CN203451288U - Compound ecological ditch for treating surface source sewage in village - Google Patents

Abstract

A composite ecological ditch for treating non-point source sewage in villages, including a grid, a sedimentation adjustment tank, a unit ecological ditch, a plant fence and a recycling device, and the unit ecological ditch includes an ecological ditch unit (1) and a wetland ditch unit (2), The two units are arranged alternately, and the water outlets of the ecological ditch unit ⑴ and the wetland ditch unit ⑵ are equipped with an interception drop dam ⑶, and the upper end of the interception dam ⑶ is provided with a triangular overflow weir, and the lower end is provided with a water outlet and a water control valve⑺ . Its advantages are: the utility model forms a composite ecological ditch system by introducing subsurface wetland ditch units, nitrogen and phosphorus interception boxes, falling water overflow dams and plant fences, which overcomes the defects in the prior art, can stably remove COD, and improve The removal rate of nitrogen and phosphorus pollutants, and prevent secondary pollution.

Description

A compound ecological ditch for treating village non-point source sewage

technical field

The utility model relates to the fields of agricultural water and soil engineering and sewage treatment, in particular to a composite ecological ditch for treating village non-point source sewage.

Background technique

Non-point source sewage has the typical characteristics of non-point source pollution, that is, "scattered discharge, huge total amount, and complicated situation". Since the "Eleventh Five-Year Plan" period, my country has invested a lot of financial resources and manpower in research and pilot projects on the control of non-point source sewage. Several large-scale demonstration projects have been established in Dianchi Lake, Taihu Lake, Chaohu Lake and Beijing, and a lot of experience and conclusions have been obtained. In a large number of research and pilot projects, non-point source sewage collection technologies mainly include hardened ditches, ecological grass ditches and other ditches; non-point source sewage treatment processes include ecological ponds, constructed wetlands, land infiltration, ecological dripping and ecological ditches In terms of nitrogen and phosphorus interception, technologies such as ecological permeable dams and front-end reservoirs have been expanded. These technologies together constitute my country's non-point source sewage control technology system.

Among the concentrated non-point source sewage treatment technologies, ecological ponds and constructed wetlands have higher treatment efficiency but occupy a larger area, and their nitrogen and phosphorus interception capabilities are not outstanding, and their cost is relatively high; land infiltration technology has a stronger treatment capacity, and its nitrogen and phosphorus interception effect is relatively high. The effect is excellent but it is troubled by clogging and short life; the effect of biological trickling is excellent, but the construction cost is high, the operation cost is high, the cost performance is low and it is not suitable for promotion; compared with other technologies, ecological ditches have higher treatment efficiency and Small footprint, low cost, and both water conservancy and ecological landscape value, the most important thing is that the ecological ditches have good prospects for improvement and expansion, and have been deeply researched and developed in recent years.

At present, there are a large number of newly built and transformed ecological ditches in my country. These ecological ditches have played a huge role in the interception and treatment of non-point source sewage, but the following problems have been found in actual use:

(1) The COD removal rate of ordinary ecological ditches can reach more than 75%, but the treatment efficiency is unstable, and the temperature and water volume have a great influence on the treatment efficiency. When the temperature is low, the biochemical and adsorption removal efficiency is generally less than 50%, while When heavy rains and floods come, it is almost impossible to treat sewage;

(2) Ordinary ecological ditches have low removal efficiency for nitrogen and phosphorus pollutants. Ordinary ecological ditches mainly rely on emergent plants and sediment microbial circles in the canal to adsorb and absorb nitrogen and phosphorus pollutants. Due to the amount of plants, contact area, and reaction Due to the limitation of efficiency and residence time, the removal rate of total nitrogen (TN) and total phosphorus (TP) is generally maintained at about 75% and 60%, and the treatment efficiency will gradually decrease after the system is saturated with adsorption;

(3) The plants growing in the ecological ditches have not been effectively disposed of after absorbing a large amount of nitrogen and phosphorus pollutants. During winter or heavy rain, the absorbed pollutants will be released into the water body in the form of leaching or dissimilation, causing secondary pollution. pollute.

Utility model content

The purpose of the utility model is to provide a compound ecological ditch for stably removing COD, improving the removal rate of nitrogen and phosphorus pollutants and preventing secondary pollution for treating non-point source sewage in villages.

A compound ecological ditch for treating non-point source sewage in villages, including a grid, a sedimentation adjustment tank, a unit ecological ditch, a plant fence and a recycling device, the unit ecological ditch includes an ecological ditch unit 1 and a wetland ditch unit 2, The two units are arranged alternately, and the water outlets of the ecological ditch unit 1 and the wetland ditch unit 2 are equipped with an interception drop dam 3, and the upper end of the interception drop dam 3 is provided with a triangular overflow weir, and the lower end is provided with a water outlet and a water control valve 7 .

The ecological ditch unit 1 has wet emergent plants 9 planted on its side walls and the bottom of the pond, and nitrogen and phosphorus interception boxes 8 are interspersedly arranged at intervals of 1-3m at the bottom of the ditch.

The nitrogen and phosphorus interception box 8 is filled with steel slag, and the outer surface is plastic or metal geogrid.

The wetland ditch unit 2 includes a multi-layer ecological filter material 5, and wetland plants 4 are planted on the upper surface of the ecological filter material 5; the filter materials of each layer of the ecological filter material 5 are in the order of decreasing particle size from top to bottom set up.

The left and right sides of the unitized ecological ditch are provided with a plant fence, and the plant fence includes a pebble belt 10, wet herbaceous emergent plants 11 and wetland trees and shrubs 12, and the pebble belt 10 has a slope of 3-10%. Wet herbaceous emergent plants 11 and wetland trees and shrubs 12 are densely planted within the range of 2 meters from the belt 10.

The wet emergent plants 9 and wet herbaceous emergent plants 11 include but are not limited to reeds, cattails, water calamus, and cannas.

The wetland trees and shrubs 12 include, but are not limited to, dandelion, hibiscus, phoenix, and wisteria.

The utility model is realized in the following way: the sewage alternately passes through the ecological ditch unit and the wetland ditch unit in the unit ecological ditch, and the main pollutants of the sewage are removed in this process.

The sewage in the ecological ditch unit is in a full flow state. Due to the horizontal construction of the ditch with no drop and the blocking and sticking effects of the nitrogen and phosphorus interception box and the emergent plants at the bottom of the canal, the flow rate of the sewage in the unit is slow and uniform. Through sedimentation, suspended solids (SS) in sewage further carry particulate organic pollutants to precipitate and condense on the emergent plant communities and sediment at the bottom and side walls of the canal. The active bacterial micelles and aquatic microorganisms in the sediment and in the water absorb organic pollutants through a large specific surface area, and absorb, transform, and assimilate organic pollutants into biomass through metabolism in an aerobic environment to complete the biochemical oxygen demand. Emergent plants and the rhizosphere biosphere attached to them absorb nitrogen-containing pollutants and some phosphorus-containing pollutants in the water through root adsorption and synergistic effect, and respectively through nitrification, denitrification, Phosphorus absorption and release phosphorus reaction is transformed into nitrogen and organic phosphorus to complete the removal; the nitrogen and phosphorus interception box in the water is filled with steel slag, firstly through the porous structure of steel slag to absorb small particle pollutants in sewage, and then through a large amount of calcium oxide (CaO) in steel slag Active components such as aluminum oxide (Al ₂ O ₃ ) and iron oxide (Fe ₂ O ₃ ) quickly form stable phosphides such as calcium hydroxyphosphate with the infinite phosphorus in sewage and deposit on the surface of steel slag, and the strengthening can be completed in only 15 minutes In the chemical process of phosphorus removal, after the adsorption and saturation of steel slag, the interception box still maintains a large specific surface area and porous structure, and can still be used as a biological filter material to complete sewage viscosity and treatment through microbial attachment. At the same time, a large amount of phosphide deposited on the surface is helpful The organism grows and flourishes steadily. The unit effluent enters the wetland ditch unit through the overflow drop dam.

Before the sewage falls into the wetland ditch unit, the reoxygenation process is completed by forming a water curtain and impact bubbling, and then directly poured into the ecological filter material. Sewage presents a horizontal and vertical compound underflow state in the ecological filter material layer. Firstly, organic pollutant particles of different particle sizes are intercepted through the blocking and screening functions of each layer of ecological filter materials, and then they are adsorbed by the filter materials and the attached microorganisms in the filter materials and transformed and removed through microbial metabolism. In this process, the wetland plant community on the surface of the filter material can strengthen reoxygenation and expand the total biomass of the wetland through the developed root system on the one hand, and on the other hand, the root biosphere can complete the adsorption, absorption, transformation and replenishment of nitrogen and phosphorus pollutants. The biomass in the deep filter material makes the unit form a complete ecological circle of "emergent plants-miniature aquatic animals-microbial communities". The unit effluent enters the next unit from the water outlet at the lower end of the overflow drop dam.

The utility model has the advantages of a composite ecological ditch for treating village non-point source sewage: the present invention forms a composite ecological ditch system by introducing subsurface wetland ditch units, nitrogen and phosphorus interception boxes, falling water overflow dams and plant fences, etc., which overcomes the existing defects in technology;

Alternately setting common ecological ditch units and wetland ditch units can not only strengthen the adaptability of the system to the impact of water quality and quantity by adjusting the water outlet methods of different units, but also ensure that when the sewage passes through two adjacent units, it is in a state of aerobic and anaerobic in sequence , this alternating change of oxygen content is beneficial to the removal of nitrogen and phosphorus pollutants. At the same time, through the reoxygenation of falling water and plant roots and the precipitation of ordinary ecological ditch units, it is ensured that the composite ecological ditch unit is not easy to block and the system failure rate is reduced. At the same time, the two units have the same construction form, and various unit configurations can be freely replaced according to changes in seasons, temperature, and water quality to achieve the best treatment effect;

The plant fence is built along the ecological ditch, and the pebble belt and the densely planted plant belt are set up next to the ecological ditch. On the one hand, it acts as an ecological slope protection to protect the ecological ditch. At the same time, when the ecological ditch overflows or floods come, the plant fence can form a wetland buffer with the ecological ditch. During the rainstorm, the plant fence can not only prevent the rainstorm from carrying foreign matter into the ditch and cause blockage or pollution through the blocking effect of the pebble belt and plant roots, stems and leaves, but also can evenly buffer Rainstorm water volume, protection of ecological ditch system. The associated system composed of plant fences and ecological ditch units can form a relatively high-level ecological community, while strengthening sewage treatment, it can also form a good coastal ecological landscape and regulate the local water, soil and climate.

Description of drawings

Fig. 1 is a structural schematic diagram of a composite ecological ditch for treating village non-point source sewage according to the utility model.

Fig. 2 is a schematic cross-sectional structure diagram of a wetland ditch unit.

In the figure, 1 is an ecological ditch unit, 2 is a wetland ditch unit, 3 is an interception drop dam, 4 is a wetland plant, 5 is an ecological filter material, 6 is an anti-seepage concrete, 7 is a water control valve, and 8 is a nitrogen and phosphorus interception box , 9 are wet emergent plants, 10 are pebble belts, 11 are wet herbaceous emergent plants, and 12 are wetland trees and shrubs.

Detailed ways

Below in conjunction with accompanying drawing, the utility model is further described:

The utility model is a composite ecological ditch for treating non-point source sewage in villages, including grilles, sedimentation adjustment tanks, unit ecological ditches, plant fences and recycling devices. Village bay sewage and irrigation and drainage collected through pipes and canals enter the system, which are successively Reuse or discharge after passing through grilles, sedimentation adjustment tanks, unitized ecological ditches and recycling devices.

The grid and the sedimentation adjustment tank are constructed as an integrated square pool by concrete, the grid distance is 2-10mm, the depth of the sedimentation adjustment tank is 1.5m, and the HDPE anti-seepage membrane is laid. The grille removes floating matter and large particles of garbage in the sewage through filtering. On the one hand, the sedimentation adjustment tank stabilizes the water quality and quantity of the sewage, and the suspended solids (SS) can be precipitated. At the same time, a facultative anaerobic condition is formed through a long residence time, and the large-particle organic pollutants in the sewage are hydrolyzed through the biochemical action of facultative microorganisms. Acidification into small particles of organic matter reduces the biochemical oxygen demand (BOD) of sewage and improves the biodegradability of sewage. The completed and treated sewage enters the compound ecological ditch unit through the overflow weir for purification treatment.

The unitized ecological ditch includes an ecological ditch unit 1 and a wetland ditch unit 2 (as shown in FIG. 1 ), and the two units are connected alternately. The end of each unit is provided with an intercepting dam 3, a triangular overflow weir is built at the upper end, and a water outlet is opened at the lower end and a water control valve 7 is set; if necessary, the middle part of the intercepting dam 3 can also be opened with a water outlet.

The ecological ditch unit 1 is constructed of anti-seepage concrete 6 , the cross-section is an inverted trapezoid with a large upper part and a smaller lower part. The lower end of the ditch is 0.5-1.0 m wide, the ditch is 0.5 m deep, and the side walls are inclined at an angle of 60 ^o . Environmentally friendly tiles are laid. The length of the canal varies from 3-10m according to the change of local terrain.

Ecological ditch unit 1, artificially plant native wet-growing emergent plants 9 on the side wall and the bottom of the pool, and arrange grid cages filled with steel slag every 1.5m at the bottom of the canal to form a nitrogen and phosphorus interception box 8; the size of the nitrogen and phosphorus interception box 8 is Cuboid structure of 0.5m×0.5m×0.3m.

The surface of the nitrogen and phosphorus interception box 8 is plastic or metal geogrid, and 174kg of steel slag or modified steel slag can be filled inside. Calculated according to the daily water treatment volume of the ecological ditch system is 50m ³ , the phosphorus content in the water is 20mg/L and 90% is removed, and the adsorption saturation of steel slag is 2.5mg/L. Each interception box is used for about 2 years to reach adsorption saturation. After reaching saturation, the interception box can be replaced immediately, and it can also be used as an ecological filler in stagnant water as a microbial nutrient base.

The wetland ditch unit 2, as shown in Figure 2, is filled with a multi-layer ecological filter material 5 composed of gravel, ceramsite and cinder, and the particle size is reduced from 15mm to 3mm from top to bottom.

Indigenous wetland plants 4 are planted on the surface of the ecological filter material 5, and an artificial nutrient base can be used if necessary.

The sectional view of the plant fence is shown in Figure 2: the width of the pebble strip 10 is 0.5m, and it is paved with pebbles with a particle size of 3-10cm, and a slope of 3%-10% is maintained. A plant fence is formed by densely planting wet herbaceous emergent plants 11 and wetland trees and shrubs 12 within a range of 2 m outward from the pebble belt 10 . The plant fence is built along the ecological ditch, and the pebble belt 10 and the densely planted plant belt are set up next to the ecological ditch. On the one hand, it acts as an ecological slope protection to protect the ecological ditch. At the same time, when the ecological ditch overflows or the flood comes, the plant fence can form a wetland with the ecological ditch. The buffer zone can fix the soil and prevent floods and prevent secondary pollution caused by the outflow of sewage; during heavy rains, the plant fence can not only prevent foreign matter from the rainstorm from entering the ditch and cause blockage or pollution through the blocking effect of the pebble belt and plant roots, stems and leaves, but also can evenly Buffer the amount of storm water and protect the ecological ditch system. The associated system composed of plant fences and ecological ditch units can form a relatively high-level ecological community, while strengthening sewage treatment, it can also form a good coastal ecological landscape and regulate the local water, soil and climate.

In particular, the emergent plants in the present invention include reeds, cattails, water calamus, cannas and local indigenous plants, and shrubs include cattails, hibiscus, phoenix, wisteria and the like. The selection of species should maximize the proportion of native plants and avoid introducing wetland plants to destroy the existing local ecological balance. The proportion of planting is determined according to local conditions.

In the utility model, the compound ecological ditches for treating non-point source sewage in villages can be equipped with overflow weirs at the end, which are respectively connected to farmland irrigation ponds and receiving water bodies and set up diversion weirs. The tail water is discharged into the ponds and ditches for reuse in the dry season, and directly discharged in the rainy season. into natural bodies of water. Constructed wetlands and pre-storage systems can also be added in areas where conditions permit for advanced treatment of sewage.

In the autumn of each year, the plants of the compound ecological ditch unit and the plant fence need to be harvested, and the plants should be disposed of through anaerobic composting, livestock feeding, and deep processing of economic plants to prevent secondary pollution of nitrogen and phosphorus pollutants, and at the same time achieve environmental protection. The economic benefits are given back to the people.

Claims (5)

1. the complex ecological irrigation canals and ditches of processing face source, village sewage, comprise grid, sedimentary adjustive pool, modular ecological canal, hedgerow plant and reclamation set, it is characterized in that: described modular ecological canal comprise ecological canal unit (1) with wetland irrigation canals and ditches unit (2), two kinds of units alternately settings, (1) (3) water outlet place is (2) equipped with interception drop dam with wetland irrigation canals and ditches unit in ecological canal unit, (3) described interception drop dam is provided with triangle overflow weir in upper end, and lower end sets out the mouth of a river and water control valve is set (7).

2. the complex ecological irrigation canals and ditches of face source, processing as claimed in claim 1 village sewage, is characterized in that: at the bottom of described ecological canal unit ⑴，Qi Bian Bi and pond, (9) kind is implanted with humidogene emergent, at the bottom of canal, every the mixed laying nitrogen of 1-3m phosphorus, tackle case (8).

3. the complex ecological irrigation canals and ditches of face source, processing as claimed in claim 2 village sewage, is characterized in that: (8) described nitrogen phosphorus interception case is filled with slag in inside, and outside surface is plastics or metal geotechnique graticule mesh.

4. the complex ecological irrigation canals and ditches of face source, processing as claimed in claim 1 village sewage, is characterized in that: (5) (2) described wetland irrigation canals and ditches unit, comprise Multi-layer ecological filtrate, and (4) ecological filtrate (5) upper surface kind is implanted with wetland plant; Described ecological filtrate each metafiltration material is (5) according to particle diameter reduces gradually from top to bottom order setting.

5. the complex ecological irrigation canals and ditches of face source, processing as claimed in claim 1 village sewage, it is characterized in that: the described modular ecological canal left and right sides is provided with hedgerow plant, hedgerow plant comprise cobble band (10), humidogene draft emergent (11) with wetland shrub (12), (10) described cobble band has the gradient of 3-10%, cobble band (10) within the scope of outside 2 meters dense planting humidogene draft emergent (11) with wetland shrub (12).

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