A rain and sewage separation and membrane treatment integrated system and method

Abstract

This application provides an integrated system and method for rainwater and wastewater separation and membrane treatment, belonging to the field of rainwater and wastewater separation technology in chemical sulfuric acid production enterprises. This application uses an initial rainwater and wastewater collection well and an automatic screen to intercept debris entering the rainwater and wastewater separation well and temporarily store corrosive wastewater. A corrosion-resistant submersible pump is installed at the bottom of the initial rainwater and wastewater collection well to directly pump the corrosive wastewater to the equalization tank, reducing the risk of contact corrosion between the corrosive wastewater and the two switching valves of the rainwater and wastewater separation well. A water quality monitoring device is installed inside the rainwater and wastewater separation well, automatically controlling the opening of the electric discharge valve or the electric inward valve based on the water quality monitoring results. Unqualified water enters the equalization tank and is then sent to the membrane module for further treatment, producing compliant permeate water. This application can effectively reduce the clogging and corrosion of the electric discharge valve and the electric inward valve, and reduce environmental risks.

Description

Technical Field

[0001] This application relates to the field of rainwater and sewage separation technology, and in particular to an integrated system and method for rainwater and sewage separation and membrane treatment. Background Technology

[0002] Currently, in the existing integrated rainwater and wastewater separation and membrane treatment systems of chemical sulfuric acid production plants, during the rainy season, large amounts of garbage and debris frequently enter the rainwater and wastewater separation wells, causing frequent blockages in the wastewater switching valves and clean water switching valves. This prevents the proper switching of initial rainwater to the initial rainwater tank, severely impacting the rainwater and wastewater separation efficiency. Simultaneously, corrosive wastewater discharged under abnormal production conditions can severely corrode the switching valves and adjacent pipelines, further reducing the valve switching reliability and service life. These problems not only lead to substandard effluent quality and frequent system cleaning and maintenance, but also easily trigger environmental risks such as wastewater overflow exceeding standards, adversely affecting the company's normal production and economic benefits. Summary of the Invention

[0003] This application provides an integrated system and method for rainwater and sewage separation and membrane treatment to solve the above-mentioned problems in the prior art.

[0004] This application provides an integrated system for rainwater and sewage separation and membrane treatment, comprising: Initial rainwater and wastewater collection wells are used to collect and temporarily store rainwater and corrosive wastewater discharged from production facilities; An automatic bar screen is installed at the inlet of the initial rainwater and sewage collection well to intercept garbage and debris in rainwater and wastewater; A liquid level monitoring device is installed inside the initial rainwater and sewage collection well to monitor the liquid level inside the initial rainwater and sewage collection well; The rainwater and sewage separation well is connected to the initial rainwater and sewage collection well via a gravity flow pipe and is used to separate rainwater and sewage from the water pretreated by the initial rainwater and sewage collection well. A water quality monitoring device is installed inside the rainwater and sewage separation well to monitor the water quality parameters entering the rainwater and sewage separation well; A corrosion-resistant submersible pump is installed at the bottom of the initial rainwater and sewage collection well to directly pump the corrosive wastewater collected in the initial rainwater and sewage collection well to the subsequent treatment unit. An electric drain valve is installed on the qualified water outlet pipe of the rainwater and sewage separation well, and is used to open and discharge water when the water quality is qualified. An electric inward valve is installed on the outlet pipe of the rainwater and sewage separation well for unqualified water, and is used to open when the water quality is unqualified in order to send the water into the subsequent treatment unit. The equalization tank is connected to the outlet of the electric inward valve and to the outlet of the corrosion-resistant submersible pump. The equalization tank is used to receive and temporarily store substandard water and corrosive wastewater pumped in. The membrane module is connected to the outlet of the equalization tank and is used to separate the pretreated water to produce qualified permeate and concentrated concentrate. The logic control cabinet is electrically connected to the liquid level monitoring device, water quality monitoring device, corrosion-resistant submersible pump, electric drain valve, electric inlet valve and membrane module, respectively. The logic control cabinet is used to receive monitoring data and automatically control the operation of each actuator according to preset logic.

[0005] In one embodiment of this application, the automatic cleaning bar screen is connected to a debris collection box, which is connected to the debris outlet of the automatic cleaning bar screen. The debris collection box is used to collect intercepted debris.

[0006] In one embodiment of this application, the liquid level monitoring device is a liquid level gauge; the water quality monitoring device includes one or more of a pH meter, a conductivity meter, a turbidity meter, and a thermometer.

[0007] In one embodiment of this application, the corrosion-resistant submersible pump is connected to a frequency converter control cabinet. The frequency converter control cabinet is electrically connected to the corrosion-resistant submersible pump and the logic control cabinet, respectively. The frequency converter control cabinet is used to automatically adjust the speed of the submersible pump according to the liquid level change to control the pumping flow rate.

[0008] In one embodiment of this application, the initial rainwater and sewage collection well is connected to an emergency overflow pipe. The inlet end of the emergency overflow pipe is connected to the side wall of the initial rainwater and sewage collection well and is located at a preset safe liquid level. The outlet end of the emergency overflow pipe is connected to a common emergency pool. The emergency overflow pipe is used to allow water to flow by gravity to the common emergency pool when the liquid level in the initial rainwater and sewage collection well exceeds the safe height.

[0009] In one embodiment of this application, a solid-liquid separation device is provided between the conditioning tank and the membrane module, the inlet of the solid-liquid separation device is connected to the outlet of the conditioning tank, and the outlet of the solid-liquid separation device is connected to the inlet of the membrane module.

[0010] In one embodiment of this application, the membrane module is connected to a cleaning unit, the cleaning unit including a cleaning water tank and a cleaning pump, the inlet of the cleaning pump being connected to the cleaning water tank, the outlet of the cleaning pump being connected to the membrane module, the cleaning pump being electrically connected to the logic control cabinet, and the cleaning unit being used to perform chemical cleaning on the membrane module to restore membrane flux.

[0011] In one embodiment of this application, the logic control cabinet is connected to a remote monitoring terminal, and the remote monitoring terminal is communicatively connected to the logic control cabinet.

[0012] In one embodiment of this application, both the electric outward discharge valve and the electric inward retraction valve are equipped with manual operation handwheels.

[0013] This application also provides a method for rainwater and wastewater separation and membrane treatment, employing the integrated rainwater and wastewater separation and membrane treatment system described above, the method comprising: Rainwater and sewage are directed into an automatic cleaning bar screen, which intercepts and separates garbage and debris, allowing the pre-treated water to enter the initial rainwater and sewage collection well. The liquid level in the initial rainwater and sewage collection well is monitored in real time by a liquid level monitoring device, and the liquid level data is transmitted to the logic control cabinet; the water quality parameters in the rainwater and sewage separation well are monitored in real time by a water quality monitoring device, and the monitoring data is transmitted to the logic control cabinet; the logic control cabinet automatically determines whether the water quality entering the rainwater and sewage separation well is qualified according to the preset water quality judgment threshold. When the water quality is deemed to be up to standard, the logic control cabinet controls the opening of the electric external discharge valve installed on the qualified water outlet pipe of the rainwater and sewage separation well, allowing the water to be discharged through the electric external discharge valve; when the water quality is deemed to be substandard, the logic control cabinet controls the opening of the electric internal control valve installed on the substandard water outlet pipe of the rainwater and sewage separation well, allowing the water to be sent into the regulating tank through the electric internal control valve. The logic control cabinet controls the operation of the corrosion-resistant submersible pump based on the liquid level changes in the initial rainwater and sewage collection well, and directly pumps the corrosive wastewater in the initial rainwater and sewage collection well to the equalization tank. Water from the equalization tank is fed into the membrane module, where the pretreated water is separated to produce qualified permeate and concentrated water. Real-time data is uploaded to the monitoring platform via a remote monitoring terminal through the logic control cabinet, and users can view the system's operating status and alarm information through terminal devices.

[0014] The beneficial effects of this application are as follows: The integrated system and method for rainwater and sewage separation and membrane treatment proposed in this application intercepts large particles of debris in advance by setting up an initial rainwater and sewage collection well and an automatic screen cleaning machine at the front end of the rainwater and sewage separation well, preventing debris from entering the electric external discharge valve and the electric internal control valve and causing blockage. This effectively reduces the frequency of blockage of the electric external discharge valve and the electric internal control valve, and lowers the cost of manual cleaning and maintenance. By using a corrosion-resistant submersible pump installed at the bottom of the initial rainwater and sewage collection well, corrosive wastewater is directly pumped to the equalization tank, avoiding contact between the corrosive wastewater and the electric external discharge valve and the electric internal control valve. The valves are designed to reduce corrosion of the electric external discharge valve and the electric internal retraction valve, thus extending their service life. A water quality monitoring device monitors water quality parameters in the rainwater and sewage separation well in real time, and the logic control cabinet automatically controls the opening of the electric external discharge valve or the electric internal retraction valve according to preset logic, achieving automatic water quality judgment and switching to ensure qualified effluent and avoid human error. Membrane modules are used for deep separation treatment of unqualified water, producing compliant wastewater, effectively reducing the environmental risk of excessive wastewater overflow and achieving overall plant water balance. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application. It is obvious that the drawings described below are merely some embodiments of this application, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort.

[0016] In the attached diagram: Figure 1 A schematic diagram of an integrated rainwater and sewage separation and membrane treatment system provided in an embodiment of this application; Figure 2 This is a flowchart of a rainwater and sewage separation and membrane treatment method provided in an embodiment of this application.

[0017] The attached figures are labeled as follows: 1. Initial rainwater and sewage collection well; 2. Automatic screen cleaning machine; 3. Liquid level monitoring device; 4. Rainwater and sewage separation well; 5. Water quality monitoring device; 6. Corrosion-resistant submersible pump; 7. Electric external discharge valve; 8. Electric internal control valve; 9. Equalization tank; 10. Membrane module; 11. Logic control cabinet; 12. Debris collection box; 13. Variable frequency control cabinet; 14. Shared emergency tank; 15. Solid-liquid separation device; 16. Cleaning unit; 17. Remote monitoring terminal. Detailed Implementation

[0018] The following specific examples illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application from the content disclosed in this specification. This application can also be implemented or applied through other different specific embodiments. Various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this application. In the absence of conflict, the following embodiments and features in the embodiments can be combined with each other.

[0019] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of this application. The drawings only show the components related to this application and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the shape, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0020] In the following description, numerous details are explored to provide a more thorough explanation of embodiments of the present application. However, it will be apparent to those skilled in the art that embodiments of the present application may be practiced without these specific details. In other embodiments, well-known structures and devices are shown in block diagram form rather than in detail to avoid obscuring embodiments of the present application.

[0021] Please combine Figure 1 As shown, this application provides an integrated system for rainwater and sewage separation and membrane treatment.

[0022] In an exemplary embodiment of this application, the integrated rainwater and sewage separation and membrane treatment system includes: an initial rainwater and sewage collection well 1, an automatic bar screen 2, a liquid level monitoring device 3, a rainwater and sewage separation well 4, a water quality monitoring device 5, a corrosion-resistant submersible pump 6, an electric external discharge valve 7, an electric internal control valve 8, a regulating tank 9, a membrane module 10, and a logic control cabinet 11.

[0023] The initial rainwater and wastewater collection well 1 is used to collect and temporarily store rainwater and corrosive wastewater discharged from production units. For example, the initial rainwater and wastewater collection well 1 is constructed of reinforced concrete with a fiberglass anti-corrosion lining on its inner wall to resist the erosion of acidic or alkaline wastewater. The initial rainwater and wastewater collection well 1 is located at the front end of the rainwater and wastewater separation well 4, serving as the inlet of the entire integrated rainwater and wastewater separation and membrane treatment system. Its inlet is connected to the plant's rainwater network or the drainage pipes of the production units. By setting up the initial rainwater and wastewater collection well 1, initial rainwater containing corrosive media or abnormally discharged wastewater can be collected and temporarily stored before the rainwater and wastewater separation switching action occurs in the rainwater and wastewater separation well 4, thus constructing the system's first line of defense.

[0024] An automatic cleaning bar screen 2 is installed at the inlet of the initial rainwater and wastewater collection well 1 to intercept garbage and debris in rainwater and wastewater. For example, the automatic cleaning bar screen 2 can be a rotary rake-tooth type bar screen with a screen gap of 5-10mm, preferably made of 316L stainless steel. When rainwater and wastewater flow through the bar screen, large particles such as plastic bags, branches, and clumps of mud and sand are intercepted by the bar screen and automatically lifted into the debris collection box 12 by the rake-tooth mechanism, thus preventing debris from entering subsequent pipes and valves. It should be understood that the form of the automatic cleaning bar screen 2 is not limited to a rotary rake-tooth type; it can also be a wire rope traction type or a drum type, as long as it can achieve solid-liquid separation. By installing the automatic cleaning bar screen 2 at the inlet, the path of debris clogging the valve is cut off at the source, solving the problem of debris easily clogging the switching valve of the rainwater and wastewater separation well 4 in traditional systems.

[0025] The liquid level monitoring device 3 is installed inside the initial rainwater and sewage collection well 1 to monitor the liquid level inside the well. The liquid level monitoring device 3 transmits the real-time liquid level signal to the logic control cabinet 11 as the basis for subsequent start-up and shutdown control of the corrosion-resistant submersible pump 6.

[0026] The rainwater and sewage separation well 4 is connected to the initial rainwater and sewage collection well 1 via a gravity flow pipe, and is used to separate rainwater and sewage from the water pretreated by the initial rainwater and sewage collection well 1. Rainwater that has been filtered by a bar screen to remove debris enters the rainwater and sewage separation well 4 through the gravity flow pipe. At this point, most of the corrosive wastewater has been temporarily stored in the initial rainwater and sewage collection well 1, and the water entering the rainwater and sewage separation well 4 is mainly lightly polluted rainwater or pre-diluted wastewater.

[0027] The water quality monitoring device 5 is installed inside the rainwater and sewage separation well 4 to monitor the water quality parameters entering the well. The water quality monitoring device 5 can detect key indicators such as pH value, conductivity, and turbidity of the water in real time, and feed the data back to the logic control cabinet 11 to provide data support for the subsequent diversion decision of the rainwater and sewage separation well 4.

[0028] A corrosion-resistant submersible pump 6 is installed at the bottom of the initial rainwater and sewage collection well 1 to directly pump the corrosive wastewater collected in the well to the subsequent treatment unit. Specifically, the corrosion-resistant submersible pump 6 is preferably made of 316L stainless steel or a higher grade corrosion-resistant alloy. The outlet pipe of the corrosion-resistant submersible pump 6 is directly connected to the equalization tank 9, bypassing the switching valve in the rainwater and sewage separation well 4. By installing the corrosion-resistant submersible pump 6 at the bottom of the initial rainwater and sewage collection well 1, an independent transport channel for corrosive wastewater is constructed. Because chemical production plant areas contain a large amount of chemical raw materials, the initial rainwater and sewage formed by initial rainwater runoff contains a large number of chemical elements and is corrosive. When initial rainwater and sewage or abnormally discharged acidic or alkaline wastewater from production units enters the initial rainwater and sewage collection well 1, these highly corrosive liquids are directly pumped to the equalization tank 9, completely bypassing the electric external discharge valve 7 and electric internal control valve 8 in the rainwater and sewage separation well 4. Through physical isolation, the risk of chemical corrosion of the valves in the rainwater and sewage separation well 4 by corrosive wastewater is eliminated, significantly extending the service life of the valves.

[0029] The electric drain valve 7 is installed on the qualified water outlet pipe of the rainwater and sewage separation well 4, and is used to open to discharge water when the water quality is qualified. The electric inward valve 8 is installed on the unqualified water outlet pipe of the rainwater and sewage separation well 4, and is used to open to send water to the subsequent treatment unit when the water quality is unqualified. Since the automatic screen cleaning machine 2 at the front end has removed large particles of debris and the corrosive wastewater has been diverted, the working environment of the electric drain valve 7 and the electric inward valve 8 is greatly improved, and blockage or corrosion jamming is less likely to occur.

[0030] The equalization tank 9 is connected to the outlet of the electric internal control valve 8 and to the outlet of the corrosion-resistant submersible pump 6. The equalization tank 9 is used to receive and temporarily store substandard water and corrosive wastewater pumped in.

[0031] Membrane module 10 is connected to the outlet of equalization tank 9 and is used to separate the pretreated water to produce qualified permeate and concentrated concentrate. Membrane module 10 can use reverse osmosis (RO), nanofiltration (NF), or ultrafiltration (UF) membrane elements, selected according to specific water quality requirements. Through the advanced treatment of the membrane module 10, the final effluent quality is ensured to meet standards, enabling water resource recycling or safe discharge.

[0032] The logic control cabinet 11 is electrically connected to the liquid level monitoring device 3, the water quality monitoring device 5, the corrosion-resistant submersible pump 6, the electric discharge valve 7, the electric inward valve 8, and the membrane module 10. The logic control cabinet 11 receives monitoring data and automatically controls the operation of each actuator according to preset logic. The logic control cabinet 11 is the brain of the entire system, and it has preset liquid level control logic and water quality judgment thresholds. For example, when the water quality monitoring device 5 detects that the pH value is between 6 and 9 and the conductivity is lower than the set value, the logic control cabinet 11 determines that the water quality is qualified and controls the electric discharge valve 7 to open, allowing the water to be discharged directly; otherwise, it controls the electric inward valve 8 to open, allowing the water to enter the equalization tank 9 for treatment. Simultaneously, when the liquid level monitoring device 3 detects that the initial rainwater and sewage collection well 1 has reached the high liquid level set value, the logic control cabinet 11 automatically starts the corrosion-resistant submersible pump 6 to discharge corrosive wastewater into the equalization tank 9.

[0033] In this embodiment, the electric external discharge valve 7 and electric internal retraction valve 8 of the rainwater and sewage separation well 4 are protected by both physical anti-clogging and chemical corrosion prevention. The automatic cleaning bar screen 2 solves the clogging problem, and the corrosion-resistant submersible pump 6, together with the independent pipeline, solves the corrosion problem. The combination of the two significantly improves the system's operational reliability and automation level.

[0034] In an exemplary embodiment of this application, the automatic cleaning bar screen 2 is connected to a debris collection box 12, which is connected to the debris outlet of the automatic cleaning bar screen 2. The debris collection box 12 is used to collect intercepted debris.

[0035] In this embodiment, the automatic screen cleaning machine 2 adopts a rotary rake tooth structure, with its rake tooth chain rotating against the direction of water flow under the drive of the transmission mechanism. When the rake teeth lift the intercepted solid debris to the unloading position at the top of the screen cleaning machine, the debris automatically falls into the debris collection box 12 connected thereto due to gravity or with the assistance of the scraper mechanism. The debris collection box 12 is located directly below the slag outlet of the automatic screen cleaning machine 2. The debris collection box 12 adopts a box structure with water filter holes, which can drain the water entrained in the debris and return it to the collection well. When the debris in the debris collection box 12 accumulates to a preset height, it can be cleaned and transported out periodically by manual labor or hoisting equipment. The setting of the debris collection box 12 realizes the automatic collection of debris and the initial separation of solid and liquid, avoiding the intercepted debris from sliding back into the well due to accumulation at the well edge and causing secondary blockage. It also improves the on-site working environment and reduces the labor intensity of workers.

[0036] In an exemplary embodiment of this application, the liquid level monitoring device 3 is a liquid level gauge; the water quality monitoring device 5 includes one or more of a pH meter, a conductivity meter, a turbidity meter, and a thermometer.

[0037] In this embodiment, the level gauge is an immersion hydrostatic level gauge or an ultrasonic level gauge, installed in the still water area inside the initial rainwater and sewage collection well 1 to avoid interference with measurement accuracy caused by the impact of the incoming water flow. The water quality monitoring device 5 is installed in the steady flow section inside the rainwater and sewage separation well 4, that is, downstream of the inlet and far from the outlet, to ensure that the water body contacted by the monitoring probe is representative and the flow is relatively stable. For example, a pH meter is used to monitor the pH of the water body in real time to determine whether there is abnormal acid or alkaline wastewater mixed in; a conductivity meter is used to reflect the total dissolved solids content in the water to help determine the degree of rainwater pollution; and a turbidity meter is used to monitor the suspended solids content. The logic control cabinet 11 can accurately determine the water quality status by collecting real-time data from the water quality monitoring device 5, thereby controlling the operation of the electric external discharge valve 7 and the electric internal control valve 8. It should be understood that the combination of water quality monitoring devices 5 can be selected according to the pollutant characteristics of the specific plant area. For example, for areas where there may be a risk of leakage of specific organic matter, an online COD (Chemical Oxygen Demand) monitor can also be added.

[0038] In an exemplary embodiment of this application, the corrosion-resistant submersible pump 6 is connected to a frequency converter control cabinet 13. The frequency converter control cabinet 13 is electrically connected to the corrosion-resistant submersible pump 6 and the logic control cabinet 11. The frequency converter control cabinet 13 is used to automatically adjust the speed of the submersible pump according to the liquid level change to control the pumping flow rate.

[0039] In this embodiment, the variable frequency control cabinet 13 integrates a frequency converter and a PID controller. The logic control cabinet 11 transmits the real-time liquid level signal collected by the liquid level monitoring device 3 to the variable frequency control cabinet 13, which compares the liquid level value with a preset liquid level setpoint. When the liquid level in the initial rainwater and sewage collection well 1 gradually rises, the output frequency of the variable frequency control cabinet 13 increases, the submersible pump speed increases, the drainage flow increases, and the liquid level in the well is quickly reduced. Conversely, when the liquid level drops, the output frequency of the variable frequency control cabinet 13 decreases, the submersible pump speed slows down, and the pump cavitation or dry running is avoided due to a sudden drop in the liquid level caused by excessive flow. Through variable frequency speed control, smooth flow regulation is achieved, avoiding drastic fluctuations in pipeline pressure and extending the service life of the submersible pump and pipeline valves. Furthermore, variable frequency speed control ensures that the submersible pump always operates in the high-efficiency range, significantly reducing energy consumption and achieving energy-saving operation.

[0040] In an exemplary embodiment of this application, the initial rainwater and sewage collection well 1 is connected to an emergency overflow pipe. The inlet end of the emergency overflow pipe is connected to the side wall of the initial rainwater and sewage collection well 1 and is located at a preset safe liquid level. The outlet end of the emergency overflow pipe is connected to a common emergency pool 14. The emergency overflow pipe is used to allow water to flow by gravity to the common emergency pool 14 when the liquid level in the initial rainwater and sewage collection well 1 exceeds the safe height.

[0041] In this embodiment, although the corrosion-resistant submersible pump 6 and automatic control logic can handle conventional corrosive wastewater and rainwater discharge in a chemical production environment, extreme abnormal conditions are considered. These include situations such as torrential rain causing the inflow to instantly exceed the system's drainage capacity, a plant-wide power outage preventing the submersible pump from operating, or a malfunction of the level monitoring device 3 causing the logic control cabinet 11 to fail to start the submersible pump in time. To prevent high-level corrosive wastewater from overflowing from the initial rainwater and sewage collection well 1 and causing environmental pollution accidents under extreme conditions, this embodiment adds an emergency overflow safety mechanism.

[0042] Specifically, the diameter of the emergency overflow pipe is designed based on the intensity of extreme rainstorms to ensure smooth drainage even under maximum inflow. The preset safe liquid level is higher than the high-level start-up setting of the corrosion-resistant submersible pump 6, but lower than the wellhead elevation of the initial rainwater and sewage collection well 1. For example, if the well depth is 4 meters, the high-level start-up point of the pump may be at 2.5 meters, then the safe liquid level can be set at 3.5 meters. Under normal operating conditions, the submersible pump starts working after the liquid level reaches the start-up point, and the liquid level will not reach the safe liquid level; the emergency overflow pipe only intervenes when the submersible pump malfunctions or the inflow is too large, causing the liquid level to rise continuously above the safety warning line.

[0043] The emergency overflow safety mechanism constructs a passive safety defense line. Unlike active drainage systems that rely on electricity and control programs, the emergency overflow pipe operates on the principle of gravity flow. Even in the event of a plant-wide power outage and control system failure, as long as the liquid level exceeds the safe height, the water can still automatically flow through the emergency overflow pipe to the shared emergency pool 14. The shared emergency pool 14 is an underground structure with sufficient volume, used to temporarily store excess wastewater during an accident. After the system returns to normal, the wastewater is returned to the equalization pool 9 for treatment via a booster pump. The design of the emergency overflow safety mechanism ensures that, under extreme failure modes, corrosive wastewater in the initial rainwater and sewage collection well 1 will not overflow, thereby completely eliminating the risk of environmental pollution and greatly improving the system's safety level.

[0044] In an exemplary embodiment of this application, a solid-liquid separation device 15 is provided between the conditioning tank 9 and the membrane module 10. The inlet of the solid-liquid separation device 15 is connected to the outlet of the conditioning tank 9, and the outlet of the solid-liquid separation device 15 is connected to the inlet of the membrane module 10.

[0045] In this embodiment, the solid-liquid separation device 15 removes residual fine suspended solids, colloids, and floating oil from the water after homogenization and conditioning in the equalization tank 9. The solid-liquid separation device 15 can be a multi-media filter, filled with anthracite, quartz sand, or other filter media, which traps solid particles through a deep filtration mechanism. Alternatively, the solid-liquid separation device 15 can be a fully automatic self-cleaning filter with an internal stainless steel filter screen that automatically initiates a backwashing process when the pressure difference between the inside and outside of the filter screen reaches a set value. It should be understood that the form of the solid-liquid separation device 15 is not limited to the above examples; it can also be a bag filter or a precision security filter. After the water in the equalization tank 9 is lifted into the solid-liquid separation device 15, solid particles larger than the filtration precision are physically intercepted. Simultaneously, dispersed oil droplets in the water collide and coalesce as they pass through the filter media layer, forming large oil droplets that float and separate. This prevents the rapid deposition of suspended solids and oily substances on the membrane surface, thereby effectively extending the chemical cleaning cycle and service life of the membrane module 10.

[0046] In an exemplary embodiment of this application, the membrane module 10 is connected to a cleaning unit 16. The cleaning unit 16 includes a cleaning water tank and a cleaning pump. The inlet of the cleaning pump is connected to the cleaning water tank, the outlet of the cleaning pump is connected to the membrane module 10, and the cleaning pump is electrically connected to the logic control cabinet 11. The cleaning unit 16 is used to perform chemical cleaning on the membrane module 10 to restore membrane flux.

[0047] In this embodiment, even with the front-end solid-liquid separation device 15, the membrane module 10 will inevitably be contaminated by dissolved organic matter or trace colloids during long-term operation, leading to increased transmembrane pressure difference and decreased permeate flow. Therefore, the cleaning unit 16 is a necessary means to maintain stable system operation.

[0048] Specifically, the cleaning tank is typically located on the ground or platform near the membrane module 10, and contains pre-prepared chemical cleaning agents. Depending on the type of fouling, the cleaning agent can be an acidic solution (such as citric acid or hydrochloric acid) to remove inorganic scale and metal oxides; or an alkaline oxidizing agent solution (such as sodium hydroxide and sodium hypochlorite) to remove organic matter and microbial contamination. The outlet pipe of the cleaning pump is connected to the inlet pipe of the membrane module 10, and a cleaning switching valve is installed on the pipe.

[0049] When the logic control cabinet 11 detects that the transmembrane pressure difference of the membrane module 10 exceeds the preset high limit, for example, an increase of 0.1 MPa from the initial value, or a decrease in permeate flow exceeding a certain percentage, the system automatically enters the cleaning mode. The logic control cabinet 11 first stops the normal permeate flow, controls the cleaning switching valve to switch to the cleaning loop, and starts the cleaning pump. The cleaning pump circulates the cleaning solution in the cleaning tank into the membrane module 10. The solution undergoes a chemical reaction on the membrane surface, dissolving or oxidizing contaminants adhering to the membrane pores and surface. After a certain period of circulation and soaking, the contaminants are stripped off and discharged with the solution. After cleaning, the system automatically switches back to permeate mode, using permeate water to rinse the membrane module 10 until it meets the required standards. The cleaning process of the membrane module 10 through the cleaning unit 16 effectively restores the permeate performance of the membrane module 10, ensuring the system continuously produces permeate that meets standards, achieving online regeneration of the membrane module 10, and greatly reducing manual maintenance costs and membrane replacement frequency.

[0050] In an exemplary embodiment of this application, the logic control cabinet 11 is connected to a remote monitoring terminal 17, and the remote monitoring terminal 17 is communicatively connected to the logic control cabinet 11.

[0051] In this embodiment, the logic control cabinet 11 integrates a communication module. This module establishes a data connection with the remote monitoring terminal 17 via a wired or wireless network, such as industrial Ethernet, fiber optic ring network, 4G, or 5G. The remote monitoring terminal 17 can be an industrial control computer located in the central control room, or a mobile terminal device running dedicated monitoring software, such as a mobile phone or tablet. The logic control cabinet 11 not only uploads real-time values ​​from various monitoring instruments, such as liquid level, pH value, and conductivity, to the remote monitoring terminal 17, but also synchronizes the operating status of various actuators in real time, such as the opening and closing status of the electric drain valve 7 and the operating frequency of the corrosion-resistant submersible pump 6. When the system detects abnormal operating conditions, such as excessively high liquid level, excessive water quality, or equipment failure, the logic control cabinet 11 automatically generates alarm information and pushes it to the remote monitoring terminal 17, prompting management personnel to handle the situation promptly. By establishing a communication connection between the remote monitoring terminal 17 and the logic control cabinet 11, the entire rainwater and sewage separation and membrane treatment system is equipped with the ability to operate unattended. Management personnel do not need to be stationed on-site for a long time, but only need to conduct regular inspections, which greatly reduces labor costs and ensures timely response to abnormal situations.

[0052] In an exemplary embodiment of this application, both the electric outward discharge valve 7 and the electric inward retraction valve 8 are equipped with manual operation handwheels.

[0053] In this embodiment, during actual system operation, unexpected situations may occur such as a plant-wide power outage, a malfunction in the logic control cabinet 11, or a burnt-out motor in the electric actuator, causing the valves to fail to open or close automatically via electrical signals. In such cases, operators can go to the site and manually operate the handwheel to force the valves open or close. Specifically, the electric valves are designed with an electric / manual switching mechanism. In normal electric mode, the valve is driven by a motor; when manual operation is required, the operator can connect the manual handwheel to the valve stem and then open or close the valve by rotating the handwheel. For example, in extreme conditions of heavy rain and power outage, if it is necessary to urgently open the electric drain valve 7 to prevent flooding in the plant area, the operator can manually open the valve to drain the rainwater using gravity. By retaining the manual opening and closing structure of the electric drain valve 7 and the electric inward valve 8, the system still possesses basic diversion control capabilities under electrical faults, avoiding environmental pollution or safety accidents caused by control failure and greatly improving the system's safety level.

[0054] Please combine Figure 2 As shown, this application also provides a method for rainwater and sewage separation and membrane treatment, which adopts the integrated rainwater and sewage separation and membrane treatment system as described above. The method includes at least steps S110 to S160.

[0055] In step S110, rainwater and sewage are introduced into the automatic cleaning bar screen 2. The automatic cleaning bar screen 2 intercepts and separates garbage and debris, allowing the pretreated water to enter the initial rainwater and sewage collection well 1.

[0056] For example, during the rainy season or when production equipment discharges abnormally, the mixed rainwater and sewage containing solid waste flows first towards the system inlet. The automatic screen cleaner 2 is in a normally open operating state, and its rake mechanism continuously rotates, intercepting large particles of debris such as plastic bags, dead branches, and clumps of silt carried in the water flow onto the screen surface, and automatically lifting and conveying them to the debris collection box 12. The water flowing through the automatic screen cleaner 2 no longer contains large solid impurities, reducing the risk of blockage in subsequent pipes and valves. The pretreated water flows by gravity through the connecting pipe into the initial rainwater and sewage collection well 1 for temporary storage.

[0057] In step S120, the liquid level in the initial rainwater and sewage collection well 1 is monitored in real time by the liquid level monitoring device 3, and the liquid level data is transmitted to the logic control cabinet 11; the water quality parameters in the rainwater and sewage separation well 4 are monitored in real time by the water quality monitoring device 5, and the monitoring data is transmitted to the logic control cabinet 11; the logic control cabinet 11 automatically determines whether the water quality entering the rainwater and sewage separation well 4 is qualified according to the preset water quality judgment threshold.

[0058] For example, the liquid level monitoring device 3 continuously collects the liquid level signal in the initial rainwater and sewage collection well 1, and the liquid level signal is used to control the start and stop of the corrosion-resistant submersible pump 6. The clear liquid in the upper layer after being buffered by the initial rainwater and sewage collection well 1 overflows into the rainwater and sewage separation well 4. The water quality monitoring device 5 installed in this well samples the key indicators of the water body in real time, such as pH value, conductivity, and turbidity. After receiving these real-time data, the logic control cabinet 11 compares them with the internally preset thresholds: if the pH value is between 6 and 9 and the conductivity is lower than the set value, the water quality is judged to be qualified; otherwise, if the pH value is abnormal or the pollutant concentration exceeds the standard, the water quality is judged to be unqualified. It should be understood that the threshold setting can be adjusted according to the specific environmental emission standards or reuse requirements of the plant area.

[0059] In step S130, when the water quality is deemed to be qualified, the electric external discharge valve 7 installed on the qualified water outlet pipe of the rainwater and sewage separation well 4 is opened by the logic control cabinet 11, so that the water is discharged through the electric external discharge valve 7; when the water quality is deemed to be unqualified, the electric internal control valve 8 installed on the unqualified water outlet pipe of the rainwater and sewage separation well 4 is opened by the logic control cabinet 11, so that the water is sent into the regulating tank 9 through the electric internal control valve 8.

[0060] For example, the logic control cabinet 11 sends a command signal to the corresponding electric valve based on the water quality judgment result in step S120. In the water quality qualified mode, the electric discharge valve 7 activates its actuator after receiving the opening signal, the valve opens, and rainwater that meets the discharge standards is directly discharged into natural water bodies or municipal stormwater networks through the discharge pipe; at the same time, the electric inward valve 8 remains closed. In the water quality unqualified mode, the electric inward valve 8 opens, the electric discharge valve 7 closes, and the polluted water is introduced into the regulating tank 9 for further treatment.

[0061] In step S140, the logic control cabinet 11 controls the operation of the corrosion-resistant submersible pump 6 according to the liquid level change in the initial rainwater and sewage collection well 1, and directly pumps the corrosive wastewater in the initial rainwater and sewage collection well 1 to the equalization tank 9.

[0062] For example, when initial rainwater or sewage or high-concentration corrosive wastewater abnormally discharged from production equipment enters the initial rainwater and sewage collection well 1, this wastewater mainly accumulates at the bottom of the initial rainwater and sewage collection well 1. When the logic control cabinet 11 detects that the liquid level in the well has reached the high liquid level set value, it starts the corrosion-resistant submersible pump 6. The submersible pump directly lifts and transports the corrosive wastewater at the bottom to the regulating tank 9 through an independent pipeline, completely bypassing the rainwater and sewage separation well 4 and its internal diversion valves. By setting the corrosion-resistant submersible pump 6 to start according to the liquid level monitoring device 3 and directly pump the initial rainwater and sewage or corrosive wastewater to the initial rainwater and sewage collection well 1, the contact path between the corrosive medium and the switching valves in the rainwater and sewage separation well 4 is cut off from the process flow, effectively reducing the risk of blockage and corrosion of the switching valves in the rainwater and sewage separation well 4.

[0063] In step S150, the water in the equalization tank 9 is sent to the membrane module 10, and the pretreated water is separated by the membrane module 10 to produce qualified permeate and concentrated concentrate.

[0064] For example, the equalization tank 9 collects substandard water from the rainwater and sewage separation well 4 and corrosive wastewater from the initial rainwater and sewage collection well 1. After homogenization and equalization, the water quality is relatively stable. The subsequent booster pump transports the water in the equalization tank 9 to the membrane module 10 for deep treatment. The membrane module 10 uses the principle of selective permeation to retain dissolved salts, organic pollutants, etc. in the water. The produced water that meets the standards can be reused in the production process or discharged in compliance with standards. The concentrated water is discharged into the subsequent evaporation and crystallization unit or outsourced for treatment.

[0065] In step S160, real-time data is uploaded to the monitoring platform via the remote monitoring terminal 17 through the logic control cabinet 11, and users can view the system operation status and alarm information through the terminal device.

[0066] For example, the logic control cabinet 11 acts as a data aggregation center, packaging real-time data such as liquid level, water quality, valve status, and pump operating frequency, and sending it to the remote monitoring terminal 17 via a communication network. Management personnel can view the system's real-time operating status on a monitoring platform or mobile terminal without being physically present on-site. In the event of abnormal situations such as excessively high liquid levels, severely substandard water quality, or equipment malfunctions, the system will automatically trigger an alarm mechanism, pushing alarm information to the user, thus achieving unattended operation and remote intelligent control throughout the entire process.

[0067] In this embodiment, the method achieves automated control from source interception, intelligent diversion, corrosion-resistant conveying to deep processing, effectively solving the problems of clogging, corrosion and environmental risks existing in traditional rainwater and sewage separation systems.

[0068] Working principle: During rainy days, rainwater washes the ground of chemical production plant areas, causing chemical raw materials and garbage debris to enter the drainage system. On the other hand, production areas may generate corrosive wastewater due to washing or leaks. Before adopting this system, traditional rainwater and wastewater separation systems often suffered from clogged switching valves due to garbage, or valve corrosion and jamming due to corrosive wastewater flowing through the switching valves, resulting in mixed rainwater and wastewater and causing environmental accidents. The working principle of this integrated rainwater and wastewater separation and membrane treatment system is as follows: Corrosive rainwater mixed with ground debris and chemical raw materials flows to the system inlet. The automatic bar screen 2 operates continuously, with a screen gap set at 8mm, effectively intercepting large particles such as plastic bags and leaves in the rainwater. The intercepted debris is automatically lifted and unloaded into the debris collection box 12 by a rake mechanism, achieving automatic garbage removal and preventing debris from entering subsequent pipes and valves. The water pretreated by the bar screen enters the initial rainwater and wastewater collection well 1 for temporary storage.

[0069] When the production unit abnormally discharges corrosive wastewater, this high-concentration wastewater mainly accumulates at the bottom of the initial rainwater and sewage collection well 1. The liquid level in the well is monitored in real time by the liquid level monitoring device 3. When the liquid level reaches the high liquid level setpoint, the logic control cabinet 11 automatically starts the corrosion-resistant submersible pump 6. The corrosion-resistant submersible pump 6 is made of 316L stainless steel and can withstand the corrosion of acidic media. The submersible pump directly lifts and transports the acidic wastewater from the bottom to the equalization tank 9 through an independent pipeline, bypassing the electric external discharge valve 7 and the electric internal control valve 8 in the rainwater and sewage separation well 4. This avoids the chemical corrosion problem of the diversion valves caused by corrosive wastewater and extends the service life of the valves.

[0070] Meanwhile, the clear liquid from the upper layer, after being buffered by the initial rainwater and sewage collection well 1, overflows into the rainwater and sewage separation well 4. A water quality monitoring device 5 installed in the rainwater and sewage separation well 4 monitors the pH value and conductivity of the water in real time. The logic control cabinet 11 judges the water based on preset thresholds: if the pH value is between 6 and 9 and the conductivity is lower than the set value, it is considered qualified rainwater, and the electric external discharge valve 7 is opened, allowing the water to be discharged directly. If the pH value is abnormal or pollutants exceed the standard, it is considered unqualified water, and the electric internal control valve 8 is opened, allowing the water to enter the regulating tank 9. Since the automatic screen cleaning machine 2 at the front end has already removed large particles of debris, the electric external discharge valve 7 and the electric internal control valve 8 operate in a clean environment, and no further clogging occurs.

[0071] The mixed wastewater in the equalization tank 9 undergoes deep treatment through the solid-liquid separation device 15 and the membrane module 10. The membrane module 10 uses an anti-fouling reverse osmosis membrane, which can effectively remove dissolved salts and organic matter from the water. The final compliant permeate is reused in the production process, realizing the recycling of water resources. The concentrated water is then sent to the evaporation and crystallization unit for further treatment.

[0072] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. An integrated system for rainwater and sewage separation and membrane treatment, characterized in that, include: Initial rainwater and wastewater collection wells are used to collect and temporarily store rainwater and corrosive wastewater discharged from production facilities; An automatic bar screen is installed at the inlet of the initial rainwater and sewage collection well to intercept garbage and debris in rainwater and wastewater; A liquid level monitoring device is installed inside the initial rainwater and sewage collection well to monitor the liquid level inside the initial rainwater and sewage collection well; The rainwater and sewage separation well is connected to the initial rainwater and sewage collection well via a gravity flow pipe and is used to separate rainwater and sewage from the water pretreated by the initial rainwater and sewage collection well. A water quality monitoring device is installed inside the rainwater and sewage separation well to monitor the water quality parameters entering the rainwater and sewage separation well; A corrosion-resistant submersible pump is installed at the bottom of the initial rainwater and sewage collection well to directly pump the corrosive wastewater collected in the initial rainwater and sewage collection well to the subsequent treatment unit. An electric drain valve is installed on the qualified water outlet pipe of the rainwater and sewage separation well, and is used to open and discharge water when the water quality is qualified. An electric inward valve is installed on the outlet pipe of the rainwater and sewage separation well for unqualified water, and is used to open when the water quality is unqualified in order to send the water into the subsequent treatment unit. The equalization tank is connected to the outlet of the electric inward valve and to the outlet of the corrosion-resistant submersible pump. The equalization tank is used to receive and temporarily store substandard water and corrosive wastewater pumped in. The membrane module is connected to the outlet of the equalization tank and is used to separate the pretreated water to produce qualified permeate and concentrated concentrate. The logic control cabinet is electrically connected to the liquid level monitoring device, water quality monitoring device, corrosion-resistant submersible pump, electric drain valve, electric inlet valve and membrane module, respectively. The logic control cabinet is used to receive monitoring data and automatically control the operation of each actuator according to preset logic.

2. The integrated rainwater and sewage separation and membrane treatment system according to claim 1, characterized in that: The automatic cleaning bar screen is connected to a debris collection box, which is connected to the debris outlet of the automatic cleaning bar screen. The debris collection box is used to collect intercepted debris.

3. The integrated rainwater and sewage separation and membrane treatment system according to claim 1, characterized in that: The liquid level monitoring device is a liquid level gauge; the water quality monitoring device includes one or more of the following: pH meter, conductivity meter, turbidity meter, and thermometer.

4. The integrated rainwater and sewage separation and membrane treatment system according to claim 1, characterized in that: The corrosion-resistant submersible pump is connected to a frequency converter control cabinet, which is electrically connected to both the corrosion-resistant submersible pump and the logic control cabinet. The frequency converter control cabinet is used to automatically adjust the speed of the submersible pump according to changes in the liquid level to control the pumping flow rate.

5. The integrated rainwater and sewage separation and membrane treatment system according to claim 1, characterized in that: The initial rainwater and sewage collection well is connected to an emergency overflow pipe. The inlet end of the emergency overflow pipe is connected to the side wall of the initial rainwater and sewage collection well and is located at a preset safe liquid level. The outlet end of the emergency overflow pipe is connected to a common emergency pool. The emergency overflow pipe is used to allow water to flow by gravity to the common emergency pool when the liquid level in the initial rainwater and sewage collection well exceeds the safe height.

6. The integrated rainwater and sewage separation and membrane treatment system according to claim 1, characterized in that: A solid-liquid separation device is provided between the equalization tank and the membrane module. The inlet of the solid-liquid separation device is connected to the outlet of the equalization tank, and the outlet of the solid-liquid separation device is connected to the inlet of the membrane module.

7. The integrated rainwater and sewage separation and membrane treatment system according to claim 1, characterized in that: The membrane module is connected to a cleaning unit, which includes a cleaning water tank and a cleaning pump. The inlet of the cleaning pump is connected to the cleaning water tank, and the outlet of the cleaning pump is connected to the membrane module. The cleaning pump is electrically connected to the logic control cabinet. The cleaning unit is used to perform chemical cleaning on the membrane module to restore membrane flux.

8. The integrated rainwater and sewage separation and membrane treatment system according to claim 1, characterized in that: The logic control cabinet is connected to a remote monitoring terminal, and the remote monitoring terminal is communicatively connected to the logic control cabinet.

9. The integrated rainwater and sewage separation and membrane treatment system according to claim 1, characterized in that: Both the electric exhaust valve and the electric retraction valve are equipped with manual operation handwheels.

10. A method for separating rainwater and wastewater and treating it with a membrane, employing the integrated system for separating rainwater and wastewater and treating it with a membrane as described in any one of claims 1 to 9, characterized in that, The method includes: Rainwater and sewage are directed into an automatic cleaning bar screen, which intercepts and separates garbage and debris, allowing the pre-treated water to enter the initial rainwater and sewage collection well. The liquid level in the initial rainwater and sewage collection well is monitored in real time by a liquid level monitoring device, and the liquid level data is transmitted to the logic control cabinet; the water quality parameters in the rainwater and sewage separation well are monitored in real time by a water quality monitoring device, and the monitoring data is transmitted to the logic control cabinet; the logic control cabinet automatically determines whether the water quality entering the rainwater and sewage separation well is qualified according to the preset water quality judgment threshold. When the water quality is deemed to be up to standard, the logic control cabinet controls the opening of the electric external discharge valve installed on the qualified water outlet pipe of the rainwater and sewage separation well, allowing the water to be discharged through the electric external discharge valve; when the water quality is deemed to be substandard, the logic control cabinet controls the opening of the electric internal control valve installed on the substandard water outlet pipe of the rainwater and sewage separation well, allowing the water to be sent into the regulating tank through the electric internal control valve. The logic control cabinet controls the operation of the corrosion-resistant submersible pump based on the liquid level changes in the initial rainwater and sewage collection well, and directly pumps the corrosive wastewater in the initial rainwater and sewage collection well to the equalization tank. Water from the equalization tank is fed into the membrane module, where the pretreated water is separated to produce qualified permeate and concentrated water. Real-time data is uploaded to the monitoring platform via a remote monitoring terminal through the logic control cabinet, and users can view the system's operating status and alarm information through terminal devices.

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