A method and system for reconstructing an urban river ecosystem based on tail water of a sewage treatment plant

Abstract

The present application relates to the technical field of urban water ecological system regulation and management, and particularly relates to a method and system for reconstructing an urban river ecological system based on tail water of a sewage treatment plant. The method comprises the following steps: introducing tail water of the sewage treatment plant into a parallel or surrounding artificial wetland deep purification corridor for purification, collecting the purified tail water quality, mixing the purified tail water quality at a water distribution hub, and implementing pulse ecological water replenishment to the downstream of the river through a pre-set intelligent dam; collecting initial topographic data of the smooth hard river, determining habitat size parameters in combination with habitat conditions required for aquatic organisms to survive, and reconstructing the river topography to form a sequence of habitat units. The present application reconstructs a tail water type river ecological system with rich biodiversity, self-purification capacity and self-maintenance capacity to improve the controllability and long-term stability of urban ecological engineering.

Description

Technical Field

[0001] This invention relates to the field of urban water ecosystem regulation and management technology, and in particular to a method and system for reconstructing urban river ecosystems based on wastewater treatment plant effluent. Background Technology

[0002] When urban natural water systems are severely damaged, many rivers become "tailwater-type rivers" primarily supplied by sewage treatment plant effluent due to a sharp decline in natural runoff, resulting in significant ecological degradation. These rivers face multiple bottlenecks: a single water source dependent on treated effluent, lacking natural runoff for dilution and scouring, leading to low ecological activity and residual trace pollutants; constant effluent discharge disrupts the natural alternation of wet and dry seasons and pulsating hydrological rhythms, hindering sediment transport, nutrient cycling, and biological life cycles; flood control channeling and hardening projects homogenize river habitats, eliminating heterogeneous units such as deep pools and shallows, failing to meet the habitat needs of aquatic organisms; ultimately resulting in scarce species, broken food chains, fragile ecosystems, and a lack of self-purification capacity; existing solutions are mostly localized and short-term improvements, such as aeration, bacterial inoculation, or planting, failing to address the interconnectedness of the water-soil-biota system and being unsuitable for the characteristics of tailwater-type rivers, thus failing to achieve structural restoration of the ecosystem. Summary of the Invention

[0003] Therefore, it is necessary to provide a method and system for reconstructing urban river ecosystems based on wastewater treatment plant effluent, in order to solve at least one of the above-mentioned technical problems.

[0004] To achieve the above objectives, a method for reconstructing urban river ecosystems based on wastewater treatment plant effluent is provided, the method comprising the following steps:

[0005] Step S1: The effluent from the wastewater treatment plant is introduced into an artificial wetland deep purification corridor that runs parallel to or surrounds the river for purification. The quality of the purified effluent is collected and mixed at the water distribution hub. Pulsed ecological water replenishment is then carried out downstream of the river through a pre-set intelligent gate dam.

[0006] Step S2: Collect initial topographic data of smooth, hard river channels, determine habitat size parameters based on the habitat conditions required for the survival of aquatic organisms, modify the river channel topography to form sequential habitat units; lay a multi-layer functional matrix composed of zeolite, limestone and hollow biological ceramic particles on the modified riverbed according to a preset ratio.

[0007] Step S3: Introduce aquatic pioneer species into the sequenced habitat unit. After monitoring and confirming the stability of the aquatic pioneer species community, introduce aquatic intermediate competing species. After monitoring and confirming the formation of the intermediate community of aquatic intermediate competing species, introduce aquatic apex indicator species to construct an aquatic food web.

[0008] Step S4: Collect water quality data, hydrological data and biological data through sensors in the river channel and serialized habitat units, and transmit them to the preset ecological brain platform; use the river ecosystem health assessment model in the ecological brain platform to provide feedback control of the intelligent gate dam and water replenishment system, and dynamically assess and adaptively regulate the ecosystem.

[0009] This invention also provides a system for reconstructing urban river ecosystems based on wastewater treatment plant effluent, which implements the above-described method for reconstructing urban river ecosystems based on wastewater treatment plant effluent. The system for reconstructing urban river ecosystems based on wastewater treatment plant effluent includes:

[0010] The water source control module is used to introduce the effluent from the sewage treatment plant into the artificial wetland deep purification corridor that runs parallel to or surrounds the river for purification, collect the water quality of the purified effluent, mix the purified effluent water quality at the water distribution hub, and implement pulsed ecological water replenishment to the downstream of the river through a preset intelligent gate dam.

[0011] The habitat creation module is used to collect initial topographic data of smooth and hard river channels, determine habitat size parameters in combination with the habitat conditions required for the survival of aquatic organisms, and modify the river channel topography to form sequential habitat units; a multi-layer functional matrix composed of zeolite, limestone and hollow biological ceramic particles is laid on the modified riverbed according to a preset ratio.

[0012] The biorecovery module is used to introduce aquatic pioneer species into the sequenced habitat unit, monitor and confirm the stability of the aquatic pioneer species community, introduce aquatic intermediate competing species, monitor and confirm the formation of the intermediate community of the aquatic intermediate competing species, and then introduce aquatic apex indicator species to construct an aquatic food web.

[0013] The intelligent operation and maintenance module is used to collect water quality data, hydrological data and biological data through sensors in the river and serialized habitat units, and transmit them to the preset ecological brain platform; through the river ecosystem health assessment model in the ecological brain platform, it provides feedback control to the intelligent gate dam and water replenishment system, dynamically assesses and adaptively regulates the ecosystem.

[0014] The beneficial effects of this invention are as follows:

[0015] I. This invention revolves around the three core ecological elements of water, soil, and life, and constructs a four-stage technical process: source water quality improvement, river habitat heterogeneity, tiered restoration of biological communities, and intelligent long-term operation and maintenance. This forms a complete chain of technical systems from pollution control to ecological reconstruction, effectively avoiding the limitations of traditional single treatment technologies that only address local problems and cannot fundamentally improve the river ecosystem, and achieving the overall reconstruction of the tailwater type urban river ecosystem.

[0016] Second, by implementing pulsed ecological water replenishment through intelligent sluice gate and dam systems, the hydrological rhythm of natural rivers alternating between high and low water levels is simulated; at the same time, the river topography is modified to form a sequence of habitat units consisting of deep pools, shallow beaches, depressions, and sandbars, which highly restores the dynamic hydrological characteristics and heterogeneous structural features of natural rivers, providing a diverse habitat environment for aquatic organisms.

[0017] Third, this invention is specifically designed for urban rivers that use wastewater treatment plant effluent as their main water source, and precisely addresses their core problems such as insufficient ecological base flow, lack of hydrological rhythm, habitat homogenization, and low biodiversity. The proposed technical solution is in line with the actual needs of ecological restoration of effluent-type rivers.

[0018] Fourth, the ecological brain platform is introduced as the core control center, integrating water quality, hydrological and biological data collected in real time by sensors. Through the river ecosystem health assessment model, dynamic diagnosis and prediction of the ecosystem status are realized, driving intelligent dams and water replenishment systems to perform adaptive control. The traditional passive operation and maintenance mode that relies on experience is upgraded to a data-driven proactive early warning and precise control mode, which significantly improves the operational controllability and long-term stability of ecological engineering.

[0019] Fifth, the deep purification of wastewater effluent from wastewater treatment plants, regional rainwater storage and regulation, and river ecological restoration will be organically combined to achieve functional coupling of wastewater treatment facilities, rainwater management facilities and river ecosystems. Attached Figure Description

[0020] Figure 1 A schematic diagram illustrating the steps of a method for reconstructing urban river ecosystems based on wastewater treatment plant effluent;

[0021] Figure 2 for Figure 1 A detailed flowchart illustrating the implementation steps of step S3.

[0022] Figure 3 A schematic diagram of the urban river ecosystem for wastewater treatment plant effluent;

[0023] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0024] The technical method of the present invention will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] Furthermore, the accompanying drawings are merely illustrative of the invention and are not necessarily drawn to scale. The same reference numerals in the drawings denote the same or similar parts, and therefore repeated descriptions of them will be omitted. Some block diagrams shown in the drawings are functional entities and do not necessarily correspond to physically or logically independent entities. These functional entities can be implemented in software, in one or more hardware modules or integrated circuits, or in different network and / or processor methods and / or microcontroller methods.

[0026] It should be understood that although the terms "first," "second," etc., may be used herein to describe various units, these units should not be limited by these terms. These terms are used merely to distinguish one unit from another. For example, without departing from the scope of the exemplary embodiments, a first unit may be referred to as a second unit, and similarly, a second unit may be referred to as a first unit. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0027] To achieve the above objectives, please refer to Figures 1 to 3 A method for reconstructing urban river ecosystems based on wastewater treatment plant effluent, the method comprising the following steps:

[0028] Preferably, step S1: the effluent from the sewage treatment plant is introduced into an artificial wetland deep purification corridor that runs parallel to or surrounds the river for purification, the quality of the purified effluent is collected, and the purified effluent is mixed at the water distribution hub, and pulsed ecological water replenishment is carried out to the downstream of the river through a preset intelligent gate dam.

[0029] Optionally, the purified effluent collected in step S1 includes ammonia nitrogen, total phosphorus, and chemical oxygen demand; the purified effluent is mixed at the water distribution hub according to a preset mixing ratio to form a mixed water body; the mixed water body is then used to implement pulsed ecological water replenishment to the downstream of the river through a preset intelligent dam.

[0030] In this embodiment, a multi-parameter online water quality monitoring instrument (model Hach HQ40d or other models can be selected, which is not limited in this embodiment) is installed at the outlet of the deep purification corridor of the constructed wetland. The water quality data of the purified effluent is collected continuously for 72 hours, once every hour. The monitoring indicators include ammonia nitrogen (accuracy ±0.01mg / L), total phosphorus (accuracy ±0.001mg / L), and chemical oxygen demand (determined by potassium dichromate method, detection limit 5mg / L). The average value of 72 hours is taken as the baseline water quality data of the purified effluent.

[0031] It should be noted that the target water quality for ecological water replenishment of the river is used as the standard, which is superior to Class IV surface water quality standard (total nitrogen ≤ 8 mg / L). The various water quality indicators of the purified effluent are compared, and the mixing ratio of the purified effluent is calculated—ensuring that the ammonia nitrogen, total phosphorus, and chemical oxygen demand in the mixed water do not exceed the upper limit of the target values, suspended solids are reduced to 10 mg / L or below, and the pH value is stable in the range of 6.5-8.5. The purified effluent is introduced into the water distribution hub (effective volume 1000 m³, with a built-in submersible mixer with a stirring power of 5.5 kW and a rotation speed of 120 r / min) according to the calculated ratio. The mixer is turned on and stirred for 30 minutes until the water is uniformly mixed. Sampling and testing confirm that the mixed water meets the target water quality for ecological water replenishment.

[0032] In another embodiment, a preset intelligent gate system (selecting a gate with a width of 10m and a height of 2m, model: hydraulic self-controlled flap gate) is then activated to implement pulsed ecological water replenishment based on the river's normal base flow (set to 1m³ / s): first, within 30 minutes, the gate opening height is increased from 0.5m (corresponding to a flow rate of 1m³ / s) to 1m (corresponding to a flow rate of 2m³ / s, twice the normal base flow), and this flow rate is maintained for 6 hours. Then, within 30 minutes, the gate opening height is reduced to 0.5m to restore the normal base flow, completing a single pulsed ecological water replenishment operation. The water replenishment cycle is set to twice a week.

[0033] Optionally, the implementation parameters for pulsed ecological water replenishment in step S1 are as follows:

[0034] Based on the preset normal base flow of the river, the replenishment flow is increased 1-2 times per week, with each flood peak pulse lasting 4-8 hours and the pulse flow rate set to 1.5-3 times the normal base flow rate.

[0035] In this embodiment, the river flow is first continuously monitored for 3 days using an ultrasonic flow meter pre-deployed upstream of the river. Flow data is recorded once each at fixed times (8:00 AM, 12:00 PM, and 6:00 PM) every day. The average of the 3 daily data is then calculated to determine the 3-day average value, which is set as the river's normal base flow. In this operation, the normal base flow is determined to be 1.0 m³ / s.

[0036] In another embodiment, pulsed ecological water replenishment is performed through an intelligent sluice gate system. This system includes a hydraulic drive module and a flow feedback module. The sluice gate is a single-span structure with a 10m wide opening and a maximum gate lifting height of 2.0m. The water replenishment cycle is set to twice a week, starting at 9:00 AM on Tuesdays and Fridays. Before each flood peak pulse starts, the intelligent sluice gate system first controls the gate to maintain an opening height of 0.5m, and the flow feedback module monitors and confirms in real time that the river flow is 1.0m³ / s (i.e., normal base flow). Subsequently, the hydraulic drive module operates according to a preset program, slowly raising the gate at a speed of 0.03m / min. During this process, the flow feedback module collects flow data every 2 minutes. After 30 minutes, the gate opening height is raised to 1.2m, at which point the flow feedback module displays a flow rate of 2.5m³ / s (normal base flow). The flow rate is 2.5 times that of 1.0 m³ / s, which meets the requirement that the pulse flow rate is 1.5-3 times the normal base flow rate. The gate opening height is maintained at 1.2 m, and the flow rate is kept stable at 2.5 m³ / s for 7 hours (within the range of 4-8 hours of flood peak pulse duration). After the flood peak pulse ends, the hydraulic drive module slowly lowers the gate at a speed of 0.03 m / min. The flow rate change is confirmed every 2 minutes through the flow feedback module. After 30 minutes, the gate opening height is lowered back to 0.5 m, and the flow rate is restored to the normal base flow of 1.0 m³ / s, completing a single pulse-type ecological water replenishment operation.

[0037] Preferably, step S2: collect initial topographic data of smooth hard river channels, determine habitat size parameters in combination with the habitat conditions required for the survival of aquatic organisms, modify the river channel topography to form sequential habitat units; lay a multi-layer functional matrix composed of zeolite, limestone and hollow biological ceramic particles on the modified riverbed according to a preset ratio.

[0038] Optionally, the habitat conditions required for the survival of aquatic organisms in step S2 include suitable water depth for benthic animals, space requirements for fish migration, and light adaptation range for aquatic plants; the habitat size parameters of the serialized habitat units are determined by combining the longitudinal slope ratio and cross-sectional dimensions in the initial topographic data of the smooth hard river channel.

[0039] In this embodiment, the preset habitat conditions are as follows: the suitable water depth for benthic animals (such as river clams) is 0.8-1.5m; the migration space requirements for fish (such as sand goby) are a lateral width of not less than 5m and a longitudinal continuous channel length of not less than 50m; and the light adaptation range for aquatic plants (such as Vallisneria natans and Hydrilla verticillata) is a depth range of 20-80cm (the light intensity within this depth must meet 3000-8000 lux). Subsequently, a total station was used to collect topographic data on the smooth, hard river channel. A measurement section was set every 50m along the longitudinal direction of the river channel, and the elevation and water depth of 8 lateral points were measured at each section. The initial longitudinal slope ratio of the river channel was calculated to be 1:1500, and the cross-sectional dimensions were: bottom width of 6m, side slope of 1:3, total river channel width of 10m at normal water level, and conventional riverbed depth of 1.0m.

[0040] It should be noted that the following parameters were determined for the serialized habitat unit dimensions: the depth of the deep pool was set to 1.8 times the depth of the conventional riverbed, i.e., 1.8m (to meet the upper limit of suitable water depth for benthic animals); the longitudinal length of the deep pool was set to 30m, and the transverse width was set to 6m, consistent with the bottom width of the river channel cross-section; the slope ratio of the shallows was set to 1:8 (a gentle slope design to suit the light requirements of aquatic plants); the longitudinal length of the shallows was set to 50m (to match the longitudinal channel length for fish migration); the highest point of the shallows had a water depth of 0.2m (at the lower limit of suitable depth for aquatic plant light); and the lowest point had a water depth of 0.8m (connecting to the deep pool depth and meeting the requirements). The lower limit of suitable water depth for benthic animals is specified; ecological depressions are 15cm below the normal water level (the normal water level is set at 1.2m based on the historical average water level of the river channel, so the bottom elevation of the depression is 15cm lower than the normal water level), and the lateral width of each depression is set at 5m (to meet the lateral width requirements for fish migration) and the longitudinal length is set at 20m; the elevation of submerged sandbars fluctuates within 10cm above and below the normal water level (i.e., the top elevation of the sandbar is between 1.1-1.3m), and the lateral width of each sandbar is set at 4m and the longitudinal length is set at 25m, and the spacing between sandbars is set at 100m (to ensure uniform distribution of habitat units).

[0041] Optionally, the sequential habitat units in step S2 include deep pools, shallow beaches, ecological depressions, and submerged sandbars, wherein the specific parameters for constructing the sequential habitat units are:

[0042] The depth of the deep pool is set to 1.5-2 times that of the normal riverbed, the slope ratio of the shallow beach is set to 1:6 to 1:10, the elevation of the ecological depression is 10-20cm lower than the normal water level, and the elevation of the submerged sandbar is set within 10cm above and below the normal water level.

[0043] In this embodiment, the depth of the conventional riverbed was measured using a level. Ten measurement points were selected every 30 meters along the longitudinal direction of the river, and the average depth of the conventional riverbed was calculated to be 1.2 meters. Simultaneously, the river level was recorded continuously for seven days using a water level monitor. The daily average water level was calculated to determine the seven-day average, which was identified as the normal water level, with a value of 1.5 meters. Based on the above data and preset construction parameters, habitat unit construction was carried out.

[0044] In another embodiment, when constructing the deep pool, an excavator is used to excavate the preset area. The excavation depth is controlled at 1.8 times the conventional riverbed depth, that is, the depth of the deep pool after excavation is 2.16m. The longitudinal length of each deep pool is set to 25m, and the transverse width is consistent with the bottom width of the current cross-section of the river channel, which is 8m. After the excavation is completed, the depth of each point of the deep pool is checked by a depth sounder to ensure that the depth deviation does not exceed ±0.05m.

[0045] In another embodiment, when constructing the shoal, a gentle area between the deep pools is selected, and the slope is adjusted by a combination of manual and mechanical methods. The slope ratio is controlled at 1:8. First, the slope baseline is marked with a slope ruler, and then the slope is gradually adjusted. During the adjustment process, a slope detection point is set every 5m to ensure that the slope at each point meets the 1:8 requirement. The longitudinal length of the shoal is set to 40m, and it covers the entire cross section of the river channel laterally.

[0046] In another embodiment, when constructing the ecological depression, depressions are excavated in the area close to the shoreline on both sides of the river. After excavation, the bottom elevation of the depression is controlled to be 15cm lower than the normal water level, that is, the bottom elevation of the depression is 1.35m. The longitudinal length of each depression is set to 18m and the transverse width is set to 6m. After excavation, the elevation of each point at the bottom of the depression is measured by a level instrument to ensure that the elevation deviation does not exceed ±0.03m.

[0047] In another embodiment, when constructing the submerged sandbar, silt generated from river dredging is piled up in the central area of ​​the river channel. After the sandbar is piled up, the elevation of the top of the sandbar is controlled within 10 cm above and below the normal water level, that is, the highest elevation of the top of the sandbar is 1.6 m and the lowest elevation is 1.4 m. The longitudinal length of each sandbar is set to 20 m and the transverse width is set to 5 m. After the sandbar is piled up, the elevation of each point on the top of the sandbar is measured by a total station to ensure that the elevation meets the set range. The distance between adjacent sandbars is set to 80 m, so that each habitat unit is alternately distributed along the longitudinal direction of the river channel.

[0048] Optionally, in step S2, the multi-layered functional matrix composed of zeolite, limestone, and hollow bio-ceramic particles is laid on the modified riverbed according to a preset ratio, specifically as follows:

[0049] The support layer consists of gravel with a particle size of 20-50mm, accounting for 40%-50% of the total mass of the multi-layer functional matrix;

[0050] The adsorption layer is made of a mixture of zeolite and limestone at a mass ratio of 3:1, accounting for 30%-40% of the total mass of the multilayer functional matrix;

[0051] The bio-attachment layer uses hollow bio-ceramic particles with a particle size of 5-10 mm, accounting for 20%-30% of the total mass of the multi-layer functional matrix.

[0052] In this embodiment, the modified riverbed is cleaned to remove debris and loose soil. Then, 10m x 10m laying units are marked out using a measuring tape and chalk. The material usage for each layer is calculated based on a total multi-layer functional matrix mass of 2000kg. During the support layer laying stage, gravel with a particle size of 20-50mm is selected, and 900kg of gravel is weighed out at a ratio of 45% of the total mass. The gravel is evenly laid on the bottom of the riverbed using a combination of manual labor and a small loader. A thickness check point is set every 2m during the laying process, and the thickness of the support layer is ensured to be a stable 15cm using a steel ruler. After laying, the gravel layer is lightly vibrated twice with a plate vibrator to ensure a compaction degree of over 90%. During the adsorption layer laying stage, zeolite and limestone are weighed out at a mass ratio of 3:1, with 500kg of zeolite weighed out at a ratio of 25% of the total mass and 160kg of limestone weighed out at a ratio of 8% of the total mass. The two materials are then poured... Mix the mixture in a mixer for 15 minutes until homogeneous. Then, spread the mixture evenly on top of the support layer, with a thickness of 10cm. Collect one sample of the mixture every 3m², and check that the ratio of zeolite to limestone does not exceed ±2%. During the bio-attachment layer laying stage, select hollow bio-ceramic granules with a particle size of 5-10mm. Weigh 440kg of ceramic granules, which account for 22% of the total mass. Manually spread the ceramic granules evenly on the surface of the adsorption layer, with a thickness of 8cm. During the laying process, select one sample every 500kg of ceramic granules by sieving. Check that the proportion of ceramic granules with a particle size of 5-10mm is not less than 95%.

[0053] Preferably, step S3: Aquatic pioneer species are introduced into the sequenced habitat unit. After monitoring and confirming that the community of aquatic pioneer species is stable, aquatic intermediate competing species are introduced. After monitoring and confirming that the intermediate community of aquatic intermediate competing species has formed, aquatic apex indicator species are introduced to construct an aquatic food web.

[0054] Optionally, step S3 includes:

[0055] Step S31: The pioneer aquatic species are Vallisneria natans, Hydrilla verticillata, and freshwater clams; Vallisneria natans and Hydrilla verticillata are planted at a density of 10-15 plants per square meter in the shallow area of ​​the sequenced habitat unit, and freshwater clams are released at a density of 5-8 clams per square meter in the transition area between the deep pool and the shallow area.

[0056] Step S32: Periodically sample to obtain species coverage. When the species coverage remains above 60% for 15 consecutive days, the pioneer species community is considered stable.

[0057] Step S33: The intermediate competitive species in aquatic life are silver carp, bighead carp, and goby; silver carp and bighead carp are released at a density of 5-8 per 100 cubic meters of water, and goby is released at a density of 3-5 per 100 square meters of water.

[0058] Step S34: When the survival density of intermediate competing species remains stable at 5 or more per square meter within the preset period and the population structure does not fluctuate significantly;

[0059] Step S35: The top indicator species for aquatic life is either freshwater jellyfish or mandarin fish. Freshwater jellyfish are introduced when the water transparency reaches 1.5m or higher, and mandarin fish are introduced when the dissolved oxygen is stable at 6mg / L or higher. The number of introduced fish is set at 2-3 per 100 cubic meters of water to construct an aquatic food web.

[0060] In this embodiment, pioneer aquatic species were planted and released: healthy seedlings of Vallisneria natans and Hydrilla verticillata with a height of 15-20cm were selected and planted in the shallow area (water depth 0.2-0.8m) of the sequential habitat unit at a density of 12 seedlings per square meter. Before planting, a 1m×1m planting grid was divided using a measuring tape, and 6 Vallisneria natans and 6 Hydrilla verticillata seedlings were planted evenly in each grid. The planting depth was controlled so that the roots were buried 10-15cm into the riverbed substrate. At the same time, healthy river clams with a shell length of 3-5cm were selected and released in the transition area between deep pools and shallow areas (water depth 1.0-1.5m) at a density of 6 clams per square meter. During release, the clams were evenly distributed by manual scattering. Subsequently, monitoring of the pioneer species community was initiated. Samples were collected every Monday and Thursday using the quadrat method. Five 1m×1m quadrats were set up in the shallow water area. The actual number of Vallisneria natans and Hydrilla verticillata and their coverage area in each quadrat were counted, and the species coverage rate was calculated. Monitoring continued until the species coverage rate remained above 60% for 15 consecutive days, at which point the pioneer species community was considered stable.

[0061] In one embodiment, after the frontal community stabilizes, intermediate-level aquatic competing species are released: silver carp and bighead carp fry with a body length of 8-10cm are selected and released at a density of 6 fry per 100 cubic meters of water. Before release, the total water volume of the release area is calculated to be 5000 cubic meters using the water volume calculation formula (water volume = cross-sectional area of ​​the river channel × river length), and a total of 150 silver carp fry and 150 bighead carp fry are released. At the same time, goby fry with a body length of 5-7cm are selected and released in the area where shallow water and deep pools meet (water area of ​​2000 square meters) at a density of 4 fry per 100 square meters of water, and a total of 80 goby fry are released. After release, sampling and monitoring were conducted every Tuesday and Friday using fishing nets. Three 20m×20m monitoring plots were set up in the release area. The number of silver carp, bighead carp, and goby surviving in each plot was counted, and the survival density was calculated. Monitoring was conducted continuously for 4 weeks. When the survival density stabilized at more than 5 fish / m² and the weekly population fluctuation did not exceed 10%, it was determined that an intermediate competitive species community had formed.

[0062] In another embodiment, a top-level indicator species of aquatic organisms were introduced: the water transparency was measured weekly using a transparency disc, and when the transparency reached 1.5m or higher for three consecutive measurements, healthy freshwater jellyfish were selected and introduced at a density of 2 per 100 cubic meters of water. The introduction area was a deep pool (water volume of 3000 cubic meters), and a total of 60 freshwater jellyfish were introduced; or the dissolved oxygen in the water was monitored daily using a dissolved oxygen meter, and when the dissolved oxygen level was stable above 6mg / L for 7 consecutive days, 10-12cm long mandarin fish were selected and introduced at a density of 2.5 per 100 cubic meters of water. The introduction area was the water area connecting the shallows and the deep pool (water volume of 4000 cubic meters), and a total of 100 mandarin fish were introduced, thus completing the aquatic food web construction.

[0063] Preferably, in step S4: water quality data, hydrological data, and biological data are collected by sensors in the river channel and sequential habitat units and transmitted to a preset ecological brain platform; the river ecosystem health assessment model in the ecological brain platform is used to provide feedback control of the intelligent dam and water replenishment system, and to dynamically assess and adaptively regulate the ecosystem.

[0064] Optionally, the river ecosystem health assessment model in the ecological brain platform in step S4 couples the water quality index, hydrological diversity index, and biological integrity index.

[0065] The water quality index is converted into a quantitative score with a unified scoring dimension, the hydrological diversity index is converted into a quantitative score with a unified scoring dimension, and the biological integrity index is converted into a quantitative score with a unified scoring dimension.

[0066] The overall health score of the ecosystem is calculated by combining the three types of quantitative scores according to the preset weight allocation ratio.

[0067] Based on the comprehensive health score of the ecosystem, different levels representing different health states of the ecosystem are divided into intervals.

[0068] In this embodiment, the water quality index is calculated to be 0.72 by collecting data on dissolved oxygen, ammonia nitrogen, total phosphorus, and chemical oxygen demand using water quality sensors deployed in the river channel; the hydrological diversity index is calculated to be 0.68 by collecting flow data within one month using hydrological sensors and calculating the frequency of flow fluctuations and the proportion of peak pulse duration; and the biological integrity index is calculated to be 0.75 by collecting data on the number of benthic animal species and fish community structure using biological monitoring equipment, according to the river biological integrity assessment method.

[0069] In one embodiment, a quantitative score conversion is performed, with a unified scoring dimension set at 0-100 points. The water quality index conversion formula is: quantitative score = water quality index × 100, converting a water quality index of 0.72 into 72 points.

[0070] The formula for converting the hydrological diversity index is: Quantitative score = Hydrological diversity index × 100, which converts a hydrological diversity index of 0.68 into 68 points.

[0071] The formula for converting the biological integrity index is: Quantitative score = Biological integrity index × 100, which converts a biological integrity index of 0.75 into 75 points.

[0072] Next, the comprehensive health score of the ecosystem is calculated according to the preset weight allocation ratio (40% for water quality index, 30% for hydrological diversity index, and 30% for biological integrity index). The calculation process is as follows: comprehensive health score = 72 × 40% + 68 × 30% + 75 × 30%, resulting in a comprehensive health score of 71.7.

[0073] In another embodiment, the overall health score is used to divide the level range. The overall health score is set as follows: 80-100 points is the excellent range, 60-79 points is the good range, 40-59 points is the average range, and below 40 points is the poor range. The overall health score of 71.7 points corresponds to the good range.

[0074] Optionally, the comprehensive health score calculated by the river ecosystem health assessment model is out of 100 points, where the comprehensive health status is in the excellent range (80-100 points), the good range (60-79 points), the average range (40-59 points), and the poor range (below 40 points). The ecological brain platform generates control strategies based on the above range divisions and evaluation results.

[0075] If the overall health score is 80-100, keep the current intelligent dam opening parameters and the flow and cycle parameters of the water replenishment system unchanged;

[0076] If the overall health score is 60-79, adjust the time interval of pulsed hydration, with the adjustment range controlled within 10%-20% of the current cycle;

[0077] If the overall health score is 40-59, adjust the flow rate of the pulse water replenishment, with the adjustment range set to 20%-30% of the current pulse flow rate.

[0078] If the overall health score is below 40, an emergency water replenishment mechanism will be activated, shortening the water replenishment cycle to 50%-70% of the normal cycle, while extending the duration of the flood peak pulse to 1.2-1.5 times the normal duration.

[0079] In this embodiment, the comprehensive health score calculated by the river ecosystem health assessment model is set to a maximum of 100 points, and is divided into four levels: excellent (80-100 points), good (60-79 points), medium (40-59 points), and poor (below 40 points). At the same time, the current intelligent dam opening parameters are set as an opening height of 0.8m (corresponding to a pulse flow of 2.5m³ / s), and the conventional parameters of the water replenishment system are a cycle of 7 days / time and a flood peak pulse duration of 6 hours.

[0080] In another embodiment, when the ecological brain platform receives sensor data and calculates a comprehensive health score of 85 points, this score falls into the excellent range. The ecological brain platform maintains the current intelligent dam opening height of 0.8m, the water replenishment system flow rate of 2.5m³ / s, the cycle of 7 days / time, and the peak pulse duration of 6 hours unchanged. When the calculated comprehensive health score is 68 points, this score falls into the good range. The ecological brain platform adjusts the pulse water replenishment interval. The current water replenishment cycle is 7 days / time. Based on a 15% adjustment, the cycle is shortened to 7 days × (1-15%) = 5.95 days (rounded to 6 days / time). The remaining intelligent dam opening and water replenishment flow parameters remain unchanged. When the calculated comprehensive health score is 45 points, this score falls into the medium range. The ecological brain platform adjusts the pulse water replenishment flow... The scale is adjusted. The current pulse flow rate is 2.5 m³ / s. Calculated with a 25% adjustment margin, the flow rate will be increased to 2.5 m³ / s × (1 + 25%) = 3.125 m³ / s. Correspondingly, the opening height of the smart sluice gate will be adjusted to 1.0 m, while the water replenishment cycle and the duration of the flood peak pulse will remain unchanged. When the calculated comprehensive health score is 35 points, which falls into the poor range, the ecological brain platform activates the emergency water replenishment mechanism. The current regular water replenishment cycle is 7 days / time, and the regular flood peak pulse duration is 6 hours. Calculated with a 60% cycle shortening ratio, the cycle will be adjusted to 7 days × 60% = 4.2 days (rounded to 4 days / time). Calculated with a 1.3 times duration extension ratio, the duration of the flood peak pulse will be adjusted to 6 hours × 1.3 = 7.8 hours (rounded to 8 hours), while keeping the opening parameters of the smart sluice gate corresponding to the pulse flow rate unchanged.

[0081] Of particular importance is that the iterative optimization function of the regulation strategy of the ecological brain platform first performs data storage operations, including:

[0082] After generating each control command, the ecological brain platform automatically associates and stores the complete parameters of the control command, including the intelligent dam opening parameters, water replenishment flow parameters, water replenishment cycle parameters, and flood peak pulse duration parameters.

[0083] The ecological brain platform sets the monitoring period after regulation to 72 hours. During this period, it continuously collects and stores water quality data, hydrological data, and biological data of the river and sequential habitat units. The stored data is uniquely associated with the corresponding regulation commands, forming a historical database of command-data matching.

[0084] In one embodiment, when performing data storage operations in the iterative optimization function of the ecological brain platform's control strategy, the ecological brain platform automatically triggers the associated storage program after generating each control instruction to store the complete parameters of the control instruction: if the current control instruction is to adjust the opening of the smart dam to 0.9m, the water replenishment flow to 2.8m³ / s, the water replenishment cycle to 6 days / time, and the duration of the flood peak pulse to 7 hours, then the platform will completely input the parameters of "smart dam opening 0.9m, water replenishment flow 2.8m³ / s, water replenishment cycle 6 days / time, and duration of the flood peak pulse 7 hours" into the storage module, and assign a unique identifier code (e.g., CMD-20240508-001) to this set of parameters.

[0085] In another embodiment, the ecological brain platform sets the monitoring period after regulation to 72 hours according to preset rules. Starting from the start time of the regulation command execution (e.g., 9:00 on May 8, 2024), it continuously collects river water quality data, hydrological data, and biological data for 72 hours through water quality sensors (monitoring indicators including dissolved oxygen, ammonia nitrogen, total phosphorus, and chemical oxygen demand, collecting data once every hour), hydrological sensors (monitoring indicators including flow rate, water depth, and flow velocity, collecting data once every 30 minutes), and biological monitoring equipment (monitoring indicators including benthic animal density and aquatic plant coverage, collecting data once every 12 hours) deployed in the river channel and sequential habitat units. During the collection process, each data point is automatically attached with the aforementioned unique identification code (e.g., CMD-20240508-001) to ensure that each set of stored water quality, hydrological, and biological data is uniquely associated with the corresponding regulation command. Finally, all associated data are integrated and stored in the historical database.

[0086] Of particular importance, the ecological brain platform performs iterative optimization operations based on stored data, including:

[0087] Extract the monitoring data before regulation, regulation instructions, and post-regulation monitoring data set for the same regulated object from the historical database, and calculate the difference in the overall ecosystem health score before and after regulation.

[0088] The impact of each control parameter on the health status of the ecosystem is determined by the magnitude of the difference. If the proportion of the difference corresponding to the water quality-related control parameter is higher than that of other parameters, the weight allocation ratio of the water quality index in the river ecosystem health assessment model is increased; if the proportion of the difference corresponding to the hydrology-related control parameter is even higher, the weight allocation ratio of the hydrology diversity index is increased.

[0089] In this embodiment, when performing iterative optimization operations based on stored data by the Ecological Brain Platform, three sets of "pre-regulation monitoring data - regulation instructions - post-regulation monitoring data" for the same regulated object (such as deep pool-shallow beach sequence habitat unit) are first extracted from the historical database. Each set of data has a unique association identifier.

[0090] In the first set of data, the comprehensive health score of the ecosystem before regulation was 65 points. The regulation instructions were: intelligent dam opening of 0.8m, water replenishment flow of 2.5m³ / s (hydrological parameters), and water replenishment cycle of 7 days / time. After regulation, the comprehensive health score was 70 points, with a change of 5 points.

[0091] In the second set of data, the comprehensive health score before regulation was 62 points, the regulation instructions were: water replenishment flow of 2.2 m³ / s (hydrological parameters) and intelligent gate dam opening of 0.7 m, and the comprehensive health score after regulation was 66 points, with a change of 4 points;

[0092] In the third set of data, the comprehensive health score before regulation was 58 points. The regulation instruction was: to adjust the operating parameters of the artificial wetland deep purification corridor (water quality-related parameters, such as increasing the flushing frequency of the packing material to once every 3 days). After regulation, the comprehensive health score was 71 points, with a change of 13 points.

[0093] In another embodiment, the proportion of the change difference corresponding to each control parameter is calculated. The total change difference is 5 + 4 + 13 = 22 points, of which the total difference corresponding to the hydrological control parameters is 5 + 4 = 9 points, accounting for 9 ÷ 22 × 100% ≈ 40.9%; the difference corresponding to the water quality control parameters is 13 points, accounting for 13 ÷ 22 × 100% ≈ 59.1%. Since the proportion of the difference corresponding to the water quality control parameters (59.1%) is higher than the proportion of the difference corresponding to the hydrological control parameters (40.9%), the Ecological Brain Platform increases the weight allocation ratio of the water quality index in the river ecosystem health assessment model from the original 40% to 45%, adjusts the weight allocation ratio of the hydrological diversity index from the original 30% to 25%, and keeps the weight of the biological integrity index unchanged at 30%, thus completing this iterative optimization operation.

[0094] Of particular importance is that the filler material of the artificial wetland deep purification corridor in the water source control module includes modified biochar and iron slag designed to remove new pollutants from the effluent; the ecological brain platform in the water source control module communicates with the urban water management platform and the meteorological forecasting system, and can predict rainfall events based on weather forecasts and formulate water replenishment strategies in advance to optimize hydrological rhythms.

[0095] It should be noted that this embodiment uses the actual reconstruction of the urban river ecosystem of a sewage treatment plant in a certain city as an example:

[0096] Take, for example, a river in a certain city that is about 3 kilometers long and relies entirely on 50,000 tons of effluent from an upstream sewage treatment plant every day.

[0097] Please see Figure 3 This is a schematic diagram of the urban river ecosystem of wastewater treatment plant effluent; the specific labels in the diagram are: wastewater treatment plant 1, artificial wetland deep purification corridor 2, rainwater storage facility 3, water distribution hub 4, intelligent gate dam 5, deep pool 6, shallow beach 7, ecological depression 8, submerged sandbar 9, multi-layer functional matrix 10.

[0098] Next to the effluent outlet of the wastewater treatment plant, an artificial wetland deep purification corridor 2 covering approximately 1.5 hectares will be constructed. 10% of the effluent (approximately 5000 tons / day) will be introduced into this artificial wetland deep purification corridor for deep purification. The purified effluent will be connected to a nearby 5000 cubic meter rainwater storage tank 3. A water distribution hub 4 and a smart dam 5 will be constructed upstream of the river.

[0099] The downstream 1.5-kilometer-long demonstration section of the river was modified in terms of terrain. A deep pool 6 (about 2 meters deep) was dug every 100-150 meters, connected to a gentle slope 7 about 50 meters long. An ecological depression 8 was excavated on one side of the river channel, and the dredged silt was used to build a submerged sandbar 9 in the middle of the river channel; then, a multi-layered functional matrix 10 with a thickness of 50 cm was laid on the entire riverbed.

[0100] First, Vallisneria natans and Hydrilla verticillata were planted in the shallows and depressions, and river clams were introduced. After two months, when the plants were growing vigorously and the river clams had a high survival rate, silver carp, bighead carp fry, and goby fry were introduced. After one year of operation, the water quality stabilized at Class II-III, and a small number of chub were introduced.

[0101] Sensors are deployed in the habitat units, and the data is wirelessly transmitted to the ecological brain platform. The platform is set to perform pulse water replenishment once a week on Wednesday mornings, lasting for 6 hours, with the flow rate increasing from 1 m³ / s to 2.5 m³ / s.

[0102] Results: One year after the project was implemented, the dissolved oxygen concentration in the river increased to over 6 mg / L, and algal blooms were completely eliminated; the number of benthic animal species increased from 3 to 15, and various aquatic insect larvae sensitive to pollution were discovered; the fish community structure became more complex, forming an effective food web.

[0103] Therefore, the embodiments should be considered as exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of the equivalents of the application are intended to be included within the invention.

[0104] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features of the invention herein.

Claims

1. A method for reconstructing an urban river ecosystem based on tail water of a sewage treatment plant, characterized in that, Includes the following steps: Step S1: The effluent from the wastewater treatment plant is introduced into an artificial wetland deep purification corridor that runs parallel to or surrounds the river for purification. The purified effluent water quality is collected, including ammonia nitrogen, total phosphorus, and chemical oxygen demand. The purified effluent water quality is mixed at the water distribution hub according to a preset mixing ratio to form a mixed water body. The mixed water body is then used to implement pulsed ecological water replenishment to the downstream of the river through a preset intelligent sluice gate. Step S2: Collect initial topographic data of smooth, hard river channels, determine habitat size parameters based on the habitat conditions required for the survival of aquatic organisms, modify the river channel topography to form sequential habitat units; lay a multi-layer functional matrix composed of zeolite, limestone and hollow biological ceramic particles on the modified riverbed according to a preset ratio. Among them, the habitat conditions required for the survival of aquatic organisms in step S2 include suitable water depth for benthic animals, space requirements for fish migration, and light adaptation range for aquatic plants; combined with the longitudinal slope ratio and cross-sectional dimensions in the initial topographic data of smooth hard river channels, the habitat size parameters of the serialized habitat units are determined. In step S2, the sequenced habitat units include deep pools, shallow beaches, ecological depressions, and submerged sandbars; Step S3: Introduce aquatic pioneer species into the sequenced habitat unit. After monitoring and confirming the stability of the aquatic pioneer species community, introduce aquatic intermediate competing species. After monitoring and confirming the formation of the intermediate community of aquatic intermediate competing species, introduce aquatic apex indicator species to construct an aquatic food web. Step S3 includes: Step S31: The pioneer aquatic species are Vallisneria natans, Hydrilla verticillata, and freshwater clams; Vallisneria natans and Hydrilla verticillata are planted at a density of 10-15 plants per square meter in the shallow area of ​​the sequenced habitat unit, and freshwater clams are released at a density of 5-8 clams per square meter in the transition area between the deep pool and the shallow area. Step S32: Periodically sample to obtain species coverage. When the species coverage remains above 60% for 15 consecutive days, the pioneer species community is considered stable. Step S33: The intermediate competitive species in aquatic life are silver carp, bighead carp, and goby; silver carp and bighead carp are released at a density of 5-8 per 100 cubic meters of water, and goby is released at a density of 3-5 per 100 square meters of water. Step S34: When the survival density of intermediate competing species remains stable at 5 individuals / m² or higher within the preset period and the population structure does not fluctuate significantly, it is determined that an intermediate competing species community has been formed. Step S35: The top indicator species for aquatic life is either freshwater jellyfish or chub. Freshwater jellyfish are introduced when the water transparency reaches 1.5m or more, and chub are introduced when the dissolved oxygen is stable at 6mg / L or more. The number of introduced species is set at 2-3 per 100 cubic meters of water to construct an aquatic food web. Step S4: Collect water quality data, hydrological data, and biological data through sensors in the river channel and sequential habitat units, and transmit them to the preset ecological brain platform; use the river ecosystem health assessment model in the ecological brain platform to provide feedback control of the intelligent gate dam and water replenishment system, and dynamically assess and adaptively regulate the ecosystem.

2. The method of reconstructing an urban river ecosystem based on tail water of a sewage treatment plant according to claim 1, characterized in that, The implementation parameters for pulsed ecological water replenishment in step S1 are as follows: Based on the preset normal base flow of the river, the replenishment flow is increased 1-2 times per week. Each flood peak pulse lasts for 4-8 hours, and the pulse flow is set to 1.5-3 times the normal base flow, of which the normal base flow of the river is set to 1 m³ / s.

3. The method for reconstructing urban river ecosystems based on wastewater treatment plant effluent according to claim 1, characterized in that, In step S2, the multi-layered functional matrix composed of zeolite, limestone, and hollow bio-ceramic particles is laid on the modified riverbed according to a preset ratio. Specifically, this involves: The support layer consists of gravel with a particle size of 20-50mm, accounting for 40%-50% of the total mass of the multi-layer functional matrix; The adsorption layer is made of a mixture of zeolite and limestone at a mass ratio of 3:1, accounting for 30%-40% of the total mass of the multilayer functional matrix; The bio-attachment layer uses hollow bio-ceramic particles with a particle size of 5-10 mm, accounting for 20%-30% of the total mass of the multi-layer functional matrix.

4. The method for reconstructing urban river ecosystems based on wastewater treatment plant effluent according to claim 1, characterized in that, In step S4, the river ecosystem health assessment model in the ecological brain platform couples water quality index, hydrological diversity index, and biological integrity index as follows: The water quality index is converted into a quantitative score with a unified scoring dimension, the hydrological diversity index is converted into a quantitative score with a unified scoring dimension, and the biological integrity index is converted into a quantitative score with a unified scoring dimension. The overall health score of the ecosystem is calculated by combining the three types of quantitative scores according to the preset weight allocation ratio. Based on the comprehensive health score of the ecosystem, different levels representing different health states of the ecosystem are divided into intervals.

5. The method for reconstructing urban river ecosystems based on wastewater treatment plant effluent according to claim 4, characterized in that, The river ecosystem health assessment model calculates a comprehensive health score out of 100 points. The comprehensive health status is categorized as follows: excellent (80-100 points), good (60-79 points), moderate (40-59 points), and poor (below 40 points). The ecological brain platform generates control strategies based on these categorizations and evaluation results. If the overall health score is 80-100, keep the current intelligent dam opening parameters and the flow and cycle parameters of the water replenishment system unchanged; If the overall health score is 60-79, adjust the time interval of pulsed hydration, with the adjustment range controlled within 10%-20% of the current cycle; If the overall health score is 40-59, adjust the flow rate of the pulse water replenishment, with the adjustment range set to 20%-30% of the current pulse flow rate. If the overall health score is below 40, an emergency water replenishment mechanism will be activated, shortening the water replenishment cycle to 50%-70% of the normal cycle, while extending the duration of the flood peak pulse to 1.2-1.5 times the normal duration. The normal water replenishment cycle is 7 days / time, and the normal duration of the flood peak pulse is 6 hours.

6. A system for reconstructing urban river ecosystems based on wastewater treatment plant effluent, characterized in that, For implementing the urban river ecosystem reconstruction method based on wastewater treatment plant effluent as described in claim 1, the urban river ecosystem reconstruction system based on wastewater treatment plant effluent includes: The water source control module is used to introduce the effluent from the sewage treatment plant into the artificial wetland deep purification corridor that runs parallel to or surrounds the river for purification, collect the water quality of the purified effluent, mix the purified effluent water quality at the water distribution hub, and implement pulsed ecological water replenishment to the downstream of the river through a preset intelligent gate dam. The habitat creation module is used to collect initial topographic data of smooth and hard river channels, determine habitat size parameters in combination with the habitat conditions required for the survival of aquatic organisms, and modify the river channel topography to form sequential habitat units; a multi-layer functional matrix composed of zeolite, limestone and hollow biological ceramic particles is laid on the modified riverbed according to a preset ratio. The biorecovery module is used to introduce aquatic pioneer species into the sequenced habitat unit, monitor and confirm the stability of the aquatic pioneer species community, introduce aquatic intermediate competing species, monitor and confirm the formation of the intermediate community of the aquatic intermediate competing species, and then introduce aquatic apex indicator species to construct an aquatic food web. The intelligent operation and maintenance module is used to collect water quality data, hydrological data and biological data through sensors in the river and serialized habitat units, and transmit them to the preset ecological brain platform; through the river ecosystem health assessment model in the ecological brain platform, it provides feedback control to the intelligent gate dam and water replenishment system, dynamically assesses and adaptively regulates the ecosystem.

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