Photovoltaic wastewater treatment system

Abstract

The utility model relates to the technical field of wastewater treatment, and provides a photovoltaic wastewater treatment system which comprises a defluorination reaction sedimentation tank, a biological enhancement denitrification tank, a secondary sedimentation tank, a carbon adsorption clarification tank and a sand filter which are communicated in sequence, a sludge return pipeline is arranged between the secondary sedimentation tank and the water inlet of the biological enhancement denitrification tank, so that part of sludge in the secondary sedimentation tank is input into the biological enhancement denitrification tank through the sludge return pipeline; a plurality of water treatment units for water treatment are arranged in the defluorination reaction sedimentation tank, and at least a plurality of same water treatment units are correspondingly arranged in the carbon adsorption clarification tank. According to the utility model, fluorine ions and suspended solids are simultaneously removed by utilizing the front-end sedimentation tank through a front-end fluorine removal process, so that the occupied area and the investment are saved, and meanwhile, the stable operation of subsequent biochemical treatment is ensured; a defluorination guarantee process is reserved at the rear end, so that the effluent is comprehensively guaranteed to reach the standard.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of wastewater treatment especially relates to a photovoltaic wastewater treatment system. BACKGROUND

[0002] Solar photovoltaic cell is a new type of photovoltaic device which converts solar energy into electricity. As a widely existing clean renewable energy, solar energy industry has developed rapidly. At present, the number of domestic solar photovoltaic cell production enterprises is increasing, and the production scale is expanding. While bringing economic benefits, it also brings new environmental problems. In the production process of solar cells, the production wastewater is divided into fluorine-containing inorganic wastewater, strong acid and alkali wastewater and ammonia and phosphorus wastewater according to its properties.

[0003] The photovoltaic enterprise gathering park covers the whole process wastewater generated by the battery project, including the crystal pulling, silicon wafer and battery production wastewater. The internal sewage treatment facilities of the enterprise have treated the generated wastewater before entering the park. The treated effluent needs to meet the relevant standards before being discharged. However, in the related technology, the concentrations of fluorine ion, suspended solids, ammonia nitrogen and total nitrogen in the wastewater are relatively high, and the chemical oxygen demand (COD, Chemical Oxygen Demand) of the treated wastewater is greatly reduced, which leads to high treatment difficulty and low treatment stability. UTILITY MODEL CONTENT

[0004] The utility model provides a photovoltaic wastewater treatment system to solve the defects of high treatment difficulty and low treatment stability of photovoltaic wastewater in the prior art.

[0005] The utility model provides a photovoltaic wastewater treatment system, which comprises a fluorine removal reaction sedimentation tank, a biological enhanced denitrification tank, a secondary sedimentation tank, a carbon adsorption clarification tank and a sand filter tank, a water inlet pipe is arranged at the water inlet of the fluorine removal reaction sedimentation tank, the water outlet of the fluorine removal reaction sedimentation tank is connected with the water inlet of the biological enhanced denitrification tank, the water outlet of the biological enhanced denitrification tank is connected with the water inlet of the secondary sedimentation tank, the water outlet of the secondary sedimentation tank is connected with the water inlet of the carbon adsorption clarification tank, the water outlet of the carbon adsorption clarification tank is connected with the water inlet of the sand filter tank, the sand filter tank is provided with a discharge outlet, and the discharge outlet is used for discharging treated wastewater; wherein a sludge return pipeline is arranged between the secondary sedimentation tank and the water inlet of the biological enhanced denitrification tank, so that part of the sludge in the secondary sedimentation tank is input into the biological enhanced denitrification tank through the sludge return pipeline; a plurality of water treatment units for water treatment are arranged in the fluorine removal reaction sedimentation tank, and at least the same number of water treatment units are arranged in the carbon adsorption clarification tank.

[0006] According to the photovoltaic wastewater treatment system, the water treatment unit comprises a defluorination reaction unit, a mixing reaction unit, a flocculation unit, a sedimentation unit and a water outlet mixing unit; the water inlet pipeline is arranged at the head end of the defluorination reaction unit; the tail end of the defluorination reaction unit is communicated with the head end of the mixing reaction unit through the first water passing opening; the tail end of the mixing reaction unit is communicated with the head end of the flocculation unit through the second water passing opening; the tail end of the flocculation unit is communicated with the head end of the sedimentation unit through the third water passing opening; the tail end of the sedimentation unit is communicated with the head end of the water outlet mixing unit through the flow passing hole; and the tail end of the water outlet mixing unit is communicated with the water inlet of the biological strengthening denitrification tank.

[0007] According to the photovoltaic wastewater treatment system, the sedimentation unit is internally provided with a sedimentation system, a mud scraping system, a mud discharging system and a water outlet collecting system; the sedimentation system is arranged at the upper portion of the sedimentation unit; the mud discharging system and the mud scraping system are arranged at the bottom of the sedimentation unit; the sedimentation system comprises a sedimentation area formed by a connecting plate, and a sedimentation device is arranged in the sedimentation area; the mud discharging system comprises a sludge pump, a mud discharging pipeline and a mud returning pipeline; the sludge pump is connected with the mud discharging pipeline and the mud returning pipeline; the mud returning pipeline is arranged between the flocculation unit and the sedimentation unit; the mud scraping system comprises a center transmission mud scraper, and the center transmission mud scraper is used for collecting sludge in wastewater; the water outlet collecting system comprises a water outlet collecting weir and a water outlet collecting pool; the water outlet collecting pool is communicated with the head end of the water outlet mixing unit; the water outlet collecting weir is used for collecting supernatant after sedimentation, and the supernatant is collected into the water outlet collecting pool, and the collected supernatant enters the water outlet mixing unit.

[0008] According to the photovoltaic wastewater treatment system, stirring devices are arranged in the defluorination reaction unit, the mixing reaction unit, the flocculation unit and the water outlet mixing unit.

[0009] According to the photovoltaic wastewater treatment system, the carbon adsorption clarification pool further comprises an activated carbon reaction unit; the activated carbon reaction unit is arranged between the defluorination reaction unit and the flocculation unit; and an activated carbon dosing pipeline is arranged in the activated carbon reaction unit.

[0010] According to the photovoltaic wastewater treatment system, the water treatment unit comprises the mixing reaction unit, the defluorination reaction unit, the activated carbon reaction unit, the flocculation unit, the sedimentation unit and the water outlet mixing unit which are sequentially communicated along the water treatment flow direction.

[0011] The photovoltaic wastewater treatment system provided by the utility model has the advantages that the biological strengthening denitrification tank comprises a first anaerobic section, a first anoxic section, a first aerobic section, a second anoxic section and a second aerobic section which are sequentially connected along the natural water flow direction.

[0012] The photovoltaic wastewater treatment system provided by the utility model has the advantages that the tail end of the second aerobic section is provided with a water outlet system; the water outlet system comprises a water outlet area surrounded by a baffle, a lifting pump is arranged in the water outlet area, and the lifting pump is communicated with the water inlet of the carbon adsorption clarifier through a communication pipeline.

[0013] The photovoltaic wastewater treatment system provided by the utility model has the advantages that the first anoxic section and the first aerobic section are provided with a mixed liquid reflux pipeline.

[0014] The photovoltaic wastewater treatment system provided by the utility model has the advantages that the first anaerobic section, the first anoxic section and the second anoxic section are all provided with stirring parts, and the first aerobic section and the second aerobic section are both provided with aeration systems.

[0015] The photovoltaic wastewater treatment system provided by the utility model has the advantages that the photovoltaic wastewater treatment system is provided with multiple water treatment units at the front end of the water treatment process, so that the fluorine particles and the suspended solids in the wastewater can be removed, the land occupation and the construction cost are saved, the subsequent biochemical treatment can be stably operated, the carbon adsorption clarifier is arranged at the rear end of the water treatment process, and multiple water treatment units in the defluorination reaction sedimentation tank are reserved in the carbon adsorption clarifier, so that the residual fluorine particles and the suspended solids in the wastewater can be further removed, the effluent can meet the standard, and the stability of the water treatment is improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] In order to more clearly illustrate the technical scheme of the utility model or the prior art, the following will briefly introduce the drawings needed to be used in the embodiment or the prior art description, and obviously, the drawings in the following description are some embodiments of the utility model, and those skilled in the art can also obtain other drawings according to these drawings without any creative effort.

[0017] Figure 1 It is a structure schematic view of the photovoltaic wastewater treatment system provided by the utility model.

[0018] Figure 2 It is a structure schematic view of the defluorination reaction sedimentation tank in the photovoltaic wastewater treatment system provided by the utility model.

[0019] Figure 3 It is a structure schematic view of the carbon adsorption clarifier in the photovoltaic wastewater treatment system provided by the utility model.

[0020] Figure 4It is the structural schematic view of the biological strengthened denitrification pool in the photovoltaic wastewater treatment system.

[0021] Reference signs:

[0022] 1, fluoride removal reaction sedimentation tank; 101, fluoride removal reaction unit; 102, mixed reaction unit; 103, flocculation unit; 104, sedimentation unit; 105, effluent mixing unit; 106, fluoride removal agent dosing pipe; 107, coagulant dosing pipe; 108, coagulant aid dosing pipe; 109, acid and alkali dosing pipe; 111, stirring device; 112, mud scraping system; 113, sedimentation system; 114, sludge pump; 115, sludge return pipeline; 116, effluent collection system; 2, biological strengthened denitrification pool; 201, primary anaerobic section; 202, primary anoxic section; 203, primary aerobic section; 204, secondary anoxic section; 205, secondary aerobic section; 206, stirring part; 207, aeration system; 208, mixed liquid return pipeline; 209, effluent system; 210, sludge return pipeline; 3, secondary sedimentation tank; 4, carbon adsorption clarifier; 401, activated carbon reaction unit; 402, activated carbon dosing pipe; 5, sand filter tank. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme of the present application will be described below in conjunction with the drawings in the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the present application.

[0024] In the description of the embodiments of the present application, it should be noted that the orientations or positional relationships indicated by the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, and are only for the convenience of describing the embodiments of the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the embodiments of the present application. In addition, the terms "first", "second", "third" are only for the purpose of description, and cannot be understood as indicating or implying relative importance.

[0025] In the description of the embodiments of the present application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected", "connected" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium. For those skilled in the art, the specific meaning of the above terms in the embodiments of the present application can be understood according to the specific circumstances.

[0026] In the embodiments of the present application, unless otherwise explicitly specified and limited, the first feature is "on" or "under" the second feature, which can be that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, the first feature "above", "over" and "on" the second feature can be that the first feature is directly above or obliquely above the second feature, or it only means that the horizontal height of the first feature is higher than that of the second feature. The first feature "below", "under" and "under" the second feature can be that the first feature is directly below or obliquely below the second feature, or it only means that the horizontal height of the first feature is less than that of the second feature.

[0027] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the embodiments of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in the present specification and the features of different embodiments or examples without contradiction.

[0028] According to the relevant provisions, the treated effluent is required to be discharged into the park sewage treatment plant after meeting the "Battery Industry Pollutant Discharge Standard", but the concentrations of fluoride ions, suspended solids, ammonia nitrogen and total nitrogen of the influent of the park sewage treatment plant are relatively high, and the chemical oxygen demand (COD, Chemical Oxygen Demand) of the wastewater after treatment is greatly reduced, which increases the difficulty of the effluent of the park sewage treatment plant to meet the first A standard in the "Urban Sewage Treatment Plant Pollutant Discharge Standard" (GB18918-2002). However, in some existing water treatment schemes, either the treatment process is relatively complex, resulting in large construction cost and period, and the relatively complex treatment process often requires a large land requirement, which limits its use scene. In some other water treatment schemes, the treatment effect is poor, and it is difficult to achieve stable and standard treatment.

[0029] In view of the problems in the related art, such asFigure 1 The utility model provides a photovoltaic wastewater treatment system, be applicable to the wastewater treatment of industrial park, including fluorine removal reaction sedimentation tank 1, biological strengthening denitrification tank 2, secondary sedimentation tank 3, carbon adsorption clarifier 4 and sand filter 5, the water inlet of fluorine removal reaction sedimentation tank 1 is equipped with water inlet pipe, the water outlet of fluorine removal reaction sedimentation tank 1 is connected with the water inlet of biological strengthening denitrification tank 2, the water outlet of biological strengthening denitrification tank 2 is connected with the water inlet of secondary sedimentation tank 3, the water outlet of secondary sedimentation tank 3 is connected with the water inlet of carbon adsorption clarifier 4, the water outlet of carbon adsorption clarifier 4 is connected with the water inlet of sand filter 5, and sand filter 5 is equipped with discharge port, and the discharge port is used for discharging the wastewater after treatment, wherein the water inlet between secondary sedimentation tank 3 and biological strengthening denitrification tank 2 is equipped with sludge backflow line 210, to make part of sludge in secondary sedimentation tank 3 input to biological strengthening denitrification tank 2 through sludge backflow line 210, fluorine removal reaction sedimentation tank 1 is equipped with multiple water treatment units for water treatment, and at least the same multiple water treatment units are arranged in carbon adsorption clarifier 4. In addition to the high concentration of ammonia nitrogen and total nitrogen in photovoltaic wastewater, the wastewater also has high concentration of fluoride ions and suspended solids (Suspended Solids, also known as SS), so it is necessary to ensure the stable removal of fluoride ions and suspended solids during treatment. In the embodiment, the removal of ammonia nitrogen and total nitrogen can be realized by biological strengthening denitrification tank 2, and fluorine removal reaction sedimentation tank 1 is arranged in the upstream of biological strengthening denitrification tank 2, and carbon adsorption clarifier 4 is arranged in the downstream of biological strengthening denitrification tank 2, wherein the water treatment units in fluorine removal reaction sedimentation tank 1 are arranged in carbon adsorption clarifier 4, so that the strong removal of fluoride ions and suspended solids can be realized by fluorine removal reaction sedimentation tank 1 and carbon adsorption clarifier 4.

[0030] Specifically, the pretreated wastewater is output through the water inlet pipe, and then the fluoride ions and suspended solids are removed through the fluorine removal reaction sedimentation tank 1, and then the removal of ammonia nitrogen and total nitrogen is realized through the biological strengthening denitrification tank 2, and then the secondary removal of fluoride ions and suspended solids is realized through the carbon adsorption clarifier 4, which improves the effect of wastewater treatment and improves the stability of wastewater treatment.

[0031] The reactions in each tank are as follows: in the defluorination reaction sedimentation tank 1, by adding defluorination agent and coagulant aid, the fluorine ions can be deeply removed, and at the same time, by adding coagulant, part of the chemical oxygen demand (hereinafter referred to as COD, Chemical Oxygen Demand) and suspended solids are removed by physical adsorption and coagulation sedimentation. In the biological enhanced denitrification tank 2 + secondary sedimentation tank 3, by setting a conventional denitrification and phosphorus removal treatment unit, ammonia nitrogen and total nitrogen can be removed, and of course, part of the COD and suspended solids can also be removed in this process. In the carbon adsorption clarification tank 4, by adding activated carbon, the refractory COD can be effectively and stably removed, and at the same time, coagulant and flocculant are added to further remove suspended solids in the water by coagulation and sedimentation. This tank also has the function of ensuring the fluorine ion effluent, and when the fluorine ion in the water is too high, the fluorine ion can be further removed by adding defluorination agent. In the sand filter tank 5, suspended solids in the water are intercepted by filter filling, so that the suspended solids effluent can meet the requirements.

[0032] It can be understood that, by the combination of the defluorination reaction sedimentation tank 1, the biological enhanced denitrification tank 2, the secondary sedimentation tank 3, the carbon adsorption clarification tank 4 and the sand filter tank 5, the water flows through the above-mentioned treatment tanks in sequence for treatment, realizing stable treatment of photovoltaic wastewater, improving the stability and treatment quality of wastewater treatment, and enabling it to meet the relevant discharge standards. The whole system improves the fluorine ion removal effect, reduces the operation cost, is simple to manage and stable in operation.

[0033] Specifically, the secondary sedimentation tank 3 is arranged downstream of the biological enhanced denitrification tank 2, and is used for solid-liquid separation to remove suspended solids and settled sludge in the wastewater. When the wastewater flows in the tank, solid particles gradually settle to the bottom due to gravity to form a precipitate (i.e. sludge), thereby improving the overall efficiency of the wastewater treatment system and ensuring that the effluent water quality meets the standards in the subsequent process.

[0034] Further, the sand filter tank 5 is the last treatment unit of the treatment system, which can effectively remove smaller suspended solids, silt and particulate matter in the water, reduce the turbidity of the water, and improve the water quality and treatment efficiency through the physical filtration of the sand layer.

[0035] In some embodiments, as shown in FIG. 1, the treatment system comprises a defluorination reaction sedimentation tank 1, a biological enhanced denitrification tank 2, a secondary sedimentation tank 3, a carbon adsorption clarification tank 4 and a sand filter tank 5. Figure 2As shown, the arrows in the figure represent the flow direction of wastewater or mixed liquid, and the water treatment unit includes a defluorination reaction unit 101, a mixing reaction unit 102, a flocculation unit 103, a sedimentation unit 104, and a water outlet mixing unit 105. The defluorination reaction unit 101, the mixing reaction unit 102, the flocculation unit 103, the sedimentation unit 104, and the water outlet mixing unit 105 each include a head end and a tail end, and the flow direction of wastewater or mixed liquid is from the head end to the tail end inside each treatment unit. For example, in the defluorination reaction unit 101, wastewater is input from the head end and flows to the tail end. Between adjacent treatment units with a processing sequence, wastewater or mixed liquid flows from the tail end of the previous treatment unit to the head end of the next treatment unit, for example, wastewater in the defluorination reaction unit 101 enters the head end of the mixing reaction unit 102 along its own tail end. In this way, wastewater or mixed liquid circulates in the wastewater treatment system, and the flow direction is determined.

[0036] The head end of the defluorination reaction unit 101 is provided with a water inlet pipeline, the tail end of the defluorination reaction unit 101 is communicated with the head end of the mixing reaction unit 102 through a first water passage, the tail end of the mixing reaction unit 102 is communicated with the head end of the flocculation unit 103 through a second water passage, the tail end of the flocculation unit 103 is communicated with the head end of the sedimentation unit 104 through a third water passage, the tail end of the sedimentation unit 104 is communicated with the head end of the water outlet mixing unit 105 through a water passage, and the tail end of the water outlet mixing unit 105 is communicated with the water inlet of the biological nitrogen removal pool 2. The defluorination reaction unit 101 is provided with a defluorination agent dosing pipe 106, the mixing reaction unit 102 is provided with a coagulant dosing pipe 107, the flocculation unit 103 is provided with a coagulant aid dosing pipe 108, and the water outlet mixing unit 105 is provided with an acid and alkali dosing pipe 109. The input pretreated wastewater is sequentially treated by the defluorination reaction unit 101, the mixing reaction unit 102, the flocculation unit 103, the sedimentation unit 104, and the water outlet mixing unit 105, and can be input into the next process for treatment.

[0037] Specifically, as shown in the figure, Figure 2 The defluorination reaction sedimentation tank 1 is provided with baffles alternately at the bottom and the top of a section close to the water inlet pipeline, and the alternately arranged baffles divide the defluorination reaction unit 101, the mixing reaction unit 102, and the flocculation unit 103, so as to realize different treatments in different areas. The baffles are arranged to form an "S"-shaped flow path, so that the wastewater flows through the flow path for treatment, prolongs the water path, and improves the quality of water treatment.

[0038] The water outlet mixing unit 105 is arranged at the upper part of the defluorination reaction sedimentation tank 1, so as to collect the treated supernatant, and the treated wastewater can enter the next process for stable treatment.

[0039] According to the embodiment provided by the utility model, the sedimentation unit 104 is internally provided with a sedimentation system 113, a mud scraping system 112, a mud discharge system and a water outlet collection system 116; the sedimentation system 113 is arranged at the upper portion of the sedimentation unit 104, the mud discharge system and the mud scraping system 112 are arranged at the bottom of the sedimentation unit 104, the sedimentation system 113 comprises a sedimentation area formed by a connecting plate, and a sedimentation device is arranged in the sedimentation area; the mud discharge system comprises a sludge pump 114, a mud discharge pipeline and a mud return pipeline 115, the sludge pump 114 is connected with the mud discharge pipeline and the mud return pipeline 115, and the mud return pipeline 115 is arranged between the flocculation unit 103 and the sedimentation unit 104; the mud scraping system 112 comprises a center transmission mud scraper, which is used for collecting sludge in wastewater; the water outlet collection system 116 comprises a water outlet collection weir (not shown in the figure because the water outlet collection weir and the water outlet collection tank are arranged side by side) and a water outlet collection tank, the water outlet collection tank is in communication with the first end of the water outlet mixing unit 105, the water outlet collection weir is used for collecting supernatant after sedimentation, the supernatant is then collected into the water outlet collection tank, and the collected supernatant enters the water outlet mixing unit 105. Through the arrangement of the multiple systems in the sedimentation unit 104, efficient separation of sludge and water can be realized, and efficient discharge and recycling of sludge can be realized.

[0040] Specifically, the center transmission mud scraper is arranged at the center of the sedimentation unit 104, the scraper of the center transmission mud scraper is located at the bottom of the sedimentation unit 104 to collect sludge after sedimentation, then part of the sludge can be discharged through the sludge pump 114, and the other part of the sludge is returned to the flocculation unit 103 for further treatment. The sedimentation device is a conventional sedimentation device, for example, a coagulation sedimentation device, a sludge-water separation device or the like. The center transmission mud scraper is a conventional mud scraping device, so the specific structure will not be described here.

[0041] When specifically arranged, the water outlet collection weir and the water outlet collection tank are arranged above the sedimentation area, and the water outlet collection weir and the water outlet collection tank are arranged side by side, which are used for collecting supernatant at the top of the sedimentation unit 104, so that the supernatant can be stably input into the water outlet mixing unit 105 and then output to the biological intensified denitrification tank 2 by the water outlet mixing unit 105.

[0042] In some embodiments, stirring devices 111 are arranged in the defluorination reaction unit 101, the mixing reaction unit 102, the flocculation unit 103 and the water outlet mixing unit 105. The arrangement of the stirring devices 111 can realize rapid mixing of the added reagents and improve the treatment efficiency. The stirring device 111 in the flocculation unit 103 is a flocculation stirrer, which can realize stirring and flocculation of the mixed liquid in the unit.

[0043] According to some embodiments of the utility model, the carbon adsorption clarifying tank 4 further comprises an activated carbon reaction unit 401, the activated carbon reaction unit 401 is arranged between the fluorine removal reaction unit 101 and the flocculation unit 103, and the activated carbon reaction unit 401 is provided with an activated carbon dosing pipe 402. The arrangement of the activated carbon reaction unit 401 can realize stable removal of refractory COD, and the activated carbon can be added through the activated carbon dosing pipe 402.

[0044] Specifically, as shown in the figure, the arrows in the figure represent the flow direction of wastewater or mixed liquid, and the structure of the carbon adsorption clarifying tank 4 in the embodiment is basically the same as that of the fluorine removal reaction and precipitation tank 1, and the difference lies in that the carbon adsorption clarifying tank 4 is additionally provided with an activated carbon reaction unit 401 in addition to the fluorine removal reaction unit 101, the mixed reaction unit 102, the flocculation unit 103, the precipitation unit 104 and the effluent mixing unit 105. Through the addition of activated carbon, stable removal of refractory COD can be realized, and at the same time, coagulant and flocculant are added, and suspended solids in water are further removed through coagulation and precipitation. Figure 3

[0045] Specifically, in the carbon adsorption clarifying tank 4, the water treatment unit comprises, in sequence along the water treatment flow direction, a mixed reaction unit 102, a fluorine removal reaction unit 101, an activated carbon reaction unit, a flocculation unit 103, a precipitation unit 104 and an effluent mixing unit 105. That is, compared with the fluorine removal reaction and precipitation tank 1, the arrangement order of the mixed reaction unit 102 and the fluorine removal reaction unit 101 in the carbon adsorption clarifying tank 4 is exchanged, so that the water treated by the biological enhanced denitrification tank 2 is first passed through the mixed reaction unit 102 and then passed through the fluorine removal reaction unit 101 for fluorine removal treatment.

[0046] Specifically, in the carbon adsorption clarifying tank 4, the mixed reaction tank, the fluorine removal reaction tank and the activated carbon reaction tank are provided with a mixed stirrer, and the flocculation reaction tank is provided with a flocculation stirrer. The precipitation unit 104 is also provided with a precipitation system 113, a mud scraping system 112, a sludge discharge system and an effluent collection system 116. The effluent collection system 116 at the top of the precipitation tank is communicated with the effluent mixing tank through an opening in the tank body, and the effluent outlet of the effluent mixing tank is connected with the sand filter tank 5 through a pipeline.

[0047] Some embodiments, as shown in the figure, the biological enhanced denitrification tank 2 comprises, in sequence along the natural water flow direction, a first anaerobic section 201, a first anoxic section 202, a first aerobic section 203, a second anoxic section 204 and a second aerobic section 205. Through the nitrification and denitrification reactions in the biological enhanced denitrification tank 2, the wastewater can be treated to achieve the effect of denitrification and phosphorus removal, and the removal of ammonia nitrogen and total nitrogen can be realized. Figure 4

[0048] ​​Specifically, in the primary anaerobic section 201, anaerobic bacteria decompose complex organic matter into simple compounds such as alcohol and acid through fermentation and hydrolysis, remove most of the organic matter, and reduce the chemical oxygen demand (COD) of the wastewater. In the primary anoxic section 202, organic matter is further removed through denitrification, and the total nitrogen content in the wastewater is reduced. After entering the primary aerobic section 203, aerobic microorganisms utilize oxygen to further decompose organic matter into carbon dioxide and water, while synthesizing new cell material, significantly reducing the COD and BOD (biological oxygen demand) of the wastewater, improving water quality, and regenerating denitrification in the secondary anoxic section 204 to further remove nitrogen from the water, improving water quality. Then, it enters the secondary aerobic section 205, which can maximize the removal of organic matter, nitrogen, and phosphorus in the water, ensuring the quality of the effluent. This series of treatment sections removes organic matter and nitrogen and other pollutants from wastewater through different microbial metabolic pathways. The operating conditions and microbial effects of each stage complement each other, ultimately achieving efficient wastewater treatment and achieving the purpose of environmental protection and resource recovery. Through this multi-stage treatment system, the efficiency of wastewater treatment and water quality can be effectively improved, thereby providing protection for subsequent water reuse or safe discharge.

[0049] It should be appreciated that the nitrification and denitrification reactions that occur during the treatment of wastewater are conventional techniques in the art and are well known to those skilled in the art as a means of treatment, and therefore the specific reaction process will not be described in detail.

[0050] In some embodiments, the tail end of the secondary aerobic section 205 is provided with an effluent system 209; the effluent system 209 includes an effluent area surrounded by a baffle, and a booster pump is provided in the effluent area, and the booster pump is in communication with the inlet of the carbon adsorption clarifier 4 through a communication pipeline. The booster pump is used to transport the treated water, improving the overall treatment efficiency.

[0051] Specifically, the effluent area is located at the upper part of the secondary aerobic section 205, and the setting of the effluent area can realize efficient discharge of the treated water, ensuring the stable treatment of the next process.

[0052] Specifically, a mixed liquid reflux pipeline 208 is provided between the primary anoxic section 202 and the primary aerobic section 203. In the anoxic section, nitrate in the wastewater can be converted to nitrogen gas by denitrifying bacteria under anoxic conditions. The refluxed mixed liquid contains a high concentration of nitrate, which helps to carry out the denitrification reaction when it enters the anoxic section, thereby effectively removing nitrogen.

[0053] In some embodiments, the bottom of the first anaerobic section 201, the first anoxic section 202 and the second anoxic section 204 is provided with a stirring device 206, and the first aerobic section 203 and the second aerobic section 205 is provided with an aeration system 207. The stirring device 206 can effectively mix the sewage, sludge and microorganisms together, ensure the uniform distribution of the reaction substances in the reaction tank, and improve the reaction efficiency. The aeration system 207 can provide sufficient dissolved oxygen for the sewage to support the growth and reproduction of microorganisms.

[0054] In some embodiments, the stirring device 206 can be a stirrer or other stirring equipment.

[0055] The above-mentioned photovoltaic wastewater treatment system will be described below through specific examples.

[0056] A certain industrial park wastewater treatment plant has a treatment capacity of 120000m³ / d, of which 85% of the influent is photovoltaic enterprise wastewater. The treatment process adopts pretreatment + "defluorination reaction sedimentation tank 1 + biological enhanced denitrification tank 2 + secondary sedimentation tank 3 and effluent tank + carbon adsorption clarification tank 4 + sand filter 5" + disinfection tank.

[0057] Specifically, after the wastewater is pretreated, it is lifted into the defluorination reaction sedimentation tank 1. In the first defluorination reaction unit 101, a defluorination agent is added, in the second mixed reaction unit 102, a coagulant is added, and in the third flocculation unit 103, a flocculant is added. After reaction, alum flowers with relatively large density are formed, and then the mud-water separation is carried out in the sedimentation system 113 and the mud scraping system 112 in the sedimentation unit 104. The sludge precipitated is partially returned to the flocculation unit 103 through the sludge discharge system, and the other part of the sludge is discharged to the sludge treatment system in the plant. The supernatant is collected through the effluent collection system 116 and enters the effluent mixing unit 105. After the pH value is adjusted to neutral by adding acid and alkali, the effluent is gravity-fed into the biological enhanced denitrification tank 2 through the effluent pipeline.

[0058] The wastewater in the biological enhanced denitrification tank 2 sequentially passes through the first anaerobic section 201, the anoxic section, the aerobic section, the second anoxic section and the aerobic section. The mixed liquid reflux system returns the nitrate nitrogen at the end of the first aerobic section 203 to the front end of the first anoxic section 202. The aerobic section is oxygenated by the aeration system 207. The supernatant is gravity-fed into the secondary sedimentation tank 3 through the effluent system 209. The mud-water separation is carried out in the secondary sedimentation tank 3. Part of the sludge is returned to the front end of the biological enhanced denitrification tank 2, and the remaining sludge is discharged to the sludge treatment system in the plant area. The supernatant in the secondary sedimentation tank 3 is gravity-fed into the effluent tank. The effluent tank is provided with a lifting pump, which enters the carbon adsorption clarification tank 4 through the lifting pipeline.

[0059] The waste water is lifted into the carbon adsorption clarifier 4, and coagulant is added in the first grid mixing reaction unit 102. Since the front end fluoride ion removal rate is high, defluorination reagent can not be added in the second grid defluorination reaction unit 101, activated carbon is added in the third grid activated carbon reaction unit 401, and flocculant is added in the fourth grid flocculation unit 103. After reaction, alum flowers with large density are formed, and then the mud-water separation is carried out through the inclined plate sedimentation system 113 and the mud scraping system 112 in the inclined plate sedimentation unit 104. The sludge precipitated is returned to the flocculation tank through the sludge discharge system, and the other part of the sludge is discharged to the sludge treatment system in the plant. The supernatant is collected through the water outlet collection system 116 and enters the water outlet mixing tank. At this time, acid and alkali are not needed to be added to adjust the pH value. The water outlet is gravity-fed into the sand filter tank 5 through the pipeline. The sand filter tank 5 adopts the upward flow form, and the water is fed from the bottom, and the water is discharged from the upper part after filtration. The water outlet is disinfected in the subsequent disinfection tank, and the water outlet is discharged up to the standard.

[0060] Finally, it should be pointed out that: the above examples are only used to illustrate the technical solutions of the present application, and not to limit them; although the present application has been described in detail with reference to the foregoing examples, those skilled in the art should understand that: it can still modify the technical solutions recorded in the foregoing examples, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A photovoltaic wastewater treatment system, characterized in that, include: Defluoridation reaction sedimentation tank, biological enhanced denitrification tank, secondary sedimentation tank, carbon adsorption clarification tank and sand filter tank; The inlet of the defluorination reaction sedimentation tank is equipped with an inlet pipe. The outlet of the defluorination reaction sedimentation tank is connected to the inlet of the biological enhanced denitrification tank. The outlet of the biological enhanced denitrification tank is connected to the inlet of the secondary sedimentation tank. The outlet of the secondary sedimentation tank is connected to the inlet of the carbon adsorption clarification tank. The outlet of the carbon adsorption clarification tank is connected to the inlet of the sand filter. The sand filter is equipped with an outlet for discharging treated wastewater. The secondary sedimentation tank and the biological enhanced denitrification tank are connected by a sludge return pipeline, so that some of the sludge in the secondary sedimentation tank is fed into the biological enhanced denitrification tank through the sludge return pipeline; the defluorination reaction sedimentation tank is equipped with multiple water treatment units for water treatment, and at least a number of the same water treatment units are provided in the carbon adsorption clarification tank.

2. The photovoltaic wastewater treatment system according to claim 1, characterized in that, The water treatment unit includes a defluoridation reaction unit, a mixing reaction unit, a flocculation unit, a sedimentation unit, and an effluent mixing unit; The defluorination reaction unit is provided with an inlet pipe at its first end. The tail end of the defluorination reaction unit is connected to the first end of the mixing reaction unit through a first water outlet. The tail end of the mixing reaction unit is connected to the first end of the flocculation unit through a second water outlet. The tail end of the flocculation unit is connected to the first end of the sedimentation unit through a third water outlet. The tail end of the sedimentation unit is connected to the first end of the effluent mixing unit through a flow passage. The tail end of the effluent mixing unit is connected to the inlet of the biological enhanced denitrification tank. The defluoridation reaction unit is equipped with a defluoridator dosing pipe, the mixing reaction unit is equipped with a coagulant dosing pipe, the flocculation unit is equipped with a coagulant aid dosing pipe, and the effluent mixing unit is equipped with an acid and alkali dosing pipe.

3. The photovoltaic wastewater treatment system according to claim 2, characterized in that, The sedimentation unit is equipped with a sedimentation system, a sludge scraping system, a sludge discharge system, and an effluent collection system. The sedimentation system is located at the top of the sedimentation unit, while the sludge discharge system and the sludge scraping system are both located at the bottom of the sedimentation unit. The sedimentation system includes a sedimentation area formed by a connecting plate, and a sedimentation device is installed in the sedimentation area. The sludge discharge system includes a sludge pump, a sludge discharge pipeline, and a sludge return pipeline. The sludge pump is connected to the sludge discharge pipeline and the sludge return pipeline. The sludge return pipeline is located between the flocculation unit and the sedimentation unit. The sludge scraping system includes a center-driven sludge scraper, which is used to collect sludge from wastewater; The effluent collection system includes an effluent collection weir and an effluent collection pool. The effluent collection pool is connected to the first end of the effluent mixing unit. The effluent collection weir is used to collect the supernatant after sedimentation, which then flows into the effluent collection pool, allowing the collected supernatant to enter the effluent mixing unit.

4. The photovoltaic wastewater treatment system according to claim 2, characterized in that, The defluorination reaction unit, the mixing reaction unit, the flocculation unit, and the effluent mixing unit are all equipped with stirring devices.

5. The photovoltaic wastewater treatment system according to any one of claims 2-4, characterized in that, The carbon adsorption clarification tank also includes an activated carbon reaction unit, which is located between the defluorination reaction unit and the flocculation unit, and the activated carbon reaction unit is equipped with an activated carbon dosing pipe.

6. The photovoltaic wastewater treatment system according to claim 5, characterized in that, The water treatment unit includes the mixing reaction unit, the defluorination reaction unit, the activated carbon reaction unit, the flocculation unit, the sedimentation unit, and the effluent mixing unit, which are connected sequentially along the water treatment flow direction.

7. The photovoltaic wastewater treatment system according to claim 1, characterized in that, The biologically enhanced denitrification tank includes a primary anaerobic section, a primary anoxic section, a primary aerobic section, a secondary anoxic section, and a secondary aerobic section that are sequentially connected along the natural flow direction of the water.

8. The photovoltaic wastewater treatment system according to claim 7, characterized in that, The tail end of the secondary aerobic section is equipped with a water outlet system; The water outlet system includes an outlet area enclosed by baffles, and a booster pump is installed in the outlet area. The booster pump is connected to the inlet of the carbon adsorption clarification tank through a connecting pipeline.

9. The photovoltaic wastewater treatment system according to claim 7, characterized in that, A mixed liquid reflux pipeline is provided between the first-level anoxic section and the first-level aerobic section.

10. The photovoltaic wastewater treatment system according to claim 7, characterized in that, The bottom of the primary anaerobic section, the primary anoxic section, and the secondary anoxic section are all equipped with stirring components, and the primary aerobic section and the secondary aerobic section are all equipped with aeration systems.

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