Rural sewage treatment method

Abstract

The invention discloses a rural sewage treatment method which comprises the following steps: dividing a rural sewage collection pipe network into a plurality of conveying sections according to spatial distribution, arranging valves at the head end and the tail end of each section, arranging monitoring points in each section, and arranging a tail end treatment unit at the most downstream; according to the sewage liquid level and the pollution index obtained by the monitoring point in real time, each section is configured to be in one of a receiving state, a reaction state or a discharge state, sewage is accumulated in the receiving state, valves at the two ends are closed to carry out facultative hydrolysis reaction in the reaction state, and the valve at the tail end is opened to convey hydrolyzed sewage to the downstream in the discharge state. A head end valve is selectively opened, and part of outlet water of the tail end treatment unit is introduced for hydraulic flushing; and the hydrolyzed sewage discharged from each section is collected to a tail end treatment unit step by step. According to the invention, cooperative operation of segmented interception, cascade pretreatment and hydraulic conveying of decentralized sewage can be realized, the system adapts to rural sewage quantity and quality fluctuation, and pipe network deposition and end impact are reduced.

Description

Technical Field

[0001] This invention relates to the technical field of wastewater treatment. More specifically, this invention relates to a method for treating rural wastewater. Background Technology

[0002] Rural domestic sewage is characterized by dispersed discharge, large fluctuations in water quality and quantity, and extensive collection network coverage in complex terrain. Unlike centralized sewage treatment in cities, rural areas typically lack comprehensive sewage collection systems, and the amount of sewage generated by different households and villages varies significantly with seasons, times of day, and residents' lifestyles. Traditional rural sewage treatment methods often employ centralized end-of-pipe treatment, where dispersed sewage is transported to a single treatment unit via a pipe network. However, due to significant differences in sewage generation across regions, the water flow within the pipe network is often intermittent and not at full capacity. This results in sewage remaining in the network for too long or too short a time, easily leading to sedimentation, putrefaction, and the generation of foul odors, affecting the efficiency of the pipe network and the surrounding environment.

[0003] To address the aforementioned problems, some improvements have been proposed in existing technologies. For example, facilities such as booster pump stations and equalization tanks are installed in the pipeline network to collect and homogenize sewage. However, the construction and operation costs of such facilities are high, and for rural areas with undulating terrain and scattered villages, the site selection, construction, and subsequent management of pump stations and equalization tanks present difficulties. Furthermore, if organic pollutants in rural sewage are not effectively controlled during long-distance transportation, they can easily produce harmful gases such as hydrogen sulfide under anaerobic conditions, which not only corrode the pipeline network but also pose safety hazards.

[0004] Therefore, it is necessary to design a technical solution that can overcome the rising defects. Summary of the Invention

[0005] One objective of this invention is to provide a rural sewage treatment method that enables the coordinated operation of segmented interception, cascade pretreatment, and hydraulic transport of decentralized sewage, adapting to fluctuations in the quantity and quality of rural sewage, and reducing pipeline sedimentation and end-of-pipe impact.

[0006] To achieve these objectives and other advantages of the present invention, according to one aspect of the present invention, a rural sewage treatment method is provided, comprising: dividing a rural sewage collection network into multiple transport sections according to spatial distribution, and setting monitoring points in each transport section; installing valves at the beginning and end of each transport section; and installing an end-of-line treatment unit at the downstream end of the rural sewage collection network; configuring the operating state of each transport section as one of receiving, reacting, or discharging states based on the real-time sewage level and pollution index obtained from the monitoring points of each transport section; when the transport section is in the receiving state, opening the valve at the beginning of the transport section and closing the valve at the end, allowing upstream water to enter the transport section and accumulate in the network ... When a section is in the reaction state, the inlet and outlet valves of that section are closed, allowing the wastewater accumulated in the pipeline to undergo anoxic hydrolysis under closed conditions, resulting in hydrolyzed wastewater. When a section is in the discharge state, the outlet valve of that section is opened, allowing the hydrolyzed wastewater to be transported downstream. Simultaneously, based on the pollution index of the downstream section, the inlet valve of the downstream section is selectively opened, introducing a portion of the effluent from the end-of-pipe treatment unit into that section for hydraulic flushing. The hydrolyzed wastewater discharged from each section is gradually collected to the end-of-pipe treatment unit, and a portion of the effluent from the end-of-pipe treatment unit is returned to the inlet of each section. The distribution ratio of the effluent returned to each section is dynamically adjusted based on the real-time pollution index obtained from each monitoring point.

[0007] Furthermore, the pollution index is calculated by weighting the chemical oxygen demand (COD), total phosphorus (TP), and ammonia nitrogen (NH3) concentrations obtained in real time from the monitoring points.

[0008] Furthermore, the criteria for determining the acceptance status are as follows: when the wastewater level obtained in real time by the monitoring point is lower than the preset acceptance level threshold of the transport section, and the pollution index is higher than the preset acceptance pollution index threshold, the transport section is configured to the acceptance status; wherein, the acceptance level threshold is determined according to the design fullness of the transport section, and the acceptance pollution index threshold is dynamically adjusted according to the discharge status of the upstream transport section. When the upstream transport section is in the discharge status, the acceptance pollution index threshold is reduced to 60-80% of the initial threshold.

[0009] Furthermore, the conditions for determining the reaction state are as follows: when the transport section is in the receiving state, if the wastewater level obtained in real time by the monitoring point reaches the preset reaction level threshold, and the real-time change rate of the pollution index meets the preset reaction triggering conditions, the transport section is switched from the receiving state to the reaction state. The reaction triggering conditions include: the rate of decrease of the pollution index per unit time is lower than the first change rate threshold, and the rate of increase of the pollution index per unit time is lower than the second change rate threshold. The reaction level threshold is determined based on the design hydraulic retention time of the transport section and the minimum volume required for the facultative hydrolysis reaction. The first change rate threshold and the second change rate threshold are dynamically set based on the statistical characteristics of the change rate of the pollution index in the historical operating cycle of the transport section. When the downstream transport section is in the discharge state and its end valve is open, the reaction level threshold of the upstream transport section is temporarily increased to 1.1-1.3 times the original threshold to prolong the wastewater accumulation time of the upstream transport section, so that the facultative hydrolysis reaction of the upstream transport section can be started after the downstream transport section has finished discharging.

[0010] Furthermore, the conditions for determining the discharge status are as follows: when the transport section is in the reaction state, if the wastewater level obtained in real time by the monitoring point reaches the preset discharge level threshold, or the pollution index is lower than the preset discharge pollution index threshold, and the downstream transport section is not in the discharge state, the transport section will be switched from the reaction state to the discharge state. The discharge level threshold is determined based on the design safety height of the transport section, and the discharge pollution index threshold is dynamically adjusted based on the treatment capacity of the end-of-pipe treatment unit and the receiving capacity of the downstream transport section. When the pollution index of the downstream transport section is higher than the preset downstream receiving threshold, the discharge pollution index threshold is temporarily reduced to 50-70% of the original threshold, extending the reaction state time of the current transport section until the pollution index of the downstream transport section drops below the downstream receiving threshold before switching to the discharge state. When the upstream transport section is in the reaction state and its pollution index is higher than the pollution index of the current transport section, the discharge pollution index threshold of the current transport section is temporarily increased to 1.2-1.5 times the original threshold, prioritizing discharge from the current transport section and freeing up receiving space for the upstream transport section.

[0011] Furthermore, it also includes a conflict adjustment method to resolve the conflict between upstream transport section discharge and downstream transport section receiving capacity. The conflict adjustment method includes: when the upstream transport section meets the discharge state switching conditions, but the downstream transport section is not currently in a receiving state, determining the real-time state of the downstream transport section: if the downstream transport section is in a reaction state, obtaining the current pollution index of the downstream transport section and comparing it with a preset reaction maturity threshold; if the current pollution index is lower than the reaction maturity threshold, forcibly interrupting the reaction state of the downstream transport section, switching it to a receiving state, and opening the first-end valve to receive the hydrolyzed wastewater discharged from the upstream transport section; if the current pollution index is not lower than the reaction maturity threshold, suspending the discharge state switching of the upstream transport section, maintaining the current state of the upstream transport section until the downstream transport section completes the reaction. After switching to the receiving state, the upstream transport section is allowed to switch to the discharge state. If the downstream transport section is in the receiving state but its sewage level has reached the receiving level threshold, the current pollution index of the downstream transport section is obtained and compared with the preset receiving pollution index threshold. If the current pollution index is lower than the receiving pollution index threshold, the downstream transport section is forced to switch to the discharge state, allowing the downstream transport section to discharge downstream to free up the receiving capacity, and then the upstream transport section is allowed to switch to the discharge state. If the current pollution index is not lower than the receiving pollution index threshold, the discharge state switching of the upstream transport section is suspended, and the receiving level threshold of the downstream transport section is temporarily increased, allowing the downstream transport section to temporarily accommodate the hydrolyzed sewage discharged by the upstream transport section. After the upstream transport section has finished discharging, the receiving level threshold of the downstream transport section is restored to the original set value.

[0012] Furthermore, the return flow priority is determined based on the current operating status of each transport section. Transport sections in the reaction state have the highest return flow priority, those in the receiving state have the second highest priority, and those in the discharge state have the lowest priority. Within the same return flow priority, each transport section is ranked from highest to lowest based on the pollution index obtained in real-time from monitoring points; the higher the pollution index, the larger the return flow allocation ratio. The return flow allocation ratio is adjusted based on the current wastewater level in each transport section. When the liquid level exceeds 80% of its designed safe level, recirculation to that transport section is prohibited. A portion of the effluent from the end-of-line treatment unit is transported to the beginning of each transport section according to the corrected recirculation distribution ratio, with priority given to transport sections in the reaction state and with a pollution index higher than the preset enhancement threshold, in order to accelerate the facultative hydrolysis reaction in that transport section. When any transport section is in the discharge state and its end valve is open for hydraulic flushing, the recirculation distribution ratio to that transport section is temporarily increased, and the original distribution ratio is restored after the discharge of that transport section is completed.

[0013] Furthermore, the sewage level in each transport section is monitored in real time, and the sewage level is compared with the preset design safety over-threshold for each transport section. The design safety over-threshold is determined based on the design fullness of the transport section and the safety factor of the pipeline structure. When the real-time sewage level in any transport section reaches 80% of its design safety over-threshold for the first time, an early warning signal is issued, and the location information and the rate of increase of the level in that transport section are recorded. When the real-time sewage level in any transport section exceeds 90% of its design safety over-threshold, a safety protection mode is triggered. In the safety protection mode, the following operations are performed: the transport section is unconditionally interrupted. The current operating status will be immediately and forcibly switched to discharge mode for all transport sections, and the end valves of the transport section will be fully opened. Starting from this transport section, all transport sections will be identified sequentially downstream along the water flow direction, and the end valves of each downstream transport section will be fully opened in order from near to far, forming a continuous pressure relief channel. During the pressure relief process, the sewage level of the transport section will be continuously monitored. When the sewage level of the transport section drops to below 60% of its designed safety over-threshold, the safety protection mode will be deactivated, and each transport section will be restored to its operating status before the safety protection mode was triggered in order from downstream to upstream.

[0014] The present invention has at least the following beneficial effects: Addressing the challenges of dispersed rural sewage and significant regional variations in sewage volume, this invention divides the collection network into independent transport sections and dynamically configures three operating states—reception, reaction, and discharge—based on real-time monitoring data, enabling simultaneous transport and treatment. Specifically, after receiving upstream water, each section undergoes anoxic hydrolysis under closed conditions by shutting off valves at both ends. This transforms the traditional pipeline network from a single transport channel into a reactor with pretreatment capabilities, allowing pollutant reduction to occur simultaneously during downstream transport. This reduces the load on end-of-pipe treatment units and prevents sewage from deteriorating due to long-distance transport. Each section autonomously switches its state based on its own liquid level and pollution index, discharging downstream after completing the hydrolysis reaction, forming a continuous operation chain of reception-reaction-discharge. The pretreated sewage discharged from the upstream section becomes the influent for the downstream section, which can choose to continue treatment or receive upstream water based on its own load, achieving a tiered utilization model where each section reacts independently while coordinating transport. Furthermore, by recirculating a portion of the effluent from the end-of-pipe treatment unit back to the beginning of each section and selectively opening the valves at the beginning for hydraulic flushing during discharge, the dynamic circulation and self-cleaning capabilities within the pipe network are further enhanced. The entire system, using the pipe network as a carrier, integrates sewage collection and pretreatment, effectively solving problems such as pipe network sedimentation, hydraulic impact, and low treatment efficiency caused by uneven water volume in decentralized rural sewage treatment scenarios, achieving highly efficient coordination between transportation and treatment.

[0015] Other advantages, objectives and features of the present invention will become apparent in part from the following description, and in part from those skilled in the art through study and practice of the invention. Attached Figure Description

[0016] Figure 1 This is a framework diagram of one embodiment of this application; Figure 2 This is a flowchart of one embodiment of this application. Detailed Implementation

[0017] The present invention will now be described in further detail so that those skilled in the art can implement it based on the description.

[0018] It should be understood that terms such as "having," "comprising," and "including" used in the embodiments of this application do not exclude the presence or addition of one or more other elements or combinations thereof. All directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of this application are only used to explain the relative positional relationship and movement of components in a specific posture. If the specific posture changes, the directional indication will also change accordingly. When an element is referred to as "fixed to" or "set on" another element, it can be directly on the other element or may have an intervening element present. When an element is referred to as "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element through an intervening element. Descriptions involving "first," "second," etc., in the embodiments of this application are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features.

[0019] It should be noted that the technical solutions of the various embodiments of this application can be combined with each other, but only if they are based on the ability of those skilled in the art to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such combination of technical solutions does not exist and is not within the scope of protection claimed by this application.

[0020] In one embodiment, the rural sewage treatment method first divides the rural sewage collection network into multiple transport sections according to spatial distribution. This division can be based on village distribution, topography, or the location of inspection wells; for example, sections can be divided every 200 to 500 meters, or a single transport section can be set up within a natural village. Each transport section has valves installed at both ends, which can be electric gate valves or pneumatic butterfly valves, to control the inflow and outflow of sewage. Monitoring points are set up within each transport section, located in the middle or near the end, equipped with level sensors and online water quality analyzers to acquire real-time sewage levels and water quality parameters such as chemical oxygen demand (COD), total phosphorus (TP), and ammonia nitrogen (MN). A terminal treatment unit is located at the downstream end of the rural sewage collection network. This unit can be an integrated sewage treatment device or an artificial wetland system for the final treatment of the collected sewage. Based on the real-time sewage levels and pollution indices acquired from the monitoring points in each transport section, the operating state of each transport section is configured as either a receiving state, a reaction state, or a discharge state. When the transport section is in the receiving state, the first valve of the section is opened and the last valve is closed, allowing upstream water to flow into the transport section by gravity and accumulate in the pipe network. This serves to retain dispersed sewage within the pipe network when the sewage volume is small, preventing the pipes from drying out and depositing due to insufficient flow. When the transport section is in the reaction state, the first and last valves of the section are closed, allowing the sewage accumulated in the pipe network to undergo facultative hydrolysis under closed conditions. This reaction relies on naturally occurring facultative microorganisms in the pipe network to decompose large organic molecules into smaller ones, thereby reducing the load on subsequent treatment units and suppressing the generation of malodorous gases such as hydrogen sulfide. When the transport section is in the discharge state, the last valve of the section is opened to transport the hydrolyzed sewage downstream. Simultaneously, based on the pollution index of the downstream transport section, the first valve of the transport section is selectively opened to introduce a portion of the effluent from the end-of-pipe treatment unit into this section for hydraulic flushing. For example, when the downstream pollution index is low, the first valve is opened to introduce return effluent to flush away deposits on the pipe walls. The hydrolyzed wastewater discharged from each transport section is collected step by step to the end treatment unit. The end treatment unit transports a portion of the effluent to the beginning of each transport section through a return pump and return pipeline. The allocation ratio of the return water to each transport section is dynamically adjusted according to the pollution index obtained in real time from each monitoring point. For example, when the pollution index of a certain section is high, a larger proportion of the return water can be allocated to enhance the dilution and reaction effect of that section.

[0021] In existing technologies, rural sewage collection pipe networks typically serve only as passive transport channels, with sewage being directly discharged downstream after entering. This lack of proactive regulation based on differences in water volume across different sections easily leads to pipe network sedimentation, corrosion, and hydraulic load surges in end-of-pipe treatment units. By dividing the pipe network into independently controlled transport sections and dynamically switching the receiving, reaction, and discharge states based on real-time liquid levels and pollution indices, each section can independently intercept sewage for facultative hydrolysis pretreatment and discharge it downstream as needed. This achieves segmented regulation and tiered utilization of decentralized sewage, effectively avoiding pipe network blockage and corrosion problems caused by uneven sewage volume. Simultaneously, it utilizes the pipe network space to simultaneously complete pollutant reduction and hydraulic transport, reducing the operational pressure on end-of-pipe treatment units.

[0022] In one embodiment, the pollution index is calculated by weighting the chemical oxygen demand (COD), total phosphorus (TP), and ammonia nitrogen (AM) concentrations obtained in real time from monitoring points. Specifically, the calculation method can involve normalizing each of the COD, TTP, and AM concentrations, and then summing them according to preset weighting coefficients. For example, the weight of COD could be set to 0.5, TTP to 0.2, and AM to 0.3; the weighted values ​​are then summed to obtain the pollution index. In another possible implementation, the weighting coefficients can be adjusted according to the actual characteristics of the local water quality, for example, appropriately increasing the weight of AM in areas with intensive aquaculture.

[0023] By introducing a weighted pollution index that includes chemical oxygen demand, total phosphorus, and ammonia nitrogen, the overall pollution level of wastewater in each section can be more comprehensively characterized, providing a quantitative basis for state switching and reflux allocation, enabling precise matching of control strategies with water quality conditions, and improving the pertinence and effectiveness of system operation.

[0024] In one embodiment, the acceptance state is determined when the wastewater level, as measured in real-time by the monitoring point, is lower than the preset acceptance level threshold of the transport section, and the pollution index is higher than the preset acceptance pollution index threshold. The transport section is then configured to accept the wastewater. The acceptance level threshold can be determined based on the designed fullness of the transport section. For example, if the designed fullness is 0.5, the acceptance level threshold can be set to 0.4 times the pipe diameter. This value ensures sufficient acceptance space within the section while avoiding frequent state switching due to excessively low levels. The acceptance pollution index threshold is dynamically adjusted based on the discharge status of the upstream transport section. When the upstream transport section is in a discharge state, the acceptance pollution index threshold can be reduced to 60% or 80% of the initial threshold. This allows the current section to promptly initiate acceptance upon receiving high-concentration wastewater from the upstream, preventing wastewater overflow or prolonged retention in the upstream section. This establishes a temporal linkage between upstream discharge behavior and downstream acceptance response.

[0025] By introducing a pollution acceptance index threshold and dynamically changing it according to the upstream discharge status, the system proactively lowers the acceptance threshold when upstream discharges, enabling the current section to enter the acceptance state in advance. This ensures that high-concentration wastewater discharged from upstream can be received in a timely manner, avoiding unorganized overflow or prolonged retention of wastewater in the pipe network, and improving the system's response speed to intermittent discharges.

[0026] In one embodiment, the reaction state is determined when, after the transport section is in the receiving state, the wastewater level obtained in real time by the monitoring point reaches a preset reaction level threshold, and the real-time change rate of the pollution index meets the preset reaction triggering condition. The transport section is then switched from the receiving state to the reaction state. The reaction triggering condition includes a pollution index decrease rate per unit time lower than a first change rate threshold and a pollution index increase rate per unit time lower than a second change rate threshold. For example, the first change rate threshold can be set to a decrease of 5% per hour and the second change rate threshold to an increase of 3% per hour. When the pollution index change becomes gradual, the influent water quality is considered stable and suitable for transitioning to the reaction state. The reaction level threshold is determined based on the designed hydraulic retention time of the transport section and the minimum volume required for the facultative hydrolysis reaction. For example, the level threshold can be calculated based on the water volume required for a designed retention time of 4 hours. The first and second change rate thresholds can be dynamically set based on the statistical characteristics of the pollution index change rate of the transport section in historical operating cycles. For example, the mean or median of historical data can be used as the threshold, allowing the triggering condition to adapt to water quality fluctuations in different seasons and time periods. When the downstream conveying section is in discharge mode and its end valve is open, the reaction liquid level threshold of the upstream conveying section can be temporarily increased to 1.1 or 1.3 times the original threshold to prolong the sewage accumulation time in the upstream conveying section. This allows the anaerobic hydrolysis reaction in the upstream conveying section to be started only after the downstream conveying section has finished discharging, thus avoiding simultaneous discharge that could overload the downstream pipeline network.

[0027] By simultaneously monitoring the liquid level and the rate of change of the pollution index, the reaction process is ensured to begin only when wastewater accumulates to a sufficient volume and the water quality tends to stabilize, thus improving the effectiveness of the anoxic hydrolysis reaction. Furthermore, by dynamically adjusting the upstream reaction liquid level threshold based on the downstream discharge status, peak-shifting coordination between the reaction and discharge sequences in the upstream and downstream sections is achieved, avoiding hydraulic conflicts and ensuring the overall smooth operation of the pipeline network.

[0028] In one embodiment, the discharge status is determined when, after the transport section is in the reaction state, the wastewater level monitored in real time reaches a preset discharge level threshold, or the pollution index is lower than a preset discharge pollution index threshold, and the downstream transport section is not in the discharge state. In this case, the transport section is switched from the reaction state to the discharge state. The discharge level threshold can be determined based on the design safety margin of the transport section, for example, it can be set to 0.8 or 0.9 times the pipe diameter to allow for a safety margin to prevent overflow. The discharge pollution index threshold is dynamically adjusted based on the processing capacity of the end-of-pipe treatment unit and the acceptance capacity of the downstream transport section. When the pollution index of the downstream transport section is higher than the preset downstream acceptance threshold, the discharge pollution index threshold can be temporarily reduced to 50% or 70% of the original threshold, extending the reaction state time of the current transport section until the pollution index of the downstream transport section drops below the downstream acceptance threshold before switching to the discharge state. This binds the discharge timing of this section to the downstream acceptance conditions. When an upstream transport section is in a reactive state and its pollution index is higher than that of the current transport section, the emission pollution index threshold of the current transport section can be temporarily increased to 1.2 or 1.5 times the original threshold, so that the current transport section can give priority to emission, freeing up space for the upstream transport section to receive it, thus forming an operational order in which the upstream high-pollution section gives priority to emission and the downstream section cooperates and yields.

[0029] By introducing a dynamic adjustment mechanism for emission pollution index thresholds, the system determines whether to extend the reaction time of a downstream section based on its pollution index, and whether to prioritize emissions based on the pollution index of the upstream section. This achieves adaptive coordination of emission timing between upstream and downstream sections, ensuring priority treatment of highly polluted sections while avoiding emission conflicts, thus improving the hydraulic stability and pollutant reduction efficiency of the entire pipeline network system.

[0030] In one embodiment, a conflict adjustment method is also included to resolve the conflict between the discharge capacity of the upstream transport section and the receiving capacity of the downstream transport section. When the upstream transport section meets the discharge state switching conditions, but the downstream transport section is not currently in the receiving state, the real-time state of the downstream transport section is determined. If the downstream transport section is in the reaction state, the current pollution index of the downstream transport section is obtained and compared with a preset reaction maturity threshold. If the current pollution index is lower than the reaction maturity threshold, it indicates that the facultative hydrolysis reaction in the downstream section has been basically completed and can be interrupted in advance without affecting the treatment effect. In this case, the reaction state of the downstream transport section is forcibly interrupted, and it is switched to the receiving state, and the first valve is opened to receive the hydrolyzed wastewater discharged from the upstream transport section. If the current pollution index is not lower than the reaction maturity threshold, it indicates that the downstream section still needs to continue reacting to complete the pollutant reduction. In this case, the discharge state switching of the upstream transport section is suspended, and the upstream transport section is kept in its current state until the downstream transport section completes the reaction and switches to the receiving state, after which the upstream transport section is allowed to switch to the discharge state. If the downstream transport section is in a receiving state but its wastewater level has reached the receiving level threshold, the current pollution index of the downstream transport section is obtained and compared with the preset receiving pollution index threshold. If the current pollution index is lower than the receiving pollution index threshold, it indicates that the wastewater concentration in the downstream section is low, and early discharge will not cause a significant increase in downstream load. In this case, the downstream transport section is forcibly switched to discharge state, allowing it to discharge downstream to free up receiving capacity before the upstream transport section is allowed to switch to discharge state. If the current pollution index is not lower than the receiving pollution index threshold, the discharge state switching of the upstream transport section is suspended, and the receiving level threshold of the downstream transport section is temporarily increased, for example, by 10% or 15%, to allow the downstream transport section to temporarily accommodate the hydrolyzed wastewater discharged from the upstream transport section. After the upstream transport section has completed its discharge, the receiving level threshold of the downstream transport section is restored to the original set value.

[0031] By introducing conflict adjustment methods, differentiated intervention measures are taken based on the actual state and pollution index of the downstream section, including forcibly interrupting the downstream reaction, forcibly discharging downstream in advance, or temporarily raising the receiving liquid level threshold. This achieves flexible coordination of the operating states of the upstream and downstream sections, maximizes hydraulic transport efficiency while ensuring the treatment effect of each section, and avoids the risk of system stagnation or overflow caused by state conflicts.

[0032] In one embodiment, the return flow priority is determined based on the current operating status of each transport section. Transport sections in a reactive state have the highest return flow priority, those in a receiving state have the second highest priority, and those in a discharging state have the lowest priority. Within the same return flow priority, each transport section is ranked from highest to lowest based on the pollution index obtained in real-time from monitoring points. The higher the pollution index, the larger the return flow allocation ratio; for example, the section with the highest pollution index receives a 30% return flow allocation ratio, followed by 20%. The return flow allocation ratio is adjusted based on the current wastewater level of each transport section. When the current wastewater level of any transport section exceeds 80% of its design safety level, return flow allocation to that transport section is prohibited to prevent overflow caused by excessively high levels. A portion of the effluent from the end-of-pipe treatment unit is distributed to the beginning of each transport section according to a modified recirculation allocation ratio. Priority is given to transport sections in the reaction phase with pollution indices exceeding a preset enhancement threshold to accelerate the anaerobic hydrolysis reaction in those sections. This ensures the recirculation volume is precisely targeted to the sections currently being treated and with the highest treatment demand. When any transport section is in discharge mode and its end valve is open for hydraulic flushing, the recirculation allocation ratio to that section is temporarily increased, for example, by 50%. The original allocation ratio is restored after the discharge from that section is complete. This concentrates the water volume during flushing, enhancing the flushing effect and preventing long-term sediment accumulation.

[0033] By establishing a dynamic adjustment mechanism for the priority and allocation ratio of recirculation based on operating status and pollution index, the recirculation water volume is accurately delivered to the most needed sections, prioritizing the strengthening of sections that are reacting and have high pollution levels. At the same time, the recirculation flow rate is temporarily increased during discharge flushing to enhance the flushing effect. This not only improves the utilization efficiency of recirculation water but also avoids hydraulic interference to low-level sections, thus achieving optimal allocation of recirculation resources.

[0034] In one embodiment, the sewage level in each transport section is monitored in real time, and the sewage level is compared with the preset design safety over-threshold for each transport section. The design safety over-threshold can be determined based on the design fullness of the transport section and the safety factor of the pipeline structure. For example, when the design fullness is 0.7, the safety over-threshold can be set to 0.85 times the pipe diameter. When the real-time sewage level in any transport section reaches 80% of its design safety over-threshold for the first time, an early warning signal is issued, and the location information and the rate of increase of the liquid level in that transport section are recorded. The early warning signal can be sent to the central control room or the mobile terminal of the maintenance personnel, allowing for response time for manual intervention. When the real-time sewage level in any transport section exceeds 90% of its design safety over-threshold, a safety protection mode is triggered. In the safety protection mode, the current operating state of the transport section is unconditionally interrupted, the transport section is immediately forced to switch to discharge state, and the end valve of the transport section is fully opened. Starting from the current transport section, all transport sections are identified sequentially downstream along the water flow direction. Following a sequence from nearest to farthest, the end valves of each downstream transport section are fully opened, forming a continuous pressure relief channel that expands downstream from the danger point. During the pressure relief process, the sewage level in the transport section is continuously monitored. When the sewage level in the transport section drops below 60% of its designed safety over-threshold, the safety protection mode is deactivated. Then, each transport section is restored to its pre-safety protection mode operating state sequentially from downstream to upstream, ensuring that the system can orderly return to its original operating logic after pressure relief is completed.

[0035] By setting up a tiered early warning and protection mechanism, an early warning is issued when the liquid level reaches the 80% threshold, and a safety protection mode is automatically triggered when the liquid level reaches the 90% threshold. This forces discharge and sequentially opens all downstream valves along the water flow direction to form a continuous pressure relief channel, which can quickly reduce the liquid level in dangerous sections. At the same time, the orderly opening of the downstream channel avoids secondary congestion. After the liquid level recovers, the operation of each section is restored in an orderly manner, effectively ensuring the safe operation of the pipeline network system.

[0036] Taking a natural village in the North China Plain as an example, combined with Figure 1 The illustrated pipeline segmentation hardware architecture and Figure 2The diagram illustrates the entire operational logic, demonstrating how the technical solution of this invention is applied to rural sewage treatment. Based on village distribution, topography, and the location of inspection wells, the village's sewage collection network is divided into four continuous transport sections, each approximately 400 meters long. Electric gate valves are installed at the beginning and end of each section, and monitoring points are set up in the middle of each section to collect real-time data on sewage level, chemical oxygen demand (COD), total phosphorus, and ammonia nitrogen concentrations, and to calculate a weighted comprehensive pollution index. An integrated sewage treatment unit is installed at the downstream end of the network as the final treatment unit. The system operates fully automatically in a closed loop according to preset rules. Section 1 enters the receiving state when the liquid level is below the preset receiving threshold and the pollution index is above the receiving pollution index threshold. The first valve opens and the last valve closes to accumulate wastewater. When the upstream section is in the discharge state, the receiving pollution index threshold of this section automatically drops to 70% of the initial value to promptly receive upstream water. Once the liquid level reaches the reaction threshold and the rate of change of the pollution index per unit time meets the triggering conditions, Section 1 switches to the reaction state, and both the first and last valves close to carry out closed anaerobic hydrolysis. If the downstream section is in the discharge state, the reaction liquid level threshold of this section is temporarily increased to 1.2 times the original value to prolong the accumulation time and achieve staggered reaction. When the liquid level reaches the discharge threshold or the pollution index drops to the discharge threshold and the downstream section is not in the discharge state, Section 1 switches to the discharge state. If the pollution index of the downstream section is high, the discharge threshold of this section is lowered to 60% of the original value to prolong the reaction. If the upstream high-pollution section is awaiting treatment, this section raises the discharge threshold to prioritize discharge and create space. When upstream and downstream discharge and reception conflict, the system automatically and flexibly coordinates. If the downstream reaction is not yet mature, reception is forcibly initiated. If the downstream reception level is saturated and pollution is low, discharge is forcibly initiated ahead of schedule. If pollution is high, the reception level is temporarily raised to store wastewater. End-of-pipe treated effluent is returned according to status priority: reaction zone first, reception zone second, and discharge zone lowest. For the same priority, water is allocated according to pollution index. Return is prohibited if the liquid level exceeds the safety threshold by 80%. During discharge flushing, the return flow rate is temporarily increased. The system simultaneously activates safety protection: a warning is issued when the liquid level reaches 80% above the safety threshold; a forced pressure relief is triggered when it exceeds 90%. Valves are fully opened downstream along the water flow to form a continuous pressure relief channel. Once the liquid level drops below 60%, the original operating state is restored. Each section follows... Figure 2 The process operates in a cyclical manner, with hydrolyzed wastewater gradually flowing to the end for deep treatment. The effluent is circulated back and controlled as needed, achieving coordinated segmented interception, cascade pretreatment, and hydraulic transport. This adapts to fluctuations in the quantity and quality of rural sewage, reducing pipeline sedimentation and end-of-pipe impact.

[0037] Although embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For those skilled in the art, other modifications can be easily made. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and embodiments shown and described herein.

Claims

1. A method for treating rural sewage, characterized in that, include: The rural sewage collection pipeline network is divided into multiple transport sections according to spatial distribution, and monitoring points are set in each transport section. Valves are installed at the beginning and end of the transport section, and an end-of-line treatment unit is installed at the downstream end of the rural sewage collection pipeline network. Based on the real-time wastewater level and pollution index obtained from the monitoring points of each transport section, the operating status of the transport section is configured as one of the following: receiving state, reaction state, or discharge state. When the transport section is in the receiving state, open the first valve of the transport section and close the last valve to allow the upstream water to enter the transport section and accumulate in the pipeline network. When the transport section is in a reaction state, close the first and last valves of the transport section to allow the sewage accumulated in the pipeline to undergo anoxic hydrolysis under closed conditions, and obtain hydrolyzed sewage. When the transport section is in the discharge state, the end valve of the transport section is opened to transport the hydrolyzed wastewater downstream. At the same time, according to the pollution index of the downstream transport section, the first valve of the transport section is selectively opened to introduce part of the effluent from the end treatment unit into the transport section for hydraulic flushing. The hydrolyzed wastewater discharged from each transport section is collected step by step to the end-of-pipe treatment unit, and a portion of the effluent from the end-of-pipe treatment unit is returned to the beginning of each transport section. The distribution ratio of the effluent returned to each transport section is dynamically adjusted according to the pollution index obtained in real time from each monitoring point.

2. The rural sewage treatment method as described in claim 1, characterized in that, The pollution index is calculated by weighting the concentrations of chemical oxygen demand, total phosphorus, and ammonia nitrogen obtained in real time from the monitoring points.

3. The rural sewage treatment method as described in claim 1, characterized in that, The condition for determining acceptance status is: When the wastewater level obtained in real time by the monitoring point is lower than the preset receiving level threshold of the transport section, and the pollution index is higher than the preset receiving pollution index threshold, the transport section will be configured as receiving. The acceptance liquid level threshold is determined based on the design fullness of the transport section, and the acceptance pollution index threshold is dynamically adjusted based on the discharge status of the upstream transport section. When the upstream transport section is in a discharge state, the acceptance pollution index threshold is reduced to 60-80% of the initial threshold.

4. The rural sewage treatment method as described in claim 3, characterized in that, The conditions for determining the reaction state are: When the transport section is in the receiving state, and the sewage level obtained in real time by the monitoring point reaches the preset reaction level threshold, and the real-time change rate of the pollution index meets the preset reaction triggering condition, the transport section is switched from the receiving state to the reaction state. The reaction triggering conditions include: the rate of decrease of the pollution index per unit time is lower than the first rate of change threshold, and the rate of increase of the pollution index per unit time is lower than the second rate of change threshold; Among them, the reaction level threshold is determined based on the design hydraulic residence time of the transport section and the minimum volume required for the anoxic hydrolysis reaction, while the first change rate threshold and the second change rate threshold are dynamically set based on the statistical characteristics of the pollution index change rate of the transport section in the historical operating cycle. When the downstream conveying section is in a discharge state and its end valve is open, the reaction liquid level threshold of the upstream conveying section is temporarily increased to 1.1-1.3 times the original threshold to prolong the sewage accumulation time in the upstream conveying section, so that the anaerobic hydrolysis reaction in the upstream conveying section can be restarted after the downstream conveying section has finished discharging.

5. The rural sewage treatment method as described in claim 4, characterized in that, The conditions for determining the emission status are: When the transport section is in the reaction state, if the wastewater level obtained in real time by the monitoring point reaches the preset discharge level threshold, or the pollution index is lower than the preset discharge pollution index threshold, and the downstream transport section is not in the discharge state, the transport section will be switched from the reaction state to the discharge state. Among them, the discharge level threshold is determined based on the design safety height of the transport section, and the discharge pollution index threshold is dynamically adjusted based on the processing capacity of the end-of-pipe treatment unit and the acceptance capacity of the downstream transport section. When the pollution index of the downstream transport section is higher than the preset downstream acceptance threshold, the emission pollution index threshold is temporarily reduced to 50-70% of the original threshold, so that the current transport section extends the reaction time until the pollution index of the downstream transport section drops below the downstream acceptance threshold before switching to emission mode. When an upstream transport section is in a reactive state and its pollution index is higher than that of the current transport section, the emission pollution index threshold of the current transport section is temporarily increased to 1.2-1.5 times the original threshold, so that the current transport section can give priority to emission and make room for the upstream transport section to receive it.

6. The rural sewage treatment method as described in claim 5, characterized in that, It also includes conflict resolution methods to resolve conflicts between emissions from upstream transport sections and the receiving capacity of downstream transport sections; these conflict resolution methods include: When the upstream conveying section meets the emission status switching conditions, but the downstream conveying section is not currently in the receiving state, determine the real-time status of the downstream conveying section: If the downstream transport section is in a reaction state, the current pollution index of the downstream transport section is obtained and compared with the preset reaction maturity threshold. If the current pollution index is lower than the reaction maturity threshold, the reaction state of the downstream transport section is forcibly interrupted, it is switched to the receiving state, and the first valve is opened to receive the hydrolyzed wastewater discharged from the upstream transport section. If the current pollution index is not lower than the reaction maturity threshold, the switching of the discharge state of the upstream transport section is suspended, and the upstream transport section is kept in its current state until the downstream transport section completes the reaction and switches to the receiving state, at which point the upstream transport section is allowed to switch to the discharge state. If the downstream transport section is in the receiving state but its wastewater level has reached the receiving level threshold, the current pollution index of the downstream transport section is obtained and compared with the preset receiving pollution index threshold. If the current pollution index is lower than the receiving pollution index threshold, the downstream transport section is forced to switch to the discharge state, allowing the downstream transport section to discharge downstream to free up the receiving capacity, and then the upstream transport section is allowed to switch to the discharge state. If the current pollution index is not lower than the receiving pollution index threshold, the discharge state switching of the upstream transport section is suspended, and the receiving level threshold of the downstream transport section is temporarily increased, allowing the downstream transport section to temporarily accommodate the hydrolyzed wastewater discharged by the upstream transport section. After the upstream transport section has finished discharging, the receiving level threshold of the downstream transport section is restored to the original set value.

7. The rural sewage treatment method as described in claim 5, characterized in that, The return priority is determined based on the current operating status of each transport section. Among them, the transport section in the reaction state has the highest return priority, the transport section in the receiving state has the second highest return priority, and the transport section in the discharge state has the lowest return priority. Within the same return priority, the pollution indexes obtained in real time from the monitoring points of each transport section are sorted from high to low. The higher the pollution index, the greater the return allocation ratio. The recirculation allocation ratio is adjusted according to the current sewage level of each transport section. When the current sewage level of any transport section exceeds 80% of its design safety level, recirculation is prohibited from being allocated to that transport section. A portion of the effluent from the end-of-pipe treatment unit is transported to the beginning of each transport section according to the corrected recirculation distribution ratio. Priority is given to transport sections that are in a reaction state and whose pollution index is higher than the preset enhancement threshold, so as to accelerate the facultative hydrolysis reaction in those transport sections. When any transport section is in discharge mode and its end valve is open for hydraulic flushing, the allocation ratio of return flow to that transport section is temporarily increased, and the original allocation ratio is restored after the discharge of that transport section is completed.

8. The rural sewage treatment method as described in claim 5, characterized in that, The sewage level in each transport section is monitored in real time, and the sewage level is compared with the preset design safety over-high threshold of each transport section. The design safety over-high threshold is determined based on the design fullness of the transport section and the safety factor of the pipeline structure. When the real-time sewage level in any transport section reaches 80% of its designed safety over-high threshold for the first time, an early warning signal is issued, and the location information and the rate of increase of the liquid level in that transport section are recorded. When the real-time sewage level in any transport section exceeds 90% of its designed safe over-limit threshold, the safety protection mode is triggered. In the safety protection mode, the following operations are performed: The current operating state of the current conveying section is unconditionally interrupted, and the current conveying section is immediately and forcibly switched to discharge state, and the end valve of the conveying section is fully opened. Starting from the current conveying section, all conveying sections are identified sequentially downstream along the water flow direction, and the end valves of each downstream conveying section are fully opened in order from near to far, forming a continuous pressure relief channel. During the pressure relief process, the sewage level of the conveying section is continuously monitored. When the sewage level of the conveying section drops to below 60% of its design safety over-threshold, the safety protection mode is deactivated, and the operating state of each conveying section is restored to that before the safety protection mode was triggered in order from downstream to upstream.

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