Surface runoff purification system and purification method

Abstract

The present invention provides a surface runoff purification system and purification method, which solves the influence of the often flooded area on the effective volume, maximizes the effective volume of the purification system, and enhances the pollutant removal effect by increasing the effective residence time of the runoff; at the same time, the above-mentioned emptying process helps to release the adsorption capacity of the often flooded area in the filling area, and after emptying, this area can be in contact with oxygen to achieve desorption and degradation of pollutants. After the adsorption site is regenerated, sufficient adsorption capacity can be provided to remove pollutants in the next rainfall runoff, and efficient utilization of the effective volume and the adsorption capacity of the filler can be achieved.

Description

Technical Field

[0001] The invention relates to the field of water pollution control, and in particular to a surface runoff purification system and a purification method. Background Art

[0002] The buffer zone of rivers and lakes is a hot spot for energy and material exchange between water and land, and is crucial to reducing the impact of land pollution on water ecology and water environment. The construction of traditional shorelines is mainly based on vegetation buffer zones, which rely on the interception and adsorption of soil and plant roots to intercept pollutants, and then achieve pollutant degradation through the metabolism of microorganisms and plants. Due to its limited effect and slow reaction rate, it often takes a lot of land to build a wider buffer zone to effectively protect the receiving water body. For urban river and lake shore areas with limited land, building a buffer zone with efficient runoff pollution purification function has become a technical problem in water environment management. The inventor has disclosed a method for purifying surface runoff (CN 116874130 A), which can achieve highly polluted initial rain entering the bottom filler matrix, and the later clean rainwater is simply treated from the surface covering vegetation layer. This method introduces the filler matrix into the buffer zone to increase the porosity and permeability, and adopts a vertical baffle structure to increase the flow path of the runoff so that the pollutants are fully in contact with the filler. Then, with the help of the biofilm on the surface of the filler, the metabolic removal effect of microorganisms on pollutants is enhanced, thereby achieving graded treatment of runoff in a limited space and increasing the volumetric load. It is suitable for the construction of river and lake buffer zones in high-density urban built-up areas.

[0003] The key to the existing technology lies in the hierarchical treatment of the water quality characteristics of runoff pollution, that is, the high concentration of pollutants in the initial rain enters the bottom filler area with high load, and the clean rainwater in the later period enters the covering vegetation layer with average surface purification effect; for the matrix filler, the gravel layer, ceramsite layer and adsorption and phosphorus removal layer are sequentially passed through the baffle design to remove SS, COD, ammonia nitrogen and TP respectively. The removal of pollutants such as COD and ammonia nitrogen is divided into two processes: one is that the runoff in the rainy period quickly filters the filler, and the pollutants are adsorbed on the filler and removed from the water; the other is that the pollutants on the surface of the filler and the biofilm in the dry period are oxidized and degraded to achieve desorption, and the adsorption sites are released to intercept the pollutants of the next rainfall runoff again. However, the following defects still need to be solved:

[0004] First, oxygen supply and pollutant degradation during the dry season are important links in desorption, which directly affect the adsorption and removal effect of pollutants in the next cycle. However, the matrix filler in the prior art is located underground and does not have a powered aeration device. In addition, the biofilm on the surface of the filler will cause a certain blockage and limit the transmission and diffusion of oxygen, which limits the desorption process and makes it difficult to ensure the decontamination effect of the buffer zone.

[0005] Secondly, due to the presence of vertical baffles, rainwater runoff will accumulate in the direction of the water coming from the bottom baffles, so that the fillers in the water accumulation area are submerged below the liquid surface even in the dry season and cannot come into contact with the air. This submerged area is defined as the "normal submerged area". The fillers and biofilms in the normal submerged area cannot come into contact with oxygen in the air, and cannot be desorbed and released in time during the dry season, resulting in a reduction in the adsorption capacity of the buffer zone. During the next rainfall, the filler area cannot provide enough adsorption sites, resulting in the leakage of pollutants or failure to achieve the set effluent water quality target, or a larger matrix filler area must be excavated to ensure the purification effect;

[0006] Finally, the frequently flooded area causes the effective volume of the buffer zone to be reduced by about 30%, which greatly reduces the effective residence time of the next runoff in the buffer zone, affects the removal of pollutants through adsorption reactions, and deteriorates the effluent water quality, thus failing to achieve the expected design goals.

[0007] Therefore, developing a river and lake buffer zone that can achieve efficient utilization of effective volume and filler adsorption capacity has become a research direction in this field. Summary of the invention

[0008] The invention provides a surface runoff treatment device, which has the characteristics of realizing efficient utilization of effective volume and filler adsorption capacity.

[0009] The invention also provides a surface runoff treatment method, which has the characteristics of high utilization rate of effective volume and filler adsorption capacity.

[0010] The present invention provides a surface runoff purification system, wherein the system comprises:

[0011] The water seepage layer is set obliquely for downstream flow and seepage of surface runoff;

[0012] A filtration zone is arranged below the water seepage layer, and surface runoff passes through the water seepage layer and enters the filtration zone for filtration;

[0013] The purification area is arranged obliquely, along the surface runoff direction, at the end of the filtering area, and the purification area purifies the filtered surface runoff, and the purified surface runoff is discharged into rivers and lakes;

[0014] The purification area is divided into a plurality of interconnected filling areas by the partition;

[0015] A water collection area, connected to the water outlet of the filtration area, where the filtered surface runoff is collected, and the water collection area is connected to the head end filling area of ​​the purification area;

[0016] A water switch is arranged at the bottom of the filter area at the end of the surface runoff water inflow direction;

[0017] At least one valve is arranged in the direction of surface runoff water at the intersection of the inner bottom of the filling area and the partition, and the valve is connected to the outside through a drain pipe;

[0018] The water switch is weakly connected to the valve.

[0019] The surface runoff purification system as described above, wherein the inlet and outlet of the filling area are respectively arranged at the upper and lower ends of the filling area; the inlet of the filling area located at the head end is at the lower end, and the outlet of the filling area located at the tail end is at the upper end.

[0020] The surface runoff purification system as described above, wherein it further comprises a water retaining plate, which protrudes upward and is arranged at the end of the water seepage layer;

[0021] The water retaining plate also blocks between the filtering area and the purification area.

[0022] The surface runoff purification system as described above, wherein at least one group of the filling areas located at the head end of the purification area is an ammonia nitrogen adsorption purification area, and at least one group of the filling areas located at the end is a phosphorus removal purification area;

[0023] The ammonia nitrogen adsorption purification zone is filled with ammonia nitrogen adsorption filler, and the phosphorus removal purification zone is filled with phosphorus removal agent.

[0024] In the surface runoff purification system as described above, the volume of the ammonia nitrogen adsorption purification zone satisfies Formula 1:

[0025] Formula 1;

[0026] Among them, V 2 is the cell capacity of the ammonia nitrogen adsorption unit, m 3 ;

[0027] α 2 is the safety factor;

[0028] is the concentration of ammonia nitrogen in the average rainfall runoff, mg / L;

[0029] is the environmental quality standard of ammonia nitrogen in receiving water, mg / L;

[0030] V 1 is the average rainfall runoff volume in the service area, m 3 ;

[0031] c is the ammonia nitrogen adsorption capacity of the filler, mg / g;

[0032] is the bulk density of the filler, kg / m 3 .

[0033] In the surface runoff purification system as described above, a ventilation pipe communicating with the outside is provided in the filling area.

[0034] In the surface runoff purification system as described above, the ventilation pipe is in contact with the bottom of the purification area, and the pipe wall of the ventilation pipe is provided with at least one ventilation hole communicating with the filling area.

[0035] The surface runoff purification system as described above, wherein a vegetation layer is provided on the top of the purification area, and the non-seepage surface runoff overflows from the water retaining plate at the end of the seepage layer and enters the vegetation layer, and then is discharged downstream into the river or lake;

[0036] A water-impermeable member is arranged between the vegetation layer and the purification area.

[0037] The present invention also provides a surface runoff purification method, wherein any of the above surface runoff purification systems is used, comprising the following steps:

[0038] The surface runoff generated by rainfall flows into the purification system, and the surface runoff infiltrates into the filtration area through the permeable layer;

[0039] The surface runoff contacts the water switch, and the water switch controls the valve to close, so that the surface runoff cannot enter the drain pipe;

[0040] The surface runoff filtered in the filtering area enters the purification area;

[0041] The surface runoff purified in the purification area is discharged into rivers and lakes;

[0042] When the rainfall stops, the water level in the filtration area drops, the accumulated water stops contacting the water switch, the water switch controls the valve to open, and the accumulated water in the filtration area and the purification area enters the drain pipe and is discharged into rivers and lakes.

[0043] The surface runoff purification method as described above, wherein, when the accumulated water in the filtering area and the purification area enters the drain pipe, air also enters the purification area through the ventilation pipe to degrade the pollutants in the purification area.

[0044] The surface runoff treatment device provided by the present invention has the characteristic of realizing efficient utilization of effective volume and filler adsorption capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0046] Figure 1 A structural diagram of the surface runoff purification system provided by the present invention;

[0047] Figure 2 Working status of surface runoff purification system Figure 1 ;

[0048] Figure 3 Working status of surface runoff purification system Figure 2 ;

[0049] Figure 4 Working status of surface runoff purification system Figure 3 ;

[0050] Figure 5 Working status of surface runoff purification system Figure 4 ;

[0051] Figure 6 This is a structural diagram of the ventilation pipe.

[0052] Description of reference numerals:

[0053] 1- water seepage layer;

[0054] 2- Filtration area;

[0055] 3- Purification area;

[0056] 4- Partition;

[0057] 5-filling area;

[0058] 6-Catchment area;

[0059] 7-Water switch;

[0060] 8- Valve;

[0061] 9-Drain pipe;

[0062] 10-water retaining plate;

[0063] 11- Ventilation tube;

[0064] 12-vegetation layer;

[0065] 13- Watertight parts;

[0066] 1101-Spiral air duct;

[0067] 1102-Perforated trachea.

[0068] The above drawings have shown clear embodiments of the present application, which will be described in more detail later. These drawings and text descriptions are not intended to limit the scope of the present application in any way, but to illustrate the concept of the present application to those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical scheme and advantages of the present application clearer, the technical scheme in the embodiment of the present application will be described in more detail below in conjunction with the drawings in the preferred embodiments of the present application. In the drawings, the same or similar reference numerals throughout represent the same or similar parts or parts with the same or similar functions. The described embodiments are part of the embodiments of the present application, not all of the embodiments. The embodiments described below with reference to the drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limitations on the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application. The embodiments of the present application are described in detail below in conjunction with the drawings.

[0070] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0071] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are orientations or positional relationships based on the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0072] The terms "first", "second" and "third" (if any) in the specification and claims of this application and the above drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence.

[0073] In addition, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or display comprising a series of steps or elements is not necessarily limited to those steps or elements explicitly listed, but may include other steps or elements not explicitly listed or inherent to such process, method, product, or display.

[0074] In the prior art, it is difficult for the filler located underground to contact oxygen, which makes it difficult to ensure the decontamination effect of the buffer zone; at the same time, the filler in the flooded area often cannot release the adsorption sites in time during the dry period, resulting in a reduction in the adsorption capacity of the buffer zone; in addition, the vertical baffle design reduces the effective volume of the buffer zone by about 30%. Therefore, if the structure of the buffer zone can be changed to make the filler easy to contact with oxygen and release the effective volume, the above problems can be solved.

[0075] Based on this, Figure 1 As shown, the first aspect of the present invention provides a surface runoff purification system, the system comprising:

[0076] The inclined seepage layer 1 is used for downstream flow and seepage of surface runoff;

[0077] The filter area 2 is arranged below the water seepage layer, and the surface runoff passes through the water seepage layer 1 and enters the filter area 2 for filtration;

[0078] The purification area 3 is arranged obliquely, along the surface runoff direction, at the end of the filtering area 2, and the purification area 3 purifies the filtered surface runoff, and the purified surface runoff is discharged into rivers and lakes;

[0079] The purification area 3 is divided into multiple groups of interconnected filling areas 5 by partitions 4;

[0080] The water collection area 6 is connected to the water outlet of the filtration area 2, and the surface runoff after filtration is collected in the water collection area 6. The water collection area 6 is connected to the filling area 5 at the head end of the purification area 3;

[0081] A water switch 7 is arranged at the bottom of the filter area 2 at the end of the surface runoff water inflow direction;

[0082] At least one valve 8 is arranged in the direction of surface runoff water at the intersection of the inner bottom of the filling area 5 and the partition 4, and the valve is connected to the outside through the drain pipe 9;

[0083] The water switch 7 is electrically connected to the valve 8 .

[0084] The surface runoff purification system provided by the present invention is also called a river and lake buffer zone, which is set up on the banks of rivers and lakes to intercept and treat the surface runoff formed in the early stage of rainfall and then discharge it into rivers and lakes, thereby reducing the impact of surface runoff with high pollutants on the water quality of rivers and lakes. The purification system is set up in a slope as a whole, constructing a flow condition for surface runoff from high to low, wherein the high end is the water inflow direction of the surface runoff, and the low end is the flow direction of the surface runoff.

[0085] The water seepage layer 1 can be paved with permeable bricks, and its function is to allow a part of the surface runoff to flow through while another part of the surface runoff infiltrates through the water seepage layer 1. The present invention does not limit the laying slope of the water seepage layer 1, and its slope can be consistent with the overall slope of the purification system. In one embodiment, the slope can be set to 10-20%. The present invention also does not limit the laying length of the water seepage layer 1, and in one embodiment, the laying length can be set to 1-2m.

[0086] The filter area 2 is arranged below the water seepage layer, and the infiltration part of the surface runoff enters the filter area 2 through the water seepage layer 1 for filtration to remove the SS contained therein. The filter area contains filter material, and the present invention does not limit the specific type of the filter material. In one embodiment, it can be gravel.

[0087] The purification zone 3 is laid at the same angle as the purification system and is arranged at the end of the filter zone 2 along the direction of the surface runoff. The purification zone 3 is used to purify the surface runoff after filtering through the filter zone 2, and the purified surface runoff is discharged into rivers and lakes. The purification zone contains purification fillers, which play a role in removing ammonia nitrogen, COD and phosphorus in the surface runoff. The present invention does not limit the specific type of filler. In one embodiment, the purification zone may be provided with ammonia nitrogen adsorption fillers for removing ammonia nitrogen and COD in the surface runoff, and a dephosphorization agent may also be provided for removing phosphorus in the surface runoff. Among them, the specific information of the ammonia nitrogen adsorption filler is one or a combination of ceramsite, zeolite, and volcanic rock, with a particle size of 5-30mm and a porosity of 40-60%. The specific information of the dephosphorization agent is kaolin, iron ore, etc., with a particle size of 3-10mm and an effective ingredient Al / Fe content greater than 30%. The ammonia nitrogen adsorption filler and the dephosphorization agent can be collectively referred to as fillers.

[0088] The purification area 3 is divided into a plurality of interconnected filling areas 5 by partitions 4. The partitions 4 play a water blocking role, so that the surface runoff is blocked by the partitions 4 and forms a flooded area in the filling area 5, thereby increasing the contact area between the surface runoff and the filler in the filling area 5.

[0089] The filtration area 2 also includes a water collection area 6, which is connected to the water outlet of the filtration area 2, and the filtered surface runoff is collected in the water collection area 6. The water collection area 6 is connected to the head end filling area 5 of the purification area 3, and the filtered surface runoff enters the purification area 3 through the head end filling area 5 of the purification area 3. Among them, the head end filling area 5 of the purification area 3 is the first section of the filling area 5 in the direction of the surface runoff in the purification area 3. Figure 1 The middle is the first filling area 5 on the left side of the purification area 3.

[0090] The system also includes a water switch 7, which is arranged at the bottom of the filter area 2 in the direction of the surface runoff water. In addition, the system also includes at least one valve 8, which is arranged in the direction of the surface runoff water at the intersection of the inner bottom of the filling area 5 and the partition 4, and the valve 8 is connected to the outside through the drain pipe 9; in addition, the water switch 7 and the valve 8 are weakly connected.

[0091] refer to Figure 1 Since the filter area 2 is inclined, its bottom is high at one end and low at the other. The water switch 7 is arranged at the bottom of the surface runoff water direction end, that is, at the highest point of the bottom of the filter area 2, and higher than the highest liquid level of the normally flooded area.

[0092] refer to Figure 1 , at least one partition 4 intersects with the inner bottom of the filling area 5 to form an intersection. The intersection is divided into two sides by the partition 4, the first side is the side of the surface runoff water direction, and the second side is the side of the surface runoff flow direction. The valve 8 is set on the first side of the surface runoff water direction of the intersection. The function realized by this structure is: when there is water accumulation in the structure formed by the intersection of the partition 4 and the inner bottom of the filling area 5, the valve 8 is set on the side of the surface runoff water direction of the intersection so that all the above-mentioned water accumulation can be emptied through the valve 8, thereby realizing the complete emptying of the filling area 5, and there will be no problem that the filler in the often flooded area cannot be desorbed and released in time during the dry period due to the inability to empty the accumulated water, thereby reducing the adsorption capacity of the buffer zone.

[0093] In addition, the valve 8 is connected to the outside through the drain pipe 9, wherein the outside refers to the environment outside the system. The valve 8 is connected to the outside through the drain pipe 9, which means that the accumulated water in the filling area 5 can be discharged to the external environment, i.e., the external water body, through the valve 8 and the drain pipe 9 in sequence.

[0094] In the system provided by the present invention, the water switch 7 has a weak electrical connection with all valves 8, that is, the water switch 7 can control all valves 8 through the electric transmission system, specifically, control the opening and closing states of all valves 8. The control logic is as follows: when the water switch 7 is in contact with water, all valves 8 are controlled to be in a closed state; when the water switch 7 is out of contact with water, all valves 8 are controlled to be in an open state.

[0095] The surface runoff purification system provided by the present invention works as follows:

[0096] refer to Figure 2 The initial rain runoff is intercepted by the water retaining plate 10, seeps through the water permeable layer 1 to the filtration area 2, and contacts the water switch 7, which controls all valves 8 to be closed, so that the runoff cannot enter the drain pipe 9. The liquid level at the upstream of the partition 4 at the bottom of the filling area 5 at the head end of the purification area 3 begins to rise, and the water level gradually fills the filling area 5.

[0097] refer to Figure 3 , the runoff fills the filling area 5 at the head end of the purification area 3 and then flows into the next filling area 5, filling each filling area 5 in turn, and finally completely filling the entire surface runoff purification system. In this process, SS in the runoff is filtered out in the purification area 3, ammonia nitrogen and COD are removed by the ammonia nitrogen adsorption filler set in the purification area 3, and phosphorus is adsorbed and removed by the phosphorus removal agent set in the purification area 3. The purified runoff is discharged into the river and lake from the outlet at the end of the purification area 3.

[0098] refer to Figure 4 After the rainfall ends, the liquid level in the surface runoff purification system begins to decrease continuously. Due to the barrier of the partition 4, the partially filled area 5 of the purification area 3 is still in a flooded state, becoming a normally flooded area. Figure 4 In the prior art, the effective volume of the buffer zone is reduced by about 30% due to the frequently flooded area, which greatly reduces the effective residence time of the next runoff in the buffer zone.

[0099] In the surface runoff purification system provided by the present invention, when the liquid level in the filtering area 2 drops below the water switch 7, the water switch 7 stops contacting with the water, and all valves 8 are controlled to be in an open state. The accumulated water in the filling area 5 is discharged into the external water body through the valve 8 and the drain pipe 9 in turn, and the surface runoff purification system is completely emptied.

[0100] The surface runoff purification system provided by the present invention solves the influence of the often flooded area on the effective volume through the design of the emptying facility, maximizes the effective volume of the purification system, and enhances the removal effect of pollutants by increasing the effective residence time of the runoff; at the same time, the above-mentioned emptying process helps to release the adsorption capacity of the often flooded area in the filling area 5. After emptying, this area can be in contact with oxygen to achieve desorption and degradation of pollutants. After the adsorption site is regenerated, sufficient adsorption capacity can be provided to remove pollutants in the next rainfall runoff. Therefore, the surface runoff purification system provided by the present invention has the characteristics of being able to achieve efficient utilization of the effective volume and the adsorption capacity of the filler.

[0101] Further, refer to Figure 1 , the inlet and outlet of the filling area 5 are respectively arranged at the upper and lower ends of the filling area 5; the inlet of the filling area 5 at the head end is at the lower end, and the outlet of the filling area 5 at the tail end is at the upper end. The above design increases the water flow path of the initial rainwater in the purification area 3 through the vertical tortuous flow of the runoff, improves the mass transfer efficiency between the soluble pollutants and the adsorption material, and improves the purification efficiency. The inlet of the filling area 5 at the head end of the purification area 3 is arranged at the lower end to correspond to the water collection area 6, so that the runoff forms a baffled channel after entering the purification area 3, which improves the mass transfer efficiency between the pollutants and the adsorption material.

[0102] In one embodiment, Figure 1As shown, the surface runoff purification system provided by the present invention further comprises a water retaining plate 10, which protrudes upward and is arranged at the end of the water seepage layer 1. The water retaining plate 10 also blocks between the filtering area 2 and the purification area 3.

[0103] The water retaining plate 10 has two functions: first, the water retaining plate 10 protrudes upward and is arranged at the end of the water seepage layer 1 to intercept a part of the initial runoff with poor water quality, so that it can enter the filter area 2 through the water seepage layer 1. The filter area 2 can ensure that the initial rainwater can completely seep into the filter area 2, and the subsequent runoff with better water quality will pass over the water retaining plate 10 and flow into the river and lake from the top of the surface runoff purification system; second, the water retaining plate 10 blocks between the filter area 2 and the purification area 3, so that the filter area 2 can only enter the purification area 3 through the water collection area 6, thereby ensuring the treatment effect of the surface runoff purification system.

[0104] Specifically, at least one group of filling areas 5 at the head end of the purification area 3 is an ammonia nitrogen adsorption purification area, and at least one group of filling areas 5 at the end is a phosphorus removal purification area; the ammonia nitrogen adsorption purification area is filled with ammonia nitrogen adsorption filler, and the phosphorus removal purification area is filled with a phosphorus removal agent. The ammonia nitrogen adsorption filler and the phosphorus removal agent can be collectively referred to as fillers. The present invention does not limit the specific number and ratio of ammonia nitrogen adsorption purification areas and phosphorus removal purification areas, and can be adjusted according to demand. For example, in one embodiment, Figure 1 In the surface runoff purification system shown, the purification area 3 is divided into five filling areas 5 by two partitions 4 arranged at the top and two partitions 4 arranged at the bottom, among which the first to fourth filling areas 5 along the surface runoff direction can be set as ammonia nitrogen adsorption purification areas and filled with nitrogen adsorption fillers; and the fifth filling area 5 along the surface runoff direction can be set as a phosphorus removal purification area and filled with a phosphorus removal agent.

[0105] In one embodiment, the volume of the ammonia nitrogen adsorption purification zone satisfies Formula 1:

[0106] Formula 1;

[0107] Among them, V 2 is the cell capacity of the ammonia nitrogen adsorption unit, m 3 ;

[0108] α 2 is the safety factor;

[0109] is the concentration of ammonia nitrogen in the average rainfall runoff, mg / L;

[0110] is the environmental quality standard of ammonia nitrogen in receiving water, mg / L;

[0111] V 1 is the total average rainfall runoff in the service area, m 3 ;

[0112] c is the ammonia nitrogen adsorption capacity of the filler, mg / g;

[0113] is the bulk density of the filler, kg / m 3 .

[0114] The above method can be used to more accurately calculate the volume of the ammonia nitrogen adsorption purification zone, thereby reducing the land area and engineering cost of the surface runoff purification system while ensuring the treatment effect.

[0115] In one embodiment, the volume of the ammonia nitrogen adsorption purification zone may be calculated using the following process:

[0116] There are many rainwater outlets along a lake, each of which serves an area of ​​0.5ha. The maximum rainfall intensity in the area is 200mm. The maximum runoff of a single rainfall without considering evaporation and infiltration is 1000m 3 ;

[0117] Through actual runoff sampling monitoring (it can also be theoretically calculated through models such as SWMM), the average rainfall runoff concentration of the outlet was measured to range from 0.20 to 14.4 mg / L, with an average concentration of 8.0 mg / L. Take 8 mg / L and the safety factor α2 as 1.8;

[0118] The ammonia nitrogen adsorption filler is ceramsite, and its bulk density is 400kg / m 3 , the ammonia nitrogen adsorption capacity is 10mg / g;

[0119] The functional area of ​​the lake is designated as Landmark Class III water, so the ammonia nitrogen effluent concentration in the buffer zone is taken as 1 mg / L.

[0120] Calculation results:

[0121] Ammonia nitrogen adsorption area volume V 2 =1.8×(8-1)×1000÷(400×10)=3.15m 3 .

[0122] If the depth and width of the purification zone 3 are designed to be 1 m, the length is 3.15 m, and can be designed into 4 grids connected up and down in sequence through folding plates, with each grid being 0.8 m long.

[0123] In one embodiment, Figure 1 As shown, a vent pipe 11 communicating with the outside is provided in the filling area 5. The vent pipe 11 can introduce external air into the filling area 5 to participate in the decomposition of pollutants adsorbed by the filler in the filling area 5.

[0124] Specifically, refer to Figure 4After the rainfall ends, the liquid level in the surface runoff purification system begins to decrease continuously. Due to the negative pressure, part of the oxygen enters the filling area 5 through the ventilation pipe 11, so that the pollutants (COD and ammonia nitrogen) adsorbed above the liquid surface are oxidized and degraded, and the capacity of the ammonia nitrogen adsorption filler is partially restored;

[0125] Further, refer to Figure 5 After the surface runoff purification system is emptied, oxygen continues to enter the deep layer of the purification system through the ventilation pipe 11 through negative pressure, so that the pollutants attached to the surface of the filler are completely oxidized and degraded, the adsorption capacity is completely restored, and it can be used cyclically, ultimately achieving rapid adsorption and removal during rainfall and complete degradation and recovery after the rain stops.

[0126] In one embodiment, the ventilation pipe 11 is in contact with the bottom of the purification area 3, and the wall of the ventilation pipe 11 is provided with at least one ventilation hole communicating with the filling area 5. Figure 6 The wall of the ventilation pipe 11 is provided with at least one ventilation hole connected to the filling area 5, and the ventilation hole is a through hole provided in the wall of the pipe and is connected to the filling area 5. When the ventilation pipe 11 contacts the bottom of the purification area 3, external oxygen can be sent into the deep packing of the purification area 3 through the ventilation hole to degrade the pollutants adsorbed therein.

[0127] More specifically, the ventilation pipe 11 is composed of a spiral wind tube 1101 located above the ground and a perforated air pipe 1102 located underground. The spiral wind tube 1101 is inserted at the axis center of the perforated air pipe 1102. The vertical gap on the surface of the spiral wind tube 1101 can be driven by natural wind force, so that the spiral wind tube 1101 rotates around the axis of the perforated air pipe 1102, and forms an outer vortex high pressure and an inner low pressure inside the wind tube.

[0128] Aiming at the problem of difficulty in reoxygenating the material in the purification zone 3, the design of the ventilation pipe 11 can increase the reoxygenation capacity of the filler during the emptying period and the pollutant degradation effect. Specifically, it includes the following processes:

[0129] Step 1: Natural wind energy drives the spiral wind tube 1101 to rotate, and at the same time, air and oxygen enter the spiral wind tube 1101 and perform swirl motion. Due to the centrifugal force, high pressure is formed at the inner edge of the spiral wind tube 1101 and low pressure is formed in the center;

[0130] Step 2: The high-pressure cyclone gas enters the deep layer of the packing along the perforated air pipe 1102, and under the action of the centrifugal force of the cyclone power, enters the pores of the packing from the through holes set on the wall of the perforated air pipe 1102, and the oxygen in the air enters the interior of the packing;

[0131] Step 3: The pollutants adsorbed by the filler come into contact with oxygen, and through a series of redox reactions, the adsorbed ammonia nitrogen and COD are completely oxidized and degraded, and waste gases such as carbon dioxide and nitrogen are produced;

[0132] Step 4: The exhaust gas generated by the packing will increase the air pressure inside the packing. Part of the exhaust gas will directly diffuse upward along the pores of the packing to the outside of the packing, and other exhaust gas will be squeezed into the perforated air pipe 1102 from the small holes by the pressure of the packing, and will be sucked upward under the action of the low pressure in the center of the perforated air pipe 1102, and finally the exhaust gas will be discharged from the spiral wind tube 1101.

[0133] The surface runoff purification system provided by the present invention uses a ventilation pipe 11 with a specific structure, which uses natural wind energy to increase the airflow dynamics of the negative pressure intake, improves the reoxygenation effect of the buffer zone filler, achieves energy saving and consumption reduction in the pollutant removal process, helps to improve the degradation and removal effect of pollutants in the buffer zone, effectively restores the adsorption capacity of the purification area 3, and ensures the sustainability of the decontamination effect of the purification system.

[0134] In one embodiment, a vegetation layer 12 is provided on the top of the purification area 3, and the non-seepage surface runoff overflows from the water retaining plate 10 at the end of the water seepage layer 1 and enters the vegetation layer 12, and then is discharged into the river or lake; a water-impermeable member 13 is provided between the vegetation layer 12 and the purification area 3. Specifically, the water-impermeable member 13 can be a geotextile. The water retaining plate 10 at the end of the water seepage layer 1 can completely intercept the initial rain runoff, allowing it to enter the filtration area 2, and the clean rainwater in the later stage can overflow the water retaining plate 10 through the vegetation layer 12 and then be discharged into the river or lake downstream.

[0135] A second aspect of the present invention provides a surface runoff purification method, which is performed using any surface runoff purification system provided by the first aspect of the present invention, and specifically comprises the following steps:

[0136] The surface runoff generated by rainfall flows into the purification system, and the surface runoff infiltrates through the permeable layer 1 to the filtration area 2;

[0137] The surface runoff contacts the water switch 7, and the water switch 7 controls the valve 8 to close, so that the surface runoff cannot enter the drain pipe 9;

[0138] The surface runoff filtered in the filtration area 2 enters the purification area 3;

[0139] The purified surface runoff in purification area 3 is discharged into rivers and lakes;

[0140] When the rainfall stops, the water level in the filtration area 2 drops, the accumulated water stops contacting the water switch 7, the water switch 7 controls the valve 8 to open, and the accumulated water in the filtration area 2 and the purification area 3 enters the drain pipe 9 and is discharged into the river or lake.

[0141] Specifically, the process includes the following:

[0142] refer to Figure 2The initial rain runoff is intercepted by the water retaining plate 10, seeps through the water permeable layer 1 to the filtration area 2, and contacts the water switch 7, which controls all valves 8 to be closed, so that the runoff cannot enter the drain pipe 9. The liquid level at the upstream of the partition 4 at the bottom of the filling area 5 at the head end of the purification area 3 begins to rise, and the water level gradually fills the filling area 5.

[0143] refer to Figure 3 , the runoff fills the filling area 5 at the head end of the purification area 3 and then flows into the next filling area 5, filling each filling area 5 in turn, and finally completely filling the entire surface runoff purification system. In this process, SS in the runoff is filtered out in the purification area 3, ammonia nitrogen and COD are removed by the ammonia nitrogen adsorption filler set in the purification area 3, and phosphorus is adsorbed and removed by the phosphorus removal agent set in the purification area 3. The purified runoff is discharged into the river and lake from the outlet at the end of the purification area 3.

[0144] refer to Figure 4 After the rainfall ends, the liquid level in the surface runoff purification system begins to decrease continuously. Due to the obstruction of the partition 4, part of the filling area 5 of the purification area 3 is still in a flooded state, becoming a normally flooded area. When the liquid level in the filtration area 2 drops below the water switch 7, the water switch 7 stops contacting with water, and all valves 8 are controlled to be in the open state. The accumulated water in the filling area 5 is discharged into the external water body through the valve 8 and the drain pipe 9 in turn, and the surface runoff purification system is completely emptied.

[0145] Furthermore, the surface runoff purification method provided by the present invention also includes: when the accumulated water in the filtration area 2 and the purification area 3 enters the drain pipe 9, air also enters the purification area 3 through the ventilation pipe 11 to degrade the pollutants in the purification area 3.

[0146] Specifically, the process includes the following:

[0147] refer to Figure 4 After the rainfall ends, the liquid level in the surface runoff purification system begins to decrease continuously. Due to the negative pressure, part of the oxygen enters the filling area 5 through the ventilation pipe 11, so that the pollutants adsorbed above the liquid surface are oxidized and degraded, and the capacity of the ammonia nitrogen adsorption filler is partially restored;

[0148] refer to Figure 5 After the surface runoff purification system is emptied, oxygen continues to enter the deep layer of the purification system through the ventilation pipe 11 through negative pressure, so that the pollutants attached to the surface of the ammonia nitrogen adsorption filler are completely oxidized and degraded, and the adsorption capacity is completely restored, which can be used cyclically, and finally achieve rapid adsorption and removal during rainfall and complete degradation and recovery after the rain stops.

[0149] Finally, it should be noted that those skilled in the art will readily conceive of other embodiments of the present invention after considering the specification and practicing the invention disclosed herein. The present invention is intended to cover any variations, uses or adaptations of the present invention, which follow the general principles of the present invention and include common knowledge or customary technical means in the art not disclosed by the present invention, are not limited to the precise structure described above and shown in the drawings, and may be modified and changed in various ways without departing from the scope thereof. The scope of the present invention is limited only by the appended claims.

Claims

1. A surface runoff purification system, characterized in that: include: The inclined seepage layer (1) is used for downstream flow and seepage of surface runoff; A filtration area (2) is arranged below the water seepage layer, and surface runoff passes through the water seepage layer (1) and enters the filtration area (2) for filtration; The purification area (3) is arranged obliquely and is arranged at the end of the filtering area (2) along the direction of the surface runoff. The purification area (3) purifies the filtered surface runoff, and the purified surface runoff is discharged into rivers and lakes; The purification area (3) is divided into a plurality of interconnected filling areas (5) by partitions (4); A water collection area (6) is connected to the water outlet of the filtration area (2), and the filtered surface runoff is collected in the water collection area (6). The water collection area (6) is connected to the head end filling area (5) of the purification area (3); A water switch (7) is arranged at the bottom of the filter area (2) at the end of the surface runoff water inflow direction; At least one valve (8) is arranged in the direction of surface runoff water at the intersection of the inner bottom of the filling area (5) and the partition (4), and the valve (8) is connected to the outside through a drain pipe (9); The water switch (7) is weakly electrically connected to the valve (8).

2. The surface runoff purification system according to claim 1, characterized in that: The inlet end and the outlet end of the filling area (5) are respectively arranged at the upper and lower ends of the filling area (5); the inlet end of the filling area (5) located at the head end is at the lower end, and the outlet end of the filling area (5) located at the tail end is at the upper end.

3. The surface runoff purification system according to claim 1, characterized in that: It also includes a water retaining plate (10) which protrudes upwards and is arranged at the end of the water permeable layer (1); The water retaining plate (10) also blocks between the filtering area (2) and the purification area (3).

4. The surface runoff purification system according to claim 1, characterized in that: At least one group of the filling areas (5) located at the head end of the purification area (3) is an ammonia nitrogen adsorption purification area, and at least one group of the filling areas (5) located at the end is a phosphorus removal purification area; The ammonia nitrogen adsorption purification zone is filled with ammonia nitrogen adsorption filler, and the phosphorus removal purification zone is filled with phosphorus removal agent.

5. The surface runoff purification system according to claim 4, characterized in that: The volume of the ammonia nitrogen adsorption purification zone satisfies Formula 1: Formula 1; Wherein, V2 is the cell capacity of the ammonia nitrogen adsorption unit, m 3 ; α2 is the safety factor; is the concentration of ammonia nitrogen in the average rainfall runoff, mg / L; is the environmental quality standard of ammonia nitrogen in receiving water, mg / L; V1 is the total average rainfall runoff in the service area, m 3 ; c is the ammonia nitrogen adsorption capacity of the filler, mg / g; is the bulk density of the filler, kg / m 3 .

6. The surface runoff purification system according to claim 1, characterized in that: A ventilation pipe (11) communicating with the outside is provided in the filling area (5).

7. The surface runoff purification system according to claim 6, characterized in that: The ventilation pipe (11) is in contact with the bottom of the purification area (3), and the wall of the ventilation pipe (11) is provided with at least one ventilation hole communicating with the filling area (5).

8. The surface runoff purification system according to claim 1, characterized in that: A vegetation layer (12) is provided on the top of the purification area (3), and non-seepage surface runoff overflows from the water retaining plate (10) at the end of the seepage layer (1) and enters the vegetation layer (12), and then is discharged downstream into rivers and lakes; A water-impermeable member (13) is provided between the vegetation layer (12) and the purification area (3).

9. A surface runoff purification method, characterized in that: The surface runoff purification system according to any one of claims 1 to 8 comprises the following steps: Surface runoff generated by rainfall flows into the purification system, and the surface runoff infiltrates through the infiltration layer (1) into the filtration area (2); The surface runoff contacts the water switch (7), and the water switch (7) controls the valve (8) to close, so that the surface runoff cannot enter the drain pipe (9); The surface runoff after filtering in the filtering area (2) enters the purification area (3); The surface runoff purified in the purification area (3) is discharged into rivers and lakes; When the rainfall stops, the water level in the filtering area (2) drops, the accumulated water stops contacting the water switch (7), the water switch (7) controls the valve (8) to open, and the accumulated water in the filtering area (2) and the purification area (3) enters the drain pipe (9) and is discharged into rivers and lakes.

10. The surface runoff purification method according to claim 9, characterized in that: The process in which the accumulated water in the filtering area (2) and the purification area (3) enters the drain pipe (9) also includes air entering the purification area (3) through the ventilation pipe (11), thereby degrading the pollutants in the purification area (3).

Images