A device and method for biochemical treatment of initial rainwater based on self-particle of suspended matter

Abstract

The application discloses a kind of based on suspended solids self granulation early rainwater biochemical treatment device and method, belong to the technical field of contaminated rainwater treatment engineering design.The device includes early rainwater storage tank, suspended solids first separation tank, biochemical treatment device, suspended solids second separation tank and sedimentation tank.The method is: first based on suspended solids first separation tank, suspended solids second separation tank and sedimentation tank respectively realize the separation of suspended solids particle size in early rainwater 3mm above, 0.2-3mm and 0.2mm below, and utilize 0.2-3mm suspended solids to strengthen sludge hydrolysis acidification, granulation and pollutant removal performance in biochemical treatment device, realize the early rainwater biochemical treatment effect based on suspended solids self granulation.The application can be in green treatment early rainwater suspended solids and phosphorus-containing pollutants, while realizing the effective use of dissolved organic matter and high load disposal of nitrogen-containing pollutants.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of pollution rainwater treatment engineering design, and relates to the treatment of initial rainwater, in particular to an initial rainwater biochemical treatment device and method based on self-particle formation of suspended solids. BACKGROUND

[0002] Initial rainwater refers to pollution rainwater formed by rainwater wrapping pollutants on the urban underlying surface and in the air to the ground during rainfall. The rainwater contains a large amount of suspended solids (SS), dissolved organic matter, nitrogen and phosphorus pollutants, and often causes water body to be black and smelly, becoming a key link that urgently needs to be treated and disposed in the prevention and control of urban water pollution.

[0003] At present, the suspended solids (SS) in the initial rainwater are mainly treated by chemical precipitation method, but this method needs to add a large amount of coagulant, increasing the operation and maintenance cost. In addition, the chemical precipitation method removes all the SS without distinction, increasing the production of sludge, improving the difficulty of resource utilization, and increasing the subsequent treatment and disposal cost.

[0004] For dissolved organic matter and nitrogen-containing pollutants in initial rainwater, a traditional flocculation biological treatment device is often arranged after the chemical precipitation method. However, in this treatment method, the dissolved organic matter is often converted into carbon dioxide by aerobic aeration, wasting the valuable carbon source in the raw water. In addition, the traditional biological treatment method only oxidizes the nitrogen-containing pollutants to nitrate nitrogen, and cannot achieve nitrogen removal, so that the water body sensitive to nitrogen still faces the risk of eutrophication. In addition, due to the low load of the traditional flocculation biological treatment method, a large-capacity reactor needs to be built to treat large-scale initial rainwater, increasing the construction cost of a large amount of infrastructure.

[0005] For phosphorus-containing pollutants in initial rainwater, chemical precipitation method or biological phosphorus removal method is often used. However, the chemical phosphorus removal method not only increases the use cost of chemical agents, but also produces a large amount of chemical sludge that is difficult to resource utilization. For the biological phosphorus removal method, due to the lack of high-quality carbon source in the initial rainwater, the performance of biological phosphorus removal is difficult to guarantee.

[0006] Therefore, the problems to be solved by the present application are to avoid the use of chemical precipitation method leading to expensive operation and maintenance, and the resource utilization of SS; to avoid the problems of low load of traditional flocculation biological treatment method, and unstable phosphorus removal and nitrogen removal caused by the insufficient utilization of low-carbon organic matter. SUMMARY

[0007] In order to solve the above problems, the purpose of the present application is to provide an initial rainwater biochemical treatment device and method based on self-particle formation of suspended solids, which can greenly treat suspended solids and phosphorus-containing pollutants, effectively utilize dissolved organic matter, and dispose nitrogen-containing pollutants at high load, so as to meet the urgent needs of initial rainwater treatment.

[0008] To achieve the above object, the present application adopts the following technical solutions:

[0009] The present application first provides a kind of based on suspended solids self granulation initial rainwater biochemical treatment device, the device includes: initial rainwater storage tank, suspended solids first separation tank, biochemical treatment device, suspended solids second separation tank and sedimentation tank;Wherein, the initial rainwater storage tank is connected with suspended solids first separation tank;Suspended solids first separation tank is connected with biochemical treatment device;

[0010] The biochemical treatment device is sequentially provided with anaerobic zone, aerobic zone and anoxic zone;Anaerobic zone of biochemical treatment device is connected with suspended solids second separation tank;Suspended solids second separation tank is also connected with anaerobic zone of biochemical treatment device and sedimentation tank respectively;Sedimentation tank is connected with suspended solids first separation tank.

[0011] As a preferred scheme of the present application, the suspended solids first separation tank is provided with first water inlet pump and first sludge discharge valve, and the initial rainwater storage tank is connected with the suspended solids first separation tank by the first water inlet pump.

[0012] As a preferred scheme of the present application, the suspended solids second separation tank is provided with first reflux pump, and the suspended solids second separation tank is connected with the anaerobic zone of the biochemical treatment device by the first reflux pump.

[0013] As a preferred scheme of the present application, the sedimentation tank is provided with second sludge discharge valve and second reflux pump, and the sedimentation tank is connected with the suspended solids first separation tank by the second reflux pump.

[0014] As a preferred scheme of the present application, the biochemical treatment device is provided with second water inlet pump, the anaerobic zone is provided with anaerobic agitator, the aerobic zone is provided with aerobic agitator, the anoxic zone is provided with anoxic agitator, and the aerobic zone is further provided with aeration device. The present application also provides a kind of based on suspended solids self granulation initial rainwater biochemical treatment method using the above-mentioned initial rainwater biochemical treatment device, including the following steps:

[0015] 1) The activated sludge of wastewater treatment plant is added to suspended solids first separation tank, suspended solids second separation tank of biochemical treatment device and sedimentation tank respectively;

[0016] 2) Start first water inlet pump to pump initial rainwater into suspended solids first separation tank, complete the adsorption and separation of suspended solids with particle size above 3mm;

[0017] 3) Start the second water inlet pump, pump the initial rainwater removing more than 3mm suspended substance into the biochemical treatment device, and simultaneously start the anaerobic agitator, the aerobic agitator, the anoxic agitator and the aeration device, so that the hydrolysis acidification of the suspended substance, the storage and release phosphorus process of the internal carbon source are completed in the anaerobic zone, the nitrification and phosphorus absorption process are completed in the aerobic zone, and the deep denitrification process is completed in the anoxic zone;

[0018] 4) The sludge and sewage mixture flowing out of the anoxic zone of the biochemical treatment device enters the suspended substance second separation tank through the water pipe, completes the precipitation of the suspended substance with a particle size of 0.2mm-3mm, and returns it to the anaerobic zone of the biochemical treatment device through the first reflux pump, so as to strengthen the granulation of the sludge in the biochemical treatment device;

[0019] 5) The sludge and sewage mixture flowing out of the suspended substance second separation tank enters the sedimentation tank through the water pipe, completes the separation of the sludge and the sewage, and returns the precipitated sludge to the suspended substance first separation tank through the second reflux pump, so as to strengthen the adsorption and separation performance of the suspended substance;

[0020] 6) After the suspended substance, ammonia nitrogen and phosphorus removal performance is stable, the hydraulic retention time of the suspended substance first separation tank, the suspended substance second separation tank and the sedimentation tank is gradually reduced, until the proportion of the sludge with a particle size of 0.2mm or more in the total sludge is more than 50%, which indicates that the initial rainwater biochemical treatment effect of the suspended substance self-granulation is finally realized.

[0021] The principle of the present application is as follows: The granular sludge, i.e. the sludge with a particle size of 0.2-3mm, is beneficial to the strengthening of the settling property and biomass of the sludge in the biological treatment unit, and has higher treatment load and biological stability than the traditional floc sludge treatment method. The SS can be classified into <0.2mm, 0.2-3mm and >3mm suspended substances according to the particle size of the granules. If the suspended substance with a particle size of 0.2-3mm is fully utilized to promote the granulation of the sludge in the biological treatment unit under the premise of the classification of the suspended substance granule particle size, the 0.2-3mm particle size in the SS can be fully utilized, and the technical bottleneck of low treatment load in the above-mentioned traditional floc biological treatment method can be improved.

[0022] Based on the above particle size grading principle, first, the first separation tank, the second separation tank and the sedimentation tank are used to realize the separation of the suspended particles with particle size of 3mm or more, 0.2-3mm and 0.2mm or less in the initial rainwater respectively, and the suspended particles with particle size of 0.2-3mm are used to strengthen the hydrolysis acidification, granulation and pollutant removal performance of the sludge in the biochemical treatment device, so that the biochemical treatment effect of the initial rainwater based on the self-granulation of the suspended particles is realized. Based on the premise of the particle size grading of the suspended particles, the green adsorption treatment of the suspended particles with particle size of more than 0.3mm is realized, the granulation of the biological disposal unit is promoted by making full use of the suspended particles with particle size of 0.2-3mm, the treatment load of the pollutants is improved, the hydrolysis acidification product of the organic suspended particles is effectively ensured, the biological phosphorus removal effect is realized, and finally the effective utilization of the dissolved organic matter and the high-load disposal of the nitrogen-containing pollutants are realized while the green treatment of the suspended particles and the phosphorus-containing pollutants is realized.

[0023] Compared with the prior art, the present application has the following beneficial effects:

[0024] 1) Under the premise of the particle size grading of the suspended particles, the SS grading utilization is realized, the green adsorption treatment of the suspended particles with particle size of more than 0.3mm is realized, and the addition of a large amount of chemical flocculating agent is avoided; the granulation of the biological disposal unit is promoted by making full use of the suspended particles with particle size of 0.2-3mm, the settling property and biomass of the sludge in the biological disposal unit are effectively strengthened, the treatment load of the pollutants is improved, and the capital cost is greatly reduced.

[0025] 2) The hydrolysis acidification product of the organic suspended particles (0.2mm or less) and the dissolved organic matter in the rainwater are stored as internal carbon source by making full use of them, the biological phosphorus removal effect is effectively ensured, and the addition of chemical phosphorus removal agent is avoided.

[0026] 3) Based on the operation mode of the post-anoxic, the removal of total nitrogen in the rainwater is effectively ensured, and the nitrogen emission footprint in the initial rainwater is reduced.

[0027] 4) The present application is simple to control and convenient to operate and manage, is conducive to realizing the low-carbon and low-energy consumption pollutant reduction of the newly-built initial rainwater treatment device, and is also suitable for realizing the upgrading and reconstruction of the initial rainwater treatment device for reducing pollution and carbon. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 It is a structural schematic view of the present application, a biochemical treatment device for initial rainwater based on self-granulation of suspended particles.

[0029] In the diagram, 1 is the initial rainwater storage tank, 2 is the first suspended solids separation tank, 3 is the biological treatment device, 4 is the second suspended solids separation tank, and 5 is the sedimentation tank; 2.1 is the first inlet pump, 2.2 is the first sludge discharge valve; 3.1 is the second inlet pump, 3.2 is the anaerobic zone, 3.3 is the anaerobic agitator, 3.4 is the aerobic zone, 3.5 is the aerobic agitator, 3.6 is the anoxic zone, 3.7 is the anoxic agitator, and 3.8 is the aeration device; 4.1 is the first return pump; 5.1 is the second sludge discharge valve, and 5.2 is the second return pump. Detailed Implementation

[0030] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0031] Example 1

[0032] like Figure 1 As shown, a biological treatment device and method for initial rainwater based on the self-granulation of suspended solids is provided, which uses the following device: an initial rainwater storage tank 1, a first suspended solids separation tank 2, a biological treatment device 3, a second suspended solids separation tank 4, and a sedimentation tank 5; wherein the initial rainwater storage tank 1 is connected to the first suspended solids separation tank 2 via a first inlet pump 2.1; the first suspended solids separation tank 2 is connected to the biological treatment device 3 via a second inlet pump 3.1.

[0033] The biochemical treatment device 3 is equipped with an anaerobic zone 3.2, an anaerobic stirrer 3.3, an aerobic zone 3.4, an aerobic stirrer 3.5, an anoxic zone 3.6, an anoxic stirrer 3.7, and an aeration device 3.8.

[0034] The anoxic zone 3.6 of the biochemical treatment device is connected to the second suspended solids separation tank 4 via a water pipe; the second suspended solids separation tank 4 is connected to the anaerobic zone 3.2 of the biochemical treatment device via a first reflux pump 4.1; the second suspended solids separation tank 4 is connected to the sedimentation tank 5 via a water pipe; the sedimentation tank 5 is connected to the first suspended solids separation tank 2 via a second reflux pump 5.2; the first suspended solids separation tank 2 is equipped with a first sludge discharge valve 2.2; the sedimentation tank 5 is equipped with a second sludge discharge valve 5.1.

[0035] During the experiment, ordinary quartz sand, granular starch, and ceramsite were used to simulate suspended solids (SS) in the initial rainwater, with a simulated concentration of 250 mg / L. Ammonium chloride, potassium dihydrogen phosphate, sodium acetate, 0.3 mL / L nutrient solution, and tap water were used to simulate dissolved pollutants in the initial rainwater, with a dissolved organic matter concentration of 50 mg COD / L, an ammonia nitrogen concentration of 10 mg / L, and a phosphorus concentration of 2 mg / L.

[0036] The nutrient solution components are as shown in Table 1.

[0037] Table 1 Nutrient solution configuration components

[0038] Substance Concentration (g / L) Substance Concentration (g / L) EDTA 15.0 NaSeO4.10H2O 0.21 H3BO3 0.014 ZnSO4·7H2O 0.43 [CuSO4·5H2O] 0.25 CoCl2-6H2O 0.24 NaMoO4·2H2O 0.22 [NiCl2·6H2O] 0.19 MnCl2.4H2O 0.99

[0039] The test system is as shown in Figure 1 Each reactor is made of organic glass, and the effective volumes of the suspended solids first separation tank 2, the biochemical treatment device 3, the suspended solids second separation tank 4, and the sedimentation tank 5 are 10 L, 50 L, 20 L, and 20 L respectively.

[0040] The specific operation is as follows:

[0041] 1) The activated sludge of a sewage plant is added to the suspended solids first separation tank 2, the biochemical treatment device 3, the suspended solids second separation tank 4, and the sedimentation tank 5 respectively, so that the sludge concentrations are 8000 mg / L, 5000 mg / L, 5000 mg / L, and 8000 mg / L respectively;

[0042] 2) The initial rainwater is pumped into the suspended solids first separation tank 2 by starting the first water inlet pump 2.1, and the hydraulic retention time is controlled to be 1 h, so as to complete the adsorption and separation of suspended solids with a particle size of 3 mm or more;

[0043] 3) The initial rainwater from which the suspended solids with a particle size of 3 mm or more are removed is pumped into the biochemical treatment device 3 by starting the second water inlet pump 3.1, and the anaerobic agitator 3.3, the aerobic agitator 3.5, the anoxic agitator 3.7, and the aeration device 3.8 are started, and the hydraulic retention times of the anaerobic zone, the aerobic zone, and the anoxic zone are controlled to be 2 h, 2 h, and 4 h respectively, so as to complete the hydrolysis acidification of the suspended solids, the storage of internal carbon source, and the phosphorus release process in the anaerobic zone 3.2, the nitrification and phosphorus absorption process in the aerobic zone 3.4, and the deep denitrification process in the anoxic zone;

[0044] 4) The sludge and wastewater mixture flowing out of the anoxic zone 3.5 of the biochemical treatment device is introduced into the suspended solids second separation tank 4 by a water pipe, the hydraulic retention time is controlled to be 1 h, the precipitation of suspended solids with a particle size of 0.2 mm-3 mm is completed, and the first backflow pump 4.1 is used to backflow the suspended solids to the anaerobic zone 3.2 of the biochemical treatment device, so as to strengthen the granulation of the sludge in the biochemical treatment device 3;

[0045] 5) The sludge and wastewater mixture flowing out of the suspended solids second separation tank 4 is introduced into the sedimentation tank 5 by a water pipe, the hydraulic retention time is controlled to be 3 h, the separation of the sludge and the wastewater is completed, and the second backflow pump 5.2 is used to backflow the precipitated sludge to the suspended solids first separation tank 2, so as to strengthen the adsorption and separation performance of the suspended solids;

[0046] 6) After the stable performance of the suspended solids, ammonia nitrogen and phosphorus removal, the hydraulic retention time of the first suspended solids separation tank 2, the second suspended solids separation tank 4 and the sedimentation tank 5 is reduced, until the proportion of the sludge with the particle size of 0.2 mm or more in the total sludge in the biochemical treatment device 3 is more than 70%, which indicates that the initial rainwater biochemical treatment effect of the suspended solids self-particle is realized.

[0047] The test results show that after the initial rainwater is treated by the device and method, the ammonia nitrogen in the effluent is less than 0.5 mg / L, the SS is less than 10 mg / L, the COD is less than 8 mg / L, and the phosphorus concentration is less than 0.2 mg / L, under the premise that no chemical flocculants and chemical phosphorus removal agents are added, the full-process biochemical treatment of the initial rainwater is realized.

[0048] The above is only an embodiment of the present application, and is not a limitation on the form and substance of the present application. It should be noted that, for those skilled in the art, without departing from the method of the present application, some improvements and supplements can also be made, which should be considered as the protection scope of the present application. For those skilled in the art, without departing from the spirit and scope of the present application, some changes, modifications and equivalent changes made by using the disclosed technical content are equivalent embodiments of the present application; at the same time, any equivalent changes, modifications and evolution of the above-mentioned embodiments according to the essential technology of the present application are still within the scope of the technical solutions of the present application.

Claims

1. A method for biochemical treatment of initial rainwater based on self- granulation of suspended matter, characterized in that, The method comprises the following steps: 1) adding activated sludge of a sewage plant to a suspended solids first separation tank, a suspended solids second separation tank and a sedimentation tank; the concentration of the activated sludge of the sewage plant in the first separation tank, the biochemical treatment device, the suspended solids second separation tank and the sedimentation tank is 8000 mg / L, 5000 mg / L, 5000 mg / L and 8000 mg / L respectively; 2) starting a first water inlet pump to pump initial rainwater into the suspended solids first separation tank to complete adsorption and separation of suspended solids with a particle size of more than 3 mm; the initial rainwater has a SS concentration of 250 mg / L, a COD of 50 mg / L, an ammonia nitrogen concentration of 10 mg / L and a phosphorus concentration of 2 mg / L; the hydraulic retention time is controlled to be 1 h; 3) starting a second water inlet pump to pump the initial rainwater from which the suspended solids with a particle size of more than 3 mm are removed into the biochemical treatment device, and simultaneously starting an anaerobic agitator, an aerobic agitator, an anoxic agitator and an aeration device to make the hydrolysis acidification of the suspended solids, the storage and release of internal carbon sources and the phosphorus release process be completed in the anaerobic zone, the nitrification and phosphorus absorption process be completed in the aerobic zone and the deep denitrification process be completed in the anoxic zone; the hydraulic retention time of the anaerobic zone, the aerobic zone and the anoxic zone is controlled to be 2 h, 2 h and 4 h respectively; 4) the sludge and wastewater mixture flowing out of the anoxic zone of the biochemical treatment device enters the suspended solids second separation tank through a water pipe, the hydraulic retention time is controlled to be 1 h, the precipitation of suspended solids with a particle size of between 0.2 mm and 3 mm is completed, and the first backflow pump is used to backflow the suspended solids to the anaerobic zone of the biochemical treatment device to strengthen the granulation of the sludge in the biochemical treatment device; 5) the sludge and wastewater mixture flowing out of the suspended solids second separation tank enters the sedimentation tank through a water pipe, the hydraulic retention time is controlled to be 3 h, the separation of the sludge and the wastewater is completed, and the second backflow pump is used to backflow the precipitated sludge to the suspended solids first separation tank to strengthen the adsorption and separation performance of the suspended solids; 6) after the suspended solids removal performance, the ammonia nitrogen removal performance and the phosphorus removal performance are stable, the hydraulic retention time of the suspended solids first separation tank, the suspended solids second separation tank and the sedimentation tank is gradually reduced until the proportion of the sludge with a particle size of more than 0.2 mm in the total sludge in the biochemical treatment device is more than 70%, the effluent ammonia nitrogen is less than 0.5 mg / L, the SS is less than 10 mg / L, the COD is less than 8 mg / L and the phosphorus concentration is less than 0.2 mg / L, and the biochemical treatment of the initial rainwater is realized under the premise that no additional chemical flocculants and chemical phosphorus removal agents are added; The biochemical treatment device for the initial rainwater used in the method comprises an initial rainwater storage tank, a suspended solids first separation tank, a biochemical treatment device, a suspended solids second separation tank and a sedimentation tank; the initial rainwater storage tank is connected with the suspended solids first separation tank; the suspended solids first separation tank is connected with the biochemical treatment device; The biochemical treatment device comprises an anaerobic zone, an aerobic zone and an anoxic zone in sequence; the anoxic zone of the biochemical treatment device is connected with the suspended solids second separation tank; the suspended solids second separation tank is connected with the anaerobic zone of the biochemical treatment device and the sedimentation tank respectively; and the sedimentation tank is connected with the suspended solids first separation tank. The first suspended substance separation tank is provided with a first water inlet pump and a first sludge discharge valve, and the initial rainwater storage tank is connected with the first suspended substance separation tank through the first water inlet pump; The second suspended substance separation tank is provided with a first backflow pump, and the second suspended substance separation tank is connected with the anaerobic zone of the biochemical treatment device through the first backflow pump; The sedimentation tank is provided with a second sludge discharge valve and a second backflow pump, and the sedimentation tank is connected with the first suspended substance separation tank through the second backflow pump; The biochemical treatment device is provided with a second water inlet pump, the anaerobic zone is provided with an anaerobic agitator, the aerobic zone is provided with an aerobic agitator, the anoxic zone is provided with an anoxic agitator, and the aerobic zone is further provided with an aeration device.

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