Small watershed river-channel and pond-separated ecological conservation system

Abstract

The present invention discloses a small watershed river-lake separation type ecological conservation system, which includes a separated conservation pond and a natural conservation pond. The separated conservation ponds are arranged at both sides of the natural conservation pond at intervals. River water is introduced through an ecological water retaining dam arranged in the main river course. The river water treated in the separated conservation pond then returns to the main river course and enters the next separated conservation pond. In this way, the ecological improvement of the river water can be carried out through circulation. The present invention establishes a "separated conservation pond" and a "sectional conservation pond for the main river course" through the "river-lake separation" method, realizes the combined operation of the steady state and dynamic state of the conservation pond, effectively avoids the damage of flood disasters to the facilities, and through the multi-type and flexible design of the conservation pond, maximally reduces pollutants such as nitrogen and phosphorus in the water body in an economic and ecological way, realizing the long-term treatment of the river course.

Description

Technical Field

[0001] The invention belongs to the technical field of small watershed wastewater treatment, and in particular relates to a "river-pond separation" type ecological conservation system for a small watershed river. Background Art

[0002] The existing pollution control of small watershed rivers generally refers to urban rivers, and generally adopts source control and pollution interception, ecological dredging, and supplemented by oxygenation and aeration, microbial agents, ecological floating islands, plant restoration and other technical measures. However, in the actual practice, the large differences between small watershed rivers and urban rivers are often ignored. In particular, urban rivers are part of the urban water system, and flood control and drainage are included in urban management. The urban drainage system is relatively complete, and the water level and water quality of the river are less affected by extreme weather such as heavy rain. Small watershed rivers flow through mountain fields. Under extreme weather conditions such as heavy rain and mountain torrents, some control facilities (such as aeration, floating islands, microbial agents, plant restoration, etc.) are faced with the possibility of being destroyed or failed, and post-disaster functional restoration takes a long time or may even be impossible to repair.

[0003] In addition, since the small river basins are spread across villages and farmlands, the influx of non-point source pollution such as initial rainwater, scattered aquaculture wastewater, and farmland drainage is difficult to control. After treatment, "re-blackening and re-stinking" occurs frequently, and the long-term effectiveness of conventional treatment measures is greatly reduced. It is urgent to propose solutions to the problems of scattered non-point source pollution on the basis of conventional treatment measures to maintain long-term treatment of small river basins. Summary of the invention

[0004] In view of the above problems, the present invention provides a "river-pond separation" type ecological conservation system for small watershed rivers to achieve long-term and stable management of the river.

[0005] The present invention is achieved through the following technical solutions:

[0006] A "river-pond separation" type ecological conservation system for a small watershed river, comprising a separated conservation pond and a natural conservation pond;

[0007] The separated conservation ponds are arranged at intervals on both sides of the natural conservation pond, and river water is introduced through the ecological water barrier arranged in the main river channel. The river water treated in the separated conservation ponds is then returned to the main river channel and enters the next separated conservation pond, and the cycle continues.

[0008] The natural conservation pond is obtained by setting an ecological water barrier in the main river channel;

[0009] The separated conservation ponds are divided into sedimentation conservation ponds, nitrogen removal conservation ponds, phosphorus removal conservation ponds, algae removal conservation ponds and composite conservation ponds, which are set up according to the water quality of the river and different functional requirements.

[0010] The ecological conservation system of the present invention sets multiple separated conservation ponds on both sides of the main river channel. The river water is introduced into the separated conservation ponds through the setting of ecological water retaining dams. After being treated in the separated conservation ponds, the river water is sent back to the main river channel, and continues to be treated in the natural conservation ponds separated by the ecological water retaining dams in the main river channel, and then enters the separated conservation ponds for treatment again. After repeating this process, it can be achieved. The separated conservation ponds are set according to the river water quality conditions and different functional requirements as sedimentation-type conservation ponds with the main function of removing sediment, denitrification-type conservation ponds with the main function of removing nitrogen pollutants, phosphorus removal-type conservation ponds with the main function of removing phosphorus pollutants, algae removal-type conservation ponds with the main function of removing cyanobacteria, and composite conservation ponds. The described composite conservation ponds are combinations of two or more of sedimentation-type conservation ponds, denitrification-type conservation ponds, phosphorus removal-type conservation ponds, and algae removal-type conservation ponds.

[0011] The river channel conservation system of the present invention separates the separated conservation ponds from the main river channel, with little interference from the main river channel water flow. When encountering extreme weather such as heavy rain and flash floods, the ecological water retaining dam is opened for flood discharge, and the flood water can be discharged through the main river channel, enabling the facilities in the pond to have strong resistance and ensuring the stable operation of the system.

[0012] As a further improvement of the present invention, the water depth of the sedimentation-type conservation pond is 3 - 3.5m, the hydraulic retention time is 0.5 - 2 days, and the length-width ratio in the water flow direction is (3 - 4):1. Emergent plants such as canna indica, thalia dealbata, scirpus validus, calamus, arundo donax, and iris are planted in the sedimentation-type conservation pond, and the planting density is 9 - 12 plants / m 2 。

[0013] Preferably, a floating silt suction boat is configured on the water surface of the sedimentation-type conservation pond. The floating silt suction boat is connected to a hose to the bottom of the pond, and the other end of the hose is a collection head. The silt is stored in the sludge bin on the boat and pumped regularly. For convenient regular silt cleaning, a wooden maintenance plank road is also provided in the pond.

[0014] As a further improvement of the present invention, the denitrification-type conservation ponds are divided into shallow-water denitrification conservation ponds and deep-water denitrification conservation ponds, which are flexibly set according to the site conditions;

[0015] The water depth of the shallow-water denitrification conservation pond is 0.5m, and it is a surface overflow type. The bottom of the pond is paved with a PE anti-seepage membrane, and there is a 0.6m thick planting soil layer on the membrane. Plants with strong nitrogen absorption ability such as pennisetum purpureum, lythrum salicaria, oenanthe javanica, thalia dealbata, and canna indica are planted, and the planting density is 9 - 12 plants / m 2 ; In order to enable the plants to fully contact the nutrients in the water, the shallow-water conservation pond can be designed in a meandering flow pattern with ecological bags as intervals.

[0016] The water depth of the deep - water nitrogen - removing conservation pond described above is 0.8 - 2.0 m, and it is equipped with a conventional floating island and a composite artificial floating bed. The conventional floating islands are arranged around the pond, and the floating islands are planted with Canna indica, Thalia dealbata, and Ludwigia peploides, with a planting density of 9 - 12 plants / m 2 ; The composite artificial floating bed is arranged in the deep - water area in the center of the pond. The upper layer is the plant area, and the lower layer is the filler area. The filler area is installed in a box - type manner, with aeration hoses arranged at the bottom of the box, and is equipped with a micro - blower. The micro - blower is powered by solar energy, which is suitable for field scenarios. The filler area uses curtain - type fillers, which are low - cost and easy to obtain, and can be used in combination with denitrifying microbial agents to enhance the denitrification effect. At the same time, because the separated conservation pond is separated from the main river channel, less microorganisms are lost, and the biofilm is not easily washed away by floods after being formed, and it can maintain long - term operation.

[0017] Preferably, the planting soil layer selects spherical granular filter materials, and the porosity of the filter materials > 40%, which also serves as a carrier for denitrifying microorganisms. A zeolite filter layer is added to the planting soil layer. The high ion - exchange capacity and high ammonia - nitrogen selectivity of zeolite filters can enhance ammonia - nitrogen removal.

[0018] As a further improvement of the present invention, the phosphorus - removing conservation pond has a water depth of 1.5 - 2.5 m and is equipped with an artificial floating island and a phosphorus - locking agent release device. The artificial floating island accounts for 30% of the area of the phosphorus - removing conservation pond and is planted with Lythrum salicaria, Oenanthe javanica, and Canna indica with strong phosphorus - absorbing ability, with a planting density of 9 - 12 plants / m 2 ; The phosphorus - locking agent release device is provided with a phosphorus - locking agent. The phosphorus - locking agent is a one - to - one chelation of lanthanum in the bentonite structure with phosphate ions to form a stable rare - earth phosphate lanthanum mineral, in which the lanthanum content is 4.75% - 5.25%. The phosphorus - locking agent release device is of a floating type, with an internal medicine box, a release pump, and a flow - maker. If the phosphorus content in the water body is relatively high, the release pump is started to release the phosphorus - locking agent in the medicine box into the water body and mix it with the water body through the flow - maker.

[0019] As a further improvement of the present invention, the algae - removing conservation pond has a water depth of 2.0 - 3.0 m and is equipped with a soft fence, a nano - aerator, and a blue - green algae collector, and an algae - liquid separator is configured on the shore. The nano - aerator is of an on - shore type or a water - surface type. After the nano - bubbles enrich the blue - green algae on the water surface, they are collected by the blue - green algae collector and pumped to the algae - liquid separator for algae - water separation. The soft fence is set 1.5 - 2.0 m below the water surface, and through the soft separation of the water body, sequential batch algae removal is achieved.

[0020] As a further improvement of the present invention, more than 1 natural conservation pond is set up, which is divided into an aerated conservation pond, a biological manipulation conservation pond, and a restoration - type conservation pond.

[0021] Preferably, for the heavily polluted and black - smelly river sections, the aerated conservation pond uses artificial aeration for oxygen supply;

[0022] The described biological manipulation conservation pond is for river sections with a large amount of algae. By releasing filter-feeding fish such as silver carp or bighead carp to directly graze on cyanobacterial blooms, the fish release time is determined according to the water quality and the monitoring of aquatic organisms.

[0023] The described restoration conservation pond is for river sections with good water quality. By planting submerged plants such as Vallisneria natans, Myriophyllum verticillatum, Ceratophyllum demersum, etc., and releasing benthic animals and other components to form an ecological community, the water body is maintained clear.

[0024] Meanwhile, the present invention provides a treatment method for the "river-pond separation" type ecological conservation system of small watershed rivers, including the following steps:

[0025] S1: Divide the main river into multiple natural conservation ponds through an ecological water retaining dam, and successively set them as aeration conservation ponds, biological manipulation conservation ponds, and restoration conservation ponds; and set multiple separated conservation ponds beside the main river, mainly including sedimentation conservation ponds, nitrogen-removing conservation ponds, phosphorus-removing conservation ponds, algae-removing conservation ponds, and composite conservation ponds.

[0026] S2: Drain the sewage into the aeration conservation pond in the main river, take samples to detect the contents of nitrogen, phosphorus, and algae in the water, and then introduce the sewage into the sedimentation conservation pond through the ecological water retaining dam, control the hydraulic retention time to be 0.5 - 2 days, and use the emergent plants in the pond to buffer the sediment in the sewage, so that the sediment is intercepted and remains stable, obtaining primary treated sewage.

[0027] S3: Introduce the primary treated sewage back into the biological manipulation conservation pond, take samples to detect the contents of nitrogen, phosphorus, and algae in the water. If it reaches the discharge standard, it can be directly discharged. If it does not reach the discharge standard, the sewage is introduced into the second separated conservation pond for purification treatment of nitrogen removal, phosphorus removal, and algae removal in sequence.

[0028] S4: When carrying out nitrogen removal purification treatment, introduce the primary treated sewage into the second separated conservation pond, which is set as a nitrogen-removing conservation pond, control the hydraulic retention time to be 6 - 8 days, and use the nitrogen-absorbing plants planted in the pond to remove the nitrogen substances in the water, obtaining secondary treated sewage.

[0029] When carrying out phosphorus removal purification treatment, introduce the primary treated sewage into the second separated conservation pond, which is set as a phosphorus-removing conservation pond, control the hydraulic retention time to be 7 - 9 days, and use the phosphorus-absorbing plants planted in the pond to remove the phosphorus substances in the water, obtaining secondary treated sewage.

[0030] When carrying out algae removal purification treatment, introduce the primary treated sewage into the second separated conservation pond, which is set as an algae-removing conservation pond, control the hydraulic retention time to be 10 - 15 days, collect through a cyanobacteria collector and pump it to an algae-liquid separator for algae-water separation, obtaining secondary treated sewage.

[0031] The processes of nitrogen removal, phosphorus removal, and algae removal are carried out sequentially, separately, or simultaneously in a composite water conservation pond;

[0032] S5: Introduce the secondary treated sewage back into the restored water conservation pond, and allow it to recover for 5 to 8 days of hydraulic retention. Then, take samples to detect the contents of nitrogen, phosphorus, and algae in the water. If the discharge standard is met, it can be directly discharged. If the discharge standard is not met, continue the purification process until the discharge standard is achieved.

[0033] The beneficial effects of the present invention are as follows:

[0034] The present invention establishes a "separated water conservation pond" and a "main river channel segmented water conservation pond" through the "river-pond separation" method, realizing the combined operation of the steady state and dynamic state of the water conservation pond, effectively avoiding damage to the facilities caused by flood disasters, and through the multi-type and flexible design of the water conservation pond, minimizing pollutants such as nitrogen and phosphorus in the water in an economical and ecological way, and achieving the long-term treatment of the river channel. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a schematic structural diagram of the "river-pond separation" type ecological water conservation system of the present invention.

[0036] Figure 2 It is a schematic structural diagram of the precipitation type water conservation pond of the present invention.

[0037] Figure 3 It is a schematic structural diagram of the shallow water type nitrogen removal water conservation pond of the present invention.

[0038] Figure 4 It is a schematic structural diagram of the deep water type nitrogen removal water conservation pond of the present invention.

[0039] Figure 5 It is a schematic structural diagram of the phosphorus removal type water conservation pond of the present invention.

[0040] Figure 6 It is a schematic structural diagram of the algae removal type water conservation pond of the present invention.

[0041] Reference numerals: 1 - separated water conservation pond, 2 - natural water conservation pond, 3 - ecological water retaining dam, 4 - floating silt suction boat, 5 - PE anti-seepage membrane, 6 - planting soil layer, 7 - conventional floating island, 8 - composite artificial floating bed, 9 - artificial floating island, 10 - phosphorus-locking release device, 11 - soft fence, 12 - nano aerator, 13 - cyanobacteria collector, 14 - algae liquid separator. DETAILED DESCRIPTION OF THE INVENTION

[0042] The present invention will be further described below with reference to the accompanying drawings. Embodiment

[0043] As Figure 1A small watershed river channel "river - pond separation" type ecological conservation system as shown, includes a separated conservation pond 1 and a natural conservation pond 2;

[0044] The separated conservation pond 1 is arranged at both sides of the natural conservation pond 2 at intervals. The river channel water is introduced through an ecological water retaining dam 3 set in the main river channel. The river channel water treated in the separated conservation pond 1 then returns to the main river channel and enters the next separated conservation pond 1, and so on in a cycle;

[0045] The natural conservation pond 2 is obtained by setting ecological water retaining dams 3 at intervals in the main river channel;

[0046] The separated conservation pond 1 is divided into a sedimentation - type conservation pond, a denitrification - type conservation pond, a dephosphorization - type conservation pond, and an algae - removal - type conservation pond, which are set according to the river channel water quality conditions and different functional requirements.

[0047] The sedimentation - type conservation pond is as Figure 2 shown, with a water depth of 3m, a hydraulic retention time of 0.5 days, and a length - width ratio in the water flow direction of 3:1. In the sedimentation - type conservation pond, emergent plants such as canna indica, thalia dealbata, scirpus validus, calamus, arundo donax, iris tectorum, etc. are planted, and the planting density is 9 plants / m 2 ; A floating silt suction boat 4 is configured on the water surface. The floating silt suction boat 4 is connected to a hose to the bottom of the pond. The other end of the hose is a collection head, and the silt is stored in the sludge bin on the boat and pumped regularly.

[0048] The denitrification - type conservation pond is a shallow - water denitrification conservation pond, as Figure 3 shown, with a water depth of 0.5m, being a surface overflow type. A PE anti - seepage membrane 5 is laid at the bottom of the pond, and there is a 0.6m - thick planting soil layer 6 on the membrane, on which plants with strong nitrogen absorption ability such as elephant grass, lythrum salicaria, oenanthe javanica, thalia dealbata, canna indica, etc. are planted, and the planting density is 9 plants / m 2 ; The planting soil layer 6 selects spherical granular filter media, and the porosity of the filter media > 40%, which also serves as a carrier for denitrifying microorganisms; A zeolite filter layer is added in the planting soil layer 6.

[0049] The dephosphorization - type conservation pond is as Figure 5 shown, with a water depth of 1.5m, and an artificial floating island 9 and a phosphorus - locking agent release device 10 are arranged inside; The artificial floating island 9 accounts for 30% of the area of the dephosphorization - type conservation pond, and plants such as lythrum salicaria, oenanthe javanica, canna indica are planted, and the planting density is 9 plants / m 2 ; The phosphorus - locking agent release device 10 is provided with a phosphorus - locking agent. The phosphorus - locking agent is a one - to - one chelation of lanthanum in the bentonite structure and phosphate radical, forming a stable rare earth phosphate lanthanum ore, in which the lanthanum content is 4.75%; The phosphorus - locking agent release device is a floating type, with an internal medicine box, a release pump and a flow - creating device.

[0050] The algae - removal - type conservation pond is as Figure 6As shown in the figure, the water depth is 2.0 meters, with a soft fence 11, a nano-aerator 12 and a cyanobacteria collector 13 installed inside, and an algae liquid separator 14 is configured on the shore; the nano-aerator 12 is a surface type. After the nano-bubbles enrich the cyanobacteria on the water surface, they are collected by the cyanobacteria collector 13 and pumped to the algae liquid separator 14 for algae-water separation; the soft fence 11 is set 1.5 meters below the water surface, and sequential batch algae removal is achieved through soft separation of the water body.

[0051] Two natural conservation ponds 2 are provided, both of which are aerated conservation ponds;

[0052] For heavily polluted and black-odor river sections, the aerated conservation pond adopts artificial aeration for oxygen supply.

[0053] The treatment method of the "river-pond separation" type ecological conservation system for the small watershed river course in this embodiment includes the following steps:

[0054] S1: The main river course is successively set as an aerated conservation pond, a biological manipulation conservation pond, and a restoration-type conservation pond through the ecological water retaining dam 3; and a sedimentation-type conservation pond, a nitrogen removal-type conservation pond, a phosphorus removal-type conservation pond, and an algae removal-type conservation pond are set beside the main river course;

[0055] S2: Drain the sewage into the aerated conservation pond in the main river course, sample and detect the contents of nitrogen, phosphorus, and algae in the water, and then introduce the sewage into the sedimentation conservation pond through the ecological water retaining dam 3, control the hydraulic retention time to be 0.5 days, and use the emergent plants in the pond to buffer the sediment in the sewage, so that the sediment is intercepted and remains stable, obtaining primary treated sewage;

[0056] S3: Introduce the primary treated sewage back into the biological manipulation conservation pond, sample and detect the contents of nitrogen, phosphorus, and algae in the water. If the discharge standard is not met, introduce the sewage into the nitrogen removal-type conservation pond for nitrogen removal treatment first;

[0057] S4: Introduce the primary treated sewage into the nitrogen removal-type conservation pond, control the hydraulic retention time to be 6 days, and use the nitrogen-absorbing plants planted in the pond to remove the nitrogen substances in the water, obtaining secondary treated sewage; introduce the secondary treated sewage back into the natural conservation pond and continue to enter the phosphorus removal conservation pond for phosphorus removal treatment;

[0058] When carrying out phosphorus removal purification treatment, control the hydraulic retention time to be 7 days, and use the phosphorus-absorbing plants planted in the pond to remove the phosphorus substances in the water, obtaining tertiary treated sewage; introduce the tertiary treated sewage back into the natural conservation pond and continue to enter the algae removal conservation pond for algae removal treatment;

[0059] When carrying out algae removal treatment, control the hydraulic retention time to be 10 days, collect through the cyanobacteria collector 13 and pump to the algae liquid separator 14 for algae-water separation, obtaining quaternary treated sewage;

[0060] S5: The quaternary treated wastewater is led back to the recovery pond and hydraulically retained for 5 days for recovery. Then samples are taken to test the nitrogen, phosphorus and algae content in the water to ensure that it meets the discharge standards. Example

[0061] Compared with Example 1, the difference of this embodiment is:

[0062] The water depth of the sedimentation-type conservation pond is 3.1m, the hydraulic retention time is 0.8 days, the length-to-width ratio in the direction of water flow is 4:1, and the density of emergent plants in the pond is 10 plants / m 2 .

[0063] The nitrogen removal type conservation pond is a shallow water type nitrogen removal conservation pond, such as Figure 3 As shown in the figure, the water depth is 0.5m, the pond is of baffled type, and the eco-bags are used as intervals; the bottom of the pond is paved with a PE anti-seepage membrane 5, and there is a 0.6m thick planting soil layer 6 on the membrane, and plants with strong nitrogen absorption capacity such as elephant grass, loosestrife, water celery, lily, canna, etc. are planted, and the planting density is 10 plants / m 2 The planting soil layer 6 uses spherical particle filter material, the porosity of the filter material is greater than 40%, and it also serves as a carrier of denitrification microorganisms; a zeolite filter material layer is added to the planting soil layer 6.

[0064] The water depth of the phosphorus removal pond is 2.0 meters, and the plant density in the pond is 10 plants / m 2 ; The lanthanum content in the phosphorus locking agent is 5.00%.

[0065] The water depth of the algae-removing conservation pond is 2.5 meters, and the soft fence 11 is set to 1.8 meters below the water surface.

[0066] The natural conservation ponds 2 are provided with three, which are divided into an aerated conservation pond, a biological manipulation conservation pond, and a recovery conservation pond.

[0067] The aerated conservation pond adopts artificial aeration to supply oxygen for heavily polluted black and smelly river sections; the biological manipulation conservation pond adopts artificial aeration to supply oxygen for river sections with more algae by releasing filter-feeding fish such as silver carp or bighead carp to directly feed on blue algae blooms, and the time of releasing fish is determined according to the monitoring of water quality and aquatic organisms; the restoration conservation pond adopts artificial aeration to supply oxygen for river sections with better water quality by planting submerged plants such as Vallisneria, Foxtail Algae, and Duckweed, and releasing benthic animals and other ecological community components to maintain the clarity of water. Example

[0068] Compared with Example 2, the difference of this embodiment is:

[0069] The water depth of the sedimentation-type conservation pond is 3.2m, the hydraulic retention time is 1.0 day, the length-to-width ratio in the direction of water flow is 3:1, and the density of emergent plants in the pond is 11 plants / m 2 .

[0070] The nitrogen-removing water conservation pond described is a deep-water nitrogen-removing water conservation pond; as Figure 4 shown, the water depth is 0.8 m, and there are conventional floating islands 7 and composite artificial floating beds 8 inside; the conventional floating islands 7 are arranged around the pond, and the conventional floating islands 7 are planted with canna indica, thalia dealbata, and jussiaea stipulacea, with a planting density of 9 plants / m 2 ; the composite artificial floating bed 8 is arranged in the deep water area in the center of the pond, with a plant area on the upper layer and a filler area on the lower layer; the filler area is installed in a box type, with aeration hoses arranged at the bottom of the box and equipped with a micro fan, and the micro fan is powered by solar energy; the filler area uses curtain-type fillers.

[0071] The phosphorus-removing water conservation pond has a water depth of 2.2 meters, and the planting density of plants in the pond is 12 plants / m 2 ; the lanthanum content in the phosphorus-locking agent is 5.25%.

[0072] The algae-removing water conservation pond has a water depth of 3.0 meters, and the soft fence 11 is set 2.0 meters below the water surface.

[0073] Two natural water conservation ponds 2 are set, which are divided into aerated water conservation ponds and restored water conservation ponds. Example

[0074] Compared with Example 2, the difference in this example is:

[0075] The sedimentation water conservation pond has a water depth of 3.3 m, a hydraulic retention time of 1.5 days, and an aspect ratio of length to width in the water flow direction of 3:1. The planting density of emergent plants in the pond is 12 plants / m 2 .

[0076] The nitrogen-removing water conservation pond described is a deep-water nitrogen-removing water conservation pond; as Figure 4 shown, the water depth is 2.0 m, and the planting density of plants in the pond is 12 plants / m 2 .

[0077] The phosphorus-removing water conservation pond has a water depth of 2.5 meters, and the planting density of plants in the pond is 12 plants / m 2 ; the lanthanum content in the phosphorus-locking agent is 5.05%.

[0078] The algae-removing water conservation pond has a water depth of 2.5 meters, and the soft fence 11 is set 1.8 meters below the water surface.

[0079] Three natural water conservation ponds 2 are set, which are divided into biomanipulation water conservation ponds and restored water conservation ponds. Example

[0080] Compared with Example 2, the difference in this example is:

[0081] The sedimentation-type water conservation pond has a water depth of 3.4 m, a hydraulic retention time of 1.5 days, a length-width ratio in the water flow direction of 4:1, and an emergent plant planting density in the pond of 10 plants / m 2 .

[0082] The nitrogen-removing water conservation pond is divided into a shallow nitrogen-removing water conservation pond, as Figure 3 shown, with a water depth of 0.5 m and a surface overflow type; the plant planting density in the pond is 10 plants / m 2 .

[0083] The phosphorus-removing water conservation pond has a water depth of 2.0 m, and the plant planting density in the pond is 10 plants / m 2 ; the lanthanum content in the phosphorus-locking agent is 5.00%.

[0084] The algae-removing water conservation pond has a water depth of 2.5 m, and the soft fence 11 is set 2.0 m below the water surface.

[0085] Two natural water conservation ponds 2 are set up, which are divided into an aerated water conservation pond and a biological manipulation water conservation pond. Example

[0086] Compared with Example 2, the differences in this example are as follows:

[0087] The sedimentation-type water conservation pond has a water depth of 3.5 m, a hydraulic retention time of 1 day, a length-width ratio in the water flow direction of 3:1, and an emergent plant planting density in the pond of 12 plants / m 2 .

[0088] The nitrogen-removing water conservation pond is a deep nitrogen-removing water conservation pond; as Figure 4 shown, with a water depth of 1.6 m and a plant planting density in the pond of 12 plants / m 2 .

[0089] The phosphorus-removing water conservation pond has a water depth of 2.2 m, and the plant planting density in the pond is 12 plants / m 2 ; the lanthanum content in the phosphorus-locking agent is 5.00%.

[0090] The algae-removing water conservation pond has a water depth of 2.4 m, and the soft fence 11 is set 1.8 m below the water surface.

[0091] Three natural water conservation ponds 2 are set up, which are divided into an aerated water conservation pond, a biological manipulation water conservation pond, and a restoration water conservation pond.

[0092] Application Example

[0093] The system of Application Example 1 was applied to an ecological comprehensive treatment project of a tributary of the Hedi Reservoir in Guangdong Province. According to the monitoring data provided by the environmental protection department, the average water quality of this tributary from January 2021 to May 2021 was inferior to Class V, and the main pollutants exceeding the standard were ammonia nitrogen and total phosphorus, as shown in Table 1 specifically.

[0094] Table 1:

[0095]

[0096] Treatment goal: Eliminate the water quality inferior to Class V and reach Class V water quality of the Surface Water Environment Quality Standard (GB3838 - 2002), that is: pH value 6 - 9, chemical oxygen demand ≤ 40mg / L, permanganate index ≤ 15mg / L, ammonia nitrogen ≤ 2.0mg / L, total phosphorus ≤ 0.4mg / L.

[0097] Treatment measures: The project involves a river section about 2500m long and the treatment of 7875m³ of river water body. The main contents include building 3 separated ecological conservation ponds and transforming the original river into 2 main - river ecological conservation ponds. The specific treatment measures include:

[0098] (1) Sedimentation - type conservation pond: There is 1 pond, with a storage capacity of about 25000m 3 , a water surface of 8000 m 2 , a water depth of 3 - 3.5m, and an aspect ratio of length to width of about 3:1. About 2000m 2 of emergent plants such as canna, thalia dealbata, scirpus validus, and arundo donax var. versicolor are planted in the conservation pond, and 1 floating dredging boat is equipped;

[0099] (2) Nitrogen - and - phosphorus - removing composite conservation pond: There are 2 ponds, with a single - pond storage capacity of about 30000m3, a water surface of 15000 m2, and a water depth of 1.8 - 2.0m; In the conservation pond, 2000 m2 of conventional ecological floating islands are set, and emergent plants such as thalia dealbata, lythrum salicaria, and oenanthe javanica are planted; 2500 m2 of composite ecological floating islands are set, and emergent plants such as canna, thalia dealbata, and lythrum salicaria are planted. 2000 m2 of curtain - type packing boxes are installed and microbial agents are supplemented regularly; 2 sets of phosphorus - locking agent release devices are configured in the conservation pond;

[0100] (3) Main - river segmented conservation pond system: There are 2 systems, with a single - segment length of 600 meters and an average water depth of 2.0 meters. Both adopt the form of aeration conservation ponds, supplemented by biological manipulation and shore - side plant purification belts; Among them, 20 water - spraying aerators and 4 surface - type nano - aerators are used as aerators, and they are installed in a floating manner, which is convenient to move to the shore during flood. 3 ecological dams are built in the main river.

[0101] Implementation effect: The project started implementation in June 2021 and was completed and accepted at the beginning of August. All systems are operating well. After continuous monitoring, the water quality of the river reached Class IV and V standards in August and September 2021, as shown in Table 2.

[0102] Table 2:

[0103]

[0104] As can be seen from Table 2, the ecology of a tributary of the Hedi Reservoir after being treated by the system of Application Example 1 has been significantly improved, reaching the standard of Class V water quality in the Environmental Quality Standards for Surface Water (GB3838 - 2002).

[0105] The above embodiments are only exemplary embodiments of the present invention and are not used to limit the present invention. The protection scope of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent replacements within the essence and protection scope of the present invention, and such modifications or equivalent replacements should also be regarded as falling within the protection scope of the present invention.

Claims

1. A treatment method for an ecological conservation system with separated river channels and ponds in a small watershed, characterized in that, Including the following steps: S1: Divide the main river channel into multiple natural conservation ponds (2) through an ecological water retaining dam (3), and sequentially set them as an aeration conservation pond, a biological manipulation conservation pond, and a restoration conservation pond; and set multiple separate conservation ponds (1) beside the main river channel, mainly divided into a sedimentation conservation pond, a nitrogen removal conservation pond, a phosphorus removal conservation pond, an algae removal conservation pond, and a composite conservation pond; S2: Drain the sewage into the aeration conservation pond in the main river channel, sample and detect the contents of nitrogen, phosphorus, and algae in the water, and then introduce the sewage into the sedimentation conservation pond through the ecological water retaining dam (3), control the hydraulic retention time to be 0.5 - 2 days, and use the emergent plants in the pond to buffer the sediment in the sewage, so that the sediment is intercepted and kept stable, obtaining primary treated sewage; S3: Introduce the primary treated sewage back into the biological manipulation conservation pond, sample and detect the contents of nitrogen, phosphorus, and algae in the water. If it meets the discharge standard, it can be directly discharged. If it does not meet the discharge standard, the sewage is introduced into the second separate conservation pond (1) for purification treatment of nitrogen removal, phosphorus removal, and algae removal in sequence; When carrying out nitrogen removal purification treatment, introduce the primary treated sewage into the second separate conservation pond, which is set according to the nitrogen removal conservation pond, control the hydraulic retention time to be 6 - 8 days, and use the nitrogen-absorbing plants planted in the pond to remove the nitrogen substances in the water, obtaining secondary treated sewage; When carrying out phosphorus removal purification treatment, introduce the primary treated sewage into the second separate conservation pond, which is set according to the phosphorus removal conservation pond, control the hydraulic retention time to be 7 - 9 days, and use the phosphorus-absorbing plants planted in the pond to remove the phosphorus substances in the water, obtaining secondary treated sewage; When carrying out algae removal purification treatment, introduce the primary treated sewage into the second separate conservation pond, which is set according to the algae removal conservation pond, control the hydraulic retention time to be 10 - 15 days, collect through a cyanobacteria collector (13) and pump it to an algae liquid separator (14) for algae-water separation, obtaining secondary treated sewage; The above nitrogen removal, phosphorus removal, and algae removal processes are carried out in sequence, separately, or simultaneously in a composite conservation pond; S5: Introduce the secondary treated sewage back into the third restoration conservation pond for restoration for 5 - 8 days, and then sample and detect the contents of nitrogen, phosphorus, and algae in the water. If it meets the discharge standard, it can be directly discharged. If it does not meet the discharge standard, continue the purification process until it meets the discharge standard.

2. The treatment method of the small watershed river channel and pond separation type ecological conservation system according to claim 1, characterized in that: The system includes a separate conservation pond (1) and a natural conservation pond (2); The separate conservation ponds (1) are arranged at intervals on both sides of the natural conservation pond (2), introduce the river water through the ecological water retaining dam (3) arranged in the main river channel, and the river water treated in the separate conservation pond (1) returns to the main river channel and enters the next separate conservation pond (1), circulating in this way; The natural conservation pond (2) is obtained by setting ecological water retaining dams (3) at intervals in the main river channel; The separated conservation pond (1) is divided into sedimentation conservation pond, nitrogen removal conservation pond, phosphorus removal conservation pond, algae removal conservation pond and composite conservation pond, and is set according to the water quality of the river and different functional requirements; the composite conservation pond is a combination of two or more of the sedimentation conservation pond, nitrogen removal conservation pond, phosphorus removal conservation pond and algae removal conservation pond.

3. The treatment method of the small watershed river channel and pond separation type ecological conservation system according to claim 2, characterized in that: The depth of the sedimentation-type retention pond is 3 - 3.5 m, the hydraulic retention time is 0.5 - 2 days, and the aspect ratio of length to width in the water flow direction is (3 - 4):

1. Emergent plants such as Canna indica, Thalia dealbata, Scirpus validus, Acorus calamus variegatus, Arundo donax, and Iris tectorum are planted in the sedimentation-type retention pond, and the planting density is 9 - 12 plants / m 2 .

4. The treatment method of the small watershed river-lake separation type ecological conservation system according to claim 3, characterized in that: The surface of the sedimentation-type conservation pond is provided with a floating silt suction boat (4), the floating silt suction boat (4) is connected to the bottom of the pond by a hose, the other end of the hose is a collecting head, and the silt is stored in a sludge bin in the boat and is pumped out regularly.

5. The treatment method of the small watershed river channel and pond separation type ecological conservation system according to claim 2, characterized in that: The nitrogen removal type conservation pond is divided into a shallow water type nitrogen removal conservation pond and a deep water type nitrogen removal conservation pond; The described shallow nitrogen-removing and water-conserving pond has a water depth of 0.5 m and is of the surface overflow type. A PE anti-seepage membrane (5) is laid at the bottom of the pond, and there is a planting soil layer (6) with a thickness of 0.6 m on the membrane. Plants with strong nitrogen absorption ability such as Pennisetum purpureum, Lythrum salicaria, Oenanthe javanica, Thalia dealbata, and Canna indica are planted, and the planting density is 9-12 plants / m 2 ; The water depth of the deep - water nitrogen - removing conservation pond described is 0.8 - 2.0 m, and it is equipped with a conventional floating island (7) and a composite artificial floating bed (8) inside; the conventional floating island (7) is arranged around the pond, and cannas, thalia dealbata, and jussiaea stipulacea are planted on the conventional floating island (7), and the planting density is 9 - 12 plants / m 2 ; the composite artificial floating bed (8) is arranged in the deep - water area in the center of the pond, with a plant area on the upper layer and a filler area on the lower layer; the filler area is installed in a box - type manner, with aeration hoses arranged at the bottom of the box, and is equipped with a micro - blower, and the micro - blower is powered by solar energy; the filler area uses curtain - type fillers.

6. The treatment method of the small watershed river channel and pond separation type ecological conservation system according to claim 5, characterized in that: The shallow water conservation pond is of baffled type, with ecological bags as partitions; the planting soil layer (6) uses spherical particle filter material, the porosity of the filter material is greater than 40%, and it also serves as a denitrification microbial carrier; a zeolite filter material layer is added to the planting soil layer (6).

7. The treatment method of the small watershed river-lake separation type ecological conservation system according to claim 2, characterized in that: The depth of the phosphorus-removing water conservation pond described above is 1.5 to 2.5 meters, and it is equipped with an artificial floating island (9) and a phosphorus-locking agent release device (10); the artificial floating island (9) accounts for 30% of the area of the phosphorus-removing water conservation pond, and is planted with Lythrum salicaria, Oenanthe javanica, and Canna indica, and the planting density is 9 to 12 plants / m 2 ; the phosphorus-locking agent release device (10) is provided with a phosphorus-locking agent, and the phosphorus-locking agent is a one-to-one chelation of lanthanum and phosphate radical in the bentonite structure to form a stable rare earth phosphate lanthanum ore, in which the lanthanum content is 4.75% to 5.25%; the phosphorus-locking agent release device is a floating type, and is internally provided with a medicine box, a release pump and a flow maker.

8. The treatment method of the small watershed river channel and pond separation type ecological conservation system according to claim 2, characterized in that: The algae-removing pond has a water depth of 2.0 to 3.0 meters, is equipped with a soft fence (11), a nano-aerator (12) and a blue algae collector (13), and is equipped with an algae liquid separator (14) on the shore; The nano aerator (12) is of a shore type or a water surface type. After the nano bubbles enrich the blue algae on the water surface, they are collected by a blue algae collector (13) and pumped to an algae liquid separator (14) for algae-water separation. The soft fence (11) is set 1.5 to 2.0 meters below the water surface, and sequential batch algae removal is achieved through soft separation of the water body.

9. The treatment method of the small watershed river channel and pond separation type ecological conservation system according to claim 2, characterized in that: The natural conservation pond (2) is provided with more than one, which is divided into an aerated conservation pond, a biological manipulation conservation pond, and a recovery conservation pond.

10. The treatment method of the small watershed river-lake separation type ecological conservation system according to claim 9, characterized in that: The aerated conservation pond adopts artificial aeration to supply oxygen for heavily polluted black and smelly river sections; The biological manipulation conservation pond is aimed at the river section with more algae, and filter-feeding fish silver carp or bighead carp are released to directly feed on the blue algae bloom. The time of fish release is determined according to the monitoring of water quality and aquatic organisms; The restoration-type conservation pond is aimed at river sections with better water quality. It maintains the clarity of the water body by planting submerged plants such as Vallisneria, Foxtail Algae, and Dermatophyte, and releasing benthic animals and other ecological community components.

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