1. A biological/photoelectric/solar energy coupling sewage treatment integrated device is characterized by comprising a biological treatment unit 1, a precipitation treatment unit 2 and a photoelectric catalysis unit 3; the biological treatment unit 1 is positioned at one side of the precipitation treatment unit 2; the photoelectrocatalysis unit 3 is positioned at the other side of the precipitation treatment unit 2, the photoelectrocatalysis unit 3 is obliquely arranged, the inclination angle is 25-40 degrees, and a gap enclosed between the photoelectrocatalysis unit 3 and the precipitation treatment unit 2 is a device accommodating unit;

the photoelectrocatalysis unit 3 comprises a reaction water tank 11 and a solar cell panel 12, the reaction water tank 11 is made of high borosilicate glass, the solar cell panel 12 is tightly attached to one side surface of the reaction water tank, sunlight is ensured to penetrate through the reaction water tank 11 and irradiate onto the solar cell panel 12, at least one pair of photoelectrocatalysis electrode pairs is arranged in the reaction water tank 11, and cathodes and anodes of the electrode pairs are arranged in a staggered mode;

sewage firstly enters the biological treatment unit 1, the treated sewage enters the precipitation treatment unit 2 to be separated into sludge and clarified liquid, the clarified liquid enters the photoelectric reaction unit 3 to be subjected to photoelectric catalytic oxidation treatment, the treated water is discharged from a water outlet of the photoelectric reaction unit, and meanwhile, sunlight penetrates through the photoelectric catalytic reaction water tank to irradiate on the solar cell panel to generate electric energy so as to provide electric energy for the operation of the whole device.

2. The integrated biological/photoelectric/solar coupled sewage treatment device according to claim 1, wherein the biological treatment unit 1 is a three-dimensional A²The O treatment unit comprises an anaerobic tank 4, an anoxic tank 5 and an aerobic tank 6 from bottom to top in sequence, sewage inflow ports are formed in the lower portions of the anaerobic tank 4, the anoxic tank 5 and the aerobic tank 6, sewage outflow ports are formed in the upper portions of the anaerobic tank 4, the anoxic tank 5 and the aerobic tank 6, the sewage outflow port of the anaerobic tank 4 is communicated with the sewage inflow port of the anoxic tank 5 through a conduit, the sewage outflow port of the anoxic tank 5 is communicated with the sewage inflow port of the aerobic tank 6 through a conduit, sewage enters the biological treatment unit 1 from the sewage inflow port in the lower portion of the anaerobic tank 4, and flows into the precipitation treatment unit 2 from the sewage outflow port in the upper portion of the aerobic tank 6 after flowing through the anoxic tank 5.

3. The integrated bio/photoelectric/solar coupled sewage treatment device of claim 2, wherein the anaerobic tank 4 and the anoxic tank 5 are internally provided with mixers, and the bottom of the aerobic tank 6 is provided with an aerator pipe.

4. The integrated biological/photoelectric/solar-coupled sewage treatment device according to claim 1, wherein the sedimentation treatment unit 2 comprises a tank body 7 and an inverted rectangular pyramid 8 arranged in the tank body 7, the inverted rectangular pyramid 8 is positioned below the tank body 7, the lowest end of the inverted rectangular pyramid 8 is communicated with one end of a sludge return pipe 9, and the other end of the sludge return pipe 9 is communicated with a sludge inlet 10 of the anaerobic tank 4; a sewage flow outlet is arranged above the tank body 7, a sewage inlet is also arranged above the inverted rectangular pyramid 8 on the tank body 7, sewage treated by the biological treatment unit 1 flows into the tank body 7 of the sedimentation treatment unit 2 through the sewage inlet, lower-layer sludge deposited by the inverted rectangular pyramid 8 flows back into the anaerobic tank 4 through a sludge return pipe 9, and supernatant liquid at the upper layer flows into the photoelectrocatalysis unit 3 through the sewage flow outlet.

5. The integrated biological/photoelectric/solar coupled sewage treatment device according to claim 1, wherein a clear liquid inlet is formed below the reaction water tank 11, and a water outlet is formed above the reaction water tank 11.

6. The integrated bio/photoelectric/solar coupled sewage treatment device according to claim 1, wherein the cathode of the electrode pair is a graphite electrode plate, and the anode is Ag/TiO₂、Mn/TiO₂、Fe/TiO₂、CdS/PbS/TiO₂Or N/F/TiO₂And (4) a polar plate.

7. The integrated bio/photoelectric/solar coupled sewage treatment device according to claim 6, wherein one end of each of the cathode plate and the anode plate of the electrode pair is connected to the reaction tank 11 through an acrylic base, the anode plate is connected to the bottom of the reaction tank 11 through a base, the cathode plate is connected to the top of the reaction tank 11 through a base, the unfixed other end of each of the cathode plate and the anode plate is kept in a space of 10-20 cm from the reaction tank 11, and the distance between the adjacent cathode plate and the anode plate is 2-7 cm.

8. According to claim 6The biological/photoelectric/solar coupling sewage treatment integrated device is characterized in that 1-5 mA/cm is applied to the cathode plate and the anode plate²Is constant current.

9. The integrated biological/photoelectric/solar-coupled sewage treatment device according to claim 7, wherein the clarified liquid flows in a serpentine shape between the cathode plate and the anode plate, and the hydraulic retention time is 2-3 h.

10. The biological/photoelectric/solar coupling integrated sewage treatment device according to claim 1, wherein the solar cell panel 12 is a single crystal silicon solar cell panel, the power generation efficiency is 100-200W/square meter, a heat preservation and insulation layer is arranged below the solar cell panel 12, the solar cell panel 12 is connected with a storage battery, the storage battery is located in the device storage unit, and the storage battery provides electric energy for the operation of the whole device.

Background

Compared with the property of urban sewage, rural domestic sewage has the characteristics of dispersibility, small yield, large change coefficient and the like, and if centralized sewage treatment is adopted, large-area construction of sewage pipe networks can bring larger economic pressure to sewage treatment plants. The existing rural household sewage treatment technologies mainly comprise biological treatment technologies such as a biological contact oxidation method, an anaerobic methane tank technology and the like, and ecological treatment technologies such as a stabilization pond, soil infiltration and the like. The technologies can utilize microorganisms to remove organic matters in water and remove nitrogen and phosphorus, have good COD removal rate, but generally have larger floor area and more complex operation and maintenance, so the replaceable domestic sewage treatment device has unique advantages. And with the continuous improvement of living standard, the degradation substances in the domestic sewage are increased, such as surfactant, antibiotic and the like, and the efficiency of common biological treatment on the organic substances is too low.

The photoelectrocatalysis oxidation technology is an advanced oxidation technology with great application prospect, and belongs to the advanced sewage treatment technology. The principle is TiO₂When a semiconductor serving as a photocatalyst, such as ZnO or ZnS, is irradiated with light having energy larger than band gap energy, electrons in the Valence Band (VB) are excited to transit to the Conduction Band (CB), and active electrons are generated on the conduction band, resulting in high energy. At the same time, positively charged holes are generated in the valence band, and electrons can be abstracted from water molecules to generate OH. Both OH and holes are strongly oxidizing and oxidize refractory organics in water. Meanwhile, a bias voltage is applied to the photocatalytic anode, a potential gradient is formed in the electrode, photogenerated electrons are promoted to leave the surface of the photoelectrode, the recombination of electrons and holes is reduced, and the pollutant degradation efficiency is improved.

The photovoltaic-photocatalytic mixed water treatment system is built in the prior art, the photocatalysis of titanium dioxide is tightly combined with the solar cell panel, the photocatalysis utilizes ultraviolet rays in sunlight, the solar cell panel utilizes visible light and infrared rays, the self-supply of system electric energy is realized, but the ultraviolet rays only account for 5 percent of the sunlight, the degradation efficiency is lower, the device can only achieve a better effect under the condition of multiple cyclic degradation of low-concentration organic sewage, water cannot continuously enter the device, and the device is not suitable for treating domestic sewage. Therefore, it is necessary to provide a system capable of efficiently utilizing sunlight to treat rural domestic sewage.

Disclosure of Invention

The invention provides a biological/photoelectric/solar coupling sewage treatment integrated device, aiming at solving the problems of low sunlight utilization efficiency, low mineralization rate of refractory organic matters and high difficulty in building large-scale water plants in rural areas in the prior art.

The technical scheme of the invention is as follows:

a biological/photoelectric/solar energy coupling sewage treatment integrated device comprises a biological treatment unit 1, a precipitation treatment unit 2 and a photoelectric catalysis unit 3; the biological treatment unit 1 is positioned at one side of the precipitation treatment unit 2; the photoelectrocatalysis unit 3 is positioned at the other side of the precipitation treatment unit 2, the photoelectrocatalysis unit 3 is obliquely arranged, the inclination angle is 25-40 degrees, and a gap enclosed between the photoelectrocatalysis unit 3 and the precipitation treatment unit 2 is a device accommodating unit;

the photoelectrocatalysis unit 3 comprises a reaction water tank 11 and a solar cell panel 12, the reaction water tank 11 is made of high borosilicate glass, the solar cell panel 12 is tightly attached to one side surface of the reaction water tank, sunlight is ensured to penetrate through the reaction water tank 11 and irradiate onto the solar cell panel 12, at least one pair of photoelectrocatalysis electrode pairs is arranged in the reaction water tank 11, and cathodes and anodes of the electrode pairs are arranged in a staggered mode;

sewage firstly enters the biological treatment unit 1, the treated sewage enters the precipitation treatment unit 2 to be separated into sludge and clarified liquid, the clarified liquid enters the photoelectric reaction unit 3 to be subjected to photoelectric catalytic oxidation treatment, the treated water is discharged from a water outlet of the photoelectric reaction unit, and meanwhile, sunlight penetrates through the photoelectric catalytic reaction water tank to irradiate on the solar cell panel to generate electric energy so as to provide electric energy for the operation of the whole device.

Further defined, the biological treatment unit 1 is a three-dimensional body A²The O treatment unit comprises an anaerobic tank 4, an anoxic tank 5 and an aerobic tank 6 from bottom to top in sequence, sewage inflow ports are formed in the lower portions of the anaerobic tank 4, the anoxic tank 5 and the aerobic tank 6, sewage outflow ports are formed in the upper portions of the anaerobic tank 4, the anoxic tank 5 and the aerobic tank 6, the sewage outflow port of the anaerobic tank 4 is communicated with the sewage inflow port of the anoxic tank 5 through a guide pipe, the sewage outflow port of the anoxic tank 5 is communicated with the sewage inflow port of the aerobic tank 6 through a guide pipe, one end of an outflow pipe of the aerobic tank 6 is connected with one end of the bottom of the anoxic tank through a tee joint and is connected with the precipitation treatment unit 2, sewage enters the biological treatment unit 1 from the sewage inflow port below the anaerobic tank 4, and flows into the precipitation treatment unit 2 from the sewage outflow port above the aerobic tank 6 after flowing through the anoxic tank 5.

Further limiting, a stirrer is arranged inside the anaerobic tank 4 and the anoxic tank 5, and an aeration pipe is arranged at the bottom of the aerobic tank 6.

Further limiting, the sedimentation treatment unit 2 comprises a tank body 7 and an inverted rectangular pyramid 8 arranged in the tank body 7, wherein the inverted rectangular pyramid 8 is positioned below the tank body 7, the lowest end of the inverted rectangular pyramid 8 is communicated with one end of a sludge return pipe 9, and the other end of the sludge return pipe 9 is communicated with a sludge inlet 10 of the anaerobic tank 4; a sewage flow outlet is arranged above the tank body 7, a sewage inlet is also arranged above the inverted rectangular pyramid 8 on the tank body 7, sewage treated by the biological treatment unit 1 flows into the tank body 7 of the sedimentation treatment unit 2 through the sewage inlet, lower-layer sludge deposited by the inverted rectangular pyramid 8 flows back into the anaerobic tank 4 through a sludge return pipe 9, and supernatant liquid at the upper layer flows into the photoelectrocatalysis unit 3 through the sewage flow outlet.

Further limiting, a clear liquid inlet is arranged below the reaction water tank 11, and a water outlet is arranged above the reaction water tank 11.

Further limited, the cathode of the electrode pair is a graphite electrode plate, and the anode is Ag/TiO₂、Mn/TiO₂、Fe/TiO₂、CdS/PbS/TiO₂Or N/F/TiO₂And (4) a polar plate.

Further defined, Ag/TiO₂The preparation method of the polar plate comprises the following steps:

(1) pretreatment of a titanium plate: polishing with sand paper, ultrasonic cleaning for 15min, and drying to remove surface water;

(2) preparing a titanium dioxide nanotube: taking the treated titanium plate as an anode and the stainless steel plate as a cathode, wherein the distance between the polar plates is 2-4 cm, and 0.5 wt% of NH is adopted as electrolyte₄F and 98 vol% of ethylene glycol, the oxidation voltage is about 50V, anodic oxidation is carried out for 2h, then the anode plate is taken out and washed by deionized water, and then dried, and finally the sample is placed in a muffle furnace to be calcined for 2h at 450 ℃ to obtain the titanium dioxide nanotube;

(3) ag doped TiO₂Preparing the nanotube: formulation 10^-2mol/L AgNO₃Soaking the plate prepared in the previous step for 2h, irradiating the whole device under 500W mercury lamp for 10min, taking out the plate, cleaning with ultrapure water, and drying to obtain Ag/TiO₂And (4) a polar plate.

Further limiting, one end of a cathode plate and one end of an anode plate of each electrode pair are connected with the reaction water tank 11 through an acrylic base, the anode plate is connected with the bottom of the reaction water tank 11 through a base, the cathode plate is connected with the top of the reaction water tank 11 through a base, the other ends, which are not fixed, of the cathode plate and the anode plate are both kept in a space of 10-20 cm with the reaction water tank 11, and the distance between the adjacent cathode plate and the anode plate is 2-7 cm.

Further limited, the negative plate and the positive plate are applied with 1-5 mA/cm²Is constant current.

Further limiting, the clear liquid flows in a snake shape between the cathode plate and the anode plate, and the hydraulic retention time is 2-3 h.

Further inject, solar cell panel 12 is single crystalline silicon solar cell panel, and the generating efficiency is 100 ~ 200W/square meter, and the below of solar cell panel 12 is equipped with the thermal insulation layer, and solar cell panel 12 is connected with the battery, and the battery is located the device storage unit, and the battery provides the electric energy for the operation of whole device.

Further inject, reaction tank 11's top glass apron has can dismantle the function, and convenient regular cleaning and change plate electrode to and throw the medicine and improve catalytic reaction and facilitate for the later stage improves, and all install the drain in reaction tank 11's the left and right sides below, make things convenient for the back flush.

The invention has the beneficial effects that: the integrated sewage treatment device provided by the invention has the advantages of compact structure, reasonable design, high treatment efficiency, convenience in installation, operation and maintenance and the like. And the electric energy self-supply performance is realized by arranging the photoelectric complementary solar power supply system.

Drawings

FIG. 1 is a side view of an integrated device provided by the present invention;

FIG. 2 is a schematic diagram of the structure of a photoelectrocatalysis unit;

FIG. 3 is a schematic diagram of a biological treatment unit;

FIG. 4 is a schematic diagram of the structure of a precipitation treatment unit;

FIG. 5 is a flow chart of sewage treatment;

FIG. 6 is a schematic view showing the flow of a clarifying solution in a photoelectrocatalysis unit;

in the figure, 1-a biological treatment unit, 2-a precipitation treatment unit, 3-a photoelectrocatalysis unit, 4-an anaerobic tank, 5-an anoxic tank, 6-an aerobic tank, 7-a tank body, 8-an inverted rectangular pyramid, 9-a sludge return pipe, 10-a sludge inlet, 11-a reaction water tank and 12-a solar cell panel.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The experimental procedures used in the following examples are conventional unless otherwise specified. The materials, reagents, methods and apparatus used, unless otherwise specified, are conventional in the art and are commercially available to those skilled in the art.

The invention is realized by the following technical scheme:

as shown in fig. 1, the integrated biological/photoelectric/solar coupling sewage treatment device comprises a biological treatment unit 1, a precipitation treatment unit 2 and a photoelectrocatalysis unit 3; the biological treatment unit 1 is positioned at one side of the precipitation treatment unit 2; the photoelectrocatalysis unit 3 is positioned at the other side of the precipitation treatment unit 2, the photoelectrocatalysis unit 3 is obliquely arranged, the inclination angle is 25-40 degrees, the front surface faces the sun, and a gap enclosed between the photoelectrocatalysis unit 3 and the precipitation treatment unit 2 is a device accommodating unit; the storage battery, the aeration motor and the water pump are arranged in the device storage unit.

As shown in fig. 2, the photoelectrocatalysis unit 3 comprises a reaction water tank 11 and a solar cell panel 12, the reaction water tank 11 is made of borosilicate glass, the solar cell panel 12 is tightly attached to one side surface of the reaction water tank, so that no gap is ensured to prevent dust from entering and affecting the power generation efficiency of the solar cell panel, and sunlight is ensured to irradiate the solar cell panel 12 through the reaction water tank 11, at least one pair of photoelectrocatalysis electrode pairs is arranged in the reaction water tank 11, and cathodes and anodes of the electrode pairs are arranged in a staggered manner;

as shown in figure 5, sewage firstly enters a biological treatment unit 1, the treated sewage enters a precipitation treatment unit 2 to be separated into sludge and clarified liquid, the clarified liquid enters a photoelectric reaction unit 3 to be subjected to photoelectric catalytic oxidation treatment, the treated water is discharged from a water outlet of the photoelectric unit, and meanwhile, sunlight penetrates through a photoelectric catalytic reaction water tank to irradiate on a solar cell panel to generate electric energy so as to provide electric energy for the operation of the whole device.

As shown in FIG. 3, the biological treatment unit 1 is a three-dimensional body A²The O treatment unit comprises an anaerobic tank 4, an anoxic tank 5 and an aerobic tank 6 from bottom to top in sequence, sewage inlets are formed in the lower portions of the anaerobic tank 4, the anoxic tank 5 and the aerobic tank 6, sewage outlets are formed in the upper portions of the anaerobic tank 4, the anoxic tank 5 and the aerobic tank 6, the sewage outlet of the anaerobic tank 4 is communicated with the sewage inlet of the anoxic tank 5 through a conduit, the sewage outlet of the anoxic tank 5 is communicated with the sewage inlet of the aerobic tank 6 through a conduit, the sewage outlet of the aerobic tank 6 is communicated with the sewage inlet of the anoxic tank 5 and the precipitation treatment unit 2 through conduits, sewage enters the biological treatment unit 1 from the sewage inlet below the anaerobic tank 4, and flows into the precipitation treatment unit 2 from the sewage outlet above the aerobic tank 6 after flowing through the anoxic tank 5. Anaerobic typeThe oxygen tank 4 and the oxygen-poor tank 5 are internally provided with a stirrer, and the bottom of the aerobic tank 6 is provided with an aeration pipe.

Sewage passes through an anaerobic tank 4, an anoxic tank 5 and an aerobic tank 6 at A²The biological treatment unit is used for removing nitrogen and phosphorus and a part of organic matters under the treatment of the O process, and the simulation operation result of the biological treatment unit shows that NH in the domestic sewage is removed by the biological treatment unit₃The removal rate of-N is more than 80%, the removal rate of COD is more than 90%, and a good treatment effect is obtained.

As shown in fig. 4, the sedimentation treatment unit 2 comprises a tank body 7 and an inverted rectangular pyramid 8 arranged in the tank body 7, wherein the inverted rectangular pyramid 8 is positioned below the tank body 7, the lowest end of the inverted rectangular pyramid 8 is communicated with one end of a sludge return pipe 9, and the other end of the sludge return pipe 9 is communicated with a sludge inlet 10 of the anaerobic tank 4; a sewage flow outlet is arranged above the tank body 7, a sewage inlet is also arranged above the inverted rectangular pyramid 8 on the tank body 7, the tank body 7 is made of transparent organic glass, and the inverted rectangular pyramid 8 is fixedly supported at the bottom of the tank body 7 by an iron stand.

The sewage treated by the biological treatment unit 1 flows into a tank body 7 of the sedimentation treatment unit 2 through a sewage inlet, part of the lower-layer sludge deposited by the inverted rectangular pyramid 8 flows back into the anaerobic tank 4 through a sludge return pipe 9, part of the lower-layer sludge is discharged through a sludge discharge pipe, and the supernatant liquid on the upper layer flows into the photoelectrocatalysis unit 3 through a sewage outlet.

As shown in fig. 6, a clear liquid inlet is formed below the reaction water tank 11, a water outlet is formed above the reaction water tank 11, water flows between the two electrode plates in a snake shape, and water in the reaction water tank has certain fluidity, high specific heat capacity and other characteristics, so that the problem of reduction of power generation efficiency caused by heating of the solar cell panel due to far infrared rays is solved. The photoelectrocatalysis unit 3 is placed with an inclination of 25-40 degrees, the front side faces the sun, the sunlight irradiates on the anode plate to excite the photocatalysis degradation reaction, and meanwhile, 1-5 mA/cm is applied to the cathode and the anode²The constant current improves the photoelectric catalytic efficiency, the water flow flows between the two polar plates in a snake shape, and the hydraulic retention time is 2-3 h.

The cathode of the electrode pair is a graphite electrode plate, and the anode is Ag/TiO₂、Mn/TiO₂、Fe/TiO₂、CdS/PbS/TiO₂Or N/F/TiO₂And (4) a polar plate. The one end of the negative plate of electrode pair and anode plate all links to each other with reaction tank 11 through ya keli material base, the anode plate passes through the base and links to each other with 11 bottoms of reaction tank, the negative plate passes through the base and links to each other with 11 tops of reaction tank, the plate electrode is continuous with the power through reserving the welding point in the base, the other end that negative plate and anode plate are not fixed all keeps 10 ~ 20cm space with reaction tank 11, the distance between adjacent negative plate and anode plate is 2 ~ 7cm, guarantee that sewage is at the water conservancy dwell time in the photoelectric reaction district 2 ~ 3 h. The anode electrode plate adopts a titanium electrode plate as a substrate to prepare the titanium dioxide nanotube, and metal elements (Ag, Fe, Mn and the like), nonmetal elements (F/N, I, S and the like) and compounds (CdS/PbS, Cu and the like) which can increase the corresponding performance of the titanium dioxide nanotube to visible light are loaded on the titanium dioxide nanotube₂O、BiVO₄Etc.) under the irradiation of sunlight, the surface generates electron hole pairs and hydroxyl free radicals, and the organic matter is further degraded to reach the reuse standard. And applying a constant current of 1-5 mA/cm on the polar plate to increase the photocatalytic efficiency, wherein the treated water can be discharged or recycled. Meanwhile, sunlight irradiates on a solar cell panel through the photoelectrocatalysis reaction water tank to generate electric energy to charge a storage battery pack, the whole device is provided with electric energy by the storage battery pack, and the storage battery pack is an 18-36W lithium battery pack.

The solar cell panel 12 is a monocrystalline silicon solar cell panel, the power generation efficiency is 100-200W/square meter, a heat insulation layer is arranged below the solar cell panel 12, the heat insulation layer is filled with polyurethane foam, and the thickness of the heat insulation layer is about 2-5 cm so as to reduce the influence of overhigh temperature or overlow temperature on the solar power generation efficiency.

Example 1:

mono, Ag/TiO₂Preparing a polar plate:

(1) pretreatment of a titanium plate: polishing with sand paper, ultrasonic cleaning for 15min, and drying to remove surface water;

(2) preparing a titanium dioxide nanotube: taking the treated titanium plate as an anode and the stainless steel plate as a cathode, wherein the distance between the polar plates is 2-4 cm, and 0.5 wt% of NH is adopted as electrolyte₄F and 98 vol% ethylene glycol, the oxidation voltage is about 50V, the anode oxidation is carried out for 2h, and then the material is takenTaking out the anode plate, washing the anode plate with deionized water, drying the anode plate, and finally putting the sample in a muffle furnace to calcine the sample for 2 hours at 450 ℃ to obtain a titanium dioxide nanotube;

(3) ag doped TiO₂Preparing the nanotube: formulation 10^-2mol/L AgNO₃Soaking the plate prepared in the previous step for 2h, irradiating the whole device under 500W mercury lamp for 10min, taking out the plate, cleaning with ultrapure water, and drying to obtain Ag/TiO₂And (4) a polar plate.

Connecting a biological/photoelectric/solar coupling sewage treatment integrated device:

arranging a photoelectrocatalysis unit 3 to be obliquely arranged at an inclination angle of 30 degrees, arranging a group of cathode and anode electrode plates in a reaction unit, wherein the distance between the electrode plates is 5cm, and applying 5mA/cm on the electrode plates²The lower part of the constant current generator is provided with a heat insulation plate with the thickness of 2cm, and the generating power is 150W/m²The solar cell panel is placed at the bottom, a 300W xenon lamp is used for simulating sunlight irradiation, the degradation efficiency of the solar cell panel is researched by taking an anionic surfactant (LAS) as a target object, and the result shows that the degradation efficiency of the reaction system on the LAS is more than 95% after the reaction is carried out for 2 hours, and the degradation is almost completely carried out after the reaction is carried out for 3 hours. And the solar cell panel can reach normal power generation power after reacting for about 10min, and not only can provide photoelectrocatalysis electric energy, but also can have surplus electric energy.

Thirdly, operating the biological/photoelectric/solar coupling sewage treatment integrated device:

domestic sewage enters the anaerobic tank 4 through the water inlet, and phosphorus release and ammoniation of partial organic matters are carried out under the action of microorganisms. The treated water enters the anoxic tank 5 through the communicating pipe for denitrification and then enters the aerobic tank 6 through the communicating pipe. BOD in the water is removed through the aeration pipe and the metabolism of aerobic microorganisms, and the treated water flowing out of the aerobic tank is mixed according to the ratio of 1: the reflux with the proportion of 1 flows to the bottom of the anoxic pond 5 and the sedimentation treatment unit 2 through a reflux pipe.

The water after biological treatment is kept stand and precipitated in the precipitation treatment unit 2, sludge is precipitated to the bottom, one part of the sludge is returned to the anaerobic tank 5 through a sludge return pipe 9, and the other part of the sludge is used as residual sludge and discharged from a sludge discharge pipe. The supernatant liquid at the upper layer in the tank body 7 passes through the water inlet pipe under the action of gravityFlows into the photoelectrocatalysis unit 3, and is subjected to photoelectrocatalysis oxidation by at least one group of anode plates and cathode plates. Ag/TiO 2₂Ag/TiO loaded on polar plate₂Under the irradiation of sunlight, electron hole pairs and hydroxyl radicals are generated on the surface, and the device has strong oxidizing property, so that organic matters are further degraded to reach the recycling standard, constant current is applied to a polar plate to increase the photocatalytic efficiency, the treated water is discharged through a water outlet, meanwhile, the sunlight penetrates through the reaction water tank 11 and irradiates on the solar cell panel 12 to generate electric energy to charge a storage battery in a device unit, and the whole device is provided with the electric energy by the storage battery.

The simulation operation result of the biological treatment unit in the embodiment shows that NH in the domestic sewage is treated by the biological treatment unit₃The removal rate of-N is more than 80%, and the removal rate of COD is more than 90%.

The removal effect of the photoelectrocatalysis unit 3 on organic matters which are difficult to biodegrade in the domestic wastewater (aromatic hydrocarbon compounds and metabolites which are newly generated when microorganisms decompose the organic matters in the wastewater) is tested by simulating the irradiation of sunlight by using a 300W xenon lamp. Compared with single photocatalytic reaction, the addition of the current improves the transfer of photo-generated electrons, so that the removal rate of the original refractory organic matters is improved to more than 90% from 60%, and the COD degradation effect is improved to more than 95% from 73% of single photocatalysis. The water finally discharged from the device conforms to the first-class A standard of pollutant discharge Standard of urban wastewater treatment plant.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents and improvements made within the spirit and principle of the present invention are intended to be included within the scope of the present invention.