A device and method for treating a river or lake water body

Abstract

The application provides a river and lake water treatment device and method. The river and lake water treatment device comprises an electric flocculation unit, a gas floatation unit, a slag removal unit, an ultrasonic algae removal unit and an ecological floating island unit. The electric flocculation unit has a shell with a reaction cavity, the reaction cavity has a water inlet and a purified water outlet, and the reaction cavity alternately has a first electrode plate and a second electrode plate. The ultrasonic algae removal unit generates ultrasonic waves to crush algae cells to obtain slag. The gas floatation unit comprises an aeration member placed in the reaction cavity. At least part of the slag removal unit is arranged at the top of the reaction cavity. The ecological floating island unit is arranged above the slag removal unit, and the ecological floating island comprises a gel matrix layer, a nutrient soil layer and a vegetation layer arranged in sequence, and the gel matrix layer is close to the slag removal unit. The treatment device can remove phosphorus pollutants in the river and lake water, recycle the phosphorus pollutants in the river and lake water, and efficiently remove algae in the river and lake water.

Description

Technical Field

[0001] This invention relates to the field of water treatment technology, and in particular to a treatment device and method for river and lake water. Background Technology

[0002] Phosphorus pollution is one of the main causes of eutrophication and cyanobacterial blooms in rivers and lakes. Current technologies primarily involve adding chemical agents to rivers and lakes, or using biological or ecological methods to remove phosphorus. While adding chemical agents is effective in removing phosphorus quickly, it carries high maintenance costs and the risk of secondary pollution. Biological or ecological methods, on the other hand, are low-cost and do not pose a risk of secondary pollution, but they are less efficient and require a larger land area.

[0003] To overcome the above-mentioned shortcomings, electrocoagulation phosphorus removal technology has emerged. Currently, it mainly uses electrocoagulation technology to convert phosphorus-containing pollutants into phosphoric acid compound flocs, which then precipitate to the bottom of rivers and lakes. However, this method still carries the risk of releasing phosphorus-containing pollutants and cannot achieve the recovery of phosphorus resources.

[0004] Although ultrasonic technology can inactivate algal cells to form algal residue, the algal residue still needs to be manually removed. This not only makes it difficult to remove floating scum from the water in a timely manner, affecting the river and lake landscape, but also has low efficiency and makes it difficult to completely separate the algal residue from the water. Summary of the Invention

[0005] This invention provides a treatment device for river and lake water. This device can remove phosphorus pollutants from river and lake water, recycle and reuse phosphorus pollutants from river and lake water, and can also efficiently remove algae from river and lake water, thus having excellent economic benefits.

[0006] This invention provides a method for treating river and lake water using the aforementioned river and lake water treatment device. This method is simple to operate and suitable for widespread application.

[0007] This invention provides a treatment device for river and lake water, which includes an electrocoagulation unit, an air flotation unit, a slag removal unit, an ultrasonic algae removal unit, and an ecological floating island unit.

[0008] The electrocoagulation unit has a shell, the shell has a reaction chamber, the reaction chamber has an inlet for the water to be treated and an outlet for purified water, and a first electrode plate and a second electrode plate are alternately arranged in the reaction chamber. Electrolyte ions generated by the electrolysis of the first electrode plate and the second electrode plate form flocs with pollutants in the water to be treated.

[0009] The ultrasonic algae removal unit generates ultrasonic waves to break down algal cells and obtain algal residue.

[0010] The air flotation unit includes an aeration element, which is placed in the reaction chamber. The air bubbles generated by the aeration element carry the flocs and algal residue to the top of the reaction chamber.

[0011] At least a portion of the slag removal unit is disposed at the top of the reaction chamber, and the slag removal unit is used to remove flocs from the top of the reaction chamber;

[0012] The ecological floating island unit is located above the slag removal unit. The ecological floating island includes a gel matrix layer, a nutrient soil layer and a vegetation layer stacked in sequence, with the gel matrix layer close to the slag removal unit.

[0013] In the processing apparatus described above, the reaction chamber includes a bottom wall and side walls perpendicular to the bottom wall. The side walls include a first side wall, a second side wall, a third side wall, and a fourth side wall that are connected end to end. The first side wall is disposed opposite to the third side wall, and the second side wall is disposed opposite to the fourth side wall.

[0014] The inlet of the water to be treated is located on the first side wall and / or the third side wall;

[0015] The first electrode plate and the second electrode plate are parallel to the first sidewall, respectively;

[0016] The first electrode plate is close to the second sidewall, and the second electrode plate is close to the fourth sidewall.

[0017] The processing apparatus described above, wherein the air flotation unit further includes a reflux booster pump, an air compressor, a pressure dissolved gas tank, and a dissolved gas release device;

[0018] The purified water outlet is connected to the inlet of the reflux booster pump, the outlet of the reflux booster pump is connected to the liquid phase inlet of the pressure dissolved gas tank, the outlet of the air compressor is connected to the gas phase inlet of the pressure dissolved gas tank, the outlet of the pressure dissolved gas tank is connected to the inlet of the dissolved gas release device, and the outlet of the dissolved gas release device is connected to the aeration element; and / or,

[0019] The slag removal unit includes a slag scraper, which has slag scraping blades and a slag outlet.

[0020] The scraper blades of the scraper scrape the flocs at the top of the reaction chamber to the slag outlet.

[0021] In the processing apparatus described above, the gel matrix layer is selected from a gel layer, a metal oxide layer, or a gel-metal oxide composite layer.

[0022] In the processing apparatus described above, the gel matrix layer is formed by sequentially baking and foaming the sludge.

[0023] In the treatment apparatus described above, the nutrient soil layer is formed by aerobic fermentation of sludge.

[0024] The processing apparatus described above, wherein the ultrasonic algae removal unit includes an electrically connected ultrasonic generator and an ultrasonic transducer.

[0025] The ultrasonic transducer is disposed on at least a portion of the surface of the housing.

[0026] The treatment apparatus described above further includes a lifting unit for controlling the position of the housing in the water body to be treated.

[0027] The processing apparatus described above further includes a control unit, which is electrically connected to at least one of the electrocoagulation unit, the air flotation unit, the slag removal unit, the ultrasonic algae removal unit, and the lifting unit.

[0028] The present invention provides a method for treating river and lake water, wherein the method uses the river and lake water treatment device described above.

[0029] The river and lake water treatment device of the present invention, through the synergistic action of an electrocoagulation unit, an air flotation unit, an ecological floating island unit, an ultrasonic algae removal unit, and a slag discharge unit, can not only remove phosphorus pollutants from river and lake water and recycle phosphorus pollutants from river and lake water, but also efficiently remove algae from river and lake water, and has excellent economic benefits.

[0030] This invention provides a method for treating river and lake water using the aforementioned treatment device. This method not only removes phosphorus pollutants from river and lake water and recycles them, but also efficiently removes algae. It is simple to operate, significantly reduces the frequency of cyanobacterial blooms, and is suitable for widespread application. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the accompanying drawings used in the description of the embodiments of the present invention or related technologies are briefly introduced below. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of a river and lake water treatment device in some embodiments of the present invention;

[0033] Figure 2 This is a schematic diagram of the inlet distribution of the water body to be treated in some embodiments of the present invention;

[0034] Figure 3 For the present invention Figure 1 Top view of section AA in the middle;

[0035] Figure 4 This is a flowchart illustrating the operation of the control unit in some embodiments of the present invention.

[0036] Explanation of reference numerals in the attached figures:

[0037] 4: Lifting unit;

[0038] 11: Shell;

[0039] 12: Purified water outlet;

[0040] 13: Inlet to the water body to be treated;

[0041] 14: First electrode plate;

[0042] 15: Second electrode plate;

[0043] 16: DC power supply;

[0044] 17: Photovoltaic power generation unit;

[0045] 21: Aeration components;

[0046] 22: Reflux booster pump;

[0047] 23: Air compressor;

[0048] 24: Pressure dissolved gas tank;

[0049] 25: Dissolved gas release device;

[0050] 31: Slag scraper;

[0051] 32: Slag scraper blade;

[0052] 33: Slag outlet;

[0053] 34: Slag collection trough;

[0054] 61: Inspection item;

[0055] 62: Control components;

[0056] 71: Gel matrix layer;

[0057] 72: Nutrient soil layer;

[0058] 73: Vegetation layer;

[0059] 81: Ultrasonic generator;

[0060] 82: Ultrasonic transducer plate;

[0061] 111: First sidewall;

[0062] 112: Second sidewall;

[0063] 113: Third sidewall;

[0064] 114: Fourth lateral wall. Detailed Implementation

[0065] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. 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.

[0066] Figure 1 This is a schematic diagram of the structure of the river and lake water treatment device in the first embodiment of the present invention; Figure 2 This is a schematic diagram showing the inlet distribution of the water body to be treated in some embodiments of the present invention. For example... Figure 1 and Figure 2 As shown, the first aspect of the present invention provides a treatment device for river and lake water, including an electrocoagulation unit, an air flotation unit, a slag removal unit, an ultrasonic algae removal unit, and an ecological floating island unit.

[0067] The electrocoagulation unit has a shell 11, a reaction chamber, a water inlet 13 and a purified water outlet 12. A first electrode 14 and a second electrode 15 are alternately arranged in the reaction chamber of the shell 11. Electrolyte ions generated by electrolysis of the first electrode 14 and the second electrode 15 form flocs with pollutants in the water to be treated.

[0068] The ultrasonic algae removal unit generates ultrasonic waves to break down algae and obtain algae residue.

[0069] The air flotation unit includes an aeration element 21, which is placed in the reaction chamber. The bubbles generated by the aeration element 21 carry flocs and algal residue to the top of the reaction chamber.

[0070] At least part of the slag removal unit is located at the top of the reaction chamber, and the slag removal unit is used to remove flocs from the top of the reaction chamber;

[0071] The ecological floating island unit is located above the slag removal unit. The ecological floating island includes a gel matrix layer 71, a nutrient soil layer 72, and a vegetation layer 73 stacked in sequence. The gel matrix layer 71 is close to the slag removal unit.

[0072] This invention does not specifically limit the water body to be treated. In some embodiments, the water body to be treated can be a river or lake containing phosphorus pollutants, nitrogen pollutants, and algae, which are commonly used in the art. For example, in the water body to be treated, the concentration of TP (total phosphorus content) is 0.2–5.0 mg / L, the concentration of NH3-N (nitrogen content) is 2.1–15.0 mg / L, and the density of algal cells is 0.5–1.0 g / L.

[0073] The present invention does not impose any particular limitation on the material of the housing 11. In some embodiments, the housing 11 may be made of corrosion-resistant material. For example, the housing 11 may be made of carbon steel.

[0074] The water treatment device for rivers and lakes of the present invention can be installed in the river or lake water body or on the shore. The present invention does not limit the shape and number of the inlets 13 for the water to be treated. There can be one or more inlets 13. When there is only one inlet 13, the water treatment device can be installed on the shore, and the water to be treated enters the housing 11 through this inlet 13; for example... Figure 2 As shown, the water inlets 13 to be treated can be evenly distributed on the side walls or bottom walls of the reaction chamber (the side walls and / or bottom walls of the shell 11 are made using a hollowing process), so that the water treatment device for rivers and lakes can be set in the rivers and lakes, and the water to be treated can enter the shell 11 through multiple water inlets 13.

[0075] The present invention does not limit the shape and number of purified water outlets 12; there may be one or more purified water outlets 12. In some embodiments, when the water treatment device for rivers and lakes is placed in the river or lake, the water to be treated enters the housing 11 through the water inlet 13. The purified water formed after being purified in the housing 11 can be output for reuse through the purified water outlet 12, or it can be released into the water to be treated through the top of the housing 11, thereby achieving the purification of the river or lake water.

[0076] The ultrasonic algae removal unit of this invention can generate ultrasonic waves, which can pulverize algae, breaking down algal cells to form algal residue, thus preventing algae accumulation in the water to be treated. Furthermore, the ultrasonic algae removal unit can dissolve ions around the first electrode plate 14 and the second electrode plate 15 into the river or lake water, further preventing passivation of the first electrode plate 14 and the second electrode plate 15 and extending the service life of the electrode plates. This invention does not limit the location of the ultrasonic algae removal unit, as long as it can break down algal cells within the housing 11. For example, the ultrasonic algae removal unit can be located on the outside of the housing 11 or at the bottom inside the housing 11.

[0077] In the reaction chamber of this invention, a first electrode plate 14 and a second electrode plate 15 (anode plate and cathode plate) are alternately arranged. In the reaction chamber, the first electrode plate 14 and the second electrode plate 15 electrolyze to generate electrolytic ions (cations). The electrolytic ions react with pollutants (such as phosphorus pollutants and nitrogen pollutants) in the water to be treated to form flocs. The ultrasonic algae removal unit generates ultrasonic waves to break up algae cells in the water to be treated to obtain algae residue. An aeration element 21 is set in the reaction chamber. The aeration element 21 generates bubbles. The generated bubbles collide with and adhere to the flocs and algae residue to form air-entrained flocs. The air-entrained flocs float to the top of the reaction chamber under the action of buoyancy, forming a stable scum layer at the top of the reaction chamber. The scum removal unit set at the top of the reaction chamber scrapes the air-entrained flocs in the scum layer to the scum collection tank 34, and then transports them to the scum outlet 33 for recycling. After dehydration, the air-entrained flocs can be used as phosphate fertilizer.

[0078] The present invention does not impose any particular limitation on the aeration element 21. In some embodiments, the aeration element 21 can be an aeration head.

[0079] The present invention does not limit the specific location or number of aeration elements 21. In some embodiments, the aeration elements 21 can be located at the bottom of the reaction chamber, and one aeration element 21 can be provided between each pair of first electrode plates 14 and second electrode plates 15.

[0080] It is understandable that the ecological floating island unit is located at or above the surface of the water to be treated, and the ecological floating island unit is located above the slag removal unit.

[0081] The ecological floating island unit of the present invention comprises, from top to bottom, a vegetation layer 73, a nutrient soil layer 72, and a gel matrix layer 71. The gel matrix layer 71 can adsorb pollutants (phosphorus pollutants) in the water to be treated, and / or, the gel matrix layer 71 reacts with H+ in the water. + After the reaction, it can form flocs with the pollutants in the water body to be treated, thereby achieving the removal of pollutants from the water body to be treated;

[0082] The plants in the vegetation layer 73 are planted in the nutrient soil layer 72. The nutrient soil layer 72 provides the planting carrier and nutrients for the plants in the vegetation layer 73. The roots of the plants in the vegetation layer 73 can absorb pollutants, further improving the purification effect.

[0083] Furthermore, the roots of the plants in the vegetation layer 73 extend below the bottom of the gel matrix layer 71.

[0084] It can be understood that the roots of the plants in the vegetation layer 73 pass through the nutrient soil layer 72 and the gel matrix layer 71 in sequence, and extend to the bottom of the gel matrix layer 71 (located at the top of the electrocoagulation unit).

[0085] When the plant roots extend below the bottom of the gel matrix layer 71, the plant roots can not only absorb pollutants in the gel matrix layer 71, realize the in-situ regeneration of the gel matrix layer 71, and extend the service life of the gel matrix layer 71, but also overcome the defects of traditional pollutant adsorbents that are easy to adsorb to saturation and difficult to regenerate; moreover, the plant roots can further absorb pollutants in the water body to be treated, and further purify the water body to be treated.

[0086] The plants in the vegetation layer 73 of this invention can be plants commonly used in the art, such as aquatic plants. The aquatic plants can be at least one of yellow iris, sweet flag and water celery. This invention does not limit the planting density of the plants in the vegetation layer 73.

[0087] In the river and lake water treatment device of the present invention, the electrocoagulation unit reacts the electrolyzed ions from the first electrode 14 and the second electrode 15 with nitrogen and phosphorus pollutants in the water to be treated to form flocs. This not only avoids the risk of secondary pollution caused by the addition of chemical agents, but also has high phosphorus removal efficiency, with a phosphorus pollutant removal rate of over 50%, effectively preventing eutrophication. The ecological floating island unit can further improve the purification effect of the water to be treated, for example, it can achieve a phosphorus removal efficiency of over 70%, and it does not introduce polymer materials, thus avoiding secondary pollution of the water. Compared with existing single river and lake water treatment devices, the phosphorus removal efficiency can be increased by 30%. The device effectively removes phosphorus, maintaining a stable total phosphorus content below 0.1 mg / L (Class II standard for river surface water and Class IV standard for lake and reservoir surface water), thus preventing eutrophication. The air flotation unit forms air-clamped flocs that float at the top of the reaction chamber, allowing them to be recovered by the sludge removal unit. This not only avoids the risk of phosphorus and nitrogen pollutants, as well as algal cells, settling at the bottom of the water, but also allows for the recovery and reuse of phosphorus and nitrogen resources, such as by forming phosphate fertilizer. The ultrasonic algae removal unit removes algae from the water, reducing the frequency of cyanobacterial blooms. This invention's river and lake water treatment device thoroughly removes pollutants and algal matter (cyanobacterial cells) from the water, and also enables the recovery and reuse of phosphorus and nitrogen resources, resulting in excellent economic benefits.

[0088] Figure 3 For the present invention Figure 1 Top view of section AA. (See image) Figure 3 As shown, in some embodiments of the present invention, the reaction chamber includes a bottom wall and side walls perpendicular to the bottom wall. The side walls include a first side wall 111, a second side wall 112, a third side wall 113, and a fourth side wall 114 connected end to end. The first side wall 111 and the third side wall 113 are arranged opposite to each other, and the second side wall 112 and the fourth side wall 114 are arranged opposite to each other.

[0089] The inlet 13 for the water to be treated is located on the first side wall 111 and / or the third side wall 113;

[0090] The first electrode plate 14 and the second electrode plate 15 are parallel to the first side wall 111, respectively;

[0091] The first electrode plate 14 is close to the second side wall 112, and the second electrode plate 15 is close to the fourth side wall 114.

[0092] It is understood that the sidewall of the reaction chamber is formed by connecting the first sidewall 111, the second sidewall 112, the third sidewall 113, and the fourth sidewall 114 end to end. The inlet 13 of the water to be treated can be set only on the first sidewall 111, only on the third sidewall 113, or simultaneously on both the first sidewall 111 and the third sidewall 113.

[0093] The first electrode plate 14 is parallel to the first sidewall 111 and positioned close to the second sidewall 112, while the second electrode plate 15 is parallel to the first sidewall 111 and positioned close to the fourth sidewall 114. This arrangement forms a back-and-forth flow channel, which helps the water to be treated to flow in a folding motion within the housing 11. This enhances the scouring effect on the first electrode plate 14 and the second electrode plate 15, delaying their passivation. It also prevents short-circuiting of the water to be treated, increases the contact opportunity between the water to be treated and the electrolytic ions, and improves the reaction rate. For example, the reaction rate can be increased by more than 30%. Furthermore, it allows the formed flocs to fully contact the bubbles generated by the flotation unit, preventing floc sedimentation compared to traditional up-and-down flow processes and improving the recovery efficiency of phosphorus resources.

[0094] In some embodiments of the present invention, the power supply of the electrocoagulation unit is a DC power supply 16, and the output voltage is a pulse voltage, wherein the output current is 0-30A and the output voltage is 0-36V.

[0095] When the output voltage is a pulse voltage, the first electrode 14 and the second electrode 1 can be periodically reversed, that is, the first electrode 14 can be periodically changed to the second electrode 15, and the second electrode 15 can be periodically changed to the first electrode 14. This can greatly slow down the passivation rate of the conductive electrode plates. Compared with the conventional power supply method, the life of the conductive electrode plates can be extended by more than 30%. In some embodiments, the electrode reversal period is 12 to 180 seconds, that is, the electrode reverses once every 12 to 180 seconds. In a specific embodiment, the electrode reversal period is 60 seconds.

[0096] In some implementations, the DC power supply 16 can be powered by the photovoltaic power generation unit 17.

[0097] The present invention does not impose any particular limitation on the first electrode plate 14 and the second electrode plate 15, and electrode plates commonly used in the art can be used. For example, they can be electrode plates made of aluminum or carbon materials, or electrode plates made of ruthenium or lanthanum materials. In some embodiments of the present invention, both the first electrode plate 14 and the second electrode plate 15 are magnesium-aluminum electrode plates. That is, both the first electrode plate 14 and the second electrode plate 15 are made of magnesium-aluminum alloy.

[0098] When both the first electrode 14 and the second electrode 15 are magnesium-aluminum electrodes, electrolysis of the first electrode 14 and the second electrode 15 will produce Mg 2+ (As shown in Equation 1), Mg 2+ It will react with NH4 in the water to be treated + and PO4 3- The reaction forms struvite MgNH4PO4·6H2O (as shown in Formula 2), or Mg 2+ It will react with PO4 in the water to be treated 3- The reaction forms Mg3(PO4)2 (as shown in Formula 3). Both MgNH4PO4·6H2O and Mg3(PO4)2 are difficult to dissolve in water, thereby achieving the removal of phosphorus and nitrogen pollutants from the water to be treated.

[0099] Mg - 2e - = Mg 2+ Formula 1

[0100] Mg 2+ + NH4 + + PO4 3- + 6H2O = MgNH4PO4·6H2O↓ Equation 2

[0101] 3Mg 2+ + 2PO4 3- = Mg3(PO4)2↓ Equation 3

[0102] Magnesium-aluminum electrode plates can also slow down the passivation rate and have an excellent lifespan, which can be extended by more than 20% compared with electrode plates made of aluminum and carbon materials. Moreover, magnesium-aluminum electrode plates have a lower manufacturing cost, which can reduce the manufacturing cost by more than 50% compared with electrode plates made of ruthenium and lanthanum materials.

[0103] Furthermore, compared to the first electrode plate 14 or the second electrode plate 15 being a magnesium-aluminum electrode plate, the fact that both the first electrode plate 14 and the second electrode plate 15 are magnesium-aluminum electrode plates allows the electrode plates to periodically switch directions. Even after the electrode plates switch directions, magnesium-aluminum ions can still be electrolyzed at the anode, thereby improving the removal efficiency of phosphorus-containing pollutants. Moreover, this periodic switching design can greatly delay electrode passivation.

[0104] The present invention does not limit the spacing between the first electrode plate 14 and the second electrode plate 15, and it can be adjusted according to actual needs. In some embodiments of the present invention, the minimum distance between adjacent first electrode plates 14 and second electrode plates 15 is 10-15 mm.

[0105] The minimum distance between adjacent first electrode plates 14 and second electrode plates 15 refers to the vertical distance between adjacent first electrode plates 14 and second electrode plates 15. When the minimum distance between adjacent first electrode plates 14 and second electrode plates 15 is within the above range, the electrolyzed ions can fully contact the phosphorus and nitrogen pollutants in the water, thereby increasing the reaction rate between the pollutants and the electrolyzed ions.

[0106] In some embodiments of the present invention, the air flotation unit further includes a reflux booster pump 22, an air compressor 23, a pressure dissolved air tank 24, and a dissolved air release device 25;

[0107] The purified water outlet 12 is connected to the inlet of the reflux booster pump 22, the outlet of the reflux booster pump 22 is connected to the liquid phase inlet of the pressure dissolved gas tank 24, the outlet of the air compressor 23 is connected to the gas phase inlet of the pressure dissolved gas tank 24, the outlet of the pressure dissolved gas tank 24 is connected to the inlet of the dissolved gas release device 25, and the outlet of the dissolved gas release device 25 is connected to the aeration element 21.

[0108] Specifically, the purified water after pollutant removal by the electrocoagulation unit can be partially output from the purified water outlet 12 and enter the return booster pump 22 through the inlet. After being pressurized by the return booster pump 22, purified water at a specific pressure is obtained. The purified water at the specific pressure is output from the outlet of the return booster pump 22 and enters the pressure dissolved air tank 24 through the liquid phase inlet. Compressed air is output from the outlet of the air compressor 23 and enters the pressure dissolved air tank 24 through the gas phase inlet. In the pressure dissolved air tank 24, purified water at a specific pressure comes into full contact with compressed air, causing the compressed air to dissolve and thus forming dissolved air water. The dissolved air water is output from the outlet of the pressure dissolved air tank 24 and enters the dissolved air release device 25 through the inlet. After the dissolved air water in the pressure dissolved air tank 24 is depressurized in the dissolved air release device 25, it is output from the outlet of the dissolved air release device 25 and enters the aeration element 21. The aeration element 21 releases the depressurized dissolved air water in the form of bubbles.

[0109] In some embodiments, the pressure provided by the reflux booster pump 22 can be 3-6 kg / cm². 3 .

[0110] In some embodiments of the present invention, when the diameter of the bubbles is 30-55 μm, the bubbles can fully collide and adhere with MgNH4PO4·6H2O and Mg3(PO4)2 flocs and algal residue to form air-entrained flocs, thus preventing the flocs and algal residue from settling; and can also fully disturb the electrode plates to prevent the electrolytic ion concentration from becoming extremely different and the electrode plates from becoming passivated.

[0111] In some embodiments of the present invention, the slag removal unit includes a slag scraper 31 and a slag outlet 33, wherein the slag scraper 31 has a slag scraper blade 32.

[0112] The scraper blades 32 of the scraper 31 scrape the flocs at the top of the reaction chamber to the slag outlet 33.

[0113] Specifically, the scraper blade 32 scrapes the air-filled flocs in the scum layer to the scum collection tank 34, and the air-filled flocs in the scum collection tank 34 are discharged through the scum outlet 33, eliminating the need for manual algae removal and improving the efficiency of phosphorus removal and algae control.

[0114] The gel matrix layer 71 of the present invention can be a gel matrix layer 71 commonly used in the art. In some embodiments of the present invention, the gel matrix layer 71 is selected from a gel layer, a metal oxide layer, or a gel-metal oxide composite layer.

[0115] The gel in the gel layer can be at least one of CaSiO3, MgSiO3, and FeSiO3. The gel has a large specific surface area and can adsorb pollutants in the water to be treated. The metal oxide in the metal oxide layer can be at least one of CaO, MgO, Al2O3, and Fe2O3. The metal oxide reacts with H+ in the water to be treated. + After the reaction, it can form flocs with pollutants (as shown in Formulas 4-11); the gel-metal oxide composite layer refers to a composite layer including at least one gel and at least one metal oxide. This invention does not limit the specific content of each component in the gel-metal oxide composite layer, as long as it can achieve the effect of removing pollutants. The gel in the gel-metal oxide composite layer can adsorb pollutants in the water to be treated, and the metal oxide can react with H in the water to be treated. + The reaction then forms flocs with the pollutants, increasing the removal rate of phosphorus pollutants in the water to be treated by more than 20%, and the formed flocs can be further adsorbed into the gel.

[0116] CaO + 2H + = Ca 2+ + H2O Formula 4

[0117] 3Ca 2+ + 2PO4 3- = Ca3(PO4)2↓ Equation 5

[0118] MgO + 2H + = Mg 2+ + H2O Formula 6

[0119] 3Mg 2+ + 2PO4 3- = Mg3(PO4)2↓ Equation 7

[0120] Al2O3 + 6H + = 2Al 3+ + 3H2O Equation 8

[0121] Al 3+ + PO4 3- = AlPO4↓ Equation 9

[0122] Fe2O3 + 6H + = 2Fe 3+ + 3H2O Formula 10

[0123] Fe 3+ + PO4 3- = FePO4↓ Equation 11

[0124] In some embodiments, the sludge can be baked and foamed in sequence to form a gel matrix layer 71.

[0125] Specifically, during the baking process, SiO2 in the sludge can react with metal oxides (e.g., CaO, MgO, Al2O3, Fe2O3) to form a gel (as shown in Formulas 12-15).

[0126] CaO + SiO2 = CaSiO3 (Equation 12)

[0127] MgO + SiO2 = MgSiO3 Equation 13

[0128] Al₂O₃ + SiO₂ = AlSiO₃ (Equation 14)

[0129] Fe2O3 + SiO2 = FeSiO3 Equation 15

[0130] In some embodiments, when the baking process is carried out at a temperature of 500-600°C for 3-4 hours, the sludge can form a gel more efficiently, thereby forming a gel matrix layer 71.

[0131] It is understandable that water, a foaming agent, and a foam stabilizer need to be added during the foaming process. The mass ratio of gel, water, foaming agent, and foam stabilizer is 100:5:4:1. The foaming agent can be H2O2, and the foam stabilizer can be calcium stearate. During the foaming process, H2O2 decomposes to form a foamed gel.

[0132] In some embodiments, the preparation of the gel matrix layer 71 further includes pretreatment of the sludge, which includes drying and sieving. Drying the sludge completely removes moisture, while sieving separates sludge powder of suitable particle size, promoting subsequent calcination and resulting in a more efficient and high-quality gel matrix layer 71. Furthermore, the drying temperature is 90-105°C, drying the sludge to a constant weight; the sludge powder obtained after sieving has a particle size of 0.5-1 mm.

[0133] The preparation of the gel matrix layer 71 also includes post-processing, which includes shaping. Specifically, the foamed gel is placed in a square mold and allowed to stand and foam until foaming is complete and the gel solidifies. The mold is then removed to form a regularly shaped gel matrix layer 71.

[0134] The present invention can also select the sludge to further improve the quality of the gel matrix layer 71. In some embodiments, the sludge includes riverbed sediment and wastewater treatment plant sludge, and the mass ratio of riverbed sediment to wastewater treatment plant sludge is (3-4):1. Further, the riverbed sediment can be river dredging silt, and the wastewater treatment plant sludge can be iron-containing sludge from the secondary sedimentation tank of a wastewater treatment plant after iron salt sedimentation and dewatering.

[0135] The nutrient soil layer 72 of the present invention can be any nutrient soil layer 72 commonly used in the art. In some embodiments, the nutrient soil layer 72 is formed by aerobic fermentation treatment of sludge.

[0136] This invention utilizes aerobic fermentation to render and stabilize sludge, resulting in a nutrient-rich soil layer 72 suitable for plant growth. In some embodiments, the sludge can be riverbed sediment.

[0137] Furthermore, during the preparation of the nutrient soil layer 72, the sludge can be pretreated, including drying. Drying dewaters the sludge, promoting aerobic fermentation.

[0138] When using sludge to prepare the gel matrix layer 71 and the nutrient soil layer 72, the raw materials are easy to obtain, the preparation process is simple, and the production cost is lower. Moreover, it can turn waste into treasure and improve economic efficiency.

[0139] Furthermore, when the thickness of the gel matrix layer 71 is the same as the thickness of the nutrient soil layer 72, further purification of the water to be treated can be achieved while conserving both the gel matrix layer 71 and the nutrient soil layer 72. In some embodiments, the total thickness of the nutrient soil layer 72 and the gel matrix layer 71 does not exceed 50 cm.

[0140] In some embodiments of the present invention, the ultrasonic algae removal unit includes an electrically connected ultrasonic generator 81 and an ultrasonic transducer 82.

[0141] An ultrasonic transducer plate 82 is disposed on at least a portion of the surface of the housing 11.

[0142] Specifically, the ultrasonic generator 81 generates ultrasonic waves, which act on the water to be treated within the housing 11 through the ultrasonic transducer 82. This disrupts the algae cell structure in the water, achieving algae removal. Furthermore, it dissolves ions around the first and second electrodes 14 and 15 into the water, further preventing passivation of the first and second electrodes 14 and extending their service life. In some embodiments, the ultrasonic generator 81 has an output power of 25-30 kHz.

[0143] In some embodiments of the present invention, a lifting unit 4 is also included, which is used to control the position of the housing 11 in the water body to be treated.

[0144] In this invention, when the river and lake water treatment device is located in the water body to be treated, the position of the housing 11 in the water body to be treated can be controlled by the lifting unit 4, thereby controlling the position of the river and lake water treatment device in the water body to be treated, and realizing the removal of pollutants at different depths in the water body to be treated.

[0145] The present invention does not impose any particular limitation on the specific structure of the lifting unit 4. In some embodiments, the lifting unit 4 can be an electric lifting arm, which is connected to the housing 11.

[0146] In some embodiments of the present invention, a control unit 6 is also included, which is electrically connected to at least one of the electrocoagulation unit, the air flotation unit, the slag removal unit, the ultrasonic algae removal unit, and the lifting unit 4.

[0147] Specifically, the control unit 6 may be electrically connected only to the electrocoagulation unit, only to the flotation unit, only to the slag removal unit, only to the lifting unit 4, or only to the ultrasonic algae removal unit; it may also be electrically connected to the electrocoagulation unit, the flotation unit, the slag removal unit, the ultrasonic algae removal unit, and the lifting unit 4 simultaneously.

[0148] In a specific implementation, the detection element 61 is used to detect the real-time content of pollutants in the water to be treated, and the control element 62 controls the opening degree of the electrocoagulation unit, the air flotation unit, the slag removal unit, and the lifting unit 4 according to the detection result of the detection element 61.

[0149] Figure 4 This is a flowchart illustrating the operation of the control unit in some embodiments of the present invention. For example... Figure 4 As shown, in some embodiments of the present invention, the detection element 61 of the control unit monitors the electrode online, obtains real-time data through the signal receiver, and then controls the water depth of the electric lifting arm through the control element 62, controls the reversal cycle, output current and output voltage of the DC power supply 16, and controls the output power of the dissolved air release device 25.

[0150] In this invention, the control unit 6 ensures that the concentration of electrolyzed ions matches the concentration of pollutants in the water to be treated. This prevents excessive consumption of the electrode plates due to over-electrolysis while ensuring effective flocculation of the ions and pollutants. Simultaneously, it adjusts the electrode plate reversal cycle based on the pollutant concentration, effectively delaying the passivation time. Furthermore, based on the pollutant concentration in the water to be treated and combined with machine learning results, it adjusts the output power of the dissolved air release device 25. This ensures that flocs and algal residue can fully adhere to air bubbles to form air-entrained flocs, achieving the effect of floc flotation, while avoiding floc disintegration and energy waste caused by excessive air bubble release.

[0151] A second aspect of the present invention provides a method for treating river and lake water, which is carried out using the river and lake water treatment apparatus of the first aspect.

[0152] The river and lake water treatment method of the present invention, by using the river and lake water treatment device of the first aspect, can efficiently remove pollutants from river and lake water and can also realize the recycling of pollutants, which has excellent economic benefits and is suitable for widespread application.

[0153] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0154] The river and lake water treatment method in this embodiment adopts... Figure 1-3 The river and lake water treatment device shown includes:

[0155] S1: Dry the riverbed sludge and sewage treatment plant sludge separately at 105℃ to constant weight to completely remove moisture and obtain riverbed sludge powder and sewage treatment plant sludge powder; first use an 18-mesh sieve to remove sludge powder with a particle size greater than 1mm, and then use a 35-mesh sieve to screen sludge powder with a particle size greater than 0.5mm, to obtain riverbed sludge powder to be baked and sewage treatment plant sludge powder to be baked, respectively.

[0156] Riverbed sediment powder and sewage treatment plant sludge powder were reacted at a ratio of 3:1 at 600℃ for 4 hours to obtain vegetative gel.

[0157] Using H2O2 as the foaming agent and calcium stearate as the foam stabilizer, and according to the ratio of plant gel: water: foaming agent: foam stabilizer of 100:5:4:1, water was first added to the plant gel and stirred for 60 seconds to make the gel into a slurry. Then the foaming agent and foam stabilizer were added and stirred slowly and evenly for 60 seconds to allow the H2O2 to decompose and form a foamed plant gel with a specific pore structure.

[0158] The foamed plant gel was filled into a square mold and allowed to stand still to foam until foaming was complete and the gel solidified. The mold was then removed to obtain the gel matrix layer 71.

[0159] S2: After drying and dehydrating the dredged sediment from the river channel and then aerobic fermenting it, a nutrient soil layer 72 is obtained.

[0160] The drying process is carried out at a temperature of 105℃.

[0161] In the aerobic fermentation process, aerobic thermophilic bacteria were used to carry out aerobic fermentation for 10 days under sufficient oxygen conditions.

[0162] S3: Set the nutrient soil layer 72 on the surface of the gel matrix layer 71, and plant aquatic plants (yellow iris seedlings, calamus seedlings, water celery seedlings) on the surface of the nutrient soil layer 72 away from the gel matrix layer 71 to form a vegetation layer 73. After the aquatic plants grow and develop until their roots extend below the bottom of the gel matrix layer 71, an ecological floating island is formed.

[0163] The thickness ratio of the nutrient soil layer 72 to the gel matrix layer 71 is 1:1, and the total thickness of the nutrient soil layer 72 and the gel matrix layer 71 is 50cm.

[0164] The planting density of aquatic plants is 16 plants per square meter;

[0165] S4: The water to be treated enters the shell 11 through the water inlet 13 in a direction perpendicular to the first sidewall 111. The Mg produced by the electrolysis of the first electrode plate 14 and the second electrode plate 15... 2+ It reacts with nitrogen and phosphorus pollutants in the water to be treated to form MgNH4PO4·6H2O (struvite) and / or Mg3(PO4)2 flocs that are insoluble in water;

[0166] The concentration of TP in the water to be treated was 3.7 mg / L, the concentration of NH3-N was 8.5 mg / L, and the density of algal cells was 0.75 g / L.

[0167] The first electrode plate 14 and the second electrode plate 15 are magnesium-aluminum electrode plates, and the distance between the first electrode plate 14 and the second electrode plate 15 is 15 mm. There are 30 first electrode plates 14 and 30 second electrode plates 15.

[0168] The power supply for the electrocoagulation unit is DC power supply 16, and the output voltage is pulse voltage, with an output current of 24A and an output voltage of 30V.

[0169] S2: The ultrasonic generator 81 drives the ultrasonic vibrating plate 82 to generate ultrasonic waves, which destroy the cyanobacterial cell structure in the water to be treated, causing the cyanobacteria to form algal residue.

[0170] Among them, the power of ultrasonic generator 81 is 25Hz;

[0171] S3: Purified water is output from purified water outlet 12, enters reflux booster pump 22 through the inlet of reflux booster pump 22, and is output to pressure dissolved air tank 24 through the outlet of reflux booster pump 22. Compressed air is delivered to pressure dissolved air tank 24 through air compressor 23. In pressure dissolved air tank 24, gas phase and liquid phase form dissolved air water. Dissolved air water is output from pressure dissolved air tank 24 and enters dissolved air release device 25. Dissolved air release device 25 is output to aeration head to generate bubbles.

[0172] After the bubbles collide with and adhere to at least one of the flocs MgNH4PO4·6H2O (guanostone), flocs Mg3(PO4)2, and algal residue, they form air-entrained flocs. Under the action of buoyancy, the air-entrained flocs float to the top of the shell 11 and form a stable scum layer.

[0173] The purified water has a TP concentration of 0.06 mg / L and an NH3-N concentration of 0.84 mg / L, which meet the Class II and Class III standards of the "Surface Water Environmental Quality Standard" (GB 3838-2002) respectively. The algal cell density is 0.13 g / L, which can effectively prevent cyanobacterial blooms.

[0174] The bubble diameter is 45 μm;

[0175] The pressure of the reflux booster pump 22 is 4.5 kg / cm². 3 The power of the dissolved gas release device 25 is 5kw;

[0176] S3: The scraper blades 32 of the slag scraper 31 scrape the air-filled flocs in the slag layer to the slag collection trough 34, and transport the air-filled flocs to the onshore recycling facility through the slag outlet 33. After dewatering, the flocs can be used as phosphate fertilizer.

[0177] S4: Use online monitoring electrodes to monitor the concentration of pollutants in the water to be treated at different depths and transmit the monitoring results to the controller;

[0178] The depth of the electric lifting arm is adjusted according to the concentration of phosphorus pollutants at different depths in the water body so that the shell 11 is placed in the water body to be treated at the depth of the highest pollution concentration, thereby accurately removing pollutants from the water body to be treated.

[0179] Based on the concentration of pollutants in the water to be treated and combined with machine learning results, the reversing cycle, output current and output voltage of the DC power supply 16 are adjusted. At the same time, the reversing cycle of the electrode plate is adjusted in combination with the concentration of pollutants, and the output power of the dissolved gas release device 25 is adjusted.

[0180] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A device for treating river and lake water, characterized in that, It includes an electrocoagulation unit, an air flotation unit, a slag removal unit, an ultrasonic algae removal unit, and an ecological floating island unit; The electrocoagulation unit has a shell, the shell has a reaction chamber, the reaction chamber has an inlet for the water to be treated and an outlet for purified water, and a first electrode plate and a second electrode plate are alternately arranged in the reaction chamber. Electrolyte ions generated by the electrolysis of the first electrode plate and the second electrode plate form flocs with pollutants in the water to be treated. The first electrode plate and the second electrode plate are both magnesium-aluminum electrode plates. The ultrasonic algae removal unit generates ultrasonic waves to pulverize algae and obtain algae residue. The air flotation unit includes an aeration element, which is placed in the reaction chamber. The air bubbles generated by the aeration element carry the flocs and algal residue to the top of the reaction chamber. At least a portion of the slag removal unit is disposed at the top of the reaction chamber, and the slag removal unit is used to remove flocs from the top of the reaction chamber; The ecological floating island unit is located above the slag removal unit. The ecological floating island includes a gel matrix layer, a nutrient soil layer, and a vegetation layer stacked sequentially. The gel matrix layer is close to the slag removal unit. The gel matrix layer is formed by sequentially baking and foaming the sludge. During the baking process, the temperature is 500-600℃ and the time is 3-4 hours. During the baking process, SiO2 in the sludge reacts with metal oxides to form a gel. The root system of the plants in the vegetation layer extends below the bottom of the gel matrix layer. The device also includes a lifting unit, which is used to control the position of the housing in the water body to be treated; The device also includes a control unit, which is electrically connected to at least one of the electrocoagulation unit, the air flotation unit, the slag removal unit, the ultrasonic algae removal unit, and the lifting unit.

2. The processing apparatus according to claim 1, characterized in that, The reaction chamber includes a bottom wall and side walls perpendicular to the bottom wall. The side walls include a first side wall, a second side wall, a third side wall, and a fourth side wall that are connected end to end. The first side wall and the third side wall are arranged opposite to each other, and the second side wall and the fourth side wall are arranged opposite to each other. The inlet of the water to be treated is located on the first side wall and / or the third side wall; The first electrode plate and the second electrode plate are parallel to the first sidewall, respectively; The first electrode plate is close to the second sidewall, and the second electrode plate is close to the fourth sidewall.

3. The processing apparatus according to claim 1 or 2, characterized in that, The air flotation unit also includes a reflux booster pump, an air compressor, a pressure dissolved gas tank, and a dissolved gas release device; The purified water outlet is connected to the inlet of the reflux booster pump, the outlet of the reflux booster pump is connected to the liquid phase inlet of the pressure dissolved gas tank, the outlet of the air compressor is connected to the gas phase inlet of the pressure dissolved gas tank, the outlet of the pressure dissolved gas tank is connected to the inlet of the dissolved gas release device, and the outlet of the dissolved gas release device is connected to the aeration element; and / or, The slag removal unit includes a slag scraper, which has slag scraping blades and a slag outlet. The scraper blades of the scraper scrape the flocs at the top of the reaction chamber to the slag outlet.

4. The processing apparatus according to claim 1 or 2, characterized in that, The gel matrix layer is selected from a gel layer or a gel-metal oxide composite layer.

5. The processing apparatus according to claim 1 or 2, characterized in that, The nutrient soil layer is formed by aerobic fermentation of sludge.

6. The processing apparatus according to claim 1 or 2, characterized in that, The ultrasonic algae removal unit includes an electrically connected ultrasonic generator and an ultrasonic transducer. The ultrasonic transducer is disposed on at least a portion of the surface of the housing.

7. A method for treating river and lake water, characterized in that, The treatment device for river and lake water bodies as described in any one of claims 1-6 shall be used.

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