A coupling reactor based on coal-based solid waste and bacteria-algae symbiosis

Abstract

The application belongs to the technical field of environmental engineering, and discloses a coupling reactor based on coal-based solid waste and bacteria-algae symbiosis. The device comprises a main cylinder, a water inlet distribution assembly, a coal-based solid waste functional filler layer, a lumen type bacteria-algae symbiotic reaction zone, an illumination assembly, a CO2 regulation and distribution assembly, an internal circulation reflux assembly and a detection and control assembly. The bacteria-algae symbiotic reaction zone is embedded in the coal-based solid waste functional filler layer, and realizes solute exchange and solid barrier through the film opening pipe wall; the CO2 distribution and reflux structure enables the pH and nutrient salt signals to be circulated and transmitted between the filler layer and the bacteria-algae zone, thereby realizing efficient and stable treatment of coal-based solid waste wastewater.

Description

Technical Field

[0001] This invention belongs to the field of environmental engineering technology, specifically relating to a coupled reactor based on coal-based solid waste and bacterial-algae symbiosis. Background Technology

[0002] Coal-based solid wastes such as coal gangue, fly ash, and coal slime are generated in large quantities during coal mining, washing, combustion, and disposal. During long-term storage and disposal, these coal-based solid wastes are susceptible to leaching by precipitation, easily producing wastewater containing phosphate, ammonium nitrogen, organic matter, and heavy metal ions. If this wastewater is discharged directly without effective treatment, it can easily cause eutrophication of water bodies and pollution of the surrounding environment.

[0003] Existing wastewater treatment technologies, such as chemical precipitation and adsorption, can remove some nutrients, but they typically suffer from high reagent consumption, high operating costs, and potential secondary pollution. Photobioreactor technology utilizes microalgae photosynthesis to absorb nitrogen and phosphorus nutrients and fix CO2, offering low energy consumption and resource utilization potential. The algae-microbe symbiotic system further leverages the feedback loop between microalgae and bacteria: microalgae photosynthesis produces oxygen for bacterial use, while bacterial metabolism produces CO2 and its byproducts to support microalgae growth, thus achieving synergistic pollutant removal.

[0004] However, existing algal-microbe symbiotic reactors still have the following shortcomings: Firstly, the packing layer and the bioreactor zone are usually arranged separately, resulting in low system integration, large footprint, and limited mass transfer efficiency.

[0005] Secondly, existing packing materials are mostly used as biological attachment carriers, lacking the functions of adsorption and retention of nutrients such as phosphate and ammonium nitrogen, as well as pH-responsive slow release, making it difficult to cope with fluctuations in the concentration of nutrients in the influent.

[0006] Third, the CO2 addition methods in existing photobioreactors are relatively crude and lack real-time feedback control based on pH and dissolved oxygen, which can easily lead to low CO2 utilization efficiency and large pH fluctuations in the system, thereby affecting microalgae growth and bacterial metabolism.

[0007] Fourth, in traditional reactors, the packing layer, biological reaction zone, CO2 control system and reflux system are independent of each other, lacking a closed-loop coupling control mechanism between nutrients, pH, CO2 and biological processes, resulting in insufficient buffering capacity of the system to the fluctuation of coal-based solid waste water quality.

[0008] Therefore, it is necessary to provide a new coupling reactor. Summary of the Invention

[0009] The purpose of this invention is to provide a coupled reactor based on coal-based solid waste and algal symbiosis to improve the removal efficiency of nutrients, CO2 utilization efficiency and system operation stability in coal-based solid waste wastewater.

[0010] To achieve the above objectives, the present invention adopts the following technical solution: This invention provides a coupled reactor based on coal-based solid waste and algal symbiosis. The reactor is a vertical integrated photobioreactor, including a main cylinder, an inlet, a water distribution plate, a coal-based solid waste functional packing layer, an algal symbiosis reaction zone, a light component, a CO2 regulating gas distribution component, an internal circulation return pipe, a return pump, a pH / DO online sensor, a control system, and an algal liquid harvesting port.

[0011] The coal-based solid waste functional packing layer is located inside the main cylinder and is composed of pretreated and modified coal-based solid waste particles, including fly ash and / or coal gangue. This packing layer is used for the initial retention of phosphate, ammonium nitrogen, and / or heavy metal ions in wastewater, and also exhibits pH-responsive nutrient adsorption and slow-release functions in response to changes in the system's pH.

[0012] The algae-bacterial symbiotic reaction zone is embedded within the functional packing layer for coal-based solid waste. This zone includes a central collection pipe and several branch pipes connected to it, arranged radially around the central pipe. The branch pipes have perforations in their walls, and a selectively permeable membrane is applied to the outside of these perforations. This allows liquid water and dissolved nutrients from the coal-based solid waste functional packing layer to enter the pipe cavity while preventing coal-based solid waste particles and some suspended solids from entering. The pipe cavity is filled with a symbiotic system composed of tolerant microalgae acclimated to the coal-based solid waste water quality conditions and functional bacteria, including phosphate-solubilizing bacteria, nitrifying bacteria, and denitrifying bacteria.

[0013] The lighting unit is used to provide the light required for microalgae growth in the algal symbiotic reaction zone.

[0014] The CO2-regulated aeration component is installed at the effluent end of the algae-microbe symbiotic reaction zone and connected to the pH / DO online sensor and control system. The control system adjusts the CO2 dosing rate based on feedback signals from the pH / DO online sensor to control the system pH. CO2 provides an inorganic carbon source for the microalgae and, through pH changes, regulates the nutrient adsorption and slow release behavior of the coal-based solid waste functional packing layer.

[0015] The internal circulation return pipe and return pump are used to return the liquid from the outlet of the algae-bacterial symbiotic reaction zone to the inlet of the bottom of the coal-based solid waste functional packing layer. This allows the nutrient concentration signal and pH signal to be transmitted and coupled bidirectionally between the coal-based solid waste functional packing layer and the algae-bacterial symbiotic reaction zone, thus forming a closed-loop coupled control path of "CO2-pH-solid waste-algae-CO2".

[0016] The algal liquid harvesting port is used to discharge or harvest algal liquid in the algal-bacterial symbiotic reaction zone.

[0017] Preferably, the main body is a transparent cylinder.

[0018] Preferably, the main body is made of PMMA material.

[0019] Preferably, the inlet is located at the bottom or lower part of the main cylinder. After the wastewater enters the main cylinder through the inlet, it is evenly distributed by the water distribution plate and enters the coal-based solid waste functional filler layer from bottom to top.

[0020] Preferably, the coal-based solid waste functional filler layer is disposed on the bottom supporting grid.

[0021] Preferably, the bottom support grid is a stainless steel support grid with a mesh size of 0.5mm.

[0022] Preferably, the height of the coal-based solid waste functional filler layer is 40% to 65% of the effective height of the main cylinder.

[0023] Preferably, the coal-based solid waste granules are prepared by mixing fly ash and coal gangue in a mass ratio of (1~3):1.

[0024] Preferably, the loss on ignition of fly ash is less than 5%, and the total content of SiO2 and Al2O3 is greater than 70%.

[0025] Preferably, the SiO2 content in the coal gangue is 40%~60%, and the Al2O3 content is 15%~30%.

[0026] Preferably, the coal-based solid waste granules are obtained by water washing and desalination, thermal activation, alkali modification, and extrusion granulation.

[0027] Preferably, the process conditions for water washing and desalination are: solid-liquid ratio of 1:5, oscillation speed of 120 rpm, oscillation time of 60 min, repeated twice, and the conductivity of the washing effluent is less than 100 μS / cm.

[0028] Preferably, the thermal activation process conditions are: holding at 350~500℃ in a muffle furnace for 1~3 hours, with a heating rate of 5℃ / min.

[0029] Preferably, the alkali modification is performed using a 0.5~2 mol / L NaOH solution, treated in a water bath at 60~80℃ for 4~8 hours, and then washed until the pH is 6.5~7.5.

[0030] Preferably, the coal-based solid waste particles after extrusion granulation have a particle size of 1~3mm and are sintered at 500℃.

[0031] Preferably, the specific surface area of ​​the pretreated coal-based solid waste particles is not less than 20 m². 2 / g, total pore volume not less than 0.08cm³ 3 / g.

[0032] Preferably, after the radial branch pipes are embedded in the coal-based solid waste functional filler layer, the coal-based solid waste particles fill the gaps between the branch pipes, and the filling density is not less than 85% of the loose particle density.

[0033] Preferably, the algal symbiotic reaction zone includes a central collection pipe and several branch pipes, with the branch pipes extending evenly outward from the central collection pipe as the axis.

[0034] Preferably, the number of branch pipes in each layer is 4 to 12.

[0035] Preferably, the central angle spacing between each layer of branch pipes is equal.

[0036] Preferably, a gap of 5-15 mm is maintained between the end of the branch pipe and the inner wall of the main cylinder.

[0037] Preferably, the central liquid collection pipe is provided with 1 to 5 layers of radial pipe groups along the longitudinal axis of the main cylinder.

[0038] Preferably, the interlayer spacing between adjacent radial tube groups is 20% to 30% of the effective height of the coal-based solid waste functional filler layer.

[0039] Preferably, the branch pipes of each layer are staggered on the horizontal projection plane, and the staggered angle between layers is 1 / 2 of the central angle of the distance between adjacent branch pipes.

[0040] Preferably, the bacterial-algae mixture can flow within the bacterial-algae symbiotic reaction zone under reflux.

[0041] Preferably, the central collection pipe and the branch pipes are provided with holes.

[0042] Preferably, the diameter of the hole is 2~5mm.

[0043] Preferably, the permeable membrane is selected as a filter membrane.

[0044] Preferably, the membrane pore size is selected to be 10~100μm.

[0045] Preferably, the selected membrane allows NH4 to pass through. + -N,PO4 3- HCO3 - It allows water molecules to pass through while preventing coal-based solid waste particles, suspended solids, and heavy metal colloids from entering the pipe cavity.

[0046] Preferably, the permeable membrane is fixed to the opening area of ​​the pipe wall by hot melt bonding or clamp sealing structure.

[0047] Preferably, the ratio of the membrane area to the total pipe wall area is not less than 40%.

[0048] Preferably, an anti-clogging outer covering net is installed on the outside of the permeable membrane.

[0049] Preferably, the mesh size of the anti-blocking outer covering net is 0.5~1.0mm, and the material is polyester fiber.

[0050] Preferably, the lighting component includes an optical fiber light-emitting core and a micro LED dot matrix light source.

[0051] Preferably, the optical fiber light-emitting core is arranged axially along the central liquid collection tube.

[0052] Preferably, the miniature LED dot matrix light source is distributed along the axis of each branch tube.

[0053] Preferably, the outer diameter of the optical fiber light-emitting core is 3~8mm, and the outer wall is provided with a lateral light-emitting structure, which emits light uniformly along the axial direction of the tube, with an emission angle of not less than 120°.

[0054] Preferably, the miniature LED dot matrix light sources are evenly arranged along the axial direction of the branch pipe, and the spacing between adjacent miniature LED dot matrix light sources is 5~10cm.

[0055] Preferably, the color temperature of the micro LED dot matrix light source is 4000~6500K, and the power of a single point is 0.1~0.5W.

[0056] Preferably, the micro LED dot matrix light source is covered with a waterproof silicone sleeve with a waterproof rating of IP68.

[0057] Preferably, the light intensity provided by the lighting component in the symbiotic area of ​​bacteria and algae inside the tube is 3000~8000 lux.

[0058] Preferably, the uniformity deviation of the light intensity of the light-emitting component is no more than 15%.

[0059] Preferably, the control system adjusts the LED power in real time based on the feedback signal from the light intensity sensor.

[0060] Preferably, the light-dark ratio of the illumination component is (14~16)h:(8~10)h, and the day-night switching is automatically executed by the control system.

[0061] Preferably, the CO2 regulating and distributing assembly includes a CO2 storage tank or an external gas supply pipe, a microporous ceramic aeration pipe, and an electric proportional regulating valve.

[0062] Preferably, the pore size of the microporous ceramic aeration tube is 0.1~0.5μm.

[0063] Preferably, the microporous ceramic aeration tube is installed in the manifold at the upper end of the central liquid collection tube, and the generated bubble diameter is no greater than 1 mm.

[0064] Preferably, the electric proportional control valve is controlled by the control system based on the real-time signal from the pH / DO online sensor.

[0065] Preferably, the CO2 injection acceleration rate is controlled within the range of 0.05~0.5L / min.

[0066] Preferably, the target pH range for the system is 6.8 to 8.5.

[0067] Preferably, when the system pH is less than 6.8, the control system automatically shuts off CO2 and turns on the auxiliary micro-air aeration pipe to prevent the system from becoming over-acidified.

[0068] Preferably, the air volume of the auxiliary micro-air aeration tube is no more than 0.02 L / min.

[0069] Preferably, the CO2 source is high-concentration CO2 obtained from the capture and purification of industrial exhaust gas.

[0070] Preferably, the purity of the high-concentration CO2 is not less than 80%.

[0071] Preferably, the internal circulation reflux assembly includes an internal circulation reflux pipe and a reflux pump.

[0072] Preferably, the inlet end of the internal circulation return pipe is located at the bottom confluence port of the central liquid collection pipe.

[0073] Preferably, the outlet end of the internal circulation return pipe is connected to the water inlet distribution chamber below the water distribution plate, so that the return liquid and the external fresh inlet water are combined and evenly distributed into the bottom of the coal-based solid waste functional filler layer through the water distribution plate.

[0074] Preferably, the reflux pump is a corrosion-resistant magnetic pump.

[0075] Preferably, the flow rate of the reflux pump is in the range of 0.05~5L / min, and the head is not less than 2m.

[0076] Preferably, the reflux pump is regulated by the control system via frequency conversion drive.

[0077] Preferably, the reflux ratio R of the internal circulation reflux is 0.5~3.0.

[0078] Preferably, when the pH / DO online sensor detects that the pH at the effluent end of the algae-bacterial symbiotic reaction zone is ≤7.2, the control system automatically increases the reflux ratio to R≥2.0 to accelerate the transfer of the low-pH reflux liquid to the coal-based solid waste functional packing layer.

[0079] Preferably, the outer wall of the internal circulation return pipe is covered with thermal insulation material.

[0080] Preferably, the thickness of the insulation material is not less than 20mm.

[0081] Preferably, the insulation material is used to prevent the temperature loss of the reflux liquid from exceeding 2°C.

[0082] Preferably, the algal liquid harvesting port is located on the side wall of the water outlet confluence cavity of the central liquid collection pipe.

[0083] Preferably, the algal liquid harvesting port is equipped with an electric shut-off valve.

[0084] Preferably, the electric shut-off valve is automatically triggered by the control system based on the turbidity sensor detection value and the preset harvest cycle.

[0085] Preferably, the preset harvesting cycle is 5 to 15 days per harvest.

[0086] Preferably, the algal liquid harvesting port is connected to a slightly inclined tube sedimentation and concentration unit outside the reactor.

[0087] Preferably, the slightly inclined tube sedimentation concentration unit is used for gravity concentration of the harvested algal solution.

[0088] Preferably, the inclination angle of the inclined tubes in the slightly inclined tube sedimentation concentration unit is 55°~60°, and the spacing between the inclined tubes is 15~25mm.

[0089] Preferably, the concentrated algal sludge has a water content of 75% to 85% and is intermittently discharged from the bottom sludge outlet.

[0090] Preferably, the supernatant produced by the slightly inclined tube sedimentation and concentration unit is returned to the inlet end via a return pipe.

[0091] Preferably, a sampling valve is provided at the algal liquid harvesting port for periodic sampling and testing of microalgal cell density, heavy metal content, and nutrient composition.

[0092] The working principle of this device is explained as follows: During reactor operation, the wastewater to be treated first enters the lower part of the main cylinder through the inlet and is evenly distributed to the coal-based solid waste functional packing layer by the water distribution plate. The fly ash and / or modified coal gangue particles in the coal-based solid waste functional packing layer retain phosphate, ammonium nitrogen, and some heavy metal ions in the wastewater. Liquid water and dissolved nutrients in the coal-based solid waste functional packing layer enter the algae-bacteria symbiotic reaction zone through a selectively permeable membrane. The tolerant microalgae and functional bacteria within the tube work synergistically to further remove nitrogen, phosphorus, and organic matter.

[0093] The CO2-regulated aeration component adds CO2 to the algae-microbe symbiotic reaction zone based on feedback signals from the pH / DO online sensors. After dissolving in the water, the CO2 provides an inorganic carbon source for the microalgae and influences the nutrient adsorption and slow release behavior of the coal-based solid waste functional packing layer by adjusting the system's pH. The internal circulation return pipe and return pump return the liquid from the algae-microbe symbiotic reaction zone to the bottom of the coal-based solid waste functional packing layer, allowing the pH and nutrient concentration signals to circulate between the two functional zones, thus forming a closed-loop regulation process of "CO2-pH-solid waste-algae-CO2".

[0094] Through the above structure and operation mode, the reactor of the present invention realizes spatial integration, mass transfer and feedback regulation of the functional packing layer of coal-based solid waste and the symbiotic reaction zone of bacteria and algae, which improves the synergistic removal effect of nitrogen, phosphorus, organic matter and heavy metals in the treatment of coal-based solid waste wastewater, while improving CO2 utilization rate and system operation stability.

[0095] Compared with the prior art, the present invention has the following beneficial effects: 1. This invention prepares coal-based solid waste such as fly ash and / or coal gangue into a functional packing layer, transforming coal-based solid waste from solid waste to be disposed of into reactor packing with nutrient salt retention and pH-responsive adsorption / slow release functions, thereby realizing the resource utilization of coal-based solid waste.

[0096] 2. This invention embeds the algae-bacterial symbiotic reaction zone inside the functional packing layer for coal-based solid waste, and adopts a pipe group structure consisting of a central liquid collection pipe and radial branch pipes, so that the algae-bacterial symbiotic system and the functional packing layer for coal-based solid waste are spatially integrated, thereby improving the contact area and mass transfer efficiency between the packing layer and the algae-bacterial reaction zone.

[0097] 3. This invention, by setting a selectively permeable membrane in the branch pipe opening area, allows NH4 to... + -N,PO4 3- HCO3 - Small molecule solutes and water molecules can enter the algae-bacterial symbiotic reaction zone, while blocking coal-based solid waste particles, suspended solids and heavy metal colloids from entering the pipe cavity. This helps protect the algae-bacterial symbiotic system and reduces the risk of particle shading and heavy metal toxicity inhibition.

[0098] 4. This invention provides illumination to the microalgae symbiotic system inside the tube through optical fiber light-emitting core and micro LED dot matrix light source, which can improve the lighting conditions in the embedded tube group and enhance the stability of microalgae photosynthesis.

[0099] 5. This invention sets up a CO2-regulated gas distribution component and realizes feedback regulation of CO2 addition through pH / DO online sensors and control system. This allows CO2 to serve as both an inorganic carbon source for microalgae photosynthesis and a pH-regulating medium to participate in the dynamic regulation of nutrient adsorption and slow release processes in the functional packing layer of coal-based solid waste, thereby improving CO2 utilization and system stability.

[0100] 6. This invention uses an internal circulation return pipe and a return pump to return the liquid from the outlet of the algae-bacterial symbiotic reaction zone to the bottom of the coal-based solid waste functional packing layer, thereby realizing the bidirectional transmission of nutrient concentration signals and pH signals between the coal-based solid waste functional packing layer and the algae-bacterial symbiotic reaction zone. This forms a closed-loop coupled control path of "CO2-pH-solid waste-algae-CO2", improving the reactor's buffering capacity against fluctuations in influent water quality.

[0101] 7. The present invention, through the algal liquid harvesting port and the external slightly inclined tube sedimentation and concentration unit, can periodically harvest algal liquid and return the supernatant, which is beneficial to maintaining the stable growth of the bacterial-algal system and facilitates the subsequent utilization of algal biomass resources. Attached Figure Description

[0102] Figure 1 This is a schematic diagram of the device provided by the present invention; Figure 2 A half-sectional view of the device provided by the present invention; Figure 3 This is a cross-sectional view of the branch pipe in the device provided by the present invention; Figure 4 This is a schematic diagram of the illumination component in the device provided by the present invention.

[0103] Figure Labels 1. Main cylinder; 2. Inlet; 3. Water distribution plate; 4. Coal-based solid waste functional packing layer; 5. Algae-bacterial symbiotic reaction zone; 5a. Central collection pipe; 5b. Branch pipe; 5c. Perforation; 5d. Selective permeability membrane; 6. Illumination component; 6a. Optical fiber light-emitting core; 6b. Miniature LED dot matrix light source; 7. CO2 regulating gas distribution component; 8. Internal circulation return pipe; 9. Return pump; 10. Algae liquid harvesting port; 10a. Electric shut-off valve; 10b. Slightly tilting inclined tube sedimentation concentration unit; 10c. Bottom sludge discharge port; 10d. Sampling valve; 11. Outlet; 12. pH / DO online sensor; 13. Control system. Detailed Implementation

[0104] To enable those skilled in the art to better understand the present application, the technical solutions in specific embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by those skilled in the art.

[0105] It should be understood that the following embodiments are for illustrative purposes only and are not intended to limit the scope of protection of the present invention. Any adaptive adjustments to component dimensions, material specifications, and operating parameters made by those skilled in the art based on the content of this specification without departing from the technical solution of the present invention should fall within the scope of protection of the present invention.

[0106] Example 1 This embodiment provides a small-scale coupled reactor based on coal-based solid waste and bacterial-algae symbiosis for treating leachate from a simulated coal gangue dump.

[0107] The main water quality parameters of the leachate from the simulated coal gangue dump are: NH4 + -N concentration is 200 mg / L, NO3 --N concentration was 15 mg / L, TP concentration was 25 mg / L, COD concentration was 80 mg / L, pH was 7.8, EC was 3200 μS / cm, and Fe... 2+ The concentration is 3.5 mg / L, Mn 2+ The concentration is 0.8 mg / L, SO4 2- The concentration is 350 mg / L.

[0108] The reactor uses a PMMA transparent cylinder. The effective volume of the main cylinder 1 is 30L, and the inner diameter is [missing information]. The main body 1 has a water inlet 2 at the bottom and a water outlet 11 at the top. A water distribution plate 3 is located above the water inlet 2, and a coal-based solid waste functional filler layer 4 is located above the water distribution plate 3. The effective height of the coal-based solid waste functional filler layer 4 is 1200mm, accounting for 45% of the effective height of the main body 1.

[0109] The algae-bacterial symbiotic reaction zone 5 is embedded within the functional packing layer for coal-based solid waste. The algae-bacterial symbiotic reaction zone 5 includes a central collection pipe 5a and several branch pipes 5b connected to the central collection pipe 5a. The inner diameter of the central collection pipe 5a is... 32mm, set along the longitudinal axis of the main cylinder 1. Three layers of radial branch pipe connecting rings are installed on the central liquid collecting pipe 5a, with eight branch pipes 5b in each layer, staggered by 22.5° between layers. The inner diameter of each branch pipe 5b is... The branch pipe 5b has a diameter of 12mm and an effective length of 42mm. A 10mm gap is maintained between the end of the branch pipe 5b and the inner wall of the main cylinder 1. The branch pipe 5b has holes 5c in its wall, and the outside of the holes 5c is covered with a permeable membrane 5d, with a membrane area coverage of 50%. The total membrane area of ​​the pipe assembly is approximately 0.18m². 2 The effective volume of the bacterial and algal zone is approximately 4.8L, accounting for 16% of the total reactor volume.

[0110] The coal-based solid waste functional packing layer 4 is composed of pretreated and modified fly ash and coal gangue particles. Wastewater enters the main cylinder 1 through the inlet 2, is evenly distributed by the water distribution plate 3, and flows from bottom to top through the coal-based solid waste functional packing layer 4. Liquid water and dissolved nutrients in the coal-based solid waste functional packing layer 4 enter the algae-bacteria symbiotic reaction zone 5 through the selectively permeable membrane 5d. The tolerant microalgae and functional bacteria in the algae-bacteria symbiotic reaction zone 5 synergistically treat nitrogen, phosphorus, and organic matter in the wastewater.

[0111] The lighting component 6 is used to provide the light required for the growth of microalgae to the algal symbiotic reaction zone 5. The lighting component 6 includes a fiber optic light-emitting core 6a and a micro LED matrix light source 6b. The fiber optic light-emitting core 6a is arranged along the central liquid collection tube 5a, and the micro LED matrix light source 6b is distributed at the axial position of the inner cavity of each branch tube 5b.

[0112] The optical fiber light-emitting core 6a has an outer diameter of 3-8 mm and a lateral light-emitting structure on its outer wall, emitting light uniformly along the tube axis at an angle of 120°. The miniature LED dot matrix light sources are uniformly arranged along the branch tube axis, with a spacing of 5-10 cm between adjacent sources. The color temperature of the miniature LED dot matrix light sources is 4000-6500 K, and the power per point is 0.1-0.5 W. An external waterproof silicone sleeve is fitted, with a waterproof rating of IP68.

[0113] The CO2 regulating and distributing assembly 7 includes a CO2 storage tank or external gas supply pipe, a microporous ceramic aeration pipe, and an electric proportional control valve. The microporous ceramic aeration pipe is installed in the manifold at the upper end of the central liquid collection pipe, and the pore size of the microporous ceramic aeration pipe is 0.1~0.5μm. The electric proportional control valve is controlled by the control system 13 based on the real-time signal from the pH / DO online sensor.

[0114] The internal circulation reflux assembly includes an internal circulation reflux pipe 8 and a reflux pump 9. The inlet end of the internal circulation reflux pipe 8 is located at the bottom confluence port of the central liquid collection pipe 5a, and the outlet end is connected to the water distribution chamber below the water distribution plate 3, so that the reflux liquid merges with the external fresh inlet water and is evenly distributed into the bottom of the coal-based solid waste functional packing layer 4 through the water distribution plate 3. The reflux pump 9 is a corrosion-resistant magnetic pump.

[0115] The reactor operating parameters are as follows: hydraulic retention time is 72 h, reaction temperature is 25 ℃, light intensity is 4000 lux, light-dark ratio is 14 h:10 h, CO2 dosing rate is 0.15 L / min, target pH is 7.5, internal circulation reflux ratio R is 1.5, and influent flow rate is 0.42 L / h.

[0116] The system ran continuously after startup. The average treatment results during the 15th to 60th day of steady-state operation were: NH4 + -N removal rate was 93.1%, effluent concentration was 13.8 mg / L; TP removal rate was 88.4%, effluent concentration was 2.9 mg / L; COD removal rate was 76.2%, effluent concentration was 19.0 mg / L; effluent pH was stable between 7.1 and 8.2; effluent Fe 2+ The concentration is 0.18 mg / L, Mn 2+ The concentration was 0.06 mg / L. The steady-state concentration of chlorophyll a in the bacterial-algae tube was 23.6 mg / L, the net algae production per day was 0.21 g / L of liquid in the tube / day, and the CO2 fixation was approximately 0.36 g CO2 / (L·d). The system operated continuously and stably for 60 days without membrane fouling, blockage, or bacterial-algae collapse.

[0117] To verify the protective effect of the selected permeable membrane 5d on the algal-bacterial symbiotic system, the Fe content in the liquid inside the algal-bacterial tube was measured during the steady-state period. 2+ Concentration. Detection results showed that Fe in the liquid inside the algal tube was...2+ The concentration was 0.31 mg / L, a 91.1% decrease compared to the 3.5 mg / L in the influent. Simultaneously, the algae-bacterial symbiotic system maintained high photosynthetic activity, with chlorophyll fluorescence Fv / Fm values ​​not lower than 0.65. These results indicate that selecting a permeable membrane for 5 days can reduce the risk of direct heavy metal toxicity to the algae-bacterial symbiotic system within the tube, thus contributing to stable reactor operation.

[0118] Example 2 This embodiment provides a pilot-scale coupled reactor based on coal-based solid waste and bacterial-algae symbiosis for treating leachate from actual fly ash stockpiles.

[0119] The main water quality parameters of the leachate from the actual fly ash stockpile are: NH4 + -N concentration was 78 mg / L, TP concentration was 12 mg / L, COD concentration was 45 mg / L, pH was 8.6, EC was 1850 μS / cm, As(V) concentration was 0.08 mg / L, Fe 3+ The concentration was 5.2 mg / L, Mn 2+ The concentration is 1.3 mg / L.

[0120] In this embodiment, the effective reactor volume is 500L. Considering the high pH of the influent and the presence of heavy metals such as As, Fe, and Mn, the proportion of coal gangue in the coal-based solid waste functional packing material is increased to 65% to enhance the ammonium nitrogen adsorption capacity under alkaline influent conditions. The target pH for CO2 is adjusted to 8.0±0.2. During the microalgae acclimation process, an additional 2 mg / L of As(V) is added for 28 days of intensive heavy metal tolerance acclimation.

[0121] In this embodiment, the central liquid collection tube 5a has a built-in optical fiber light-emitting core 6a with a high-brightness light guide beam and an output power of 800 lm. At the same time, in each of the eight branch tubes 5b of the connecting ring, an LED dot matrix light source is added every other tube to ensure that the overall uniformity deviation of the illumination coverage of the multi-layer tube group is no more than 12%.

[0122] The average treatment result of the system during steady-state operation from day 10 to day 45 is: NH4 + The nitrogen (N) removal rate was 89.3%, with an effluent concentration of 8.3 mg / L; the total phosphorus (TP) removal rate was 84.7%, with an effluent concentration of 1.8 mg / L; the as (V) removal rate was 94.2%, with an effluent as (A) concentration below 0.005 mg / L; and the daily net algae production was 0.16 g / L of influent / day. The as (A) content in the algal sludge met the relevant standards for organic fertilizers. The system operated continuously for 45 days without significant fluctuations in effluent quality.

[0123] To verify the reactor's adaptive buffering capacity, during stable system operation, the influent NH4 was... +The -N concentration increased from 78 mg / L to 200 mg / L and remained there for 7 days. Test results showed that the effluent NH4 concentration... + -N concentration remained stable below 20 mg / L; after normal influent flow was restored, the system returned to steady state within 3 days. This result indicates that the reactor of the present invention, through the closed-loop coupling of the coal-based solid waste functional packing layer 4, the bacterial-algae symbiotic reaction zone 5, the CO2 regulating gas distribution component 7, and the internal circulation reflux system, can improve the buffering capacity against fluctuations in influent water quality.

[0124] Finally, it should be noted that the described embodiments are merely some, not all, of the embodiments of the present invention. Those skilled in the art will understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents; that is, all other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A coupled reactor based on coal-based solid waste and algal symbiosis, characterized in that, It includes the main cylinder, water inlet distribution components, coal-based solid waste functional packing layer, bacteria and algae symbiotic reaction zone, lighting components, CO2 regulation and gas distribution components, internal circulation reflux components, and detection and control components. The inlet distribution assembly is located at the bottom of the main cylinder and is used to distribute the wastewater to be treated to the coal-based solid waste functional packing layer. The coal-based solid waste functional packing layer is set inside the main cylinder and forms a packing flow channel for wastewater to pass through; The algae-bacteria symbiotic reaction zone is a tubular reaction zone embedded in the coal-based solid waste functional filler layer. The tubular reaction zone includes a central liquid collection pipe arranged along the axial direction of the main cylinder and multiple branch pipes connected to the central liquid collection pipe. The branch pipes extend into the coal-based solid waste functional filler layer. The lighting components are used to supply light to the algae-bacteria symbiotic reaction zone; The CO2 regulating gas distribution component is connected to the algae-bacterial symbiotic reaction zone and is used to supply CO2 to the algae-bacterial symbiotic reaction zone; The inlet end of the internal circulation reflux component is connected to the outlet end of the algae-bacteria symbiotic reaction zone, and the outlet end is connected to the inlet distribution component. The detection and control components are connected to the CO2 regulation and distribution components and the internal circulation reflux components, respectively.

2. The coupled reactor according to claim 1, characterized in that, The water inlet distribution assembly includes an inlet, an inlet distribution chamber, and a water distribution plate. The inlet is connected to the inlet distribution chamber, and the water distribution plate is located between the inlet distribution chamber and the coal-based solid waste functional packing layer. The liquid outlet of the internal circulation reflux assembly is connected to the inlet distribution chamber.

3. The coupled reactor according to claim 2, characterized in that, The coal-based solid waste functional filler layer is set on the supporting grid, which is located above or adjacent to the water distribution plate, and is used to support the coal-based solid waste functional filler layer and allow liquid to pass through.

4. The coupled reactor according to claim 1, characterized in that, The coal-based solid waste functional filler layer is composed of filler containing coal-based solid waste particles. The coal-based solid waste functional filler layer surrounds and covers at least part of the outer periphery of the bacterial-algae symbiotic reaction zone, and the filler containing coal-based solid waste particles fills the gaps between adjacent branch pipes and between the branch pipes and the inner wall of the main cylinder.

5. The coupled reactor according to claim 1, characterized in that, Multiple branch pipes are distributed radially outward from the central liquid collection pipe as the axis, forming a radial pipe group; the radial pipe group is set as one or more layers along the axial direction of the main cylinder.

6. The coupled reactor according to claim 5, characterized in that, When the radial tube group is multi-layered, the branch tubes in the adjacent two layers of radial tube groups are staggered in the circumferential direction, so that the corresponding tube wall exchange areas of the adjacent two layers of branch tubes are at least partially staggered on the horizontal projection plane.

7. The coupled reactor according to claim 1, characterized in that, The coupled reactor also includes a selective permeation membrane, which is disposed on the outer wall of the central collection pipe and / or branch pipes. An anti-clogging outer cover is provided on the outside of the selective permeation membrane, which is located between the selective permeation membrane and the coal-based solid waste functional packing layer.

8. The coupled reactor according to claim 1, characterized in that, The illumination assembly includes an axial light guide installed in the central liquid collection pipe and / or a linear dot matrix light source installed in the branch pipe, wherein the axial light guide and / or the linear dot matrix light source are located inside the tubular reaction zone.

9. The coupled reactor according to claim 1, characterized in that, The upper end of the central liquid collection pipe forms an outlet water collection cavity. The CO2 control and gas distribution component includes a gas supply component, a gas regulation component, and a gas distribution component. The gas distribution component is located in the outlet water collection cavity or connected to the outlet water collection cavity. The detection and control component includes a sensor and a controller. The sensor is located in the outlet water collection cavity, the outlet end of the algae-bacteria symbiotic reaction zone, or on the pipeline of the internal circulation return component.

10. The coupled reactor according to claim 9, characterized in that, It also includes an algae liquid harvesting component, which includes an algae liquid harvesting port connected to the outlet water collection chamber and a control valve located at the algae liquid harvesting port; the internal circulation reflux component includes a reflux bypass located outside the main body and a reflux pump located on the reflux bypass, the liquid inlet of the reflux bypass is connected to the outlet water collection chamber, and the liquid outlet of the reflux bypass is connected to the inlet water distribution component.

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