A device and method for treating a contaminated landscape water body

Abstract

The present application relates to a kind of contaminated landscape water body treatment device and treatment method, including coupling type microbial fuel cell and external circuit, the coupling type microbial fuel cell includes cell cathode, fixed ring, air bag, cell anode, PVC hose, proton exchange membrane, the PVC hose is filled with electrolyte, the cell anode is planted with submerged plant, the external circuit includes light-emitting circuit, resistance circuit and heating circuit parallelly connected between cell cathode and cell anode.The present application utilizes the electric energy generated by microbial fuel cell to provide power for photocatalytic oxidation, magnetic flocculation recovery and water body heating in treatment process, without external power supply, while greatly improving water body treatment ability, reduce the operation and maintenance cost in later period, introduce aquatic plant and microbial treatment into system, can promote each other with microbial fuel cell, so that cell power generation capacity and system processing capacity are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of landscape water body treatment, in particular to a polluted landscape water body treatment device and method. BACKGROUND

[0002] Landscape water body is one of the urban landscapes most closely related to people's daily life, and most of the landscape water bodies have simple structure and function, weak self-regulation ability of the ecological system, poor resistance to external interference, and problems such as small water area and weak water circulation, which are more prominent in small and medium-sized landscape water bodies. Therefore, the landscape water body often needs active management, and if the management is not good, it is easy to cause water body eutrophication and black odor phenomenon.

[0003] Biological method is the most commonly used method in water body repair because of its low cost and long-acting, but it is greatly affected by external temperature and takes a long time to process. For seriously polluted small and medium-sized water bodies, single biological repair cannot achieve good repair effect. The introduction of chemical and physical methods often causes secondary pollution to the water body. Therefore, how to organically combine multiple methods to improve the processing efficiency and also to maintain the water quality of the small landscape water body after processing is the key to solving this problem. SUMMARY

[0004] In order to solve the problem of weak self-purification ability of small and medium-sized landscape water bodies, easy pollution and deterioration of water quality, the present application provides a polluted landscape water body treatment device and method, which uses a coupled microbial fuel cell to efficiently treat and long-term maintain water quality.

[0005] To achieve the above purpose, the present application provides a polluted landscape water body treatment device, which comprises a coupled microbial fuel cell arranged in the water body and an external circuit connected in parallel with the coupled microbial fuel cell, the coupled microbial fuel cell comprises a cell cathode, air bags arranged on both sides of the cell cathode, fixing rings arranged on four corners of the cell cathode, a cell anode arranged under the sludge layer, a plurality of PVC hoses connecting the cell cathode and the cell anode, a proton exchange membrane arranged at the connection between the PVC hose and the cell anode, the PVC hose is filled with electrolyte, the outer side of the PVC hose is provided with biological rope or carbon fiber artificial water grass, the cell anode is planted with submerged plants, the external circuit comprises a light-emitting circuit, a resistance circuit and a heating circuit connected in parallel between the cell cathode and the cell anode, the light-emitting circuit comprises an LED lamp arranged in the water body and a series-connected electromagnet, the resistance circuit comprises a photocatalyst fixed on the outer side of the wire and a series-connected external resistance, and the heating circuit comprises a heating resistor arranged in series between the PVC hoses.

[0006] Preferably, the battery cathode is a silver oxide material box with a top opening, a rubber plug is arranged in the opening, and the box is filled with electrolyte.

[0007] Preferably, the battery anode is a graphite felt with an embedded mesh metal plate, the mesh metal plate is connected with a PVC hose, and a plurality of groups of stainless steel wires are welded on both sides of the mesh metal plate and inserted into the graphite felt.

[0008] Preferably, the electrolyte is a mixture of 0.4 mol / L NaCl and 0.2 mol / L K3[Fe(CN)6] in a volume ratio of 3:2.

[0009] Preferably, the battery cathode is a box with a length of 50 cm, a width of 50 cm and a height of 10 cm, the thickness of the box is 0.5-1 cm, and a fixing ring is arranged on each corner; the battery anode has a length of 50 cm, a width of 50 cm and a thickness of 5 cm, and is buried in the sludge layer below 5-10 cm; and the diameter of the PVC hose is 10 cm.

[0010] Preferably, the battery cathode is connected to each other by the fixing ring on the four corners and the steel wire rope to form a module, and the plastic rod is inserted into the bottom mud through the fixing ring on the outermost side of the module.

[0011] Preferably, the submerged plant is one or more of black algae, bitter grass and elodea.

[0012] Preferably, the electromagnet is composed of a wire of an LED lamp, a "j" shaped iron core and a square iron plate. The LED lamp uses copper as the wire, which is wound on the "j" shaped iron core in a spiral manner. The "j" shaped iron core is divided into four parts on average at both ends, and the "j" shaped iron core is connected to the square iron plate with a missing corner through a bolt structure.

[0013] Another object of the present application is to provide a method for treating a polluted landscape water body, comprising the following steps:

[0014] A, constructing a polluted landscape water body treatment device, combining the coupling type microbial fuel cell, connecting the battery cathode with the steel wire rope at least partially through the fixing ring to form a module, inserting the plastic rod at least partially through the fixing ring on the four corners of the module into the bottom mud to fix the module, determining the number of installations according to the water area or the water surface width interval, taking the battery cathode as the reference, the water surface coverage rate after installation is between 50% and 80% in a small water body, the installation coverage rate is 30-50% in a medium water body, and the installation position is selected in the area with a water depth of 1.5 m or more.

[0015] B, turn on the external circuit, in the battery cathode gap in turn add flocculating agent, magnetic seed, coagulant aid, after flocculation and precipitation, the electromagnet is taken out from the water, and the magnetic powder is recovered;

[0016] C, after the precipitation is completed, the LED light is continuously turned on, so that the emitted light can sufficiently irradiate the photocatalyst on which the ink-phase carbon nitride is fixed.

[0017] D, routine maintenance is carried out, when the water temperature is lower than 15 DEG C, the heating circuit is turned on, when the temperature is lower than 5 DEG C, the light emitting circuit and the resistance circuit are cut off, and the heating circuit is turned on alone.

[0018] Preferably, the flocculating agent is PAC, the dosage is 30-90 mg / L, the magnetic seed is ferroferric oxide, the dosage is 80-250 mg / L, and the coagulant aid is PAM, the dosage is 0.3-2 mg / L.

[0019] Based on the above technical scheme, the application has the following advantages:

[0020] The application reforms the traditional sediment microbial fuel cell, increases the electrolyte mass transfer structure in the anode and cathode to reduce the internal resistance of the cell, changes the cathode of the cell into a silver oxide cavity structure to increase the electrode area, solves the problem of low power generation efficiency of the sediment microbial fuel cell, changes the external circuit into an electromagnetic structure to collect and process the flocculating agent added in the early stage, and solves the problem of difficult recovery of the flocculating agent in the natural water body.

[0021] Secondly, the photocatalyst is fixed outside the lead of the heating resistor and is connected in parallel with the LED lamp, so as to supplement the light source for the submerged plant and promote the photocatalytic oxidation reaction. In addition, the artificial water grass is arranged on the electrolyte pipe, and the formation of the biological membrane is utilized to further degrade the organic matter. The heating resistor is added to the external circuit to heat the water body to a certain extent, so as to solve the problem of low microbial activity and weak water treatment capacity in winter.

[0022] The application reforms the sediment microbial fuel cell, improves the power generation performance, completely utilizes the electric energy generated by the microbial fuel cell to provide power for the photocatalytic oxidation, magnetic flocculation recovery and water body heating in the treatment process, has no external power supply, greatly improves the water treatment capacity, and reduces the operation and maintenance cost in the later stage. In addition, the aquatic plant and microbial treatment are introduced into the system, can promote each other with the microbial fuel cell, and the power generation capacity of the cell and the treatment capacity of the system are improved. BRIEF DESCRIPTION OF DRAWINGS

[0023] The drawings described herein are used to provide further understanding of the application, constitute a part of the application, and the illustrative embodiments of the application and the description thereof are used to explain the application, and do not constitute improper limitation on the application. In the drawings:

[0024] Figure 1 A schematic diagram of a device for treating a polluted landscape water body;

[0025] Figure 2 A schematic diagram of a device for treating a polluted landscape water body. DETAILED DESCRIPTION

[0026] The technical solutions of the present application are described in further detail below with reference to the accompanying drawings and examples.

[0027] The present application provides a device for treating a polluted landscape water body, aiming at treating a small or medium-sized landscape water body with serious pollution, a water flow less than 0.02 m / s, and a water depth of about 1.5-2.5 m. The device is obtained by modifying a sediment microbial fuel cell, adding a metal plate to the anode, planting submerged plants, designing the cathode as a silver oxide cavity, and adding an electrolyte mass transfer structure between the anode and the cathode to improve the power generation performance of the cell. An LED lamp is installed in the external circuit, and a photocatalyst is added to solve the problem that the photocatalytic reaction is difficult to perform in a polluted water body with low visibility. At the same time, the LED lamp supplies light to the submerged plants, and an electromagnetic structure is added to realize the recovery of flocculants. A heating resistor is added to the external circuit resistance to increase the water temperature. In the implementation process of the present application, the water quality and temperature conditions are combined to control the cell system and achieve efficient treatment of the water body.

[0028] As shown in Figure 1 The device for treating a polluted landscape water body includes a coupled microbial fuel cell arranged in a water body and an external circuit connected in parallel with the coupled microbial fuel cell. The coupled microbial fuel cell includes a cell cathode 1, air bags 2 arranged on both sides of the cell cathode 1, fixing rings 16 arranged at the four corners of the cathode 1, a cell anode 8 arranged below a sludge layer 7, a plurality of PVC hoses 5 connecting the cell cathode 1 and the cell anode 8, a proton exchange membrane 10 arranged at the connection between the PVC hose 5 and the cell anode 8, electrolyte filled in the PVC hose 5, biological rope or carbon fiber artificial water grass 3 arranged on the outside of the PVC hose 5, and submerged plants 6 planted on the cell anode 8. The external circuit includes a light-emitting circuit, a resistance circuit, and a heating circuit connected in parallel between the cell cathode 1 and the cell anode 8. The light-emitting circuit includes an LED lamp 12 arranged in the water body and a magnet 11 connected in series. The resistance circuit includes a photocatalyst 13 fixed on the outside of a wire and an external resistor 14 connected in series. The heating circuit includes a heating resistor 4 arranged in series between the PVC hoses 5.

[0029] The silver oxide is selected as the battery cathode 1, the top is opened, the rubber plug is installed, the box with the length, width and height of 50cm*50cm*10cm is made, the thickness of the box is 0.5-1cm, the electrolyte is filled in the box, the cathode area is increased, and the proton exchange efficiency is improved. The air bag 2 is fixed on the two sides of the cathode, and the air bag 2 is floated above the water surface. The cathode is connected with each other through the fixed ring 16 on the four corners and the steel wire rope 17, the plastic rod 18 is inserted into the bottom mud through the fixed ring 16 on the four outermost corners, and the module is fixed.

[0030] The silver oxide is selected as the battery cathode, and the energy conversion efficiency of the battery can be increased to more than 30%. When the silver oxide on the cathode is reduced to silver after obtaining electrons, the silver oxide can be oxidized again to be recycled, so that the electrode can be reused. The traditional solid electrode is changed into a cavity, so that the contact area of the electrolyte and the electrode is greatly increased, and the exchange rate of the electrons is accelerated. The module is fixed by the plastic rod passing through the fixed hole, so that the problem of module drift is solved, and the module can float up and down with the water level.

[0031] The graphite felt is selected as the battery anode 8, the length, width and thickness of the graphite felt are 50cm*50cm*5cm, the mesh metal plate 9 is arranged in the graphite felt, and the graphite felt is buried in the silt layer 7 below 5-10cm. The mesh metal plate 9 is connected with the PVC hose 5 by selecting stainless steel, a plurality of groups of stainless steel wires are welded on the two sides of the mesh metal plate 9, and the stainless steel wires are inserted into the graphite felt, so that the conductivity is enhanced. The metal plate is added in the graphite felt, so that the contact area of the graphite felt with the power-generating microorganisms is increased, the conductivity of the electrode is improved, and the internal resistance of the battery is reduced.

[0032] Preferably, the battery cathode 1 and the battery anode 8 are connected through four PVC hoses 5, the diameter of the PVC hose 5 is 10cm, and the PVC hose 5 is filled with electrolyte. Preferably, the electrolyte is 0.4mol / L NaCl and 0.2mol / L K3[Fe(CN)6] mixed in a volume ratio of 3:2. The cathode and the anode are isolated by the proton exchange membrane 10 at the anode interface.

[0033] The mass transfer channel filled with the electrolyte is established between the cathode and the anode, so that the problems of low salt content in fresh water and slow electron transfer rate are solved. The soft PVC pipe is used as the channel carrier, the distance between the electrodes can change according to the floating of the water level, the cathode is always above the water surface, and enough oxygen is contacted.

[0034] The external circuit is divided into three parts of resistance circuit, light-emitting circuit and heating circuit, and is connected with the parallel and coupled microbial fuel cell.

[0035] Small power LED lamp 12 is installed on the light-emitting circuit, and the installation position is preferably selected at the middle and lower layer of the water body to solve the problem that natural light cannot penetrate the deep water area. Copper is selected as the lead, which is spirally wound on the "J" shaped iron core 15. The two ends of the "J" shaped iron core 15 are evenly divided into four parts (two parts per end), and the square iron plates with missing corners are connected by bolt structure. Each iron plate has a side length of about 30 cm, and the square side length of the missing corner part is about 14 cm. Four iron plates are connected to each other to form an electromagnet 11. A nylon rope is provided in the middle of the iron core to facilitate the salvage of the electromagnet 11.

[0036] The photocatalyst 13 is fixed outside the resistance circuit lead to cooperate with the LED lamp 12 to treat the refractory organic matter. The photocatalyst 13 is graphite phase carbon nitride which is environmentally friendly and can play a photocatalytic role under ordinary visible light. The heating resistor 4 is connected to the heating circuit and is placed in the center of the four PVC hoses 5 to heat the water body when the water temperature is low.

[0037] The voltage of the external circuit is increased by installing an external resistor, and the photocatalyst is fixed on the lead to provide a basis for photocatalytic reaction. The LED lamp is installed on the light-emitting circuit parallel to the external resistor, and the lead of the LED lamp is spirally wound on the iron core to form an electromagnet. The electrical energy generated by the microbial fuel cell is used to provide power for photocatalytic oxidation and flocculant recovery.

[0038] The heating resistor is connected in parallel with the resistance circuit and the light-emitting circuit, and a single control is installed. According to the water temperature, the resistor is heated by controlling the switch. When the water temperature is too low (<5℃) in winter, the heating circuit is started alone, which can maximize the conversion of electrical energy into heat energy, so that the water temperature rises, and the death of microorganisms at low temperature is avoided.

[0039] Further, the submerged plant 6 is planted in the anode 8 of the battery, and the plant species can be selected from one or more of black algae, bitter grass, and elodea. The biological rope or carbon fiber artificial water grass 3 is arranged outside the PVC hose 5.

[0040] The present application improves the power generation performance of the sediment microbial fuel cell, fully utilizes the electrical energy generated by the microbial fuel cell to provide power for photocatalytic oxidation, magnetic flocculation recovery and water temperature rise in the treatment process, and has no external power supply. While greatly improving the water treatment ability, the operation and maintenance cost in the later stage is reduced. In addition, the aquatic plant and microbial treatment are introduced into the system, which can promote each other with the microbial fuel cell, so that the power generation capacity of the battery and the treatment capacity of the system are improved.

[0041] Further, based on the polluted landscape water body treatment device, the present application also provides a polluted landscape water body treatment method, which comprises the following steps:

[0042] A, Constructing the device for treating the contaminated landscape water body, combining the coupling microbial fuel cell, connecting the modules by the steel wire rope 17 through the fixing ring 16 at the cathode 1 of the cell, inserting the plastic rod 18 through the fixing ring 16 into the bottom mud at the four corners of the module, fixing the module, taking the cathode 1 of the cell as the reference, determining the number of installations according to the water area or the water surface width interval, the water surface coverage rate after installation is between 50% and 80% in small water body, the installation coverage rate is 30-50% in medium water body, the installation position is selected in the area with the water depth of 1.5 m and above, the electromagnet 11 is placed on the bottom mud below the gap between the cathodes 1 of the cells to receive the flocs generated by the magnetic flocculation.

[0043] Preferably, the plastic rod 18 is inserted into the bottom mud through the fixing ring 16 at the outermost side of the module to obtain a better installation position of the electromagnet 11.

[0044] B, turning on the external circuit, sequentially adding the flocculant, magnetic seed and coagulant aid in the gap between the cathodes 1 of the cells, taking out the electromagnet 11 from the water after the completion of the flocculation and precipitation, removing the flocs adsorbed on the electromagnet 11 by turning off the switch, and recovering the magnetic powder. The preliminary removal of ammonia nitrogen and COD in the water is completed, and the water transparency is improved.

[0045] Preferably, the flocculant is PAC, the dosage is 30-90 mg / L; the magnetic seed is ferroferric oxide, the dosage is 80-250 mg / L; and the coagulant aid is PAM, the dosage is 0.3-2 mg / L.

[0046] C, after the completion of the precipitation, the transparency of the water body is improved, the light emitted by the LED lamp 12 is continuously turned on to make the light emitted sufficiently irradiate on the photocatalyst 13 fixed with the nitrogen of carbonized ink, promote the photocatalytic oxidation reaction, further remove the refractory organic matter in the water, and simultaneously supplement the light for the underwater plants to promote the growth of the plants.

[0047] D, performing the daily maintenance, due to the high content of the water pollutants in the early stage, the artificial water grass arranged outside the PVC hose can quickly form the membrane, and has a good treatment effect on the slightly polluted water body after the flocculation, precipitation and catalytic oxidation. The submerged plants planted in the anode can also control the phosphorus release of the sediment.

[0048] When the water body is a black and odorous water body or a eutrophic water body, the pollution is serious and the content of the sediment microorganism is high, the rubber gasket is added between the fixing ring and the steel wire rope, the insulation is good, and each cell circuit is operated individually. When the water pollution is slight, the electricity generation capacity is small, the gasket is removed, the cathodes are connected in series, and part of the external circuit is turned on to ensure the output of the current.

[0049] It should be noted that the above-mentioned current control mode is only one specific embodiment, and those skilled in the art can know that when the battery power generation is large, other insulation modes can also be used between the fixed ring and the steel wire rope, so that each battery circuit operates independently; when the power generation is small, the cathodes of the batteries are connected in series, and part of the external circuit is turned on to ensure the output of the current.

[0050] When the water temperature is lower than 15 DEG C, the heating circuit is automatically connected through the heat sensor, so that the microorganisms attached to the artificial water grass have strong activity. When the temperature is lower than 5 DEG C, the light emitting circuit and the external resistance circuit are automatically cut off, so that the heating circuit operates alone, the temperature of the nearby water body rises rapidly, and the death of the microorganisms attached to the artificial water grass is prevented.

[0051] The application is a method for treating contaminated landscape water bodies. In the early stage of serious water pollution, flocculation and sedimentation are used to improve water quality and enhance the sense of landscape water bodies in a short time, and to provide basic conditions for photocatalytic oxidation. The flocculation body is collected by the electromagnetic structure arranged in advance, and the problem of secondary pollution caused by difficult flocculation body collection in natural water bodies is solved.

[0052] After sedimentation, the visibility of the water body is improved, but the content of dissolved organic matter in the water is still high. At this time, under the irradiation of the LED lamp, the catalytic oxidation reaction can occur rapidly near the fixed photocatalyst, and the organic matter in the water is effectively degraded.

[0053] After sedimentation and oxidation reaction, the content of organic matter in the water is greatly reduced. The artificial water grass arranged by the PVC hose can carry out long-acting treatment on the micro water body after biofilm formation, and the submerged plants planted at the bottom can also release nitrogen and phosphorus in the sediment, thereby playing a long-acting role in maintaining water quality. The heating power of the heating resistor can be controlled by changing the switch of the heating circuit, so as to meet the needs of water treatment microorganisms for water temperature under different temperature conditions.

[0054] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application, but not to limit it; although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalent ones; without departing from the spirit of the technical solutions of the present application, they should be covered in the technical solution range of the present application.

Claims

1. A device for remediation of a contaminated landscape water body, characterized in that: The application relates to a coupling type microbial fuel cell arranged in a water body and an external circuit connected in parallel with the coupling type microbial fuel cell, wherein the coupling type microbial fuel cell comprises a cell cathode (1), air bags (2) arranged on both sides of the cell cathode (1), fixing rings (16) arranged on four corners of the cell cathode (1), a cell anode (8) arranged below a sludge layer (7), a plurality of PVC hoses (5) connecting the cell cathode (1) and the cell anode (8), and a proton exchange membrane (10) arranged at a connection position of the PVC hose (5) and the cell anode (8), the cell cathode (1) is a silver oxide material box body with a top opening, a rubber plug is arranged in the opening, the inside of the box body is filled with electrolyte, the PVC hose (5) is filled with electrolyte, biological rope or carbon fiber artificial water grass (3) is arranged on the outside of the PVC hose (5), the cell anode (8) is planted with submerged plants (6), the submerged plants (6) are one or more of black algae, Vallisneria and Elodea, the external circuit comprises a light emitting circuit, a resistance circuit and a heating circuit connected in parallel between the cell cathode (1) and the cell anode (8), the light emitting circuit comprises LED lamps (12) arranged in the water body and an electromagnet (11) connected in series, the resistance circuit comprises a photocatalyst (13) fixed on the outside of a wire and an external resistor (14) connected in series, and the heating circuit comprises heating resistors (4) arranged in series between the PVC hoses (5).

2. The apparatus of claim 1, wherein: The cell anode (8) is graphite felt with a built-in mesh metal plate (9), the mesh metal plate is connected with the PVC hose (5), and a plurality of groups of stainless steel wires are welded on both sides of the mesh metal plate (9) and inserted into the graphite felt.

3. The apparatus of claim 1, wherein: The electrolyte is a mixture of 0.4 mol / L NaCl and 0.2 mol / L K3[Fe (CN) 6] in a volume ratio of 3:

2.

4. The apparatus of claim 1, wherein: The cell cathode (1) is a box body with a length*width*height of 50cm*50cm*10cm, the thickness of the box body is 0.5-1cm, and the fixing rings (16) are arranged on four corners of the box body; the length*width*thickness of the cell anode (8) is 50cm*50cm*5cm, and the cell anode (8) is buried below 5-10cm of the sludge layer (7); and the diameter of the PVC hose (5) is 10cm.

5. The apparatus of claim 1, wherein: The cell cathode (1) is connected with each other through the fixing rings (16) and steel wire ropes (17) on four corners, and plastic rods (18) pass through the outermost fixing rings (16) and are inserted into the bottom mud.

6. The apparatus of claim 1, wherein: The electromagnet (11) is composed of a wire of the LED lamp, a "few" type iron core (15) and a square iron plate, the LED lamp (12) adopts copper as the wire, the wire is wound on the "few" type iron core (15) in a spiral mode, two ends of the "few" type iron core (15) are evenly divided into four parts, and the "few" type iron core (15) is connected with the square iron plate with a missing corner through a bolt structure.

7. A method for treating a contaminated landscape water body, the method comprising: introducing a composition comprising a biocide into the contaminated landscape water body. The application further relates to a method for treating water bodies, and the method comprises the following steps: A, the polluted landscape water body treatment device as claimed in any one of claims 1-6 is constructed, the coupling type microbial fuel cell is combined, the battery cathode (1) is connected to form a module by at least partially penetrating the fixing ring (16) with a steel wire rope (17), and the module is fixed by at least partially penetrating the fixing ring (16) with a plastic pole (18) inserted into the bottom mud at four corners of the module; the number of installations is determined according to the water area or the water surface width interval with the battery cathode (1) as a reference; the water surface coverage rate after installation is between 50% and 80% in a small water body, the installation coverage rate is between 30% and 50% in a medium water body, and the installation position is selected in an area with a water depth of 1.5 m or more; the electromagnet (11) is placed on the bottom mud below the gap of the battery cathode (1); B, the external circuit is turned on, the flocculating agent, the magnetic seed and the coagulant aid are sequentially added in the gap of the battery cathode (1), the electromagnet (11) is taken out of the water after the flocculation and precipitation are completed, and the magnetic powder is recovered; C, after the precipitation is completed, the LED lamp (12) is continuously turned on so that the light emitted can sufficiently irradiate the photocatalyst (13) fixed with the graphite phase nitrogen carbide; D, routine maintenance is performed, the heating circuit is turned on when the water temperature is lower than 15 DEG C, and the light emitting circuit and the resistance circuit are cut off when the temperature is lower than 5 DEG C, and the heating circuit is turned on alone.

8. The method of remediating a contaminated landscape water body of claim 7, wherein: The flocculating agent is PAC, the addition amount is 30-90 mg / L; the magnetic seed is ferroferric oxide, the addition amount is 80-250 mg / L; and the coagulant aid is PAM, the addition amount is 0.3-2 mg / L.

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