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CN-121974479-A - Rural sewage treatment method

CN121974479ACN 121974479 ACN121974479 ACN 121974479ACN-121974479-A

Abstract

The invention discloses a rural sewage treatment method which comprises the steps of dividing a rural sewage collection pipe network into a plurality of conveying sections according to space distribution, arranging valves at the head end and the tail end of each section, arranging monitoring points in the sections, arranging tail end treatment units at the most downstream, configuring each section into one of a receiving state, a reaction state or a discharge state according to sewage liquid level and pollution indexes acquired by the monitoring points in real time, accumulating sewage in the receiving state, closing valves at two ends in the reaction state for facultative hydrolysis reaction, opening the tail end valves in the discharge state for conveying hydrolyzed sewage downstream, selectively opening part of water discharged from the head end valves to be introduced into the tail end treatment units for hydraulic flushing, and gradually collecting the hydrolyzed sewage discharged by each section to the tail end treatment units. The invention can realize the cooperative operation of the sectional interception, the step pretreatment and the hydraulic conveying of the dispersed sewage, is suitable for rural sewage water quantity and quality fluctuation, and reduces the pipeline network deposition and the tail end impact.

Inventors

  • MIAO JIAYI
  • WANG JINGUI

Assignees

  • 河北工程大学

Dates

Publication Date
20260505
Application Date
20260404

Claims (8)

  1. 1. The rural sewage treatment method is characterized by comprising the following steps: Dividing a rural sewage collection pipe network into a plurality of conveying sections according to spatial distribution, setting monitoring points in each conveying section, respectively setting valves at the head end and the tail end of the conveying section, and setting a tail end treatment unit at the most downstream of the rural sewage collection pipe network; According to the sewage liquid level and pollution index obtained by the monitoring points of each conveying section in real time, the running state of the conveying section is configured into one of an accepting state, a reacting state or a discharging state; when the conveying section is in a receiving state, a head end valve of the conveying section is opened, and a tail end valve is closed, so that upstream water enters the conveying section and is accumulated in a pipe network; When the conveying section is in a reaction state, closing a head end valve and a tail end valve of the conveying section, so that sewage accumulated in a pipe network undergoes facultative hydrolysis reaction under a closed condition to obtain hydrolyzed sewage; When the conveying section is in a discharge state, opening a tail end valve of the conveying section, conveying the hydrolyzed sewage to the downstream, and simultaneously selectively opening a head end valve of the conveying section according to the pollution index of the downstream conveying section, and introducing part of water discharged from the tail end treatment unit into the conveying section for hydraulic flushing; And gradually collecting the hydrolyzed sewage discharged by each conveying section to a tail end treatment unit, and refluxing part of effluent of the tail end treatment unit to the head end of each conveying section, and dynamically adjusting the distribution ratio of the returned water to each conveying section according to the pollution index obtained by each monitoring point in real time.
  2. 2. The rural sewage treatment method according to claim 1, wherein the pollution index is obtained by weighting and calculating the chemical oxygen demand concentration, the total phosphorus concentration and the ammonia nitrogen concentration obtained in real time according to the monitoring point.
  3. 3. The rural sewage treatment method according to claim 1, wherein the condition for judging the admission state is: when the sewage liquid level obtained by the monitoring point in real time is lower than a preset admittance liquid level threshold value of the conveying section and the pollution index is higher than a preset admittance pollution index threshold value, configuring the conveying section into an admittance state; Wherein the admission level threshold is determined based on the design fullness of the conveyor section, the admission pollution index threshold is dynamically adjusted based on the discharge status of the upstream located conveyor section, and the admission pollution index threshold is reduced to 60-80% of the initial threshold when the upstream located conveyor section is in the discharge status.
  4. 4. The rural sewage treatment method according to claim 3, wherein the judgment conditions of the reaction state are: When the sewage liquid level obtained by the monitoring point in real time reaches a preset reaction liquid level threshold after the conveying section is in the admitting state, and the real-time change rate of the pollution index meets a preset reaction triggering condition, switching the conveying section from the admitting state to the reaction state; The reaction triggering condition comprises that the unit time falling rate of the pollution index is lower than a first change rate threshold value, and the unit time rising rate of the pollution index is lower than a second change rate threshold value; the first change rate threshold and the second change rate threshold are dynamically set according to the statistical characteristics of the pollution index change rate of the conveying section in a historical operation period; When the downstream conveying section is in a discharging state and the tail end valve of the downstream conveying section is opened, the reaction liquid level threshold of the upstream conveying section is temporarily increased to 1.1-1.3 times of the original threshold, so that the sewage accumulation time of the upstream conveying section is prolonged, and the facultative hydrolysis reaction of the upstream conveying section is started after the downstream conveying section is discharged.
  5. 5. The rural sewage treatment method as set forth in claim 4, wherein the judgment conditions of the discharge state are: when the conveying section is in a reaction state, the sewage liquid level obtained by the monitoring point in real time reaches a preset discharge liquid level threshold value, or the pollution index is lower than a preset discharge pollution index threshold value, and the downstream conveying section is not in a discharge state, the conveying section is switched from the reaction state to the discharge state; Wherein, the discharge liquid level threshold value is determined according to the design safety super-high of the conveying section, and the discharge pollution index threshold value is dynamically adjusted according to the processing capacity of the tail end processing unit and the receiving capacity of the downstream conveying section; when the pollution index of the downstream conveying section is higher than a preset downstream admission threshold, temporarily reducing the discharge pollution index threshold to 50-70% of the original threshold, prolonging the time of the reaction state of the current conveying section until the pollution index of the downstream conveying section is reduced below the downstream admission threshold, and then switching to the discharge state; When the upstream conveying section is in a reaction state and the pollution index of the upstream conveying section is higher than that of the current conveying section, the emission pollution index threshold of the current conveying section is temporarily increased to 1.2-1.5 times of the original threshold, so that the current conveying section is preferentially discharged, and a receiving space is reserved for the upstream conveying section.
  6. 6. The rural sewage treatment method according to claim 5, further comprising a conflict adjustment method for resolving a conflict between an upstream conveying section discharge and a downstream conveying section admittance capacity, wherein the conflict adjustment method comprises: When the upstream conveying section meets the discharge state switching condition and the downstream conveying section is not currently in the admission state, judging the real-time state of the downstream conveying section: If the current pollution index is lower than the reaction maturity threshold, the reaction state of the downstream conveying section is forcibly interrupted, the downstream conveying section is switched into a receiving state, and a head end valve is opened to receive the hydrolyzed sewage discharged by the upstream conveying section; if the current pollution index is not lower than the reaction maturity threshold, suspending the switching of the discharge state of the upstream conveying section to enable the upstream conveying section to maintain the current state, and allowing the upstream conveying section to be switched to the discharge state after the downstream conveying section finishes the reaction and is switched to the receiving state; If the downstream conveying section is in the receiving state but the sewage level of the downstream conveying section reaches the receiving level threshold value, the current pollution index of the downstream conveying section is obtained, the pollution index is compared with the preset receiving pollution index threshold value, if the current pollution index is lower than the receiving pollution index threshold value, the downstream conveying section is forced to be switched to the discharging state, after the downstream conveying section is discharged to vacate the receiving capacity, the upstream conveying section is allowed to be switched to the discharging state, if the current pollution index is not lower than the receiving pollution index threshold value, the discharging state of the upstream conveying section is paused, the receiving level threshold value of the downstream conveying section is temporarily increased, the downstream conveying section temporarily accommodates the hydrolyzed sewage discharged by the upstream conveying section, and after the discharging of the upstream conveying section is completed, the receiving level threshold value of the downstream conveying section is restored to the original set value.
  7. 7. The rural sewage treatment method according to claim 5, wherein the return priority is determined according to the current operation state of each of the transport sections, wherein the transport section in the reaction state has the highest return priority, the transport section in the receiving state has the next highest return priority, and the transport section in the discharge state has the lowest return priority; In the same reflux priority, sorting is carried out from high to low according to pollution indexes obtained in real time by monitoring points of all conveying sections, and the higher the pollution index is, the larger the reflux distribution proportion is; Correcting the reflux distribution proportion according to the current sewage liquid level of each conveying section, and prohibiting the distribution of reflux to the conveying section when the current sewage liquid level of any conveying section exceeds 80% of the design safety liquid level of the conveying section; part of effluent of the tail end treatment unit is respectively conveyed to the head end of each conveying section according to the corrected reflux distribution proportion, and the conveying sections which are in a reaction state and have pollution indexes higher than a preset strengthening threshold are preferentially conveyed to reflux so as to accelerate the facultative hydrolysis reaction of the conveying sections; when any conveying section is in a discharging state and the end valve of the conveying section is opened to conduct hydraulic flushing, the distribution proportion of conveying back flow to the conveying section is temporarily increased, and the original distribution proportion is restored after the conveying section finishes discharging.
  8. 8. The rural sewage treatment method according to claim 5, wherein the sewage level of each conveying section is monitored in real time, and compared with a design safety ultra-high threshold preset for each conveying section, wherein the design safety ultra-high threshold is determined according to the design fullness of the conveying section and the safety coefficient of the pipe network structure; when the real-time sewage liquid level of any conveying section reaches 80% of the designed safety ultrahigh threshold value for the first time, sending out an early warning signal, and recording the position information and the liquid level rising rate of the conveying section; when the real-time sewage level of any conveying section exceeds 90% of the design safety ultrahigh threshold value, triggering a safety protection mode, and executing the following operations in the safety protection mode: The method comprises the steps of stopping the current running state of the conveying section without condition, immediately and forcibly switching the conveying section into a discharge state, fully opening the tail end valve of the conveying section, sequentially identifying all the conveying sections downstream in the water flow direction by taking the conveying section as a starting point, sequentially fully opening the tail end valves of all the downstream conveying sections in sequence from the near to the far to form a continuous pressure relief channel, continuously monitoring the sewage liquid level of the conveying section in the pressure relief process, and when the sewage liquid level of the conveying section falls below 60% of the designed safety ultrahigh threshold value, releasing the safety protection mode, and sequentially recovering the running state of each conveying section before the triggering of the safety protection mode in sequence from the downstream to the upstream.

Description

Rural sewage treatment method Technical Field The invention relates to the technical field related to sewage treatment. More particularly, the invention relates to a rural sewage treatment method. Background The rural domestic sewage has the characteristics of dispersed discharge, large fluctuation of water quality and water quantity, wide coverage of a collecting pipe network, complex topography and the like. Unlike urban sewage centralized treatment mode, rural areas generally lack perfect sewage collection systems, and the sewage production among farmers and villages is obviously unbalanced along with the factors such as seasons, time periods, resident living habits and the like. The traditional rural sewage treatment mode mostly adopts terminal centralized treatment, namely, scattered sewage is uniformly conveyed to a terminal treatment unit for treatment through a pipe network. However, because the sewage generation amount in each area is large in difference, the water flow in the pipe network is in an intermittent and non-full pipe flow state, so that the sewage stays in the pipe network for too long or too short time, deposition and decomposition are easy to occur, malodorous gas is generated, and the pipe network operation efficiency and the surrounding environment are affected. In order to solve the above problems, some improvements have been proposed in the prior art. For example, sewage is collected and homogenized by arranging facilities such as a lifting pump station, an adjusting tank and the like in a pipe network. However, the construction and operation costs of the facilities are high, and the site selection, construction and subsequent management of the pump station and the regulating reservoir are difficult for rural areas with large relief and scattered village distribution. In addition, if organic pollutants in rural sewage cannot be effectively controlled in the long-distance conveying process, harmful gases such as hydrogen sulfide and the like are easily generated under anaerobic conditions, so that a pipe network is corroded, and potential safety hazards exist. Therefore, it is necessary to design a technical solution that can overcome the rising defect. Disclosure of Invention The invention aims to provide a rural sewage treatment method which can realize the cooperative operation of sectional interception, step pretreatment and hydraulic conveying of dispersed sewage, adapt to rural sewage water quantity and quality fluctuation and reduce pipe network deposition and end impact. In order to achieve these objects and other advantages and in accordance with one aspect of the present invention, there is provided a rural sewage treatment method comprising dividing a rural sewage collection pipe network into a plurality of conveying sections according to spatial distribution, and arranging monitoring points in each of the conveying sections, the head and tail ends of the conveying sections being respectively provided with valves, the most downstream of the rural sewage collection pipe network being provided with a tail end treatment unit, configuring an operation state of the conveying sections to one of a receiving state, a reaction state or a discharge state according to a sewage level and a pollution index obtained in real time by the monitoring points of each of the conveying sections, opening the head valve of the conveying sections and closing the tail end valve of the conveying sections when the conveying sections are in the receiving state, allowing upstream water to enter the conveying sections and accumulate in the pipe network, closing the head valve and the tail end valve of the conveying sections when the conveying sections are in the reaction state, allowing the sewage accumulated in the pipe network to undergo concurrent hydrolysis reaction under closed conditions, obtaining hydrolyzed sewage, opening the tail end valve of the conveying sections when the conveying sections are in the discharge state, allowing the hydrolyzed sewage to be conveyed downstream according to the sewage level and the pollution index obtained, simultaneously, selectively collecting the tail end of the conveying sections to the respective monitoring units, and dynamically flushing the tail end of the conveying sections to the head and the tail end of the conveying sections to be subjected to the dynamic reflux treatment unit according to the pollution index. Further, the pollution index is obtained by weighting and calculating the chemical oxygen demand concentration, the total phosphorus concentration and the ammonia nitrogen concentration obtained in real time according to the monitoring point. Further, the judging condition of the admitting state is that when the sewage liquid level obtained by the monitoring point in real time is lower than a preset admitting liquid level threshold value of the conveying section and the pollution index is higher than a preset admitting pollution index threshol