CN112479498A

CN112479498A - Intermittent water inlet filler type biological rotating cage efficient sewage treatment device and treatment method thereof

Info

Publication number: CN112479498A
Application number: CN202011353856.9A
Authority: CN
Inventors: 成亮; 陈申良; 黎启明; 何广宏; 秦余春; 张晓锋; 鹿野; 常圣强
Original assignee: China National Coal Mining Equipment Co ltd; Jiangsu University
Current assignee: China National Coal Mining Equipment Co ltd; Jiangsu University
Priority date: 2020-11-26
Filing date: 2020-11-26
Publication date: 2021-03-12

Abstract

The application provides an intermittent water inlet filler type biological rotating cage efficient sewage treatment device and a treatment method thereof, wherein the treatment device comprises an anaerobic tank, an anoxic tank, a sedimentation tank and a reaction tank which are sequentially connected, wherein a biological rotating cage is arranged in the reaction tank, and a decanter is arranged on the inner wall of the sedimentation tank; the device can be used for sewage treatment, and its creative use intermittent type of intaking has built the environment that does benefit to the growth of glycan fungus, and then utilizes the glycan fungus to realize getting rid of efficient carbon nitrogen pollutant, effectively solves the problem that biological rotating cage biomembrane drops when intermittent type formula operation, and the device goes out the water and need not two heavy ponds, practices thrift the capital construction expense, and area is little, is applicable to small-scale such as rural domestic sewage treatment more.

Description

Intermittent water inlet filler type biological rotating cage efficient sewage treatment device and treatment method thereof

Technical Field

The invention relates to the technical field of sewage treatment, in particular to an intermittent water inlet filler type biological rotating cage device and a method for treating sewage by applying the device.

Background

In recent years, with the urbanization of rural areas and the improvement of the living standard of farmers, the discharge and the load of domestic sewage are increased rapidly. At the present stage, the discharge amount of domestic sewage obviously exceeds that of industrial wastewater, and becomes the key point of treatment. And in addition, most of villages and towns in China have imperfect drainage systems and low capital, and fewer small-scale domestic sewage treatment facilities are built. Therefore, the development of a small-sized domestic sewage treatment device and a matched process with good treatment effect, low investment, low operation cost, small occupied area and convenient operation are urgently needed.

The Biological Rotating disc technology (RBC for short) is a technology combining sewage treatment by a biofilm process and water treatment, was pioneered in the 20 th century and 60 th century by the original Federal Germany, was developed on the basis of a Biological filter, and is also called as an immersed Biological filter. The process has the advantages of flexible system design, convenient installation, simple operation, reliable system, low operation and running cost and the like; does not need aeration and sludge backflow, saves energy, can obtain higher purification effect within shorter contact time, and is widely applied to the treatment of various domestic sewage and industrial sewage. The biological rotating cage technology is further upgraded on the biological rotating disc technology, the rotating cage is filled with blocky porous filler with high specific surface area, and microorganisms form a high-concentration biological film on the surface of the filler to digest and decompose pollutants in water. Compared with the biological rotating disc, the rotating cage has more biomass and higher treatment efficiency.

Similar to the biological rotating disk, the biological rotating cage is composed of a rotating cage, a contact reaction tank, a rotating shaft and a driving device. When the disc shaft rotates, the filler in the rotating cage is alternately contacted with the wastewater and the air, the surface of the filler is covered by a film-shaped object formed by the growth of microorganisms, and the biological film is alternately and fully contacted with the wastewater and the air to continuously obtain pollutants and oxygen and purify the wastewater. When the filling material in the rotating cage is submerged by water, the biological membrane in the filling material adsorbs pollutants, and when the filling material in the rotating cage contacts air, the pollutants are oxidized and decomposed.

At present, the fillers applied to the biological rotating cage can be divided into inorganic fillers and organic fillers. Because of the large specific gravity, inorganic filler is generally used for immersion type filler, and various organic materials such as PP, PE, PVC and the like have the advantages of high strength, difficult abrasion, easy back flush and the like, but the surfaces of the materials are smooth and are not beneficial to the attachment of microorganisms, thereby reducing the effect of wastewater treatment. The porous suspension filler is widely applied to biological rotating cages due to the appropriate specific gravity and large specific surface area. The common suspension filler comprises hollow cylindrical filler, hollow spherical filler, cage-shaped combined filler with built-in silk-strip weaves, sponge block-shaped soft filler and the like.

The pollutant removing effect of the biological rotating cage is larger along with the change of hydraulic retention time and rotating speed of the rotating cage, the removal rate of COD and ammonia nitrogen by the biological rotating cage is found to rise and then fall along with the increase of the rotating speed in water purification lotus and the like (see the literature, "the research on the technology for treating domestic sewage by using a novel biological rotating cage purifier"), 3mm of active carbon and phi 25mm and phi 38mm of porous hollow spheres are used as fillers in Tangyi and the like (see the literature, "the comparison between two carriers for treating domestic sewage by using the biological rotating cage"), the fillers are retained outside the rotating cage by using a screen, and when the hydraulic retention time is 6 hours, the removal rate of total nitrogen by the biological rotating cage using the active carbon as the fillers is only 50%, and the removal rate of COD is only 55%; the biological rotating cage with the polyhedral hollow spheres as the filler has the total nitrogen removal rate of only 55 percent and the COD removal rate of only 60 percent.

Meanwhile, in the conventional rotating biological disk, proteobacteria, actinomycetes and bacteroides are the most abundant three types of populations, and common heterotrophic bacteria, nitrosobacteria and nitrobacteria are the types of bacteria which have the main removing effect on pollutants. The denitrifying bacteria needs the water body to be in an anoxic environment for denitrifying and denitrogenating, the traditional biological rotating disk adopts continuous water inlet, sewage enters the rotating disk reactor at a uniform speed, the organic matter concentration at the front and the rear parts of the reactor is obviously graded, the organic matter concentration at the rear section is low, the dissolved oxygen content in the water is high, the anoxic area is small, the denitrifying reaction is inhibited, and therefore the total nitrogen removal effect is poor. Research shows that glycan bacteria (GAOs) can absorb organic matters in solution under the conditions of anaerobic and organic carbon sources, and then synthesize intracellular carbon sources, namely Polyhydroxyalkanoates (PHAs), and store the intracellular carbon sources in vivo (Cheng et al 2018). The denitrifying glycan bacteria can utilize intracellular carbon source PHAs for denitrification. Because the nitrite accumulation can be realized, the glycan strain is mainly applied to the coupling process with the anaerobic ammonia oxidation in the field of water pollution treatment, and the GAOs is utilized to provide stable nitrite for the anaerobic ammonia oxidation. The existing biological rotating disc/biological rotating cage is difficult to realize the enrichment of the GAOs because the cultivation of the GAOs requires an instantaneous high-concentration organic carbon source to form a famine-banquet environment, and the traditional continuous water inlet mode cannot meet the requirement.

The Sequencing Batch Reactor (SBR) is operated by periodically feeding water, reacting, precipitating, draining and idling, and can generate instantaneous high-concentration organic carbon source in the initial stage of water feeding. However, the water outlet rate is high during intermittent water drainage, and the disturbance to the biological membrane exists, so that the water treatment effect is influenced. Meanwhile, the biological film on the surface of the biological rotating cage filler is easy to fall off, the biological film is greatly lost when the biological rotating cage is operated intermittently, and the stable removal effect of pollutants cannot be maintained by the biological rotating cage.

At present, no report of treating sewage by a biological rotating cage operated in an intermittent water inlet mode is found.

Disclosure of Invention

In order to overcome the defects in the prior art, the invention provides a method for efficiently treating nitrogen-containing sewage by using a biological rotating cage, which effectively improves the removal efficiency of the biological rotating cage on total nitrogen.

In order to achieve the above object, the present invention adopts the following technical solutions:

firstly, the application provides an intermittent water inlet filler type biological rotating cage high-efficiency sewage treatment device, which comprises an anaerobic tank, an anoxic tank, a sedimentation tank and a reaction tank;

the water inlet of the anaerobic tank is connected with the main water inlet pipe, and the water outlet is arranged above the inner wall and is connected with the water inlet of the anoxic tank through the flow guide pipe; the water inlet of the anoxic tank is arranged above the inner wall of the anoxic tank, the middle of the water inlet is provided with a baffle plate, and the water outlet is arranged above the inner wall opposite to the water inlet and is connected with the water inlet of the sedimentation tank through a guide pipe; a water inlet of the sedimentation tank is arranged above the inner wall, and a decanter is arranged on the inner wall opposite to the water inlet; the decanter (preferably a rotary decanter) is connected with the water inlet of the reaction tank through a drain pipe; the water inlet of the reaction tank is arranged above the inner wall, the water outlet is arranged below the inner wall opposite to the water inlet and is connected with the main water outlet pipe, and an overflow pipe is also arranged above the inner wall of the reaction tank;

the sedimentation tank is connected with the anaerobic tank through a sludge return pipe, a return valve can be further arranged on the sludge return pipe, and a part of sludge in the sedimentation tank can return to the anaerobic tank through the sludge return pipe so as to maintain the biomass of the whole system;

the anoxic tank is connected with the reaction tank through a nitrifying liquid return pipe;

the decanter comprises an underwater bracket, a drain pipe, an electric push rod, an effluent weir and a bracket, wherein the underwater bracket is arranged on the inner wall of the sedimentation tank and is rotationally connected with the effluent weir, the drain pipe is positioned at the joint of the underwater bracket and the effluent weir, the bracket is arranged at the top end of the inner wall of the sedimentation tank, one section of the electric push rod is movably connected with the effluent weir, the other end of the electric push rod is connected with a motor, the motor controls the electric push rod to rotate and drives the effluent weir to rotate along the underwater bracket, and when the electric push rod is positioned at a low water level, supernatant in the sedimentation tank enters the drain pipe through;

a biological rotating cage is arranged in the reaction tank, the biological rotating cage is a cylindrical cage body, the reaction tank is of a semi-cylindrical structure, and the shape of the reaction tank is matched with that of the biological rotating cage; a transmission shaft and a corresponding bearing are axially arranged in the biological transmission cage, the transmission shaft is movably connected with the inner wall of the reaction tank, and one end of the transmission shaft penetrates through the outer side of the reaction tank and is connected with a variable speed motor; the interior of the biological rotating cage is provided with a grid, the surface of the biological rotating cage is covered with a filter screen, and the surface of the cage body is provided with a feeding hole; the filler with the surface attached with the microorganisms is arranged inside the biological rotating cage through the feeding hole, when the biological rotating cage works, the grid drives the filler to rotate, the filter screen can prevent the filler from losing, the pore diameters of the grid and the filter screen are determined according to the size of the filler, and the pore diameter of the grid and the filter screen is generally 1-2 mm smaller than the diameter of the filler; the effluent of the sedimentation tank is discharged into the reaction tank through a drain pipe, slowly flows through a baffle plate and then is contacted with the filler in the biological rotating cage; the water outlet of the reaction tank is intermittently controlled by an electromagnetic valve.

Preferably, among the high-efficient sewage treatment plant of filler formula biological rotating cage is intake to intermittent type that this application provided, the anaerobism pond still is equipped with the anaerobism pond agitator, the oxygen deficiency pond still is equipped with oxygen deficiency pond agitator.

Further, among the high-efficient sewage treatment plant of filler formula biological rotating cage is intake to intermittent type that this application provided, still be equipped with an at least baffle in the biological rotating cage, this baffle can play relatively fixed biofilm carrier and drive biofilm carrier pivoted effect.

Furthermore, in the intermittent water feeding filler type biological rotating cage efficient sewage treatment device provided by the application, the biological filler is made of porous plastic foam (preferably porous polyurethane foam), and the size of a single filler is about 1-3cm³The cubic body of the filler is not beneficial to material exchange when the volume of the filler is too large, and is easy to collapse when the volume of the filler is too small; the massive porous three-dimensional soft polyurethane foam/sponge biological filler has excellent elasticity, flexibility, elongation and compressive strength, good chemical stability, can construct a dissolved oxygen concentration gradient from outside to inside on a centimeter scale, and is beneficial to forming a rich anaerobic zone inside a filler core.

Furthermore, in the intermittent water feeding filler type biological rotating cage high-efficiency sewage treatment device provided by the application, microorganisms are attached to and grow on the surface of the biological filler, wherein the amount of biofilm-forming microorganisms is 5-15 g dry weight/liter of filler. Because the oxygen concentration is greatly different between the inner part and the outer part of the filler, the nitrification reaction is carried out in the aerobic area of the filler, and the denitrification reaction is carried out by the denitrifying polysaccharide bacteria in the anoxic area of the filler by utilizing the endogenous carbon source, thereby realizing the high-efficiency synchronous nitrification and denitrification in the reactor.

Secondly, the application also provides an application method for treating sewage by applying the intermittent water inlet filler type biological rotating cage device, which comprises the following specific steps:

(1) after biofilm formation is carried out on the surface of the filler by a conventional method in the field, the filler (biofilm formation microorganism amount is preferably 5-15 g dry weight/liter of filler) with microorganism loaded on the surface is filled into a biological rotating cage, and the biomass on the surface of the filler is 5-15 g dry weight/liter of filler; adding sludge into the anaerobic tank and the anoxic tank, wherein the sludge content is preferably 2000-40000 mg/L, and the sludge age is preferably 20-60 days;

(2) opening a water valve, and allowing sewage containing pollutants to enter an anaerobic tank from a main water inlet pipe, wherein the pollutants are aminated and hydrolyzed;

(3) the effluent of the anaerobic tank enters an anoxic tank through a pipeline, and organic matters in the effluent of the anaerobic tank and effluent (containing nitrate) flowing back to the anoxic tank from the reaction tank are mixed to generate denitrification reaction;

(4) the effluent of the anoxic tank enters a sedimentation tank, sludge is settled at the bottom of the sedimentation tank, and supernatant on the upper layer of the sedimentation tank enters a reaction tank through a drain pipe of a decanter, so that pollutants are further degraded under the action of a biofilm attached to the surface of a filler in a biological rotating cage in the reaction tank;

(5) the sludge precipitated in the sedimentation tank enters the anaerobic tank through a sludge return pipe and is mixed with the water entering the anaerobic tank;

(6) part of effluent (namely nitrifying liquid) of the reaction tank enters the anoxic tank through the nitrifying liquid return pipe, and the rest of effluent is discharged through the main water outlet pipe.

The above-mentioned sewage containing pollutants, wherein the pollutants refer to pollutants commonly found in current sewage treatment, such as NH₄ ⁺、NO₃ ^-、 NO₂ ^-And the like.

Further, in the method, the hydraulic retention time of the anaerobic tank is 1-2 h, the hydraulic retention time of the anoxic tank is 1-3 h, the hydraulic retention time of the biological rotating cage reactor is 3-6h, the hydraulic retention time of the sedimentation tank is consistent with that of the biological rotating cage, and the decanting time is 20-30 min; the longer the hydraulic retention time, the better the removal of the contaminants, and according to the measurement results of the examples, the contaminants in the reaction cell were continuously reduced in the first 3 hours, so the above time is preferred.

In the method, the concentration of the sludge in the anaerobic tank and the anoxic tank is preferably 2000-40000 mg/L, and the sludge age is preferably 20-60 days. In the specific implementation, the used sludge can be sludge generated by an anoxic tank or an aerobic tank of a common sewage plant, the biological membrane on the surface of the filler in the reaction tank can be cultured by sewage in the aerobic tank, and the biological rotating cage is placed after the membrane hanging is finished to maintain the operation of the reverse reactor.

Further, the sludge reflux ratio of the sedimentation tank is 75%, and the reflux ratio of the internal circulation nitrifying liquid is 100%.

Further, in the method, the rotating speed of the biological rotating cage reactor is 1-3 rpm, and the submergence ratio of the rotating cage is 40%.

Further, in the method, the ratio of the total volume of the filler in the cage of the biological rotating cage reactor to the volume of the reaction tank is 1: 1-1: 3.

In the application, the microorganism attached to the surface of the biological filler can be one or more of nitrobacteria (AOB and NOB), denitrifying bacteria, glycan bacteria and the like, and the microorganisms are conventional microbial flora in wastewater treatment. Wherein, the ratio of glycan bacteria (endogenous denitrifying bacteria) in the total flora is not less than 4% so as to improve the removal rate of total nitrogen; the glycan strain includes Candida species competitive (Candida species competitive, see "Mcilroy S J, Albertsen M, Andersen E K, et al." Candida species competitive from metallic species dependent catalytic conversion [ J ]. The ISME journal,2014,8(3): 613-.

Nitrifying bacteria, including AOB and NOB, oxidize ammonia nitrogen to nitrite and nitrate (e.g., nitrosolomas, see "Koops H,

B,

U,et al.Classification of eight new species of ammonia-oxidizing bacteria:Nitrosomonas communis sp.nov.,Nitrosomonas ureae sp. nov.,Nitrosomonas aestuarii sp.nov.,Nitrosomonas marina sp.nov.,Nitrosomonas nitrosa sp.nov.,Nitrosomonas eutropha sp.nov.,Nitrosomonas oligotropha sp.nov. and Nitrosomonas halophila sp.nov[J]microbiology,1991,137(7) 1689 and 1699; for example Nitrospira, see the literature "Watson S W, Bock E, Valois F W, et al Nitrospira marina gen. nov.sp.nov.: a chemical nitrile-oxidizing bacterium [ J].Archives of Microbiology,1986,144(1):1-7.”)

The method adopts the operation mode of an intermittent porous three-dimensional biological filler biological rotating cage reactor device, the biological rotating cage system operates under the condition of intermittent water inlet and outlet, the cooperation of the porous massive biological filler is beneficial to simultaneously obtaining high-concentration organic matters and anoxic areas in the biological filler, and the biological rotating cage can automatically enrich DGAOs in the operation process, so that the growth of glycan bacteria (GAOs) bacteria is promoted, and the denitrification is carried out by utilizing an endogenous carbon source, thereby improving the removal rate of total nitrogen; the reason is that the intermittent water inlet biological rotating cage is periodically changed due to the special water quality fluctuation, and particularly, the growth of microorganisms is promoted by instantaneous high-concentration organic carbon at the initial water inlet stage; meanwhile, the porous biological filler constructs a dissolved oxygen concentration gradient from outside to inside on a centimeter scale, which is beneficial to the enrichment and growth of glycan bacteria (GAOs) in a bacterial community inside the filler core. The denitrifying glycan bacteria (DGAOs) can realize synchronous nitrification and denitrification in the biological rotating cage reactor under aerobic conditions by utilizing an endogenous carbon source denitrification metabolic pathway, so that the capability of removing total nitrogen is better than that of continuous water inlet operation, and the efficiency can be improved by more than one time.

In addition, the intermittent water feeding filler type biological rotating cage efficient sewage treatment device provided by the application can be combined with a preposed anaerobic tank and an anoxic tank, so that the removal of total nitrogen can be further enhanced; the sedimentation tank has the function of regulating water quantity, and can be combined with a decanter to realize intermittent water inlet and outlet of the biological rotating cage.

The device is suitable for treating common organic wastewater such as domestic sewage, livestock wastewater and the like.

Compared with the prior art, the method creatively uses intermittent water inlet to create an environment beneficial to the growth of the polysaccharide bacteria, and then the polysaccharide bacteria are utilized to realize efficient removal of carbon and nitrogen pollutants; meanwhile, the PU filler is selected as the filler used in the biological rotating cage through selecting the filler, the polyurethane filler has high biological loading capacity due to large specific surface area, and compared with the traditional porous hollow sphere and HDPE filler, the porous hollow sphere and HDPE filler can avoid the reduction of the removal rate of pollutants in long-term operation and effectively solve the problem that the biological rotating cage biomembrane falls off in intermittent operation.

Compared with an aeration activated sludge process, the aerobic section adopts a biological rotating cage process, so that the energy is saved, a secondary sedimentation tank is not needed for yielding water, the capital construction cost is saved, the occupied area is small, and the aerobic section is more suitable for small-scale treatment of domestic sewage such as rural areas; the environment of instantaneous carbon source supply realized by intermittent water inflow is easy to establish an endogenous denitrifying glycan bacterial (DGAOs) denitrification system based on glycan bacteria (GAOs), and the microbial system can utilize the carbon source in sewage to the maximum extent for denitrification, reduce the input of an additional carbon source and reduce the emission of greenhouse gas; compared with the traditional continuous water inlet, under the condition that other operation conditions are not changed, the water inlet condition is changed into intermittent water inlet, the denitrification capacity can be improved by more than 1 time, the total nitrogen removal rate can reach more than 60-80%, the residual nitrified liquid flows back to the anoxic tank for denitrification, and the denitrification efficiency of the whole process can reach more than 90%.

Drawings

FIG. 1 is a schematic structural diagram of a biological rotating cage sewage treatment device based on intermittent water inflow.

In the figure: 1-anaerobic tank, 2-anoxic tank, 3-sedimentation tank, 4-reaction tank, 5-biological rotating cage, 6-sludge return pipe, 7-nitrifying liquid return pipe, 8-anaerobic tank stirrer, 9-anoxic tank stirrer, 10-decanter, 11-total water inlet pipe, 12-total water outlet pipe, 13-baffle plate, 14-draft tube, 15-underwater support, 16-drain pipe, 17-electric push rod, 18-water outlet weir, 19-overflow pipe, 20-variable speed motor, 21-transmission shaft, 22-feed inlet, 23-grid, 24-filter screen, 25-support, 26-water outlet pipe and 27-electromagnetic valve.

FIG. 2 is a schematic view of a draining device for rotary decanting water in a sedimentation tank according to the present invention.

FIG. 3 is a schematic view of a biotransformation cage monomer according to the present invention.

Fig. 4 shows the operation monitoring result of the biological rotating cage in one period.

FIG. 5 is a comparison of the removal of batch feed water at the treatment capacity during the first month after the start of the reactor run.

FIG. 6 shows the COD removal rate.

FIG. 7 shows the nitrate concentration.

Fig. 8 shows the total nitrogen removal capacity found after one month of operation of the biotransformation cage.

FIG. 9 shows the formation of biofilm for intermittent and continuous influent feed after 100 days of operation.

Detailed Description

The following embodiments are described in order to provide those skilled in the art with a more complete, accurate and thorough understanding of the inventive concepts and technical solutions of the present invention.

The filler used in the following examples is a polyurethane foam.

Example 1 intermittent water feeding filler type biological rotating cage high-efficiency sewage treatment device and application of device to remove total nitrogen in sewage

As shown in figure 1, the intermittent water inlet filler type biological rotating cage high-efficiency sewage treatment device comprises an anaerobic tank 1, an anoxic tank 2, a sedimentation tank 3 and a reaction tank 4; the water inlet of the anaerobic tank 1 is connected with a main water inlet pipe 11, and the water outlet is arranged above the inner wall and is connected with the water inlet of the anoxic tank 2 through a guide pipe 14; the water inlet of the anoxic tank 2 is arranged above the inner wall of the anoxic tank, the middle of the water inlet is provided with a baffle plate, and the water outlet is arranged above the inner wall opposite to the water inlet and is connected with the water inlet of the sedimentation tank 3 through a guide pipe 14; a water inlet of the sedimentation tank 3 is arranged above the inner wall, and a decanter 10 is arranged on the inner wall opposite to the water inlet; the decanter 10 is connected with the water inlet of the reaction tank 4 through a drain pipe 22; the water inlet of the reaction tank 4 is arranged above the inner wall, the water outlet is arranged below the inner wall opposite to the water inlet and is connected with the main water outlet pipe 26, and an overflow pipe 19 is also arranged above the inner wall of the reaction tank; the sedimentation tank 3 is connected with the anaerobic tank 1 through a sludge return pipe 6, the sludge return pipe 6 is provided with a return valve, and a part of sludge in the sedimentation tank 3 can return to the anaerobic tank 1 through the sludge return pipe 6; the anoxic tank 2 is connected with the reaction tank 4 through a nitrifying liquid return pipe 7;

as shown in fig. 2, in the present embodiment, the decanter 10 (rotary decanter) includes an underwater support 15, a drain pipe 16, an electric push rod 17, an effluent weir 18, and a support 25; the underwater support 15 is arranged on the inner wall of the sedimentation tank 3 and is rotationally connected with the effluent weir 18, the drain pipe 16 is positioned at the joint of the underwater support 13 and the effluent weir 18, the support 23 is arranged at the top end of the inner wall of the sedimentation tank 3, one section of the electric push rod 17 is movably connected with the effluent weir 18, the other end of the electric push rod is connected with a motor, the motor controls the electric push rod to rotate and drives the effluent weir 18 to rotate along the underwater support 15, and when the electric push rod 17 is positioned at a low water level, supernatant in the sedimentation tank 3 enters the drain pipe 16 through the effluent weir 18 and then enters the;

as shown in fig. 3, a biological rotating cage 5 is arranged in the reaction tank 4, the biological rotating cage 5 is a cylindrical cage body, and the reaction tank 4 is of a semi-cylindrical structure, and the shape of the reaction tank is matched with that of the biological rotating cage 5; a transmission shaft 21 and a corresponding bearing are axially arranged in the biological transmission cage, the transmission shaft 21 is movably connected with the inner wall of the reaction tank 4, and one end of the transmission shaft 21 penetrates through the outer side of the reaction tank 4 and is connected with a variable speed motor 20; a grid 23 is arranged inside the biological rotating cage 5, a filter screen 24 is covered on the surface of the biological rotating cage, and a feeding hole 22 is formed in the surface of the biological rotating cage; the filler with the surface attached with the microorganism is arranged inside the biological rotating cage 5 through the feed inlet 22; the effluent of the sedimentation tank is discharged into the reaction tank 4 through a drain pipe 16, and contacts with the filler in the biological rotating cage 5 after being slowly flowed by the baffle plate 13; the water outlet of the reaction tank 4 is intermittently controlled by an electromagnetic valve 27; in this embodiment, at least one partition plate is further disposed in the biological rotating cage 5.

In this embodiment, an anaerobic tank stirrer 8 is further arranged in the anaerobic tank 1, and an anoxic tank stirrer 9 is further arranged in the anoxic tank 2.

In this example, the biological filler usedIs made of porous polyurethane foam, and the size of a single filler is about 1-3cm³The cube of (1).

In the embodiment, the reaction tank 4 is a semi-cylindrical water tank phi 24cm multiplied by 25cm, the size of the biological rotating cage 5 is phi 20cm multiplied by 20cm, the aperture of the grid 23 and the aperture of the filter screen 24 are both phi 1.3cm, the grid 23 is used for dividing the interior of the object rotating cage 5 into 4 spaces, the size of the filler in the object rotating cage 5 is 1.5cm multiplied by 1.5cm, the filling volume of the filler is 4L, and the actual volume of the filler is 2.5L.

The effluent of the simulated anoxic pond is used as the influent of the biological rotating cage, the sewage is respectively treated by using an intermittent influent mode and a continuous influent mode, the biofilm on the filler in the biological rotating cage 5 is firstly loaded in an acrylic plate column reactor (purchased from Zhenjiang self-carrying vehicle industries, Ltd.) with the diameter of 9cm multiplied by 45cm, a film hanging method used by Hossain and the like (see documents 'Hossain M.I, Paparini A, Cord-Ruwisch R.2017, Rapid adaptation of activated sludge bacteria inter-ocular and microbiological culture method, Bioresource Technology, 2281-8' (in specific application, other conventional methods in the field can be adopted for film hanging) is adopted, the COD load is 0.15kgBOD/kg, MLSS/kg and MLSS/8 kg under the flow rate of the ammonia nitrogen load of 0.01kg and MLSS/kg, after 1-2 days, the biofilm can be successfully loaded, in this example, the biomass is 7g dry weight/L filler (in the specific operation, the microbial load on the surface of the filler is in the range of 5-15 g dry weight/L filler, which can achieve the purpose of the invention).

In the embodiment, the sewage is taken from an aerobic tank of a second sewage treatment plant in the Jing district of Zhenjiang city; the sludge in the anaerobic tank 1 and the anoxic tank 2 is also taken from an aerobic tank of a second sewage treatment plant in the Jing district of Zhenjiang city, the sludge age is 20 days (in specific implementation, the sludge age can be selected to be 20-60 days), and common heterotrophic bacteria OHO and nitrobacteria NOB are taken as main microorganisms in the sludge liquid.

In this embodiment, the sewage treatment operation steps are as follows:

(1) filling the filler after film forming into a biological rotating cage 5; adding sludge into the anaerobic tank 1 and the anoxic tank 2, wherein the concentration of the added sludge is about 10g/L (in specific application, the concentration of the sludge in the anaerobic tank and the anoxic tank can be selected within 2000-40000 mg/L according to actual conditions);

(2) opening a valve, leading the sewage to enter the anaerobic tank 1 from the main water inlet pipe 11, and ammoniating and hydrolyzing pollutants in the sewage;

(2) the effluent of the anaerobic tank 1 enters the anoxic tank 2 through a pipeline, and organic matters in the effluent of the anaerobic tank 1 and the effluent (namely nitrifying liquid containing nitrate) flowing back to the anoxic tank 2 from the reaction tank 4 are mixed to carry out denitrification reaction;

(3) the effluent of the anoxic tank 2 enters a sedimentation tank 3, sludge is settled at the bottom of the sedimentation tank 3, the supernatant of the sedimentation tank 3 enters a reaction tank 4 through a drain pipe 14 of a decanter 10, and pollutants are further degraded under the action of a biofilm attached to the surface of a filler in a biological rotating cage 5;

(4) sludge precipitated in the sedimentation tank 3 enters the anaerobic tank 1 through a sludge return pipe 6 to be mixed with the water entering the anaerobic tank;

(5) part of effluent water of the reaction tank 4 enters the anoxic tank 2 through the nitrifying liquid return pipe 7, and the rest of effluent water is discharged through the main water outlet pipe 12.

The device and the method are applied to detecting the effluent quality as follows:

(1) the effluent from anoxic tank 2 (biological rotating cage 5 reactor influent) is shown in table 1 below:

TABLE 1 samples of influent

(2) The removal rate calculation method comprises the following steps:

(3) the hydraulic and operating conditions of the system are as follows:

in this embodiment, the hydraulic retention time of the anaerobic tank 1 is 2 hours, the hydraulic retention time of the anoxic tank 2 is 2 hours, the hydraulic retention time of the biological rotating cage reactor 5 is 6 hours, and the decanting time is 10 minutes. The sludge concentration of the anaerobic tank 1 is 10g/L, the sludge concentration of the anoxic tank 2 is 10g/L, and the sludge age is 20 days. The sludge reflux ratio of the sedimentation tank 3 is 50 percent, and the reflux ratio of the internal circulation nitrifying liquid is 100 percent.

(4) Biological rotating cage reactor: the rotation speed is 3rpm, and the immersion ratio is 40%.

The polyurethane foam filler is transferred into a biological rotating cage after being filmed, the biological rotating cage 5 intermittently feeds water, the water feeding time is 10min, the flow rate is 24L/h, the hydraulic retention time is 6h, and the water treatment amount in one period is 4L.

(4) The biological rotating cage reactor with intermittent water feeding has the following pollutant concentration change conditions in one period:

the results of monitoring the operation of the biological rotating cage in one period are shown in fig. 4, the change of the COD concentration in the sewage reaches the lowest value basically 0.5 hour after water inlet, however, the total nitrogen concentration is still continuously reduced in the subsequent operation, which shows that the denitrification reaction is continuously performed on the microbial membrane, and a certain amount of organic matters for maintaining denitrification are used as energy sources.

(5) The embodiment compares the running conditions of the biological rotating cage in the continuous water inlet mode with the same period, wherein the biological rotating cage device for continuously feeding water is the same as the device for continuously feeding water, the biological membrane loading mode is the same as the device for continuously feeding water, and the water quality, the hydraulic retention time, the rotating speed and the like of the water feeding are the same as the device for continuously feeding water. The only difference is that: the flow rate of the water inflow in the continuous mode is 11.1mL/min, so that the amount of the water treated in the reactor for 6 hours is the same as that of the batch biological rotating cage. The batch feed water removal rate profile for the first month of processing capacity after the start of reactor operation is shown in fig. 5.

In fig. 5, a is a continuous water inflow detection result, and B is an intermittent water inflow detection result. As can be seen from the detection results in FIG. 5, the biological rotating cage with intermittent water feeding operation has obvious advantages in total nitrogen removal capability compared with the biological rotating cage with continuous water feeding, the total nitrogen removal efficiency is increased by 100%, and COD and ammonia nitrogen both reach the first-level A standard of pollutant discharge Standard of urban wastewater treatment plant. Meanwhile, the load-shedding conditions of the biological films on the surfaces of the two groups of fillers are not different.

Example 2 capacity of biological rotating cage reactor for actual sewage treatment:

the reaction apparatus of this example is the same as that of example 1, except that the wastewater to be treated is taken from the effluent of the anoxic tank of the second wastewater treatment plant in the Jing district of Zhenjiang City, and the sludge in the anaerobic tank 1 and the anoxic tank 2 is also from the anoxic tank of the second wastewater treatment plant in the Jing district of Zhenjiang city, and the sludge age is 30 days.

Biological rotating cage reactor: the rotating speed is 3rpm, and the immersion ratio is 40%; the biological rotating cage reactor is intermittently fed with water, the water feeding time is 10min, the water decanting time is 10min, and the hydraulic power stays for 6 hours.

The hydraulic retention time of the anaerobic tank 2 is 2 hours, the hydraulic retention time of the anoxic tank 2 is 2 hours,

the sludge concentration of the anaerobic tank 1 is 10g/L, the sludge concentration of the anoxic tank 2 is 10g/L, the sludge reflux ratio of the sedimentation tank 3 is 50%, and the internal circulation nitration liquid reflux ratio is 100%.

The water inlet and outlet data of the biological rotating cage 5 are shown in the following table 2:

TABLE 2

The effluent results of the biological rotating cage 5 are shown in fig. 6 and 7, COD and ammonia nitrogen both reach the first-level A standard, the effluent quality detection is the same as that after the simulated wastewater treatment in the example 1, and the intermittent total nitrogen removal rate is 2 times of the continuous total nitrogen removal rate.

Example 3 high-efficiency Total Nitrogen removal in high Biomass batch-type influent biological rotating cage reactor treatment of wastewater

The influent water sample of the biological rotating cage reactor of this example is shown in Table 3 below:

TABLE 3

(1) Biological rotating cage reactor: the rotating speed is 3rpm, and the immersion ratio is 40%;

and transferring the polyurethane foam filler into a biological rotating cage after film formation (the film formation method is the same as that in example 1), wherein water is intermittently fed, the water feeding time is 10min, and the hydraulic retention time is 6h (other operation parameters are the same as those in example 1).

(3) High biomass intermittent water inlet biological rotating cage reactor sewage treatment capacity detection

By increasing the biofilm formation biomass (from 7g/L filler to about 10g/L filler) starting on day 22, a further increase in total nitrogen removal capacity was found after one month of operation, from an initial average of 60% to an average of 80% (fig. 8).

EXAMPLE 4 biofilm formation in batch influent biological rotating cage reactor

(1) The influent water sample of the biological cage reactor of this example is shown in table 4 below:

TABLE 4

(2) Biological rotating cage reactor: the rotation speed is 3rpm, and the immersion ratio is 40%.

Transferring the polyurethane foam filler (7g/L) after film hanging into a biological rotating cage, and intermittently feeding water for 10min and 6 h; the other reaction parameters were the same as in example 1. The quality of the outlet water after stable operation is consistent with that of the outlet water in the embodiment 1.

(3) The difference between the biofilm formation of the intermittent and continuous influent after 100 days of operation (FIG. 9) was determined by Nanjing Centipeda Biotech Co., Ltd and the biofilm microbial community analysis was performed as described in the literature (Hossain M I.evaluation and evaluation of passive aeration and differentiation (PASND) in a biological reactor for Low-Energy water waste treatment [ D ]. Murdoch University, 2017.).

FIG. 9 shows that the abundance of Candida within biofilms in batch-fed biotransporters was increased by about 27-fold (from 0.15% to 4.02%) compared to biofilms in conventional continuous-fed biotransporters, whereas the abundance of denitrifying polysaccharide bacteria defluviveccus was increased by about 8-fold (from 0.01% to 0.08%), and the proportion of total polysaccharide bacteria in the biocenosis was increased by 3.96%. Common bacteria in the conventional biological rotating disc comprise common heterotrophic bacteria OHO, nitrosobacteria AOB and nitrobacteria NOB, and the intermittent biological rotating cage is different from the conventional biological rotating disc in that the intermittent biological rotating cage can enrich glycan bacteria, and simultaneously, sewage in the biological rotating cage box body has no pollutant concentration gradient in the intermittent environment, so that the uniformity of oxygen concentration is realized, and an anoxic zone inside the filler is reserved.

In general, the content of GAO in the biofilm in the batch-type influent biological rotating cage reactor is increased by about 4% compared with the biofilm in the ordinary continuous influent biological rotating cage. Common bacteria in the conventional biological transfer cage include common heterotrophic bacteria, ammonia oxidizing bacteria AOB and nitrite oxidizing bacteria NOB, and the intermittent biological transfer cage is different from the conventional biological transfer cage in that the intermittent biological transfer cage can enrich glycan bacteria.

The foregoing illustrates and describes the principles, general features, and advantages of the present invention. It should be understood by those skilled in the art that the above embodiments do not limit the present invention in any way, and all technical solutions obtained by using equivalent alternatives or equivalent variations fall within the scope of the present invention.

Claims

1. An intermittent water inlet filler type biological rotating cage high-efficiency sewage treatment device is characterized by comprising an anaerobic tank, an anoxic tank, a sedimentation tank and a reaction tank;

the water inlet of the anaerobic tank is connected with the main water inlet pipe, and the water outlet of the anaerobic tank is arranged above the inner wall of the anaerobic tank and is connected with the water inlet of the anoxic tank through the flow guide pipe; the water inlet of the anoxic tank is arranged above the inner wall of the anoxic tank, the middle of the water inlet of the anoxic tank is provided with a baffle plate, and the water outlet of the anoxic tank is arranged above the inner wall of the anoxic tank relative to the water inlet of the anoxic tank and is connected with the water inlet of the sedimentation tank through a guide pipe; the water inlet of the sedimentation tank is arranged above the inner wall, and a decanter is arranged on the inner wall of the sedimentation tank opposite to the water inlet of the sedimentation tank; the decanter is connected with the water inlet of the reaction tank through a drain pipe; the water inlet of the reaction tank is arranged above the inner wall of the reaction tank, the water outlet is arranged below the inner wall of the reaction tank opposite to the water inlet and is connected with the main water outlet pipe, and the overflow pipe is also arranged above the inner wall of the reaction tank;

the sedimentation tank is connected with the anaerobic tank through a sludge return pipe, and the anoxic tank is connected with the reaction tank through a nitrifying liquid return pipe;

a matched biological rotating cage is arranged in the reaction tank, a transmission shaft and a corresponding bearing are axially arranged in the biological transmission cage, the transmission shaft is movably connected with the inner wall of the reaction tank, and one end of the transmission shaft penetrates through the outer side of the reaction tank and is connected with a variable speed motor; the inside of biological rotating cage is equipped with the grid, and the surface covers the filter screen, and the cage body surface is equipped with the feed inlet.

2. The intermittent water inlet stuffing type biological rotating cage high-efficiency sewage treatment device according to claim 1, wherein the decanter comprises an underwater support, a water outlet pipe, an electric push rod, a water outlet weir and a support, the underwater support is arranged on the inner wall of the sedimentation tank and is rotationally connected with the water outlet weir, the water outlet pipe is arranged at the joint of the underwater support and the water outlet weir, the support is arranged at the top end of the inner wall of the sedimentation tank, one section of the electric push rod is movably connected with the water outlet weir, the other end of the electric push rod is connected with a motor, and the motor controls the electric push rod to rotate and drives the water outlet weir to rotate.

3. The intermittent water feeding filler type biological rotating cage high-efficiency sewage treatment device according to claim 1, wherein the anaerobic tank is further provided with an anaerobic tank stirrer, the anoxic tank is further provided with an anoxic tank stirrer, and the sludge return pipe is provided with a return valve.

4. The device for high-efficiency sewage treatment by the biological rotating cage with the intermittent water feeding stuffing according to claim 1, wherein at least one clapboard is arranged in the biological rotating cage.

5. The intermittent water feeding stuffing type biological rotating cage high-efficiency sewage treatment device according to claim 1, wherein the stuffing shape is 1-3cm³The cube of (1).

6. A method for treating sewage by using the intermittent water feeding filler type biological rotating cage high-efficiency sewage treatment device as claimed in any one of claims 1 to 5 is characterized by comprising the following specific steps:

1) filling a filler with the surface loaded with microorganisms into a biological rotating cage, and adding sludge into an anoxic tank and an anaerobic tank;

2) sewage containing pollutants enters the anaerobic tank from the main water inlet pipe, and the pollutants are aminated and hydrolyzed in the anaerobic tank;

3) the effluent of the anaerobic tank enters the anoxic tank through a pipeline, and organic matters in the effluent of the anaerobic tank are mixed with the effluent returned to the anoxic tank by the reaction tank to generate denitrification reaction;

4) the effluent of the anoxic tank enters a sedimentation tank, sludge in the effluent is settled at the bottom of the sedimentation tank, and supernatant on the upper layer of the sedimentation tank enters a reaction tank through a decanter, so that pollutants are further degraded under the action of a biofilm attached to the surface of filler in a biological rotating cage;

5) sludge in the sedimentation tank enters the anaerobic tank through a sludge return pipe and is mixed with inlet water of the anaerobic tank;

6) part of effluent of the reaction tank enters the anoxic tank through the nitrifying liquid return pipe, and the rest of effluent is discharged through the main water outlet pipe.

7. The method of claim 6, wherein the filler surface-loaded with microorganisms of step 1) is a filler having a biomass on the surface of 5 to 15 g dry weight per liter of filler.

8. The method of claim 7, wherein the anaerobic tank is hydraulically stayed for 1-2 h, the anoxic tank is hydraulically stayed for 1-3 h, the biological rotating cage is hydraulically stayed for 3-6h, the hydraulic retention time of the sedimentation tank is consistent with that of the biological rotating cage, and the water decanter is hydraulically stayed for 20-30 min.

9. The method of claim 7, wherein the rotating speed of the biological rotating cage is 1-3 rpm, and the submergence ratio of the rotating cage is 40%.

10. The method of claim 7, wherein the ratio of the total volume of the packing to the volume of the reaction cell is 1:1 to 3.