Sewage treatment system

Abstract

The utility model discloses a sewage treatment system which is characterized in that an inlet of an oxidation tower is communicated with a sewage pipeline; the catalyst adding system is arranged at the top of the oxidation tower and is used for adding a Fenton catalyst for removing pollutants in sewage into the oxidation tower; the autotrophic reaction tank is communicated with the outlet of the oxidation tower and is internally provided with activated sludge for denitrification; the solid substance adding system is arranged at the top of the autotrophic reaction tank and is used for adding an electron donor into the autotrophic reaction tank; the sedimentation tank is communicated with the outlet of the autotrophic reaction tank and is used for precipitating the electron donor and the activated sludge after the denitrification reaction and discharging the treated wastewater. According to the sewage treatment system, sulfur powder and other electron donors are added in a fluidized bed form, so that the feeding cost is reduced; and ions separated out by the electron donor and the Fenton catalyst jointly provide electrons required for removing nitrate nitrogen, so that the autotrophic nitrogen removal efficiency is improved, the sewage treatment effect is ensured, and the sewage treatment cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to sewage treatment technical field more specifically, relate to a sewage treatment system. BACKGROUND

[0002] The industries such as medicine, steel and photovoltaic use nitric acid as raw material, and the small water volume and high concentration chemical industrial wastewater produced has the problems of difficult biochemical degradation of organic matter and high nitrate nitrogen.

[0003] For such small water volume and high concentration chemical industrial wastewater, the related art removes chemical oxygen demand by advanced oxidation and membrane filtration, and removes nitrate nitrogen by biochemical method, electrodialysis and ion exchange materialization method. Considering cost, process maturity and operation difficulty, the more suitable method for such wastewater is biochemical method, which needs to consume organic matter in water body to provide electrons when removing nitrate nitrogen in the actual application process, and the remaining organic matter in the actual wastewater is insufficient to provide enough electrons, and additional electron donor needs to be added.

[0004] In the related art, there are two forms of adding electron donor, one is to add organic matter (such as glucose, sodium acetate and composite carbon source) that can be used by heterotrophic bacteria, which has high operation cost, and the other is to add inorganic matter (such as sulfur iron) that can be used by autotrophic bacteria, which is added in the form of filler fixed bed, and has high investment cost in the early stage.

[0005] In summary, how to reduce the cost of chemical industrial wastewater treatment is a problem to be solved by the technical personnel in the field. UTILITY MODEL CONTENT

[0006] Therefore, the utility model aims to provide a sewage treatment system, which adds sulfur powder in the form of fluidized bed of electron donor such as sulfur powder, which can reduce the cost compared with the one-time filling of fixed bed and the addition of organic matter, and provides the required electrons for removing nitrate nitrogen by the ions generated by the electron donor and the Fenton catalyst, improves the autotrophic denitrification efficiency, ensures the treatment effect of wastewater and reduces the cost of wastewater treatment.

[0007] In order to achieve the above purpose, the utility model provides the following technical scheme:

[0008] A sewage treatment system comprises:

[0009] An oxidation tower, which is connected to a sewage pipeline at the inlet;

[0010] A catalyst adding system is arranged at the top of the oxidation tower, which is used to add Fenton catalyst for removing pollutants in wastewater into the oxidation tower;

[0011] An autotrophic reaction tank is connected to the outlet of the oxidation tower and is internally provided with activated sludge for denitrification.

[0012] A solid matter adding system is arranged at the top of the autotrophic reaction tank for adding an electron donor into the autotrophic reaction tank.

[0013] A sedimentation tank is communicated with the outlet of the autotrophic reaction tank for precipitating the electron donor and the activated sludge after the denitrification reaction and discharging the treated wastewater.

[0014] Preferably, the inlet end of the oxidation tower is provided with a hydrogen peroxide adding system and an acidic matter adding system for adjusting the pH of the wastewater to neutral or acidic.

[0015] Preferably, the oxidation tower is provided with a first stirring system for stirring, and the autotrophic reaction tank is provided with a second stirring system for stirring, and the first and second stirring systems are vertically suspended.

[0016] Preferably, a reflux system is arranged between the bottom and the top of the oxidation tower, the top end of the reflux system is the outlet of the oxidation tower, and the outlet of the oxidation tower is communicated with the bottom of the autotrophic reaction tank through a first pipeline.

[0017] Preferably, the bottom of the sedimentation tank is communicated with the bottom of the autotrophic reaction tank through a second pipeline.

[0018] Preferably, the outlet of the autotrophic reaction tank is arranged at the top thereof and communicated with the sedimentation tank, and the outlet of the sedimentation tank is arranged at the top thereof for discharging the treated wastewater.

[0019] Preferably, a mud scraper is rotatably arranged in the sedimentation tank, the mud scraper is used for scraping the unreacted electron donor and activated sludge from the inner wall of the sedimentation tank, and the lower end of the mud scraper is provided with a submersible pump for sending the electron donor and activated sludge into the autotrophic reaction tank.

[0020] Preferably, a pipeline mixer is arranged between the inlet of the oxidation tower and the sewage pipeline for uniformly mixing the hydrogen peroxide, the acidic substance and the sewage. The sewage treatment system provided by the utility model, comprising an oxidation tower, a catalyst adding system, an autotrophic reaction tank, a solid substance adding system and a sedimentation tank, wherein the inlet of the oxidation tower is used for connecting the sewage pipeline, after the sewage is uniformly mixed with the hydrogen peroxide and the acidic substance and enters the oxidation tower, pollutants in the sewage are removed through reaction with the Fenton catalyst added by the catalyst adding system; the autotrophic reaction tank is communicated with the outlet of the oxidation tower and is internally provided with activated sludge for denitrification, the electron donor added into the autotrophic reaction tank by the solid substance adding system and the ions separated out after the Fenton catalyst reaction jointly serve as the electron donor of the activated sludge, the sewage with pollutants is subjected to denitrification through denitrification reaction in the autotrophic reaction tank, the fluidized bed form of adding the electron donor reduces the cost of the traditional fixed bed; the sedimentation tank is communicated with the outlet of the autotrophic reaction tank and is used for sedimentation of the electron donor and the activated sludge which are not completely reacted after the denitrification reaction and discharge of the treated wastewater, so as to complete the whole sewage purification process; the electron donor and the activated sludge which are not completely reacted after the denitrification reaction can be recycled after sedimentation, the resource is maximally utilized, and the cost of the sewage treatment is reduced. The above sewage treatment system adds sulfur powder in the form of the fluidized bed of adding sulfur powder, compared with the one-time filling fixed bed mode, the cost is reduced; the electrons required for removing the nitrate nitrogen are jointly provided by the electron donor and the ions separated out by the Fenton catalyst, the autotrophic denitrification efficiency is improved, the sewage pollutants are effectively removed, the treatment effect of the sewage is ensured, and the cost of the sewage treatment is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical scheme in the embodiments of the utility model or the prior art, below will be to the drawings needed to be used in the embodiment or prior art description simple introduction, obviously, below description in the drawings only is the embodiment of the utility model, for the ordinary skilled person in the art comes, under the premise of not paying the creative labor, still can obtain other drawings according to the provided drawings.

[0022] Figure 1 It is the structure diagram of the sewage treatment system provided by the utility model.

[0023] Figure 1 In the drawings, the reference signs include:

[0024] 1-catalyst adding system;2-first stirring system;3-oxidation tower;4-first pipeline;5-solid substance adding system;6-second stirring system;7-autotrophic reaction tank;8-mud scraper;9-acidic substance adding system;10-hydrogen peroxide adding system;11-pipeline mixer;12-submerged sewage pump;13-backflow system;14-sedimentation tank;15-second pipeline. DETAILED DESCRIPTION

[0025] The technical solutions in the embodiments of the utility model will be clearly and completely described below with reference to the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, rather than all the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the utility model.

[0026] The core of the utility model provides a kind of sewage treatment system, by adding sulfur powder such as electron donor fluidized bed form addition sulfur powder, compared with disposable filling fixed bed and the mode of adding organic matter, can reduce cost;By the ion provided by electron donor and fenton catalyst together, the required electron for removing nitrate nitrogen is provided, the autotrophic denitrification efficiency is improved, the sewage pollutants are effectively removed, the treatment effect of sewage is guaranteed, and the cost of sewage treatment is reduced.

[0027] The sewage treatment system provided by the utility model comprises an oxidation tower 3, a catalyst adding system 1, an autotrophic reaction tank 7, a solid matter adding system 5 and a sedimentation tank 14, please refer to Figure 1 .

[0028] The inlet of the oxidation tower 3 is communicated with the sewage pipeline, and the top of the oxidation tower 3 is provided with the catalyst adding system 1, which is used for adding fenton catalyst into the oxidation tower 3. After the sewage enters the oxidation tower 3, the pollutants in the wastewater are removed under the action of the fenton catalyst. The fenton catalyst herein is preferably composed of sulfur powder and iron powder. The sulfur powder and the iron powder are ball milled into a powder catalyst according to a certain proportion. Firstly, the catalyst can be used as fenton catalyst, and secondly, the catalyst also has the function of leaching ferrous ions in the reaction process, so as to provide electrons for denitrification reaction.

[0029] In the above process, the fenton catalyst removes the pollutants in the wastewater. Specifically, the fenton reaction principle is used to treat the organic pollutants in the wastewater, effectively removes the chemical oxygen demand in the wastewater, and guarantees the treatment effect of the wastewater.

[0030] Optionally, to ensure the sufficient reaction of the fenton catalyst and the wastewater, the oxidation tower 3 can be provided with two, so as to prolong the reaction time and guarantee the removal efficiency of the pollutants and the removal effect of the wastewater pollutants.

[0031] The autotrophic reaction tank 7 is communicated with the outlet of the oxidation tower 3, and the activated sludge for denitrification is arranged in the autotrophic reaction tank 7. The solid matter adding system 5 is used for adding electron donor into the autotrophic reaction tank 7. The added electron donor and the ferrous ions leached by the fenton catalyst can both be utilized by the activated sludge, so as to improve the utilization rate of resources and reduce unnecessary waste.

[0032] Specifically, the electron donor is any one of sulfur powder or sulfur in a negative state (sodium thiosulfate, ferrous disulfide).

[0033] Taking sulfur powder as an example of the electron donor added by the solid matter dosing system 5, the sulfur powder is added in the form of timed addition, rather than continuous operation. The specific addition time can be determined based on the ferrous ions leached by the Fenton catalyst, the concentration of nitrate nitrogen, and the activity of the activated sludge, so as to ensure the effective removal of nitrate nitrogen from the wastewater.

[0034] Compared to a one-time filling of a fixed bed and the addition of organic matter, the fluidized bed form by adding electron donors through the solid material addition system 5 reduces costs. The electron donors coupled with the ions dissolved from the Fenton catalyst jointly provide the electrons needed to remove nitrate nitrogen, improve the autotrophic denitrification efficiency, ensure the treatment effect of wastewater, and reduce the cost of wastewater treatment.

[0035] Preferably, since the autotrophic denitrification reaction has a faster reaction rate under alkaline conditions, the solid material addition system 5 can simultaneously add alkaline substances when adding electron donors such as sulfur powder to the autotrophic reaction tank 7 to ensure an alkaline environment during the denitrification reaction. The addition of alkaline substances is not continuous; they can be added periodically or selectively according to the actual operating conditions, without any restrictions.

[0036] Preferably, the sulfur powder addition system and the alkaline substance addition system are relatively independent and both are set towards the interior of the autotrophic reaction tank 7. The specific placement location is not limited and can be flexibly set.

[0037] Sedimentation tank 14 is connected to the outlet of autotrophic reaction tank 7. It is used to settle the electron donors such as sulfur powder and activated sludge after the denitrification reaction, and to discharge the treated wastewater. The unreacted substances (electron donors and activated sludge) can be recycled to avoid waste of resources and reduce the cost of sewage treatment.

[0038] After passing through sedimentation tank 14, the wastewater has been decontaminated and nitrate nitrogen removed. It can be discharged by connecting to the drainage pipeline or connected to the next process equipment for removing other pollutants for further decontamination.

[0039] The sewage treatment system comprises an oxidation tower 3, a catalyst adding system 1, an autotrophic reaction tank 7, a solid matter adding system 5 and a sedimentation tank 14, wherein the inlet of the oxidation tower 3 is connected with a sewage pipeline, and the sewage in the oxidation tower 3 is reacted with the Fenton catalyst added by the catalyst adding system 1 to remove the pollutants in the sewage; the autotrophic reaction tank 7 is connected with the outlet of the oxidation tower 3 and is internally provided with activated sludge for denitrification, the electrons required by the activated sludge are provided by the electron donor added into the autotrophic reaction tank 7 by the solid matter adding system 5 and the ions separated after the Fenton catalyst reaction, the sewage with pollutants removed is subjected to autotrophic denitrification in the autotrophic reaction tank 7, the fluidized bed form of adding the electron donor reduces the cost of the traditional fixed bed and the cost of sewage treatment; the sedimentation tank 14 is connected with the outlet of the autotrophic reaction tank 7, is used for sedimentation of the electron donor and the activated sludge which are not completely reacted after the denitrification reaction and discharge of the treated wastewater, and completes the whole sewage purification process; the electron donor and the activated sludge which are not completely reacted after the denitrification reaction can be recycled after sedimentation, realizes the maximum utilization of resources and reduces the cost of sewage treatment. The sewage treatment system adds sulfur powder in the form of fluidized bed of adding sulfur powder, which reduces the cost compared with the one-time filling of fixed bed and the addition of organic matters; the electrons required for removing nitrate nitrogen are provided by the electron donor and the ions separated by the Fenton catalyst, which improves the autotrophic denitrification efficiency, guarantees the treatment effect of the sewage and reduces the cost of sewage treatment.

[0040] On the basis of the above embodiment, the inlet end of the oxidation tower 3 is provided with a hydrogen peroxide adding system 10 and an acidic substance adding system 9, and the acidic substance adding system 9 is used to adjust the pH value of the sewage to neutral or acidic.

[0041] Please refer to Figure 1 The inlet end of the oxidation tower 3 is provided with a hydrogen peroxide adding system 10, which realizes the mixing of hydrogen peroxide and sewage, and the mixed liquid enters the oxidation tower 3, the hydrogen peroxide and the Fenton catalyst in the oxidation tower 3 jointly generate active substances such as hydroxyl radicals, remove the chemical oxygen demand of the sewage in the oxidation tower 3, complete the decontamination operation and guarantee the treatment effect of the sewage.

[0042] The inlet end of the oxidation tower 3 is also provided with an acidic substance adding system 9, which adjusts the alkaline sewage to neutral or acidic before being sent to the oxidation tower 3, so as to improve the catalytic oxidation reaction rate.

[0043] For example, the acid substance adding system 9 adjusts the pH value in the reaction process according to the concentration of the initial chemical oxygen demand in the sewage. When the chemical oxygen demand is small, such as 500 mg / L, only the pH value of the sewage needs to be maintained at neutral, and then the acid substance adding system 9 is closed, the Fenton catalyst is used in the environment of the surrounding slight acidity, and the reaction is normally carried out. When the chemical oxygen demand is large, such as 1000 mg / L, the acid substance adding system 9 is opened, and the pH value of the sewage is maintained at 5-7.

[0044] On the basis of any of the above embodiments, the oxidation tower 3 is provided with a first stirring system 2 for stirring, and the autotrophic reaction tank 7 is provided with a second stirring system 6 for stirring, and the first stirring system 2 and the second stirring system 6 are both vertically suspended.

[0045] Please refer to Figure 1 , the first stirring system 2 and the second stirring system 6 are both vertically suspended, the first stirring system 2 is used to realize the full reaction of the sewage and the Fenton catalyst in the oxidation tower 3, and the efficiency of removing the pollutants in the sewage is improved.

[0046] The second stirring system 6 is used to realize that the mixture of the sulfur powder and the activated sludge in the autotrophic reaction tank 7 can be fully in a suspended state, the effect of efficient denitrification is achieved, and the efficiency of removing the nitrate nitrogen in the sewage is improved.

[0047] Optionally, the first stirring system 2 and the second stirring system 6 can be set as systems with adjustable speed, and can be flexibly changed according to the operation condition.

[0048] On the basis of any of the above embodiments, the bottom of the oxidation tower 3 and the top thereof are provided with a reflux system 13, the top upper end of the reflux system 13 is the outlet of the oxidation tower 3, and the outlet of the oxidation tower 3 is connected to the bottom of the autotrophic reaction tank 7 through the first pipeline 4.

[0049] Please refer to Figure 1 , the bottom of the oxidation tower 3 and the top thereof are connected with the reflux system 13, the reflux system 13 is used to ensure that the sewage has sufficient upward flow rate, and the Fenton catalyst is dispersed in the oxidation tower 3 by coupling the first stirring system 2, so that the uniform and sufficient contact between the Fenton catalyst and the sewage is ensured, and the removal efficiency of the pollutants in the sewage is improved.

[0050] The top upper end of the reflux system 13 is the outlet of the oxidation tower 3, after the reflux system 13 and the first stirring system 2 are operated together, the sewage is discharged through the outlet of the top upper end of the reflux system 13, and is connected to the bottom of the autotrophic reaction tank 7 through the first pipeline 4 to perform the denitrification reaction in the autotrophic reaction tank 7.

[0051] Please refer to Figure 1The sewage treatment process is continuous, sewage is continuously introduced from the sewage pipe into the oxidation tower 3, and then the sewage is introduced into the autotrophic reaction tank 7 through the first pipeline 4. The top of the oxidation tower 3 is communicated with the bottom of the autotrophic reaction tank 7 through the first pipeline 4. The sewage in the oxidation tower 3 is introduced into the autotrophic reaction tank 7 by using the high and low liquid level difference, so as to avoid the introduction of oxygen to affect the denitrification reaction in the autotrophic reaction tank 7, and ensure the denitrification effect.

[0052] The first pipeline 4 can be provided with a control valve group to control the on-off of the sewage, which can be automatic or manual.

[0053] On the basis of any of the above embodiments, the bottom of the sedimentation tank 14 is communicated with the bottom of the autotrophic reaction tank 7 through the second pipeline 15, please refer to Figure 1 The second pipeline 15 is used to send the unreacted electron donor and activated sludge to the autotrophic reaction tank 7, so as to realize recycling and avoid waste of resources.

[0054] The second pipeline 15 is provided in a T-shaped structure, that is, a three-way pipeline, the first end is communicated with the bottom of the autotrophic reaction tank 7, the second end is communicated with the discharge pipeline, and the third end is communicated with the bottom of the sedimentation tank 14. Switch valves can be provided on the first end and the second end to open the corresponding switch valves according to the recycling needs.

[0055] On the basis of any of the above embodiments, the outlet of the autotrophic reaction tank 7 is arranged at the top thereof and communicated with the sedimentation tank 14, and the outlet of the sedimentation tank 14 is arranged at the top thereof and used for discharging the treated wastewater.

[0056] Please refer to Figure 1 The outlet of the autotrophic reaction tank 7 is arranged at the top thereof and used for communicating with the top of the sedimentation tank 14, and the water outlet of the autotrophic reaction tank 7 enters the sedimentation tank 14 from the top. When the electron donor is sulfur powder, the unreacted sulfur powder and activated sludge will quickly deposit on the wall of the sedimentation tank 14 due to the special hydrophobic properties of sulfur powder and the characteristics of activated sludge, and will not be discharged with the outlet of the sedimentation tank 14.

[0057] The outlets of the autotrophic reaction tank 7 and the sedimentation tank 14 are both arranged at the top to ensure that the unreacted sulfur powder will not flow out with the wastewater, thereby avoiding waste of resources.

[0058] On the basis of any of the above embodiments, a mud scraper 8 is rotatably arranged in the sedimentation tank 14. The mud scraper 8 is used for scraping the unreacted electron donor and activated sludge from the inner wall of the sedimentation tank 14. The lower end of the mud scraper 8 is provided with a submersible pump 12 for sending the unreacted electron donor and activated sludge to the autotrophic reaction tank 7.

[0059] Please refer to Figure 1The effluent from the autotrophic reaction tank 7 enters the sedimentation tank 14 from the top, the mud scraper 8 is used to scrape the unreacted electron donor and activated sludge from the inner wall of the sedimentation tank 14, and the unreacted electron donor and activated sludge are deposited at the lower end of the sedimentation tank 14 under the action of gravity, and then the unreacted electron donor and activated sludge are sent to the autotrophic reaction tank 7 through the submerged sewage pump 12 at the lower end of the mud scraper 8 and the second pipeline 15, so as to realize recycling and avoid waste of resources.

[0060] In some specific application scenarios, the unreacted electron donor and activated sludge can also be discharged after a period of time.

[0061] On the basis of any of the above embodiments, a pipeline mixer 11 is arranged between the inlet of the oxidation tower 3 and the sewage pipeline, for uniformly mixing the hydrogen peroxide, the acidic substance and the sewage.

[0062] Please refer to Figure 1 The pipeline mixer 11 is arranged at the rear end of the hydrogen peroxide adding system 10 and the acidic substance adding system 9, for uniformly mixing the hydrogen peroxide, the acidic substance and the sewage, completing the pH value treatment of the sewage, and then the sewage treated by the pipeline mixer 11 is sent to the oxidation tower 3 to react with the Fenton catalyst to remove the pollutants in the sewage.

[0063] The embodiments in the specification are described in a progressive manner, and each embodiment focuses on the difference from other embodiments, and the same and similar parts between the embodiments can be referred to each other.

[0064] The above describes in detail the sewage treatment system provided by the present application. The principle and implementation mode of the present application are described by applying specific examples, and the above embodiment is only used to help understand the method and core idea of the present application. It should be pointed out that, for ordinary skilled persons in the technical field, some improvements and modifications can be made to the present application without departing from the principle of the present application, and these improvements and modifications also fall within the protection scope of the present application.

Claims

1. A sewage treatment system characterised in that, The application relates to a wastewater treatment device, which comprises: an oxidation tower (3) with an inlet connected to a sewage pipeline; a catalyst adding system (1) arranged at the top of the oxidation tower (3) and used for adding Fenton catalyst for removing pollutants in sewage into the oxidation tower (3); an autotrophic reaction tank (7) connected to the outlet of the oxidation tower (3) and internally provided with activated sludge for denitrification; a solid matter adding system (5) arranged at the top of the autotrophic reaction tank (7) and used for adding an electron donor into the autotrophic reaction tank (7); a sedimentation tank (14) connected to the outlet of the autotrophic reaction tank (7) and used for precipitating the electron donor and the activated sludge after denitrification reaction and discharging treated wastewater.

2. The sewage treatment system of claim 1, wherein, The inlet end of the oxidation tower (3) is provided with a hydrogen peroxide adding system (10) and an acidic substance adding system (9) used for adjusting the pH value of the sewage to neutral or acidic.

3. The sewage treatment system of claim 2, wherein, The oxidation tower (3) is provided with a first stirring system (2) for stirring, the autotrophic reaction tank (7) is provided with a second stirring system (6) for stirring, and the first stirring system (2) and the second stirring system (6) are vertically hung.

4. The sewage treatment system of claim 3, wherein, A reflux system (13) is arranged between the bottom of the oxidation tower (3) and the top of the oxidation tower (3), the top end of the reflux system (13) is the outlet of the oxidation tower (3), and the outlet of the oxidation tower (3) is connected to the bottom of the autotrophic reaction tank (7) through a first pipeline (4).

5. The sewage treatment system of claim 4, wherein, The bottom of the sedimentation tank (14) is connected to the bottom of the autotrophic reaction tank (7) through a second pipeline (15).

6. The sewage treatment system of claim 5, wherein, The outlet of the autotrophic reaction tank (7) is arranged at the top of the autotrophic reaction tank (7) and connected to the sedimentation tank (14), and the outlet of the sedimentation tank (14) is arranged at the top of the sedimentation tank (14) and used for discharging treated wastewater.

7. The sewage treatment system of claim 6, wherein, A mud scraper (8) is arranged in the sedimentation tank (14) and used for scraping the unreacted electron donor and activated sludge from the inner wall of the sedimentation tank (14), and the lower end of the mud scraper (8) is provided with a sewage pump (12) used for sending the electron donor and the activated sludge into the autotrophic reaction tank (7).

8. A sewage treatment system as claimed in any one of claims 3 to 7, characterised in that, A pipeline mixer (11) is arranged between the inlet of the oxidation tower (3) and the sewage pipeline and used for uniformly mixing hydrogen peroxide, acidic substances and sewage.

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