each portion. The 9 groups of mine wastewater 1 were reacted according to the procedures of Examples 1-3 and Comparative Examples 1-6, respectively. After the same reaction time, the pH, TFe removal rate, and sulfate reduction rate of the treated mine wastewater 1 in Examples 1-3 and Comparative Examples 1-6 were tested. The test results are shown below:

[0108] Case pH after treatment of mine wastewater TFe removal rate % Sulfate reduction rate % Example 1 7.31 71 74 Example 2 7.32 74 78 Example 3 7.48 76 79 Comparative Example 1 5.64 41 62 Comparative Example 2 6.86 55 70 Comparative Example 3 6.91 59 71 Comparative Example 4 7.10 62 71 Comparative Example 5 7.23 66 70 Comparative Example 6 6.36 61 72 Comparative Example 7 6.78 62 70

[0109] By comparing Example 1 with Comparative Examples 1-6, it was found that when the amount of *Thiobacillus ferrooxidans* was 15 ml, the pH of the treated wastewater was closer to neutral, and the TFe removal rate and sulfate reduction rate were significantly higher than those in Comparative Example 1. This proves that the amount of *Thiobacillus ferrooxidans* used in this invention can effectively improve the Fe... 2+ The faster ion removal rate results in a higher treatment speed.

[0110] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

[0111] The terms such as "upper," "lower," "left," "right," and "middle" used in this specification are merely for clarity of description and are not intended to limit the scope of the invention. Any changes or adjustments to their relative relationships, without substantially altering the technical content, should also be considered within the scope of the invention.

Claims

1. A multi-stage heavy metal control device for wastewater in roadways, characterized in that, The reactor (2) and the reaction tank (3) are located in the water outlet tunnel of the adit mining. One end of the reactor (2) is connected to the mine wastewater (1) through a pipeline. One end of the reaction tank (3) and the other end of the reactor (2) are connected through a pipeline. The other end of the reaction tank (3) is connected to the artificial wetland (42) at the entrance of the adit. The reactor (2) includes a reaction shell (21). Multiple partition plates (211) are provided inside the reaction shell (21). The multiple partition plates (211) divide the chamber inside the reaction shell (21) into an anaerobic chamber (213), a culture chamber (214) and a microbial chamber (215). Each partition plate (211) has a water passage hole (212). The anaerobic chamber (213) is connected to the mine wastewater (1) through the water passage (212), the culture chamber (214) is connected to the anaerobic chamber (213) through the water passage (212), the microbial chamber (215) is connected to the culture chamber (214) through the water passage (212), and the reaction tank (3) is connected to the microbial chamber (215) through the water passage (212). The anaerobic chamber (213) is provided with acidophilic iron-oxidizing bacteria. The reactor (2) further includes multiple sedimentation frames (231) and multiple sedimentation racks (232), with the multiple sedimentation racks (232) and the multiple sedimentation frames (231) being slidably connected in a one-to-one correspondence; The lower surface of the reaction shell (21) is provided with a plurality of lower openings (216), and the plurality of lower openings (216) are respectively connected to the anaerobic chamber (213), the culture chamber (214) and the microbial chamber (215). The plurality of sedimentation racks (232) are detachably connected to the lower openings (216) of the reaction shell (21). The reactor (2) also includes a side cover (22), which is connected to the reaction shell (21) by bolts or welding. When the side cover (22) is connected to the reaction shell (21) by bolts, a sealing strip is provided between the side cover (22) and the reaction shell (21). A feed hole (221) is provided on the side cover (22), and the feed hole (221) is blocked by a plug (25). The side wall of the lower opening (216) of the reaction shell (21) is provided with a first groove (217). The sedimentation frame (231) includes a frame body (2311). A top cover plate (2313) is provided on the top of the frame body (2311). A first protrusion (2315) is provided on the surface of the top cover plate (2313) away from the frame body (2311). A sliding groove cavity (2312) is provided in the frame body (2311). A plurality of sedimentation holes (2316) are provided on the top cover plate (2313). The first protrusion (2315) is inserted into the first groove (217). A sealing strip is provided between the first protrusion (2315) and the side wall of the first groove (217). The reaction tank (3) includes a mine wastewater inlet (30), a primary sedimentation tank (31), a carbon tank (32), a calcium carbonate tank (33), a secondary sedimentation tank (34), a mine wastewater outlet (37), and a filter (35) connected in sequence. The microbial chamber (215) is connected to the mine wastewater inlet (30) through the water passage (212), and the mine wastewater outlet (37) is connected to the artificial wetland (42) through the filter (35).

2. The multi-stage heavy metal control device for wastewater in roadways according to claim 1, characterized in that, The reaction tank (3) also includes a residue tank (36), the primary sedimentation tank (31) is connected to the residue tank (36) via a pipeline, the carbon tank (32) is connected to the residue tank (36) via a pipeline, the calcium carbonate tank (33) is connected to the residue tank (36) via a pipeline, and the secondary sedimentation tank (34) is connected to the residue tank (36) via a pipeline.

3. A method for treating wastewater in roadways, characterized in that, In addition to the multi-stage heavy metal control device for wastewater in tunnels as described in any one of claims 1 or 2, the method further includes the following steps: Step S100: The reactor (2) and the reaction tank (3) are placed in the water outlet tunnel of the adit mining. The mine wastewater (1) in the mine flows into the anaerobic chamber (213) of the reactor (2), so that the acidophilic iron oxidizing bacteria come into contact with the mine wastewater (1). After the reaction, the supernatant is separated to obtain the filtrate. Step S200: The filtrate flows into the anaerobic chamber (213) through the water passage (212), and the pH value of the filtrate is neutralized to 6-8 by the carbonate rocks in the anaerobic chamber (213) to obtain neutral wastewater; Step S300: Neutral wastewater flows into the culture chamber (214) of the reactor (2), and the bacteria are cultured by the organic matter in the culture chamber (214) to obtain organic liquid; Step S400: The organic liquid flows into the microbial chamber (215) of the reactor (2) through the water passage (212), and the sulfate-reducing bacteria in the microbial chamber (215) react the heavy metals in the organic liquid to form heavy metal sulfide precipitates; Step S500: The sedimented liquid flows into the primary sedimentation tank (31) after sedimentation, resulting in residue and primary sedimentation wastewater; Step S600: The primary sedimentation wastewater flows sequentially into the carbon tank (32) and the calcium carbonate tank (33) for filtration, resulting in residue and primary filtration wastewater; Step S700: The primary filtered wastewater flows into the secondary sedimentation tank (34) for sedimentation, resulting in residue and secondary sedimented wastewater; Step S800: The secondary sedimentation wastewater flows out after being filtered by the filter (35) to obtain clean water; after being adsorbed by iron powder and the artificial wetland (42), the effluent (5) is discharged into the river.

4. The method for treating wastewater in a tunnel according to claim 3, characterized in that, The acidophilic iron-oxidizing bacteria in step S100 is *Thiobacillus ferrooxidans*.

5. The method for treating wastewater in a tunnel according to claim 3, characterized in that, The carbonate rock in step S200 has a grain size of 10 mm to 20 mm.

6. The method for treating wastewater in a tunnel according to claim 3, characterized in that, The organic matter in step S300 is crushed straw.

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