CN110745958B - Subsurface flow constructed wetland system for enhancing denitrification and unpowered reoxygenation and application thereof - Google Patents
Subsurface flow constructed wetland system for enhancing denitrification and unpowered reoxygenation and application thereof Download PDFInfo
- Publication number
- CN110745958B CN110745958B CN201911055455.2A CN201911055455A CN110745958B CN 110745958 B CN110745958 B CN 110745958B CN 201911055455 A CN201911055455 A CN 201911055455A CN 110745958 B CN110745958 B CN 110745958B
- Authority
- CN
- China
- Prior art keywords
- wetland
- subsurface flow
- bed body
- flow constructed
- constructed wetland
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/32—Biological treatment of water, waste water, or sewage characterised by the animals or plants used, e.g. algae
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/30—Aerobic and anaerobic processes
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/30—Aerobic and anaerobic processes
- C02F3/302—Nitrification and denitrification treatment
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/34—Biological treatment of water, waste water, or sewage characterised by the microorganisms used
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Engineering & Computer Science (AREA)
- Microbiology (AREA)
- Water Supply & Treatment (AREA)
- Hydrology & Water Resources (AREA)
- Environmental & Geological Engineering (AREA)
- Biodiversity & Conservation Biology (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Biotechnology (AREA)
- Botany (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
- Biological Treatment Of Waste Water (AREA)
Abstract
The invention provides an underflow artificial wetland system for strengthening denitrification and unpowered reoxygenation and application thereof, wherein the underflow artificial wetland system comprises: the wetland bed body is communicated with the water injection part and the water drainage part; the wetland bed body is also provided with an aeration component; the drainage component comprises a water collecting straight pipe and a water outlet channel, wherein the water collecting straight pipe is arranged in an inverted U shape; the aeration part comprises an air duct which is embedded in the wetland bed body; and the wall of the air duct is provided with a through hole; the aeration part also comprises a pair of aeration pipes, the aeration pipes are vertically arranged, one end of each aeration pipe is connected with one end of each air guide pipe, and the other end of each air guide pipe extends to the outside of the wetland bed body. The method effectively overcomes the defects of poor denitrification effect, high energy consumption, high operating cost and the like in the prior art, can realize unpowered operation, greatly improves the denitrification efficiency, and has good practical application value.
Description
Technical Field
The invention belongs to the technical field of ecological water treatment, and particularly relates to an enhanced denitrification unpowered reoxygenation subsurface flow constructed wetland system and application thereof.
Background
The information disclosed in this background of the invention is only for enhancement of understanding of the general background of the invention and is not necessarily to be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
Because of the limitation of centralized sewage treatment in rural and medium and small town areas, sewage in the areas is usually purified by adopting a distributed treatment system, wherein the artificial wetland has the advantages of simple structure, low investment, convenient operation and maintenance, low cost and the like, and the practicability is high.
In the operation process of the artificial wetland, nitrifying bacteria and denitrifying bacteria respectively generate nitrification and denitrification in aerobic and anoxic environments to finish the biological denitrification process, but the flooding structure and the respiration of plants and microorganisms cause insufficient dissolved oxygen in the system and are in an anoxic or anaerobic state, so that the nitrification is greatly limited, and the denitrification effect is reduced. In addition, suspended matters and microbial extracellular polymers cannot be degraded and accumulated in the anaerobic environment of the artificial wetland, so that blockage is caused.
In order to realize efficient reoxygenation and improve the denitrification efficiency of the wetland, researchers make a great deal of research and provide various technical improvements such as drop aeration, artificial intermittent aeration, tidal flow artificial wetland and the like, wherein the artificial intermittent aeration and tidal flow artificial wetland technology is widely applied. The artificial intermittent aeration is to artificially utilize an air pump to form alternate aerobic and anoxic environments on the substrate of the artificial wetland, so that the denitrification effect of the wetland can be greatly improved, the blockage phenomenon can be relieved, and the service life of the wetland is prolonged. But the intermittent aeration needs the operation of power equipment such as an air pump and the like, the operation is complex, the operation cost is high, and the energy consumption is high. The tidal flow artificial wetland is proposed by Bimingham university in recent years, the tidal flow artificial wetland is periodically filled with water and drained in the operation process, air is extruded out in the water filling process of a bed body, fresh air is brought into the bed in the drainage process, sewage is like a timing air pump, alternate anoxic and aerobic environments are provided, the denitrification effect is improved, the tidal flow artificial wetland is widely applied and popularized due to the advantages of simple operation management and high removal efficiency, but energy-consuming equipment such as a water pump and the like is still needed to create tides in the operation process, and the problem of high operation cost is still solved; at the same time, researchers have pointed out that tidal flow constructed wetlands are not adequately oxygenated during the reoxygenation phase of emptying. In the stage of water flooding of the tidal flow artificial wetland, the oxygen inhaled by emptying and reoxygenation can be used up in a short time, so that the substrate is still in an anaerobic or anoxic environment in most of the water flooding stage. Therefore, the tidal flow artificial wetland has the defects of high operation cost and poor reoxygenation capability.
In conclusion, the prior art has the defects of poor denitrification effect, high energy consumption, high operating cost, weak reoxygenation capability, easy blockage of the wetland and the like, can not meet the requirement of high-efficiency reoxygenation denitrification, and is lack of effective solutions and technologies.
Disclosure of Invention
Aiming at the defects in the prior art, the invention provides an enhanced nitrogen removal unpowered reoxygenation subsurface flow constructed wetland system and application thereof, which effectively overcome the defects of poor nitrogen removal effect, high energy consumption, high operating cost and the like of the conventional constructed wetland, can realize unpowered operation, are not easy to block, have strong reoxygenation capability and greatly improve the nitrogen removal efficiency, and have good practical application value.
In order to achieve the technical purpose, the technical scheme of the invention is as follows:
in a first aspect of the present invention, there is provided an underflow artificial wetland system for enhanced denitrification without power reoxygenation, comprising:
the wetland bed body is communicated with the water injection part and the water drainage part;
the wetland bed body is also provided with an aeration component;
the drainage component comprises a water collecting straight pipe and a water outlet channel, wherein the water collecting straight pipe is arranged in an inverted U shape and is used for collecting sewage treated in the artificial wetland system and discharging the sewage into the water outlet channel, and simultaneously, the water collecting straight pipe can trigger the siphon action;
the aeration part comprises an air duct which is embedded in the wetland bed body; and the wall of the air duct is provided with a through hole;
the aeration part also comprises a pair of vent pipes, the vent pipes are vertically arranged, one end of each vent pipe is connected with one end of each gas guide pipe, and the other end of each vent pipe extends to the outside of the wetland bed body; the two vent tubes are different in length; preferably, the height difference between the ventilation pipes is 0.5-1.2m, such as 0.5m, 0.6m, 0.7m, 0.8m, 0.9m, 1.0m, 1.1m or 1.2 m.
In one or more embodiments of the invention, a ventilation cap is arranged at one end part of the ventilation pipe extending to the outside of the wetland bed body, so that sundries are prevented from falling in.
In one or more embodiments of the invention, the water injection part at least comprises a water inlet channel and a perforated water inlet pipe, and the perforated water inlet pipe is embedded in the wetland bed body; thereby distributing the sewage in the water inlet channel into the bed body; the distance between the burying position of the air duct and the ground surface of the wetland bed body is smaller than the distance between the burying position of the air duct and the ground surface of the wetland bed body.
In one or more embodiments of the present invention, the wall of the perforated water inlet pipe is provided with small holes with a diameter of 2-5mm, such as 2mm, 3mm, 4mm or 5 mm; in order to prevent the small holes from being blocked, a film and the like can be used for wrapping, so that sewage is ensured to flow out of the small holes, and meanwhile, the small holes are prevented from being blocked by external impurity particles;
in one or more embodiments of the invention, the horizontal height of the buried position of the perforated water inlet pipe is equal to the horizontal height of the top of the water collecting straight pipe.
In one or more embodiments of the invention, the bottom of the wetland bed body is also provided with a emptying part, so that the wetland can be drained periodically, the wetland can be prevented from being blocked, and the service life of the wetland can be prolonged. The emptying part comprises an emptying pipe and a valve arranged on the emptying pipe.
In one or more embodiments of the invention, the wetland bed body is sequentially provided with a fine pebble layer, a coarse pebble layer and a pebble bottom layer from top to bottom (from the surface of the wetland bed body to the bottom of the wetland bed body);
in one or more embodiments of the invention, the thickness of the fine pebble layer is controlled to be 20-40cm, for example 20cm, 30cm or 40 cm; the particle size of the fine pebbles is 1-3cm, such as 1cm, 2cm or 3 cm;
in one or more embodiments of the invention, the thickness of the cobble is controlled to be 50-80cm, for example 50cm, 60cm, 70cm or 80 cm; the particle size of the coarse pebbles is 3-5cm, such as 3cm, 4cm or 5 cm;
in one or more embodiments of the invention, the thickness of the pebble bed is controlled to be 20-50cm, such as 20cm, 30cm, 40cm or 50 cm; the pebbles in the bottom layer have a particle size of 5-8cm, for example 5cm, 6cm, 7cm or 8 cm.
In one or more embodiments of the present invention, the matrix layer may be one or more of gravel, crushed stone, zeolite, gravel, and the like.
In one or more embodiments of the invention, the perforated water inlet pipe is embedded in the fine pebble layer, and the pipe interval of the perforated water inlet pipe is set to be 8-10%, such as 8%, 9% or 10% of the width of the wetland; the sewage is more conveniently and evenly distributed in the whole subsurface flow constructed wetland system.
In one or more embodiments of the invention, the air duct is arranged at a wetland bed height 1/3-2/3, such as 1/3, 1/2 or 2/3; the bed body can be selected in a thick pebble layer, the bed body is uniformly arranged at intervals of 30-100cm (such as 30cm, 40cm, 50cm, 60cm, 70cm, 80cm, 90cm or 100cm) along the length direction, through holes with the diameter of 2-5mm (such as 2cm, 3cm, 4cm or 5cm) are uniformly arranged on the tube wall of the air guide tube, air tubes with the height difference of 0.5-1.2m (such as 0.5m, 0.6m, 0.7m, 0.8m, 0.9m, 1.0m, 1.1m or 1.2m) are connected at two ends of the air guide tube, and when the water level falls, the air tubes can be used for ventilating, so that the dissolved oxygen concentration in the bed body is increased.
In one or more embodiments of the invention, aquatic plants can be cultivated on the wetland bed; the aquatic plants include but are not limited to reed, calamus, iris, canna, etc.; by cultivating the aquatic plants, certain economic and landscape values can be formed, the sewage percolation effect is enhanced, and the sewage treatment efficiency of the constructed wetland system is improved.
In one or more embodiments of the invention, the aspect ratio of the subsurface flow constructed wetland system is designed to be not more than 3:1, such as 1:1, 2:1 or 3:1, and the water depth is 0.6-1.5m, such as 0.6m, 0.7m, 0.8m, 0.9m, 1.0m, 1.1m, 1.2m, 1.3m, 1.4m or 1.5 m.
In one or more embodiments of the invention, the subsurface flow constructed wetland system is of a horizontal subsurface flow type, adopts a concrete structure, and has the bottom subjected to anti-seepage treatment.
In a second aspect of the invention, the subsurface flow constructed wetland system is applied to sewage treatment.
The third aspect of the invention provides a sewage treatment method, in particular to an operation method of the artificial subsurface flow wetland system, which comprises the steps of placing sewage in the subsurface flow artificial wetland system for treatment, wherein the subsurface flow artificial wetland system periodically operates according to tide, the Hydraulic Retention Time (HRT) is controlled to be 4-8 h (preferably 6h), and the operation method is divided into two stages of submerging and emptying.
Wherein, the flooding stage: the sewage of the water inlet channel is uniformly distributed into the bed body through the uniformly distributed perforated water inlet pipes, and the sewage passes through the fillers such as fine pebbles, coarse pebbles and the like in the bed body through permeation and flowing. Along with the entering of sewage, the air duct is immersed by the sewage, and the interior of the wetland presents an anoxic environment, so that the denitrification effect of the wetland is improved. In the submerging stage, the sewage fully reacts with the substrate and microorganisms in the bed body to purify the sewage.
An emptying stage: along with the continuous entering of sewage, the bed body water level constantly risees, when the sewage water level reaches the straight tube top that catchments, triggers the siphon effect, and the straight tube that catchments begins the drainage, and the water level also descends thereupon, has produced the hole suction simultaneously that the water level descends, and oxygen in the atmosphere is inhaled, and the decline in-process, the air duct that lies in the wetland inside exposes, utilizes the negative pressure suction effect of siphon principle and atmospheric pressure difference to realize the pipeline ventilation, has increased bed body inside dissolved oxygen concentration once more. The treatment effect of the wetland on organic matters and ammonia nitrogen is improved. Until the water level is reduced to the bottom of the water collecting straight pipe, air enters, siphoning is broken, the water collecting straight pipe does not discharge water, and the water level rises again.
When the water level rises, the air duct is blocked, and the interior of the wetland presents an anoxic (or anaerobic) environment. Thus, the continuous water feeding and the intermittent water discharging are realized under the condition of no power by the cyclic reciprocation, and the alternate anoxic and aerobic environment is formed on the wetland substrate. In addition, the wetland has the advantages that the water collecting straight pipe and the air guide pipe are coupled and combined with each other in the emptying and reoxygenation stage, so that the oxygenation effect is better.
The invention has the following advantages:
(1) the subsurface flow constructed wetland system has simple structure, does not need a water pump or an air pump during operation, can realize unpowered operation, has no energy consumption and low operation cost.
(2) The upper part of the wetland bed body is provided with a vent pipe, the bottom of the wetland bed body is communicated with the bottom of the wetland bed body through a gas guide pipe, the wall of the gas guide pipe is uniformly perforated, and the pipeline can be ventilated and oxygenated by utilizing atmospheric pressure to increase the concentration of dissolved oxygen in the wetland bed body. The defect of low dissolved oxygen concentration in the traditional subsurface flow constructed wetland is overcome, and meanwhile, the traditional energy-consuming blast aeration equipment is also omitted, so that the construction and operation costs are saved.
(3) The wetland is provided with the straight tube that catchments at the bed body end, utilizes the siphon principle, realizes the straight tube automatic drainage that catchments, realizes the automatic rising of water level. Can form alternate anoxic and aerobic environments in the wetland, realize the time sequencing batch denitrification A/O process, increase the diversity of microorganisms in the wetland and greatly improve the denitrification efficiency.
(4) The device realizes the coupling of automatic lifting of the water level and aeration of the air guide pipe. When the water level descends, oxygen is inhaled under the effect of pore suction generated when the saturated wetting surface descends, meanwhile, the air guide pipe is exposed, the air guide pipe realizes pipeline ventilation by utilizing the negative pressure suction and the atmospheric pressure difference of the siphon effect, the dissolved oxygen concentration in the bed body is increased again, the nitrification of microorganisms is promoted, and the limiting factor that the TN removal rate of the traditional constructed wetland is not high is overcome. When the water level rises, the air duct is immersed in the water again, and the interior of the wetland presents an anoxic (or anaerobic) environment. Therefore, the oxygenation effect of the wetland is better than that of the wetland only depending on the tidal process, and the treatment effect is better.
(5) The wetland creates alternate anoxic and aerobic environments instead of anaerobic and anoxic environments of the traditional undercurrent artificial wetland, avoids the accumulation of suspended matters and extracellular polymers, effectively prevents soil blockage and prolongs the service life of the wetland.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings needed to be used in the embodiments will be briefly described below, it should be understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and for those skilled in the art, other related drawings can be obtained according to the drawings without inventive efforts.
Fig. 1 is a schematic view of the overall structure of an underflow constructed wetland system in embodiment 1 of the invention;
fig. 2 is a cross-sectional view of an underflow constructed wetland system in example 1 of the present invention.
Description of the reference numerals
1-a removable cover plate; 2-wetland plants; 3-a breather pipe; 4-a ventilation cap; 5-water inlet channel; 6-perforating a water inlet pipe; 7-water collecting straight pipe; 8-water outlet channel; 9-an emptying pipe; 10-airway tube.
Detailed Description
In order to facilitate understanding of the present invention, the subsurface flow constructed wetland system and the sewage treatment method thereof will be more fully described with reference to the related drawings. The attached drawings show a preferred embodiment of the subsurface flow constructed wetland system and the sewage treatment method thereof. However, the subsurface flow constructed wetland system and the sewage treatment method thereof may be implemented in many different forms and are not limited to the embodiments described herein. Rather, these embodiments are provided to make the disclosure of the subsurface flow constructed wetland system and the sewage treatment method thereof more thorough and complete.
It is noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments according to the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, and it should be understood that when the terms "comprises" and/or "comprising" are used in this specification, they specify the presence of stated features, steps, operations, devices, components, and/or combinations thereof, unless the context clearly indicates otherwise. In the description of the present invention, it is to be understood that the terms "longitudinal", "lateral", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like, indicate orientations or positional relationships based on those shown in the drawings, and are used merely for convenience of description and for simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed in a particular orientation, and be operated, and thus, are not to be construed as limiting the present invention.
In the description herein, references to the description of the term "one embodiment," "embodiments," "an example," "a specific example" or the like are intended to mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The present invention will now be further described with reference to specific examples, which are provided for the purpose of illustration only and are not intended to be limiting.
As mentioned above, the existing artificial wetland has the defects of poor denitrification effect, high energy consumption, high operating cost, weak reoxygenation capability, easy blockage of the wetland and the like in sewage treatment.
In view of the above, in an exemplary embodiment of the present invention, an enhanced denitrification unpowered reoxygenation subsurface flow constructed wetland system is provided, which adopts a concrete structure, has an anti-seepage treatment on the bottom, and has an aspect ratio of 1:1 to 3:1 and a water depth of 0.6 to 1.5 m. The whole wetland mainly comprises a water inlet channel 5, a water outlet channel 8 and a bed body. The wetland inlet channel, the bed body and the water outlet channel are provided with a perforated water inlet pipe 6, an emptying pipe 9 and a water collecting straight pipe 7. The perforated water collecting pipes are uniformly distributed on the upper fine pebble layer (the thickness is 20-40cm, the particle size of the fine pebbles is 1-3cm), the spacing is designed to be 8% -10% of the width of the wetland, and the pipe walls of the perforated pipes are uniformly provided with small holes with the diameter of 2-5mm and are wrapped by films to prevent blockage. The emptying pipe is positioned at the bottom of the right side of the bed body and is provided with a butterfly valve. The straight tube design of catchmenting is the type of falling U, and the collector tube is connected in one end and the wetland, collects the sewage of wetland internal treatment, and one end is unsettled at the play ditch, and its top height flushes with the perforation inlet tube, and the bottom flushes with the bed body end, prevents that the stagnant water district from appearing. The filling material of the wetland comprises a fine pebble layer, a coarse pebble layer (the thickness is 50-80cm, the particle size of coarse pebbles is 3-5cm), a pebble bottom layer (the thickness is 20-50cm, the particle size of bottom pebbles is 5-8cm) from top to bottom in sequence, and one or more of substrates such as gravel, broken stones, zeolite, gravel and the like can also be used. The upper soil layer is planted with aquatic plants such as reed, calamus, iris, canna, etc. The air ducts 10 are positioned at the wetland height 1/3-2/3, the bed body is uniformly arranged at intervals of 30-100cm along the length direction, small holes with the diameter of 2-5mm are uniformly punched on the tube wall, the two ends of the air duct are connected with the air ducts 3 with the height difference of 0.5-1.2m, and when the water level falls, the air ducts can be utilized for ventilation, so that the dissolved oxygen concentration in the bed body is increased. The ventilation cap 4 is additionally arranged on the ventilation pipe to prevent sundries from entering.
The subsurface flow constructed wetland system is designed to run periodically by tides, the Hydraulic Retention Time (HRT) is designed to be 6h, and the system is divided into two stages of submerging and emptying.
A submerging stage: the sewage in the water inlet channel 5 is uniformly distributed into the bed body through the uniformly distributed perforated water inlet pipes 6, and the sewage passes through the fillers such as fine pebbles, coarse pebbles and the like in the bed body through permeation and flowing. Along with the entering of the sewage, the air duct 10 is immersed by the sewage, and the interior of the wetland presents an anoxic environment, so that the denitrification effect of the wetland is improved. In the submerging stage, the sewage fully reacts with the substrate and microorganisms in the bed body to purify the sewage.
An emptying stage: along with the continuous entering of sewage, bed body water level constantly risees, when the sewage water level reaches catchment straight tube 7 top, triggers siphonage, catchment straight tube begins the drainage, and the water level also descends thereupon, and the water level has produced the hole suction simultaneously, and oxygen in the atmosphere is inhaled, and in the decline process, the air duct 10 that is located wetland height 1/3-2/3 department exposes, and it utilizes atmospheric pressure with two breather pipes 3 that differ in height of being connected to realize the pipeline ventilation, has increased the inside dissolved oxygen concentration of bed body once more. The treatment effect of the wetland on organic matters and ammonia nitrogen is improved. Until the water level is reduced to the bottom of the water collecting straight pipe 7, air enters, siphoning is broken, the water collecting straight pipe does not discharge water, and the water level rises again.
When the water level rises, the air duct 10 is blocked, and the interior of the wetland presents an anoxic (or anaerobic) environment. Thus, the continuous water feeding and the intermittent water discharging are realized under the condition of no power by the cyclic reciprocation, and the alternate anoxic and aerobic environment is formed on the wetland substrate. In addition, the wetland has the advantages that the water collecting straight pipe 7 and the air guide pipe 10 are coupled and combined with each other in the emptying and reoxygenation stage, so that the oxygenation effect is better.
In order to make the technical solutions of the present invention more clearly understood by those skilled in the art, the technical solutions of the present invention will be described in detail below with reference to specific embodiments.
Example 1
The unpowered reinforced reoxygenation constructed wetland is designed into a horizontal subsurface flow type in engineering, has a concrete structure, is provided with an impermeable layer at the bottom, and has the water inflow of 10m3And d, the size is designed to be 5.00m multiplied by 2.00m multiplied by 1.35 m. The wetland bed consists of three parts, namely a water inlet channel 5, a bed body and a water outlet channel 8, wherein the water inlet channel is provided with 9 DN25 perforated water inlet pipes 6 which are uniformly distributed and uniformly flow into the wetland bed body, the distance between the perforated pipes is 20cm, and the pipe wall is uniformly provided with small holes with the diameter of 4mm and is wrapped by a film to prevent blockage. The substrate layer is designed to be a fine pebble layer with the thickness of 30cm and the grain diameter of 1cm, a coarse pebble layer with the thickness of 70cm and the grain diameter of 3cm, a pebble bottom layer with the thickness of 35cm and the grain diameter of 6cm and the like, a water collecting straight pipe 7 of DN50 is arranged at the tail end of the bed body, and the treated water is discharged to a water outlet channel. A sump of 0.3m multiplied by 0.3m is arranged at the bottom of the right bottom of the bed body, and a blow-down pipe 9 of DN50 is connected, so that the wetland can be dried periodically, the wetland can be prevented from being blocked, and the service life of the wetland can be prolonged. Uniformly designing an air duct 10 in the middle of the cobble layer every 1m, uniformly drilling small holes with the diameter of 4mm on the pipe wall of the air duct, designing the height of the air duct at a position 0.7m away from the bottom of the wetland, connecting air ducts 3 with different heights at two ends, designing the height difference to be 1m, and additionally installing an air cap 4 on each air duct 3. Canna planted above the designed wetland has certain economic and landscape values.
When the artificial wetland is used in the embodiment, sewage uniformly enters the bed body from the wetland inlet channel DN25 perforated water inlet pipe, then horizontally flows in the bed body and passes through the fine pebble layer, the coarse pebble layer and the pebble bottom layer of the bed body from top to bottom. The water level rises continuously with the inflow of water until reaching the top end of the straight water collecting pipe 7. When arriving the straight tube 7 top of catchmenting, can trigger the siphon effect, the water level descends rapidly, and the oxygen in the atmosphere can be inhaled to the pore suction of production, and meanwhile, the air duct 10 of bed internal design is also exposed, utilizes pipeline ventilation reoxygenation once more, has increased dissolved oxygen concentration in the wetland, strengthens the microorganism in the wetland and gets metabolism effect. When the water level drops to the bottom end of the water collecting straight pipe 7, air enters, the siphon action is destroyed, the water collecting straight pipe 7 does not discharge water any more, the perforated pipe still enters water, and the water level rises again to submerge the substrate to form an oxygen-deficient environment.
In actual operation, a blank control group was set. The wetland inlet water is of a first-grade B standard, the average COD of the inlet water is 60mg/L, and the average ammonia nitrogen is 15 mg/L. The specific data are as follows:
| COD treatment rate | NH4 +-N treatment rate | Electric charge (Yuan) | |
| Experimental group | 85.6％-89.2％ | 58.5％-63.2％ | 0 |
| Control group | 65.8％-69.7％ | 38.6％-43.8％ | 4642 |
Note: a1 kw air pump is needed in the control wetland operation process, the control wetland operation process is carried out 24h each day, and the electricity fee is calculated according to 0.53 KWh.
The high removal rate of COD and ammonia nitrogen also shows that the coupling of the water collecting straight pipe and the air guide pipe ensures that the dissolved oxygen in the wetland is more sufficient, the nitration reaction is more sufficient, and no power is input in the operation process, so that the wetland has low operation cost and obvious advantages in application.
In conclusion, the unpowered reoxygenation constructed wetland realizes automatic and continuous lifting of the water level on the premise of not using energy consumption equipment such as a water pump, an air pump and the like, and strengthens the oxygenation effect of the wetland in the emptying stage. The wetland system is constantly in an anoxic and aerobic alternate environment during operation, a time sequencing batch A/O process is realized, an excellent treatment effect on organic matters and nitrogen is achieved, and the wetland system has the advantages of low construction and operation cost, simplicity and convenience in operation and management and good effluent quality, and is very suitable for treating domestic sewage in villages and towns in China.
The above embodiments are preferred embodiments of the present invention, but the present invention is not limited to the above embodiments, and any other changes, modifications, substitutions, combinations, and simplifications which do not depart from the spirit and principle of the present invention should be construed as equivalents thereof, and all such changes, modifications, substitutions, combinations, and simplifications are intended to be included in the scope of the present invention.
Claims (15)
1. An enhanced denitrification unpowered reoxygenation subsurface flow constructed wetland system is characterized by comprising:
the wetland bed body is communicated with the water injection part and the water drainage part;
the wetland bed body is also provided with an aeration component;
the drainage component comprises a water collecting straight pipe and a water outlet channel, wherein the water collecting straight pipe is arranged in an inverted U shape;
the aeration part comprises an air duct which is embedded in the wetland bed body; and the wall of the air duct is provided with a through hole;
the aeration part also comprises a pair of vent pipes, the vent pipes are vertically arranged, one end of each vent pipe is connected with one end of each gas guide pipe, and the other end of each vent pipe extends to the outside of the wetland bed body;
a ventilation cap is arranged at one end part of the ventilation pipe extending to the outside of the wetland bed body;
the water injection part at least comprises a water inlet channel and a perforated water inlet pipe, and the perforated water inlet pipe is embedded in the wetland bed body;
the horizontal height of the embedding position of the perforated water inlet pipe is equal to the horizontal height of the top of the water collecting straight pipe;
the air guide pipe is arranged at the height 1/3-2/3 of the wetland bed body; the air ducts are uniformly arranged along the length direction of the wetland bed body at intervals of 30-100cm, through holes with the diameter of 2-5mm are uniformly arranged on the walls of the air ducts, and the two ends of each air duct are connected with the air ducts with the height difference of 0.5-1.2 m.
2. The subsurface flow constructed wetland system of claim 1, wherein the wall of the perforated water inlet pipe is provided with small holes with the diameter of 2-5 mm.
3. The subsurface flow constructed wetland system of claim 2, further characterized in that the small holes of the perforated water inlet pipe are wrapped with a film.
4. The subsurface flow constructed wetland system of claim 1, wherein a vent member is arranged at the bottom of the wetland bed.
5. The subsurface flow constructed wetland system of claim 4, wherein the vent assembly comprises a vent and a valve disposed on the vent.
6. The subsurface flow constructed wetland system of claim 1, wherein the wetland bed is sequentially provided with a fine pebble layer, a coarse pebble layer and a pebble bottom layer from top to bottom.
7. The subsurface flow constructed wetland system according to claim 6, wherein the thickness of the fine pebble layer is controlled to be 20-40 cm; the particle size of the fine pebbles is 1-3 cm.
8. The subsurface flow constructed wetland system according to claim 6, wherein the thickness of the pebble layer is controlled to be 50-80 cm; the particle size of the coarse pebbles is 3-5 cm.
9. The subsurface flow constructed wetland system according to claim 6, wherein the thickness of the pebble bed is controlled to be 20-50 cm; the particle size of the pebbles at the bottom layer of the pebbles is 5-8 cm.
10. The subsurface flow constructed wetland system of claim 6, wherein the perforated water inlet pipes are embedded in the fine pebble layer, and the interval between the perforated water inlet pipes is set to be 8-10% of the width of the wetland.
11. The subsurface flow constructed wetland system of claim 1 wherein aquatic plants are grown in said wetland bed.
12. The subsurface flow constructed wetland system of claim 11 wherein said aquatic plants comprise reeds, calamus, iris and canna.
13. Use of the subsurface flow constructed wetland system of any one of claims 1 to 3 in sewage treatment.
14. A method for treating sewage, which is characterized by comprising the step of treating the sewage by placing the sewage in the subsurface flow constructed wetland system of any one of claims 1 to 3, wherein the subsurface flow constructed wetland system periodically operates according to tides, and the hydraulic retention time is controlled to be 4-8 h.
15. A method for treating sewage, which is characterized in that the method comprises the step of treating the sewage by placing the sewage in the subsurface flow constructed wetland system of any one of claims 1 to 3, wherein the subsurface flow constructed wetland system is operated periodically according to tides, and the hydraulic retention time is controlled to be 6 h.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911055455.2A CN110745958B (en) | 2019-10-31 | 2019-10-31 | Subsurface flow constructed wetland system for enhancing denitrification and unpowered reoxygenation and application thereof |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911055455.2A CN110745958B (en) | 2019-10-31 | 2019-10-31 | Subsurface flow constructed wetland system for enhancing denitrification and unpowered reoxygenation and application thereof |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110745958A CN110745958A (en) | 2020-02-04 |
| CN110745958B true CN110745958B (en) | 2021-09-07 |
Family
ID=69281656
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911055455.2A Active CN110745958B (en) | 2019-10-31 | 2019-10-31 | Subsurface flow constructed wetland system for enhancing denitrification and unpowered reoxygenation and application thereof |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110745958B (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111943359B (en) * | 2020-07-24 | 2022-06-03 | 山东大学 | Artificial wetland coupled with iron ore enhanced denitrification, operation method and application |
| CN113073706B (en) * | 2021-04-08 | 2022-09-23 | 中国电建集团贵阳勘测设计研究院有限公司 | Submerged flow intercepting water intake structure and construction method |
| CN114835333A (en) * | 2022-03-02 | 2022-08-02 | 武汉大学 | Automatic oxygenation type constructed wetland system |
| CN117776401A (en) * | 2024-02-27 | 2024-03-29 | 河北雄安德荫源环境科技有限公司 | Anti-clogging subsurface flow wetland system |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5863433A (en) * | 1996-12-02 | 1999-01-26 | Tennessee Valley Authority United States Corp. | Reciprocating subsurface-flow constructed wetlands for improving wastewater treatment |
| CN202080988U (en) * | 2011-05-12 | 2011-12-21 | 北京科技大学 | Natural-aeration percolation type land treatment device for rural domestic sewage |
| CN102633365A (en) * | 2012-04-24 | 2012-08-15 | 山东建筑大学 | Wind-energy superimposed-negative-pressure ventilation reoxygenation wastewater treatment system for artificial wetland |
| CN102923860A (en) * | 2012-11-26 | 2013-02-13 | 中国农业大学 | Method for enhanced nitrogen removal of tidal flow-horizontal subsurface flow hybrid constructed wetland and system thereof |
| CN106006983A (en) * | 2016-07-07 | 2016-10-12 | 凯天环保科技股份有限公司 | Hydrocone type unpowered constructed wetland and reoxygenation method thereof |
| CN108314186A (en) * | 2018-03-12 | 2018-07-24 | 山东大学 | The efficient oxygenating wet land system of aerobic-anoxia-aerobic three-phase |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6881338B2 (en) * | 2002-06-17 | 2005-04-19 | Dharma Living Systems, Inc. | Integrated tidal wastewater treatment system and method |
| CN101891304A (en) * | 2010-07-13 | 2010-11-24 | 江西省环境保护科学研究院 | Tidal flow constructed wetland with rich reoxygenation |
| CN104085990B (en) * | 2014-07-17 | 2016-02-17 | 交通运输部科学研究院 | A kind of auxiliary highway facilities sewage multimedium biological and ecological coprocessing system and method |
-
2019
- 2019-10-31 CN CN201911055455.2A patent/CN110745958B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5863433A (en) * | 1996-12-02 | 1999-01-26 | Tennessee Valley Authority United States Corp. | Reciprocating subsurface-flow constructed wetlands for improving wastewater treatment |
| CN202080988U (en) * | 2011-05-12 | 2011-12-21 | 北京科技大学 | Natural-aeration percolation type land treatment device for rural domestic sewage |
| CN102633365A (en) * | 2012-04-24 | 2012-08-15 | 山东建筑大学 | Wind-energy superimposed-negative-pressure ventilation reoxygenation wastewater treatment system for artificial wetland |
| CN102923860A (en) * | 2012-11-26 | 2013-02-13 | 中国农业大学 | Method for enhanced nitrogen removal of tidal flow-horizontal subsurface flow hybrid constructed wetland and system thereof |
| CN106006983A (en) * | 2016-07-07 | 2016-10-12 | 凯天环保科技股份有限公司 | Hydrocone type unpowered constructed wetland and reoxygenation method thereof |
| CN108314186A (en) * | 2018-03-12 | 2018-07-24 | 山东大学 | The efficient oxygenating wet land system of aerobic-anoxia-aerobic three-phase |
Non-Patent Citations (1)
| Title |
|---|
| 新型虹吸补氧湿地***的构建及其优化运行研究;宋希冉;《中国优秀硕士学位论文全文数据库工程科技I辑》;20190915;第2.1.2节 新型湿地***构建总体思路 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110745958A (en) | 2020-02-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN110745958B (en) | Subsurface flow constructed wetland system for enhancing denitrification and unpowered reoxygenation and application thereof | |
| CN101423297B (en) | Composite vertical current artificial wetland oxygenation system | |
| CN107720973A (en) | A kind of sewage treatment plant tail water artificial wet land treating system | |
| CN201305511Y (en) | Integrated vertical flow constructed wetland aerator | |
| CN107188379A (en) | A kind of domestic sewage of villages and small towns rural area landscape type total system | |
| CN110386666A (en) | A kind of compound pool system of free water surface wetland-for sewage treatment | |
| CN110127959B (en) | Artificial wetland water purification method | |
| CN110818199A (en) | Distributed rural domestic sewage low-energy-consumption integrated treatment equipment | |
| CN111943359B (en) | Artificial wetland coupled with iron ore enhanced denitrification, operation method and application | |
| CN208071547U (en) | A kind of rural domestic sewage treatment small-sized biological contact purification tank | |
| CN112142258B (en) | Resource and standard treatment method for domestic sewage of villages and towns | |
| CN207047066U (en) | A kind of domestic sewage of villages and small towns rural area landscape type total system | |
| CN104326574B (en) | The horizontal subsurface flow wetland system of strengthening micropollutant water denitrogenation in winter | |
| CN211896515U (en) | Artificial wetland system applied to super-limit purification treatment of low-concentration polluted water body | |
| CN105217893B (en) | A kind of Sloping Hearth subsurface flow constructed wetland combination system | |
| CN104030442B (en) | Integrated domestic sewage treatment device | |
| CN207726821U (en) | A kind of sewage treatment plant tail water artificial wet land treating system | |
| CN211035627U (en) | Distributed rural domestic sewage low-energy-consumption integrated treatment equipment | |
| CN213596109U (en) | Landscape type domestic sewage ecological treatment integrated facility | |
| CN109592791B (en) | Composite artificial wetland system and operation method thereof | |
| CN203922850U (en) | Integral life sewage handler | |
| CN211035602U (en) | Black smelly water intensive treatment system | |
| CN211770568U (en) | Stepped artificial wetland system | |
| CN109111040B (en) | Efficient and stable domestic sewage ecological treatment device and operation method | |
| CN111333182A (en) | Reciprocating type biological-ecological retention filter bed combined sewage treatment device and method |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |