CN108975599A - Reed wetland sewage purification system and effluent purification method - Google Patents

Abstract

The present invention relates to a kind of reed wetland sewage purification systems, including the first wetland pond, grille well, conditioning tank, anaerobic pond, anoxic pond, aerobic tank, sedimentation basin, the second wetland pond, the third wetland pond being sequentially connected；First wetland pond, grille well, conditioning tank are arranged from high to low；Anaerobic pond, anoxic pond, aerobic tank, sedimentation basin are arranged from high to low；Second wetland pond and third wetland pond are arranged from high to low.Setting mixes return pipe between the end of aerobic tank and the front end of anoxic pond, and the first water quality detection well is arranged between the water outlet in the second wetland pond and the water inlet in third wetland pond, and the second water quality detection well is arranged in the water outlet end in third wetland pond.Purification system of the invention reduces utilization and the site operation personnel of mechanical equipment, increases the design of reflux, improve Nitrogen/Phosphorus Removal using stepped design.

Description

Reed wetland sewage purification system and sewage purification method

technical field

The invention belongs to the technical field of sewage purification, and in particular relates to a reed wetland sewage purification system and a sewage purification method.

Background technique

In the past ten years, the water quality of some coastal areas in my country has gradually deteriorated, and red tide ecological disasters have occurred frequently, posing a great threat to the economic development of the coastal zone and people's living standards. The reason is that a large number of pollutants carried by urban domestic sewage, industrial wastewater and farmland water are important sources of pollution that lead to eutrophication of water bodies and deterioration of water quality. In particular, the excessive nitrogen and phosphorus content in wastewater can stimulate the explosive growth of algae in spring and summer, resulting in serious algal blooms, and its harm has aroused widespread concern among coastal people. Government departments and scientific researchers are also making great efforts to control the eutrophication of water bodies.

Wetlands, forests, and oceans are listed as the three major types of ecosystems in the world. It is a unique ecosystem formed by the interaction of water and land. It has extremely high biodiversity and biological productivity, and has strong self-purification and sewage purification capabilities. Therefore, Known as the "kidney of the earth". How to use the "kidney of the earth" to purify urban domestic sewage, industrial wastewater and farmland water to serve the society has become a hot issue in the development of wetland service functions.

In recent years, reed wetlands have begun to be used for sewage treatment. Because of their advantages of low cost, green and environmental protection, and avoiding the defects of conventional sewage treatment plants, such as high cost, high energy consumption, and complicated operation and management, it is gradually becoming an efficient More and more attention has been paid by researchers and government departments to the bioremediation approach. Reed wetland sewage treatment technology utilizes the synergy of physical, chemical, biological and other multiple processes in multi-circle ecosystems such as terrestrial vegetation, soil microorganisms, and water plankton in artificial or natural wetlands to treat impurities and harmful elements in sewage. Treatment, its action mechanism includes various biochemical actions such as retention, filtration, adsorption, redox, precipitation, microbial decomposition, degradation transformation, plant absorption, residue accumulation, etc., is an extremely complex process. And the technology itself needs to be combined with other sewage treatment technologies to achieve better results. Therefore, the reed wetland sewage treatment technology is often a comprehensive and multivariate systemic technology, and different design methods need to be adopted according to the source, specific nature and pollution status of sewage.

The survey found that the existing wetland sewage treatment technology has the following problems: (1) Excessive use of mechanical equipment in the wetland treatment system increases energy consumption and costs in a disguised form. For example, in the past, many sewage pumps were often used to transfer sewage from different units, and the operation of sewage pumps required personnel or automatic systems, and also consumed electricity, which undoubtedly increased operating costs. (2) There is a lack of scientific monitoring of the effect of sewage treatment, and there is often a lack of nodes for testing water quality during the treatment process. Therefore, it is not very clear how effective the sewage system treatment system is. (3) Lack of reflux equipment for nitrogen and phosphorus removal. In sewage treatment, the "anaerobic tank-anoxic tank-aerobic tank" (A/A/O) system is a key process for nitrogen and phosphorus removal, but many designs lack the design for the reflux of the effluent from the aerobic tank , which limits the effectiveness of the process of "anaerobic pool - anoxic pool - aerobic pool". (4) The effect of nitrogen and phosphorus removal and sewage treatment is not ideal, and the maintenance cost is high, requiring personnel to operate on-site for a long time.

Contents of the invention

In view of the above-mentioned problems of high operating cost, nitrogen and phosphorus removal and unsatisfactory sewage treatment effect of the existing wetland sewage treatment system, the present invention provides a reed wetland sewage purification system, which has the advantages of simple structure, energy saving, small footprint and high efficiency. High, wide application range, long service life, safe and reliable; the invention also provides a method for purifying sewage by using reed wetlands, using a stepped design, reducing the use of mechanical equipment and on-site operators, increasing the design of backflow, and improving Nitrogen and phosphorus removal effect.

The present invention is achieved through the following technical solutions:

A reed wetland sewage purification system, comprising a first wetland pool, a grid well, a regulating pool, an anaerobic pool, an anoxic pool, an aerobic pool, a sedimentation pool, a second wetland pool, and a third wetland pool;

The first wetland pool is provided with a water inlet and a water outlet, and the water outlet is connected to the water inlet of the grid well, and the water outlet of the grid well is set at the bottom of the grid well to connect with the regulating pool, and the regulating pool is connected to the anaerobic pool through a water pipe. The front end of the anoxic pool is connected, and the first sewage pump is installed on the water pipe; the outlet of the anaerobic pool is connected with the water inlet of the anoxic pool, the outlet of the anoxic pool is connected with the water inlet of the aerobic pool, and the end of the aerobic pool is connected with the anoxic pool. A mixing return pipe is arranged between the front ends of the pool, and a second sewage pump is arranged on the mixing return pipe; the outlet of the aerobic pool is connected to the sedimentation tank, and the sedimentation tank is connected to the water inlet of the second wetland pool through a water pipe, and a third sewage pump is installed on the water pipe. Sewage pump; the water outlet of the second wetland pool is connected to the water inlet of the third wetland pool, and the first water quality testing well is set between the two, and a detector is installed in the water quality testing well; the water outlet of the third wetland pool is equipped with a second The water quality testing well, the second water quality testing well is connected to the water outlet pipe, and the valve is set on the water outlet pipe;

The first wetland pool, the second wetland pool and the third wetland pool are all provided with biological substrates, reeds grow on the biological substrates, and the water inlet and water outlet are respectively arranged above and below the biological substrates;

The first wetland pool, grid well, and regulating pool are arranged from high to low; the anaerobic pool, anoxic pool, aerobic pool, and sedimentation pool are arranged from high to low; the second wetland pool and the third wetland pool are arranged to low profile.

A method for purifying sewage by using reed wetlands, comprising the following steps:

(1) Introduce the sewage into the first wetland pool, plant reeds in the first wetland pool, fill the bottom with biological matrix materials, the sewage flows through the roots of the reeds and the surface of the matrix, and then automatically flows into the grid well;

(2) A grid is arranged in the grid well to trap larger suspended solids or particles in the water body, and the sewage automatically flows into the regulating tank from the outlet pipe at the bottom of the grid;

(3) The adjustment tank is connected to the first sewage pump, and the first sewage pump adjusts the flow of sewage and lifts it into the anaerobic tank;

(4) In the anaerobic tank, the refractory high-molecular organic matter in the sewage is transformed into a low-molecular organic matter that is easily degraded;

(5) The sewage enters the anoxic pool automatically from the bottom of the anaerobic pool, and the sewage is denitrified in the anoxic pool;

(6) The sewage enters the aerobic pool automatically from the bottom of the anoxic pool, and the organic matter in the sewage is further decomposed into inorganic matter; the sewage at the end of the aerobic pool is returned to the front end of the anoxic pool by the second sewage pump;

(7) Sewage from the aerobic tank automatically enters the sedimentation tank for preliminary precipitation, and some mineralized substances or sludge or particles that cannot undergo biochemical reactions are precipitated;

(8) The settled sewage is lifted to the second wetland pool through the third sewage pump, and through the double filtration and biochemical reaction of reeds and biological substrates, the excess nitrogen, phosphorus, silicon and heavy metal pollutants in the sewage are removed;

(9) The sewage that automatically flows out of the second wetland pool passes through the first water quality testing well, and the water quality detector performs real-time online water quality sampling and testing; then the sewage automatically enters the third wetland pool, undergoes filtration and biochemical treatment again, and finally automatically It flows into the second water quality testing well, and flows out after being tested by the water quality testing instrument.

Further, the dissolved oxygen content in the anaerobic pool is controlled below 0.2mg/L, the dissolved oxygen content in the anoxic pool is controlled at 0.4mg/L-0.6mg/L, and the dissolved oxygen in the aerobic pool The content is controlled at 2mg/L-5mg/L.

The reed wetland sewage purification system and the sewage treatment method provided by the present invention have the following beneficial effects:

(1) All key units adopt a stepped design, using natural gravity to drive water flow, reducing the use of mechanical equipment and on-site operators, achieving the effect of saving energy, reducing consumption, and reducing operating costs.

(2) A reed wetland pool is added in front of the grid well to effectively slow down the water flow velocity. At the same time, the filter function and mechanical blocking effect of the reed itself are used to block the large sewage impurities outside the grid well and reduce the water flow rate of the grid well. pressure.

(3) The mixed liquid reflux design of "the end of the aerobic pool → the front end of the anoxic pool" can achieve better nitrogen and phosphorus removal effects.

(4) Water quality testing wells were added between the two wetland pools and at the back end of the wetland pool for sewage treatment, and automatic water quality detectors were used to detect the effect of sewage treatment on-line to ensure that the sewage treatment results meet the discharge standards.

The present invention makes full use of the synergistic effect of physical, chemical, biological and other multiple processes in multi-circle ecosystems such as reed vegetation, soil microorganisms, and water body plankton in artificial/natural wetlands to process impurities and harmful elements in sewage; it has a structure Simple and ingenious use of gravity to save energy, small footprint, high efficiency, wide application range, etc., long practical life, safe and reliable performance and function.

Description of drawings

Fig. 1 is a schematic structural diagram of the reed wetland sewage purification system in Embodiment 1.

In the figure: 1. The first wetland pool; 2. Grid well; 3. Regulating pool; 4. Anaerobic pool; 5. Anoxic pool; 6. Aerobic pool; 7. Sedimentation pool; 8. Second wetland pool 9. The third wetland pool; 10. The first sewage pump; 11. The mixed return pipe; 12. The second sewage pump; 13. The third sewage pump; 14. The first water quality testing well; 15. The second water quality testing well ; 16, outlet pipe; 17, valve; 18, biological matrix; 19, reed.

Detailed ways

The present invention will be described in further detail below in conjunction with specific embodiments and accompanying drawings.

Example 1

This embodiment provides a reed wetland sewage purification system, as shown in Figure 1, including a first wetland pool 1, a grid well 2, a regulating pool 3, an anaerobic pool 4, an anoxic pool 5, and an aerobic pool connected in sequence 6. Sedimentation pond 7, second wetland pond 8, and third wetland pond 9. The arrows in the figure indicate the direction of water flow.

The first wetland pool, grid well, and regulating pool are arranged from high to low; the anaerobic pool, anoxic pool, aerobic pool, and sedimentation pool are arranged from high to low; the second wetland pool and the third wetland pool are also arranged from Arranged from high to low. The stepped design makes each unit have a certain height difference, so that gravity can be used to promote the automatic flow of water, thereby reducing the frequency of use of the sewage pump.

The first wetland pool 1 is provided with a water inlet and a water outlet, and a biological matrix 18 is set at the bottom. The biological matrix 18 can satisfy the basic growth of reeds, but the nitrogen and phosphorus content is not rich. Reeds 19 grow on the biological matrix, and the water inlet is set at the bottom of the biological matrix 18. Above, the water outlet is set under the biological matrix 18 , and the water outlet is connected to the water inlet of the grid well 2 . The reed wetland pool 1 is set in front of the grid well 2, which can effectively slow down the water flow speed, and at the same time, use the filtering function and mechanical blocking function of the reed itself to block the larger sewage impurities, such as foam plastic bags and larger suspended solids. outside the grill well, thereby relieving the pressure on the grill well.

The water outlet of the grid well 2 is set at the bottom of the grid well 2 and is connected with the adjustment tank 3. The adjustment tank 3 is connected with the front end of the anaerobic tank 4 through a water pipe, and the first sewage pump 10 is arranged on the water pipe. The water outlet is connected to the water inlet of the anoxic pool 5, and the water outlet of the anoxic pool 5 is connected to the water inlet of the aerobic pool 6, and a mixing return pipe 11 is set between the end of the aerobic pool 6 and the front end of the anoxic pool 5, A second sewage pump 12 is arranged on the mixing return pipe 11 . The mixed liquid reflux design of "the end of the aerobic pool → the front end of the anoxic pool" can achieve better nitrogen and phosphorus removal effects.

The water outlet of the aerobic pool 6 is connected with the sedimentation tank 7, and the third sewage pump 13 is installed in the sedimentation tank 7, and the third sewage pump 13 is connected with the water inlet of the second wetland pool 8 through a water pipe, and the water outlet of the second wetland pool 8 It is connected with the water inlet of the third wetland pool 9. The structure of the second wetland pool and the third wetland pool is the same as that of the first wetland pool, and biological matrix and reeds are arranged inside. In the sewage treatment unit of the wetland pool, the design of connecting multiple wetland pools is adopted: the wetland pool in the front section makes full use of the well-developed root system of the reed wetland and the microorganisms proliferating in the rhizosphere to quickly degrade the organic matter in the sewage and purify the sewage; The oxygen released by the reeds in the wetland pool diffuses into the water, forming many anoxic and aerobic zones at the bottom of the water body. In the aerobic zone, through the action of aerobic microorganisms attached to the root system, the organic matter in the sewage is decomposed, and part of the mineralized inorganic matter (such as nitrogen and phosphorus) can be used by plants; Nitrification and denitrification, so that sewage can be purified. After the above two purifications, the sewage treatment effect is more ideal.

A first water quality testing well 14 is set between the water outlet of the second wetland pool 8 and the water inlet of the third wetland pool 9, and a detector is set in the first water quality testing well; a second water quality testing is set at the water outlet of the third wetland pool 9 The well 15 and the second water quality detection well are connected to a water outlet pipe 16, and a valve 17 is arranged on the water outlet pipe. Water quality detection wells are designed between the two wetland pools and at the end of the wetland pool, and the automatic water quality online detector is used to detect the water quality in real time, thereby reducing labor costs and ensuring the effect of sewage treatment.

Example 2

This embodiment provides a method for purifying sewage by using reed wetlands, including the following steps:

(1) The sewage is introduced into the first wetland pool 1, reeds are planted in the first wetland pool 1, the bottom is filled with biological matrix materials, the sewage flows through the roots of the reeds and the surface of the matrix, and then automatically flows into the grid well 2;

(2) A grid is arranged in the grid well 2 to trap larger suspended solids or particles in the water body, and the sewage automatically flows into the regulating tank 3 from the outlet pipe at the bottom of the grid well;

(3) The adjustment pool 3 is connected to the first sewage lifting pump 10, and the first sewage pump 10 lifts the sewage into the anaerobic pool 4;

(4) control the content of dissolved oxygen in the anaerobic tank 4 at 0.1 mg/L, and the refractory high-molecular organic matter in the sewage is converted into an easily degradable low-molecular organic matter;

(5) sewage enters in the anoxic pond 5 automatically from the bottom of the anoxic pond 4, controls the content of dissolved oxygen in the anoxic pond 5 at 0.5 mg/L, and denitrification occurs in the sewage in the anoxic pond 5;

(6) sewage enters in the aerobic pond 6 automatically from the bottom of the anoxic pond 5, and the content of dissolved oxygen in the aerobic pond 6 is controlled at 4mg/L, and the organic matter in the sewage is further decomposed into inorganic matter; the aerobic pond 6 The sewage at the end flows back to the front end of the anoxic pool 5 through the second sewage pump 12;

(7) The sewage enters the sedimentation tank 7 from the aerobic pool 6 for initial precipitation, and some mineralized substances or sludge or particles that cannot undergo biochemical reactions are deposited;

(8) The settled sewage is lifted to the second wetland pool 8 through the third sewage pump 13, and through double filtration and biochemical reaction of reeds and biological substrates, excess nitrogen, phosphorus, silicon and heavy metal pollutants in the sewage are removed ;

(9) The sewage automatically flowing out of the second wetland pool 8 passes through the first water quality detection well 14, and the water quality detector performs online water quality sampling and testing in real time; then, the sewage automatically enters the third wetland pool 9, and is filtered and biochemically processed again. processing, and finally automatically flows into the second water quality testing well 15, and flows out from the water outlet pipe 16 after the water quality testing instrument is qualified.

The above-mentioned embodiments are only descriptions of preferred implementations of the present invention, and are not intended to limit the scope of the present invention. Variations and improvements should fall within the scope of protection defined by the claims of the present invention.

Claims (3)

1. A reed wetland sewage purification system is characterized in that it comprises the first wetland pond, grid well, regulating pond, anaerobic pond, anoxic pond, aerobic pond, sedimentation pond, second wetland pond, The third wetland pool; The first wetland pool is provided with a water inlet and a water outlet, and the water outlet is connected to the water inlet of the grid well, and the water outlet of the grid well is set at the bottom of the grid well to connect with the regulating pool, and the regulating pool is connected to the anaerobic pool through a water pipe. The front end of the anoxic pool is connected, and the first sewage pump is installed on the water pipe; the outlet of the anaerobic pool is connected with the water inlet of the anoxic pool, the outlet of the anoxic pool is connected with the water inlet of the aerobic pool, and the end of the aerobic pool is connected with the anoxic pool. A mixing return pipe is arranged between the front ends of the pool, and a second sewage pump is arranged on the mixing return pipe; the outlet of the aerobic pool is connected to the sedimentation tank, and the sedimentation tank is connected to the water inlet of the second wetland pool through a water pipe, and a third sewage pump is installed on the water pipe. Sewage pump; the water outlet of the second wetland pool is connected to the water inlet of the third wetland pool, and the first water quality testing well is set between the two, and a detector is installed in the water quality testing well; the water outlet of the third wetland pool is equipped with a second The water quality testing well, the second water quality testing well is connected to the water outlet pipe, and the valve is set on the water outlet pipe; The first wetland pool, the second wetland pool and the third wetland pool are all provided with biological substrates, reeds grow on the biological substrates, and the water inlet and water outlet are respectively arranged above and below the biological substrates; The first wetland pool, grid well, and regulating pool are arranged from high to low; the anaerobic pool, anoxic pool, aerobic pool, and sedimentation pool are arranged from high to low; the second wetland pool and the third wetland pool are arranged to low profile. 2. A method for utilizing reed wetlands to purify sewage, is characterized in that, comprises the following steps: (1) Introduce the sewage into the first wetland pool, plant reeds in the first wetland pool, fill the bottom with biological matrix materials, the sewage flows through the roots of the reeds and the surface of the matrix, and then automatically flows into the grid well; (2) A grid is arranged in the grid well to trap larger suspended solids or particles in the water body, and the sewage automatically flows into the regulating tank from the outlet pipe at the bottom of the grid; (3) The adjusting tank is connected with the first sewage pump, and the first sewage pump lifts and regulates the sewage into the anaerobic tank; (4) In the anaerobic tank, the refractory high-molecular organic matter in the sewage is transformed into a low-molecular organic matter that is easily degraded; (5) The sewage enters the anoxic pool automatically from the bottom of the anaerobic pool, and the sewage is denitrified in the anoxic pool; (6) The sewage enters the aerobic pool automatically from the bottom of the anoxic pool, and the organic matter in the sewage is further decomposed into inorganic matter; the sewage at the end of the aerobic pool is returned to the front end of the anoxic pool by the second sewage pump; (7) Sewage from the aerobic tank automatically enters the sedimentation tank for preliminary precipitation, and some mineralized substances or sludge or particles that cannot undergo biochemical reactions are precipitated; (8) The settled sewage is lifted to the second wetland pool through the third sewage pump, and through the double filtration and biochemical reaction of reeds and biological substrates, the excess nitrogen, phosphorus, silicon and heavy metal pollutants in the sewage are removed; (9) The sewage that automatically flows out of the second wetland pool passes through the first water quality testing well, and the water quality detector performs real-time online water quality sampling and testing; then the sewage automatically enters the third wetland pool, undergoes filtration and biochemical treatment again, and finally automatically It flows into the second water quality testing well, and flows out after being tested by the water quality testing instrument. 3. the method for purifying sewage according to claim 2, is characterized in that, the content of the dissolved oxygen in the described anaerobic pond is controlled below 0.2mg/L, and the content of the dissolved oxygen in the anoxic pond is controlled at 0.4mg /L-0.6mg/L, the content of dissolved oxygen in the aerobic pool is controlled at 2mg/L-5mg/L.