Urban multi-source water purification system and purification treatment method

Abstract

The present application relates to water purification process technical field, especially to a kind of urban multi-source water purification system and water purification treatment method, water purification system includes switching pipeline, first processing unit and second processing unit connected with switching pipeline, water outlet pipeline is arranged on the other end of first processing unit and second processing unit, and control assembly for controlling raw water flow direction;The first processing unit includes flocculation sedimentation tank, sand filter and ozone activated carbon pool communicated in sequence;The second processing unit includes pre-ozone treatment pool, flocculation sedimentation tank, sand filter, ozone activated carbon pool, ultrafiltration membrane pool and nanofiltration membrane pool communicated in sequence.By the setting of control assembly, cooperate with switching pipeline, so that the flow direction of raw water can be adjusted according to the pH value of raw water, compared with the existing single raw water corresponding to the water purification process, the water purification device of the present application is more flexible, can make raw water to different water purification treatment according to the change of raw water, to improve water purification effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of water purification process, and particularly relates to a city multi-source water purification system and a water purification treatment method. BACKGROUND

[0002] With the development of urbanization, the population and the industrial scale of many cities are expanding, and the water consumption of the city is also increasing. Generally, in order to cope with this situation, the city water supply plant uses multiple water sources for water supply, such as rivers, lakes, and city wetlands, reservoir water sources, etc.

[0003] The water quantity of natural water sources such as rivers and lakes will be affected by seasons and climate conditions, and there will be changes in dry season and wet season. A single water source may not be able to meet the water supply demand of the city in the dry season, so multiple different water sources, such as reservoirs, rivers, wetlands, lakes, etc. are needed to provide stable water sources for the city.

[0004] However, different water sources require different treatment processes, and even for the same water source, different seasons require different treatment processes. Specifically, when the impurities in the raw water are too much, the raw water needs to remove the impurities; and some raw water may have seasonal algae outbreaks, which can cause the pH value of the water body to rise sharply, and the pH value needs to be adjusted. The existing treatment device cannot be adjusted in time according to the raw water conditions, which affects the purification effect of the raw water.

[0005] Therefore, it is necessary to provide a water purification system and a treatment method that can purify different water qualities. SUMMARY

[0006] The present application provides a city multi-source water purification system and a water purification treatment method. The water purification system can not only reduce water treatment energy consumption, but also effectively improve the coagulation and sedimentation effect and reduce the concentration of aluminum ions in the water body, thereby promoting the efficient operation of the entire water purification system through the distribution of different water treatment processes and the control of precise CO2 addition.

[0007] The specific technical solutions are as follows:

[0008] In a first aspect, the present application provides a city multi-source water purification system, comprising: a switching pipeline, a first treatment unit and a second treatment unit connected with the switching pipeline, a water outlet pipeline arranged on the other end of the first treatment unit and the second treatment unit, and an automatic control system; the first treatment unit comprises a coagulation and sedimentation tank, a sand filter tank and an ozone activated carbon tank which are sequentially connected; the second treatment unit comprises a pre-ozone treatment tank, a coagulation and sedimentation tank, a sand filter tank, an ozone activated carbon tank, an ultrafiltration membrane tank and a nanofiltration membrane tank which are sequentially connected;

[0009] The automatic control system comprises a water quality sensor, a CO2 dosing device, a coagulant dosing device and a controller; the water quality sensor is provided with water quality monitoring probes respectively installed at the inlet of the coagulation sedimentation tank, the outlet of the coagulation sedimentation tank, the outlet of the ozone activated carbon tank, the outlet of the ultrafiltration membrane tank and the outlet of the nanofiltration membrane tank; the CO2 dosing device is provided with CO2 aeration ports respectively communicating with the coagulation sedimentation tank, the ozone activated carbon tank, the ultrafiltration membrane tank and the nanofiltration membrane tank; the coagulant dosing device is provided with a coagulant dosing port communicating with the coagulation sedimentation tank.

[0010] The controller comprises an information acquisition module, a data processing and analysis module and a feedback control module; the information acquisition module is used for receiving water quality data information of the water quality monitoring probes and feeding back the water quality data information to the data processing and analysis module; the data processing and analysis module receives data information of the information acquisition module, judges the type of the water source and calculates and corrects the CO2 aeration amount and the coagulant addition amount; the feedback control module comprises a water source switching control submodule, a CO2 dosing control submodule and a coagulant dosing control submodule; the water source switching control submodule controls the opening and closing of the switching pipeline; the CO2 dosing control submodule receives data information of the data processing and analysis module and controls the opening and closing of the CO2 aeration ports and the gas flow; the coagulant dosing control submodule controls the opening and closing of the coagulant dosing port and the dosing flow of the coagulant.

[0011] Further, the switching pipeline comprises a plurality of raw water pipes, two-position three-way valves arranged on the raw water pipes, a first unit pipe and a second unit pipe communicating with the two-position three-way valves, a first water inlet pipe communicating with the first treatment unit, and a second water inlet pipe communicating with the second treatment unit, the second water inlet pipe communicating with the second unit pipe, and the first water inlet pipe communicating with the first unit pipe; the two-position three-way valves are connected with the water source switching control submodule; the water quality monitoring probes are arranged on the raw water pipes.

[0012] Further, the pre-ozone treatment tank comprises a pre-ozone tank body, first baffles arranged at equal intervals in the pre-ozone tank body, and second baffles arranged in the pre-ozone tank body and staggered with the first baffles; the first baffles are provided with a plurality of air holes, ozone inlet pipes arranged on the air holes, ozone aeration heads arranged on both end faces of the first baffles and communicating with the air holes; a first water passage is formed between the bottom surface of the first baffles and the bottom surface of the inner cavity of the pre-ozone tank body, and a second water passage is formed between the top surface of the second baffles and the top surface of the pre-ozone tank body.

[0013] Further, the ultrafiltration membrane tank comprises an ultrafiltration tank body, an ultrafiltration membrane assembly arranged in the ultrafiltration tank body, and an aeration pipe arranged on the ultrafiltration tank body; the bottom of the ultrafiltration membrane assembly is connected with a water outlet pipeline;

[0014] The nanofiltration membrane tank comprises a nanofiltration membrane tank body, a nanofiltration membrane assembly installed in the nanofiltration membrane tank body, and an aeration pipe installed on the nanofiltration membrane tank body, wherein the bottom of the nanofiltration membrane assembly is connected with a water outlet pipeline;

[0015] The aeration pipe is connected with an aeration pump, and the air inlet end of the aeration pump is connected with an oxygen storage tank and a CO2 storage tank;

[0016] The ends of the aeration branch pipes located in the ultrafiltration tank body and the nanofiltration membrane tank body are annularly arranged around the membrane assembly.

[0017] In the second aspect, the present application provides a method for treating raw water by using the urban multi-water-source water purification system, comprising:

[0018] (1) monitoring the water quality of the raw water pipe, determining whether the raw water is of type A or type B, and controlling the type A raw water to enter the first treatment unit and the type B raw water to enter the second treatment unit by a water source switching control submodule; the first treatment unit adopts method A for water quality treatment, and the second treatment unit adopts method B for water quality treatment;

[0019] The water quality judgment condition of the type A raw water is that the pH is lower than 7.6 and the turbidity is lower than 12 NTU; and the raw water with other water quality conditions is determined as type B raw water.

[0020] Method A:

[0021] A-S1: taking the type A raw water as a water sample to obtain a first theoretical relationship curve between the pH value and the CO2 aeration amount and a second theoretical relationship curve between the turbidity and the coagulant addition amount;

[0022] A-S2: real-time monitoring of the pH value at the inlet of the coagulation sedimentation tank, the pH value at the inlet of the ozone activated carbon filter tank, and the turbidity at the outlet of the coagulation sedimentation tank;

[0023] A-S3: calling the pH value data of A-S2, obtaining the real-time CO2 aeration amount in the coagulation sedimentation tank, the ozone activated carbon filter tank and the ultrafiltration membrane filter tank according to the first theoretical relationship curve; calling the turbidity data of A-S2, and obtaining the real-time coagulant addition amount in the coagulation sedimentation tank according to the second theoretical relationship curve;

[0024] A-S4: controlling the discharge amount of CO2 in the ozone activated carbon filter tank and the ultrafiltration membrane filter tank and the discharge amount of CO2 and the addition amount of coagulant in the coagulation sedimentation tank according to the real-time CO2 aeration amount and the real-time coagulant addition amount obtained in A-S3;

[0025] Method B:

[0026] B-S1: obtaining the following data information:

[0027] 1) using the B-type raw water as the water sample, a first deviation relationship curve between the pH value and the CO2 aeration amount is obtained;

[0028] 2) CO2 average deviation coefficient;

[0029] 3) using the B-type raw water as the water sample, a second deviation relationship curve between the turbidity and the coagulant addition amount is obtained;

[0030] 4) coagulant average deviation coefficient;

[0031] B-S2: the pH value at the inlet of the coagulation sedimentation tank, the pH value at the inlet of the ozone activated carbon filter tank, the pH value at the inlet of the membrane filter tank, and the turbidity at the outlet of the coagulation sedimentation tank are monitored in real time;

[0032] B-S3: the pH value data of B-S2 is substituted into the first deviation relationship curve to obtain the CO2 real-time deviation aeration amount in the coagulation sedimentation tank, the ozone activated carbon filter tank and the ultrafiltration membrane filter tank, and the CO2 real-time correction aeration amount is obtained according to the CO2 average deviation coefficient;

[0033] The turbidity data of B-S2 is substituted into the second deviation relationship curve to obtain the coagulant real-time deviation addition amount, and the coagulant real-time correction addition amount in the coagulation sedimentation tank is calculated according to the built-in coagulant average deviation coefficient;

[0034] B-S4: according to the CO2 real-time correction aeration amount and the coagulant real-time correction addition amount obtained by B-S3, the discharge amount of CO2 in the ozone activated carbon filter tank and the ultrafiltration membrane tank, and the discharge amount of CO2 and the addition amount of coagulant in the coagulation sedimentation tank are controlled.

[0035] Further, the first theoretical relationship curve in method A is obtained by using the A-type raw water as the water sample, preparing simulated water samples A with different pH values, exposing CO2 gas into the simulated water samples A, measuring the changes of the pH value and the CO2 aeration amount, and establishing the first theoretical relationship curve between the pH value and the CO2 aeration amount;

[0036] The second theoretical relationship curve is obtained by using the A-type raw water as the water sample, adding an aluminum salt coagulant into the water sample, measuring the changes of the turbidity and the coagulant addition amount, and establishing the second theoretical relationship curve between the turbidity and the coagulant addition amount.

[0037] Further, in B-S1 of method B, the first deviation relationship curve is obtained by using the B-type raw water as the water sample, exposing CO2 gas into the water sample, measuring the changes of the pH value and the CO2 aeration amount, and establishing the first deviation relationship curve between the pH value and the CO2 aeration amount;

[0038] The second deviation relationship curve is obtained by adding an aluminum salt coagulant into B-type raw water as a water sample, measuring the turbidity and the coagulant addition amount, and establishing a second deviation relationship curve between the turbidity and the coagulant addition amount.

[0039] Further, in B-S1 of method B, the CO2 average deviation coefficient is obtained by:

[0040] A third theoretical relationship curve between the pH value and the CO2 aeration amount is established by taking the treated water of B-type raw water as a water sample; and a first deviation relationship curve between the pH value and the CO2 aeration amount is established by taking B-type raw water as a water sample.

[0041] According to formula (1), the CO2 average deviation coefficient is calculated.

[0042] (1);

[0043] wherein, represents the CO2 average deviation coefficient; i represents a numerical value of the pH value change of the simulated water sample B, i is from high to low, the initial value of i is the initial pH value of the simulated water sample B, and is generally 7.5-9.0, n is the lowest value after the pH value decreases, and is generally 6.0-7.0; N represents the measurement times of the pH value and the corresponding CO2 deviation aeration amount in the process of the pH value decreasing from i to n; represents the CO2 deviation aeration amount when the pH value is i, which is obtained by the first deviation relationship curve; represents the CO2 theoretical aeration amount when the pH value is i, which is obtained by the third theoretical relationship curve.

[0044] Further, in B-S1 of method B, the coagulant average deviation coefficient is obtained by:

[0045] A fourth theoretical relationship curve between the turbidity and the coagulant addition amount is established by taking the treated water of B-type raw water as a water sample; and a second deviation relationship curve between the turbidity and the coagulant addition amount is established by taking B-type raw water as a water sample.

[0046] According to formula (2), the coagulant average deviation coefficient is calculated.

[0047] (2);

[0048] wherein, represents the average deviation coefficient of the coagulant; j represents the value of the change of the turbidity in the simulated water sample B, j is from high to low, the initial value of j is the initial turbidity value of the simulated water sample B, and j is generally 20.0-25.0, m is the minimum value after the turbidity decreases, and m is generally 0-1.0; M represents the number of times of measuring the turbidity and the corresponding coagulant dosage in the process of the turbidity decreasing from j to m; the coagulant deviation dosage D dj represents the coagulant deviation dosage when the turbidity is j in the second deviation relationship curve; D tj represents the coagulant theoretical dosage when the turbidity is j.

[0049] Further, in B-S4 of method B, the calculation formula of the CO2 real-time correction aeration amount is: CO2 real-time correction aeration amount=CO2 real-time deviation aeration amount*CO2 average deviation coefficient;

[0050] The calculation formula of the coagulant real-time correction addition amount is: coagulant real-time correction addition amount=coagulant real-time deviation addition amount*coagulant average deviation coefficient.

[0051] Compared with the prior art, the present application has the following beneficial effects:

[0052] (1) The urban multi-water source water purification system provided by the present application can adjust the flow direction of raw water according to the pH value of the raw water by controlling the setting of the control assembly and cooperating with the switching pipeline, so that the raw water can select different treatment units. Compared with the existing single raw water cooperating with the corresponding water purification process, the water purification device of the present application is more flexible, can make the raw water undergo different water purification treatment according to the change of the raw water, and thus improves the water purification effect.

[0053] (2) The present application can effectively improve the effect of coagulation and sedimentation and reduce the concentration of aluminum ions in the water body through fine CO2 automatic dosing control, thereby prolonging the membrane life and promoting the effective operation of the entire water purification process.

[0054] (3) Improve the coagulation efficiency: by accurately controlling the CO2 dosage and optimizing the pH value, the coagulation efficiency of the aluminum salt coagulant is significantly improved, the use amount of the aluminum salt coagulant is reduced, the flocculation time is reduced, and the treatment speed is improved. BRIEF DESCRIPTION OF DRAWINGS

[0055] Figure 1 It is a schematic diagram of the overall structure of the urban multi-water source water purification system of the present application.

[0056] Figure 2 It is a schematic diagram of the structure of the pre-ozone treatment tank of the urban multi-water source water purification system of the present application.

[0057] Figure 3The structural schematic diagram of the flocculation sedimentation tank of the urban multi-water source water purification system.

[0058] Figure 4 The structural schematic diagram of an embodiment of the automatic program control system.

[0059] Figure 5 The structural schematic diagram of the controller in the automatic program control device.

[0060] Figure 6 The structural schematic diagram of the feedback control module in the controller.

[0061] Figure 7 The flow schematic diagram of an embodiment of the control method of the urban multi-water source water purification system.

[0062] 1 switching pipeline; 11 raw water pipe; 12 two-position three-way valve; 13 first unit pipe; 14 second unit pipe; 15 first water inlet pipe; 16 second water inlet pipe; 2 pre-ozone treatment tank; 22 first baffle; 23 second baffle; 24 air hole; 25 ozone gas inlet pipe; 26 ozone aeration head; 27 first water passage; 28 second water passage; 3 coagulation sedimentation tank; 31 sedimentation tank body; 32 resistance plate; 33 filter mounting plate; 4 sand filter tank; 5 ozone activated carbon tank; 6 ultrafiltration membrane tank; 7 nanofiltration membrane tank; 8 water outlet pipeline; 9 automatic control system; 91 water quality sensor; 92 CO2 adding device; 93 coagulant adding device; 94 controller; 911 water quality monitoring probe; 921 CO2 aeration port; 931 coagulant adding port; 941 information acquisition module; 942 data processing and analysis module; 943 feedback control module; 9431 water source switching control submodule; 9432 CO2 adding control submodule; 9433 coagulant adding control submodule; 10 storage device; 101 ozone storage tank; 102 coagulant storage tank; 103 CO2 storage tank; 104 oxygen storage tank. DETAILED DESCRIPTION

[0063] To make the objectives, technical solutions and advantages of the present application clearer and more comprehensible, the specific embodiments of the high-pH raw water purification control system and control method are described below with reference to the drawings. It should be understood that the specific embodiments described herein are only used to explain the present application and do not limit the present application.

[0064] The B-type raw water described in the present application refers to the raw water with a pH of 7.6-8.8, a permanganate index of 2.4-4.8 mg / L, ammonia nitrogen of 0.1-0.6 mg / L, and a turbidity of 12-25 NTU, which is generally derived from wetland water, lake water and river water, etc.

[0065] The A-type raw water described in the present application refers to the raw water whose pH is lower than 7.6 and turbidity is lower than 12 NTU, which is treated as A-type raw water for subsequent treatment according to the provisions of B-type raw water.

[0066] The water treatment standard effluent described in the present application has a pH of 6.5-7.5, a permanganate index of 1.0-2.5 mg / L, ammonia nitrogen of 0.04-0.1 mg / L, and turbidity of 0-0.2 NTU.

[0067] As shown in Figure 1 , the present application provides a city multi-water source water purification system, which comprises a switching pipeline, a first treatment unit and a second treatment unit connected with the switching pipeline, a water outlet pipeline arranged on the other end of the first treatment unit and the second treatment unit, and an automatic control system.

[0068] Specifically, the switching pipeline comprises a plurality of raw water pipes, two-position three-way valves arranged on the raw water pipes, first unit pipes and second unit pipes in communication with the two-position three-way valves, a first water inlet pipe in communication with the first treatment unit, and a second water inlet pipe in communication with the second treatment unit, the second water inlet pipe being in communication with the second unit pipe, and the first water inlet pipe being in communication with the first unit pipe; the two-position three-way valves are connected with a water source switching control sub-module; water quality monitoring probes are arranged on the raw water pipes.

[0069] Specifically, the first treatment unit comprises a coagulation sedimentation tank, a sand filter tank and an ozone activated carbon tank which are sequentially connected.

[0070] Specifically, the second treatment unit comprises a pre-ozone treatment tank, a coagulation sedimentation tank, a sand filter tank, an ozone activated carbon tank, an ultrafiltration membrane tank and a nanofiltration membrane tank which are sequentially connected.

[0071] Specifically, as shown in Figure 2 , in one embodiment, the pre-ozone treatment tank 2 comprises a pre-ozone tank body, first baffles arranged at equal intervals in the pre-ozone tank body, second baffles arranged in the pre-ozone tank body and staggered with the first baffles, a plurality of air holes arranged on the first baffles, ozone gas inlet pipes mounted on the air holes, ozone aeration heads mounted on the two end faces of the first baffles and in communication with the air holes, a first water passing channel formed between the bottom surface of the first baffles and the bottom surface of the inner cavity of the pre-ozone tank body, and a second water passing channel formed between the top surface of the second baffles and the top surface of the pre-ozone tank body.

[0072] Specifically, as shown in Figure 3 , in one embodiment, the flocculation sedimentation tank 3 comprises a sedimentation tank body 31, a coagulant dosing port 931 mounted on the sedimentation tank body, a plurality of baffle plates 32 staggered mounted in the sedimentation tank body, and a filter mounting plate 33 mounted on the baffle plates 32 and the sedimentation tank body 31.

[0073] Specifically, the ultrafiltration membrane pool 6 comprises an ultrafiltration pool body, an ultrafiltration membrane assembly installed in the ultrafiltration pool body, an aeration pipe installed on the ultrafiltration pool body, and the bottom of the ultrafiltration membrane assembly is connected with a water outlet pipeline; the nanofiltration membrane pool 7 comprises a nanofiltration pool body, a nanofiltration membrane assembly installed in the nanofiltration pool body, and an aeration pipe installed on the nanofiltration pool body, and the bottom of the nanofiltration membrane assembly is connected with a water outlet pipeline; the aeration pipes are connected with aeration pumps, the air inlet ends of the aeration pumps are connected with oxygen storage tanks and CO2 storage tanks; the ends of the aeration branch pipes located in the ultrafiltration pool body and the nanofiltration pool body are annularly arranged around the membrane assemblies.

[0074] Specifically, as shown in Figure 4 one embodiment, the automatic control system 9 comprises a water quality sensor 91, a CO2 dosing device 92, a coagulant dosing device 93, and a controller 94; the automatic control can adopt a PLC control system or a DCS control system.

[0075] Specifically, the water quality sensor 91 is provided with water quality monitoring probes 911 installed at the water inlets of the coagulation sedimentation pool, the water outlets of the coagulation sedimentation pool, the outlets of the ozone activated carbon pool, the outlets of the ultrafiltration membrane pool, and the outlets of the nanofiltration membrane pool; the CO2 dosing device 92 is provided with CO2 aeration ports 921 in communication with the coagulation sedimentation pool, the ozone activated carbon pool, the ultrafiltration membrane pool, and the nanofiltration membrane pool; the coagulant dosing device 93 is provided with a coagulant dosing port 931 in communication with the coagulation sedimentation pool.

[0076] Specifically, as shown in Figure 5 and Figure 6 one embodiment, the controller 94 comprises an information acquisition module 941, a data processing and analysis module 942, and a feedback control module 943; the information acquisition module 941 is used to receive water quality data information of the water quality monitoring probes 911 and feed back the water quality data information to the data processing and analysis module 942; the data processing and analysis module 942 receives data information of the information acquisition module 941, judges the type of the water source, and calculates and corrects the CO2 aeration amount and the coagulant addition amount; the feedback control module 943 comprises a water source switching control submodule 9431, a CO2 dosing control submodule 9432, and a coagulant dosing control submodule 9433; the water source switching control submodule 9431 controls the opening and closing of the switching pipeline; the CO2 dosing control submodule 9432 receives data information of the data processing and analysis module, controls the opening and closing of the CO2 aeration ports 921 and the gas flow; and the coagulant dosing control submodule 9433 controls the opening and closing of the coagulant dosing port 931 and the coagulant dosing flow.

[0077] Specifically, as shown in Figure 1As shown, in one embodiment, the urban multi-source water purification system is also provided with a discharging device 10, which includes an ozone storage tank 101, a coagulant storage tank 102, a CO2 storage tank 103, and an oxygen storage tank 104. The ozone storage tank 101 is in communication with the pre-ozone treatment pool 2 and the ozone activated carbon pool 5; the coagulant storage tank 102 is in communication with the coagulant adding port 931 in the coagulation sedimentation pool 3 and is controlled by a coagulant adding control submodule 9433; the CO2 storage tank 103 is in communication with the CO2 aeration ports in the coagulation sedimentation pool 3, the ozone activated carbon pool 5, the ultrafiltration membrane pool 6, and the nanofiltration membrane pool 7 and can be controlled by a CO2 adding control submodule 9432; and the oxygen storage tank 104 is in communication with the ultrafiltration membrane pool and the nanofiltration membrane pool.

[0078] As shown, Figure 7 The application provides a control method for the urban multi-source water purification system, and the control method is as follows:

[0079] According to the pH value data of the raw water at the water inlet of the coagulation sedimentation pool, it is determined whether the raw water is A-type raw water or B-type raw water, and the treatment mode is selected according to the type of the raw water.

[0080] Specifically, the water quality monitoring probe arranged on the raw water pipe feeds back data to the data processing and analysis module, the data processing and analysis module determines whether the raw water is A-type raw water or B-type raw water according to the pH value and the turbidity of the raw water, when the raw water is A-type raw water, the water source switching control submodule controls the two-position three-way valve to connect the raw water pipe with the first treatment unit, so that the A-type raw water is introduced into the first treatment unit for treatment, and when the raw water is B-type raw water, the water source switching control submodule controls the two-position three-way valve to connect the raw water pipe with the second treatment unit, so that the B-type raw water is introduced into the second treatment unit for treatment.

[0081] The first treatment unit adopts a control method A, which includes:

[0082] A-S1: obtaining a first theoretical relationship curve between the pH value and the CO2 aeration amount and a second theoretical relationship curve between the turbidity and the coagulant adding amount by taking A-type raw water as a water sample.

[0083] Specifically, in the control method A, in A-S1, the first theoretical relationship curve is obtained by taking A-type raw water as a water sample, preparing simulated water samples A with different pH values, exposing CO2 gas into the simulated water samples A, and measuring the changes of the pH value and the CO2 aeration amount to establish the first theoretical relationship curve between the pH value and the CO2 aeration amount; and the second theoretical relationship curve is obtained by taking A-type raw water as a water sample, adding an aluminum salt coagulant into the water sample, measuring the changes of the turbidity and the coagulant adding amount, and establishing the second theoretical relationship curve between the turbidity and the coagulant adding amount.

[0084] Specifically, in the control method A, the first theoretical relationship curve and the second theoretical relationship curve need to be input into the data processing and analysis module before the system runs.

[0085] A-S2: Real-time monitoring of the pH value of the coagulation sedimentation tank inlet, the pH value of the ozone activated carbon tank inlet, and the turbidity of the coagulation sedimentation tank outlet.

[0086] A-S3: Retrieve the pH value data of A-S2, and according to the first theoretical relationship curve, obtain the coagulant real-time dosage in the coagulation sedimentation tank and the ozone activated carbon tank; retrieve the turbidity data of A-S2, and according to the second theoretical relationship curve, obtain the coagulant real-time dosage in the coagulation sedimentation tank.

[0087] Specifically, in the control method of the urban multi-water source water purification system, the turbidity of the final effluent is required to be 0 ~ 0.2 NTU, therefore, in the data processing and analysis module, the turbidity of the coagulation sedimentation tank effluent is reduced to 0.1 NTU, and in actual use, the coagulant real-time dosage in the coagulation sedimentation tank is obtained according to the second theoretical relationship curve combined with the raw water turbidity.

[0088] Specifically, in the control method of the urban multi-water source water purification system, in the data processing and analysis module, the pH value in the coagulation sedimentation tank is reduced to 7, and in actual use, the CO2 real-time aeration amount in the coagulation sedimentation tank is obtained according to the first theoretical relationship curve combined with the pH value of the coagulation sedimentation tank inlet.

[0089] Specifically, in the control method of the urban multi-water source water purification system, in the data processing and analysis module, the pH value of the water in the ozone activated carbon tank is maintained at 7, and in actual use, the CO2 real-time aeration amount in the ozone activated carbon tank is obtained according to the first theoretical relationship curve combined with the pH value of the ozone activated carbon tank inlet.

[0090] A-S4: According to the CO2 real-time aeration amount and the coagulant real-time addition amount obtained by A-S3, control the discharge amount of CO2 in the ozone activated carbon tank, and the discharge amount of CO2 and the addition amount of coagulant in the coagulation sedimentation tank.

[0091] Specifically, the turbidity data of the raw water, the pH value of the coagulation sedimentation tank inlet obtained by A-S2, and the pH value of the ozone activated carbon tank inlet are input into the data processing and analysis module, the data processing and analysis module obtains the CO2 real-time aeration amount in the coagulation sedimentation tank, the CO2 real-time aeration amount in the ozone activated carbon tank, and the coagulant real-time dosage in the coagulation sedimentation tank according to the pre-input first theoretical relationship curve and second theoretical relationship curve, and outputs to the feedback control module to control the CO2 and coagulant addition of the CO2 addition device and coagulant addition device.

[0092] The second processing unit adopts the control method B, which comprises:

[0093] B-S1: setting the following data information in the automation control system:

[0094] 1) a first deviation relationship curve between pH value and CO2 aeration amount;

[0095] 2) a CO2 average deviation coefficient;

[0096] 3) a second deviation relationship curve between turbidity and coagulant addition amount;

[0097] 4) a coagulant average deviation coefficient;

[0098] The first deviation relationship curve is obtained by taking B-type raw water as a simulated water sample B, adding CO2 gas into the simulated water sample B, measuring the changes of pH value and CO2 aeration amount, and establishing a first deviation relationship curve between pH value and CO2 aeration amount.

[0099] The second deviation relationship curve is obtained by taking the simulated water sample B, adding an aluminum salt coagulant into the simulated water sample B, measuring the changes of turbidity and coagulant addition amount, and establishing a second deviation relationship curve between turbidity and coagulant addition amount.

[0100] The CO2 average deviation coefficient is obtained by:

[0101] taking the B-type raw water treated by water purification as a water sample, establishing a third theoretical relationship curve between pH value and CO2 aeration amount; and taking the B-type raw water as a water sample, establishing a first deviation relationship curve between pH value and CO2 aeration amount.

[0102] According to formula (1), the CO2 average deviation coefficient is calculated.

[0103] (1);

[0104] wherein, the CO2 average deviation coefficient; i represents the value of the change of pH value in the simulated water sample B, i is from high to low, the initial value of i is the initial pH value of the simulated water sample B, which is generally 7.5 ~ 9.0, n is the lowest value after the pH value decreases, which is generally 6.0 ~ 7.0; N represents the measurement times of pH and the corresponding CO2 deviation aeration amount in the process of the decrease of pH from i to n; represents the CO2 deviation aeration amount when the pH value is i, which is obtained by the first deviation relationship curve; represents the CO2 theoretical aeration amount when the pH value is i, which is obtained by the third theoretical relationship curve.

[0105] The coagulant average deviation coefficient is obtained by:

[0106] The fourth theoretical relationship curve between turbidity and coagulant dosage is established by taking the treated water of the B-type raw water as the water sample, and the fifth theoretical relationship curve between Al 3+ The second deviation relationship curve between turbidity and coagulant dosage is established by taking the B-type raw water as the water sample;

[0107] The average deviation coefficient of the coagulant is calculated according to formula (2);

[0108] (2);

[0109] wherein, represents the average deviation coefficient of the coagulant; j represents the value of the change of the turbidity of the simulated water sample B, j is from high to low, the initial value of j is the initial turbidity value of the simulated water sample B, and is generally 20.0 ~ 25.0, m is the lowest value after the turbidity decreases, and is generally 0 ~ 1.0; M represents the number of times of measuring the turbidity and the corresponding coagulant dosage in the process of the turbidity decreasing from j to m; the coagulant deviation dosage D dj represents the coagulant deviation dosage when the turbidity is j in the second deviation relationship curve; D tj represents the coagulant theoretical dosage when the turbidity is j.

[0110] B-S2: Real-time monitoring of the pH value at the inlet of the coagulation sedimentation tank, the pH value at the inlet of the ozone activated carbon tank, the pH value at the inlet of the membrane filtration tank, and the turbidity at the outlet of the coagulation sedimentation tank.

[0111] The pH value and turbidity data in B-S2 are acquired in the same way as in A-S2.

[0112] B-S3: The pH value data of B-S2 are substituted into the first deviation relationship curve to obtain the real-time deviation aeration amount of CO2 in the coagulation sedimentation tank, the ozone activated carbon tank, the ultrafiltration membrane tank and the nanofiltration membrane tank, and then the real-time corrected aeration amount of CO2 is obtained according to the average deviation coefficient of CO2;

[0113] The turbidity data of B-S2 are substituted into the second deviation relationship curve to obtain the real-time deviation addition amount of the coagulant, and then the real-time corrected addition amount of the coagulant in the coagulation sedimentation tank is calculated according to the average deviation coefficient of the coagulant;

[0114] B-S4: According to the real-time corrected aeration amount of CO2 and the real-time corrected addition amount of the coagulant obtained by B-S3, the discharge amount of CO2 in the ozone activated carbon tank, the ultrafiltration membrane tank and the nanofiltration membrane tank, and the discharge amount of CO2 and the addition amount of the coagulant in the coagulation sedimentation tank are controlled.

[0115] Specifically, in B-S4, the calculation formula of the CO2 real-time correction aeration amount is: CO2 real-time correction aeration amount = CO2 real-time deviation aeration amount * CO2 average deviation coefficient; and the calculation formula of the coagulant real-time correction addition amount is: coagulant real-time correction addition amount = coagulant real-time deviation addition amount * coagulant average deviation coefficient.

[0116] Specifically, the turbidity data of raw water, the pH value of the coagulation sedimentation tank inlet obtained by B-S2, the pH value of the ozone activated carbon tank inlet, the pH value of the ultrafiltration membrane tank inlet, and the turbidity of the coagulation sedimentation tank outlet are input into the data processing and analysis module. The data processing and analysis module obtains the CO2 real-time aeration amount in the coagulation sedimentation tank, the CO2 real-time aeration amount in the ozone activated carbon tank, the CO2 real-time aeration amount in the ultrafiltration membrane tank, and the coagulant real-time addition amount in the coagulation sedimentation tank according to the pre-input first deviation relationship curve and the second deviation relationship curve, and outputs them to the feedback control module to control the CO2 addition device and the coagulant addition device to add CO2 and coagulant.

[0117] During the treatment of raw water controlled by the control method A or the control method B, the Al 3+ concentration of the ozone activated carbon tank outlet is monitored in real time. If the Al 3+ concentration is 0.05-0.2 mg / L, the effluent of the aeration ozone activated carbon tank is reflowed to the coagulation sedimentation tank.

[0118] Specifically, after the water body is treated by the first treatment unit or the second treatment unit, it flows out of the treatment device through the effluent pipeline 8.

[0119] The specific conditions of the water treatment of the urban multi-water source water purification system controlled by the control method are as follows:

[0120] For a certain water plant in a city, the raw water of the water plant comes from urban wetland water and lakes. In August, the water quality is as follows: the pH is 7.8-8.4; the permanganate index is 2.8-3.8 mg / L; the ammonia nitrogen is 0.1-0.3 mg / L; and the turbidity is 13.5-17.8 NTU. Through the water purification system and the matched control method, the CO2 aeration amount can be reduced from 13 mg / L to 9 mg / L, the coagulant dosage is reduced by 25%-35%, and the final water purification efficiency can be improved by 15%-20%. The effluent water quality is as follows: the pH is 6.8-7.5; the permanganate index is 1.4-1.9 mg / L; the ammonia nitrogen is 0.04-0.07 mg / L; and the turbidity is 0-0.12 NTU.

[0121] Also for the waterworks, in December, the water quality is: pH is 7.1~7.5; permanganate index is 2.3~3.1 mg / L; ammonia nitrogen is 0.1~0.2 mg / L; turbidity is 7.3~9.8 NTU. Through the water purification system and the matched control method thereof, the water quality of the effluent is: pH is 6.8~7.2; permanganate index is 0.9~1.5 mg / L; ammonia nitrogen is 0.02~0.05 mg / L; turbidity is 0~0.10 NTU.

[0122] The above detailed description of the specific embodiments has described the technical solutions and beneficial effects of the present application, and it should be understood that the above description is only the most preferred embodiment of the present application and is not intended to limit the present application. Any modifications, supplements and equivalent replacements made within the principle range of the present application shall be included in the protection scope of the present application.

Claims

1. A multi-source urban water purification system, characterized in that, include: The system includes a switching pipeline, a first treatment unit and a second treatment unit connected to the switching pipeline, an outlet pipeline installed at the other end of the first treatment unit and the second treatment unit, and an automated control system; the first treatment unit includes a coagulation sedimentation tank, a sand filter tank and an ozone activated carbon tank connected in sequence; the second treatment unit includes a pre-ozone treatment tank, a coagulation sedimentation tank, a sand filter tank, an ozone activated carbon tank, an ultrafiltration membrane tank and a nanofiltration membrane tank connected in sequence. The automated control system includes a water quality sensor, a CO2 dosing device, a coagulant dosing device, and a controller. The water quality sensor is equipped with water quality monitoring probes installed at the inlet of the coagulation sedimentation tank, the outlet of the coagulation sedimentation tank, the outlet of the ozone activated carbon tank, the outlet of the ultrafiltration membrane tank, and the outlet of the nanofiltration membrane tank. The CO2 dosing device is equipped with CO2 aeration ports that are connected to the coagulation sedimentation tank, the ozone activated carbon tank, the ultrafiltration membrane tank, and the nanofiltration membrane tank, respectively. The coagulant dosing device is equipped with a coagulant dosing port that is connected to the coagulation sedimentation tank. The controller includes an information acquisition module, a data processing and analysis module, and a feedback control module. The information acquisition module receives water quality data from the water quality monitoring probe and feeds it back to the data processing and analysis module. The data processing and analysis module receives the data from the information acquisition module, determines the water source type, and calculates and corrects the CO2 aeration rate and coagulant dosage. The feedback control module includes a water source switching control submodule, a CO2 dosing control submodule, and a coagulant dosing control submodule. The water source switching control submodule controls the opening and closing of the switching pipeline. The CO2 dosing control submodule receives the data from the data processing and analysis module and controls the opening and closing of the CO2 aeration port and the gas flow rate. The coagulant dosing control submodule controls the opening and closing of the coagulant dosing port and the coagulant dosing rate.

2. The urban multi-source water purification system as described in claim 1, characterized in that, The switching pipeline includes multiple raw water pipes, a two-position three-way valve installed on the raw water pipes, a first unit pipe and a second unit pipe connected to the two-position three-way valve, a first inlet pipe connected to the first treatment unit, and a second inlet pipe connected to the second treatment unit. The second inlet pipe is connected to the second unit pipe, and the first inlet pipe is connected to the first unit pipe. The two-position three-way valve is connected to the water source switching control submodule. Each raw water pipe is equipped with a water quality monitoring probe.

3. The urban multi-source water purification system as described in claim 1, characterized in that, The pre-ozone treatment tank includes a pre-ozone tank body, first baffles evenly spaced within the pre-ozone tank body, and second baffles disposed within the pre-ozone tank body and staggered with the first baffles. The first baffles are provided with multiple vent holes, ozone inlet pipes installed on the vent holes, and ozone aerators installed on both ends of the first baffles and connected to the vent holes. A first water passage is formed between the bottom surface of the first baffles and the bottom surface of the pre-ozone tank body cavity, and a second water passage is formed between the top surface of the second baffles and the top surface of the pre-ozone tank body.

4. The urban multi-source water purification system as described in claim 1, characterized in that, The ultrafiltration membrane tank includes an ultrafiltration tank body, an ultrafiltration membrane module installed inside the ultrafiltration tank body, and an aeration pipe installed on the ultrafiltration tank body. The bottom of the ultrafiltration membrane module is connected to the effluent pipeline. The nanofiltration membrane tank includes a nanofiltration membrane tank body, a nanofiltration membrane module installed in the nanofiltration membrane tank body, and an aeration pipe installed on the nanofiltration membrane tank body. The bottom of the nanofiltration membrane module is connected to the effluent pipeline. The aeration pipe is connected to an aeration pump, and the air inlet of the aeration pump is connected to an oxygen storage tank and a CO2 storage tank. The ends of the aeration pipes located in the ultrafiltration tank and the nanofiltration membrane tank are arranged in a ring around the membrane module.

5. A method for treating raw water using an urban multi-source water purification system as described in any one of claims 1 to 4, characterized in that, include: (1) Monitor the water quality of the raw water pipe and determine whether the raw water type is type A or type B. The water source switching control submodule controls type A raw water to enter the first treatment unit and type B raw water to enter the second treatment unit. The first treatment unit uses method A to treat the water quality and the second treatment unit uses method B to treat the water quality. The water quality criteria for Type A raw water are: pH below 7.6 and turbidity below 12 NTU; raw water meeting other water quality conditions is classified as Type B raw water. Method A: A-S1: Using type A raw water as a water sample, the first theoretical relationship curve between pH value and CO2 aeration rate and the second theoretical relationship curve between turbidity and coagulant addition amount were obtained; A-S2: Real-time monitoring of pH and turbidity at the inlet of the coagulation sedimentation tank, pH at the inlet of the ozone activated carbon filter, and turbidity at the outlet of the coagulation sedimentation tank. A-S3: Retrieve the pH data from A-S2 and, based on the first theoretical relationship curve, obtain the real-time CO2 aeration rate in the coagulation sedimentation tank, the ozone activated carbon filter, and the ultrafiltration membrane filter; retrieve the turbidity data from A-S2 and, based on the second theoretical relationship curve, obtain the real-time coagulant addition amount in the coagulation sedimentation tank. A-S4: Based on the real-time CO2 aeration rate and real-time coagulant addition amount obtained from A-S3, control the CO2 emission rate in the ozone activated carbon filter and the ultrafiltration membrane filter, as well as the CO2 emission rate and coagulant addition amount in the coagulation sedimentation tank. Method B: B-S1: Obtain the following data information: 1) Using type B raw water as the water sample, the first deviation relationship curve between pH value and CO2 aeration rate was obtained; 2) CO2 average deviation coefficient; 3) Using type B raw water as the water sample, obtain the second deviation relationship curve between turbidity and coagulant addition amount; 4) Average deviation coefficient of coagulant; B-S2: Real-time monitoring of the pH value at the inlet of the coagulation sedimentation tank, the pH value at the inlet of the ozone activated carbon filter, the pH value at the inlet of the membrane filter, and the turbidity at the outlet of the coagulation sedimentation tank. B-S3: Substitute the pH data of B-S2 into the first deviation relationship curve to obtain the real-time deviation aeration amount of CO2 in the coagulation sedimentation tank, the ozone activated carbon filter tank and the ultrafiltration membrane filter tank. Then, based on the average deviation coefficient of CO2, obtain the real-time corrected aeration amount of CO2. Substitute the turbidity data of B-S2 into the second deviation relationship curve to obtain the real-time deviation addition amount of coagulant. Then, based on the built-in average deviation coefficient of coagulant, calculate the real-time correction addition amount of coagulant in the coagulation sedimentation tank. B-S4: Based on the real-time correction of CO2 aeration rate and coagulant addition amount obtained from B-S3, control the CO2 emissions in the ozone activated carbon filter and ultrafiltration membrane tank, as well as the CO2 emissions and coagulant addition amount in the coagulation sedimentation tank.

6. The method as described in claim 5, characterized in that, The method for obtaining the first theoretical relationship curve in Method A is as follows: using raw water of type A as the water sample, prepare simulated water samples A with different pH values, aerate CO2 gas into simulated water samples A, measure the changes in pH value and CO2 aeration rate, and establish the first theoretical relationship curve between pH value and CO2 aeration rate. The second theoretical relationship curve is obtained by using type A raw water as a water sample, adding aluminum salt coagulant to it, measuring the changes in turbidity and coagulant addition amount, and establishing the second theoretical relationship curve between turbidity and coagulant addition amount.

7. The method as described in claim 6, characterized in that, In Method B-S1, the method for obtaining the first deviation relationship curve is as follows: using type B raw water as a water sample, CO2 gas is introduced into it, the changes in pH value and CO2 aeration rate are measured, and the first deviation relationship curve between pH value and CO2 aeration rate is established. The method for obtaining the second deviation relationship curve is as follows: using type B raw water as a water sample, adding aluminum salt coagulant to it, measuring the changes in turbidity and coagulant addition amount, and establishing the second deviation relationship curve between turbidity and coagulant addition amount.

8. The method as described in claim 7, characterized in that, In method B's B-S1, the method for obtaining the average CO2 deviation coefficient is as follows: Using the treated effluent from type B raw water as a water sample, a third theoretical relationship curve between pH value and CO2 aeration rate was established; using type B raw water as a water sample, a first deviation relationship curve between pH value and CO2 aeration rate was established. The average deviation coefficient of CO2 is calculated according to formula (1); （1）； in, denoted as CO2 average deviation coefficient; i represents the pH value change in simulated water sample B, i from high to low, the initial value of i is the initial pH value of simulated water sample B, generally 7.5 ~ 9.0, n is the lowest value after the pH value decreases, generally 6.0 ~ 7.0; N represents the number of times pH and its corresponding CO2 deviation aeration amount are measured during the process of pH decreasing from i to n. The CO2 deviation aeration rate at pH value i is obtained through the first deviation relationship curve. This represents the theoretical CO2 aeration rate at pH value i, which is obtained through the third theoretical relationship curve.

9. The method as described in claim 8, characterized in that, In Method B's B-S1, the method for obtaining the average deviation coefficient of the coagulant is as follows: Using the treated effluent from type B raw water as a water sample, a fourth theoretical relationship curve between turbidity and coagulant dosage was established; using type B raw water as a water sample, a second deviation relationship curve between turbidity and coagulant dosage was established. The average deviation coefficient of the coagulant is calculated according to formula (2); （2）； in, This represents the average deviation coefficient of the coagulant; j represents the numerical value of the turbidity change in simulated water sample B, from high to low, with the initial value of j being the initial turbidity value of simulated water sample B, typically 20.0 ~ 25.0; m is the lowest value after the turbidity decreases, typically 0 ~ 1.0; M represents the number of measurements of turbidity and its corresponding coagulant dosage during the process of turbidity decreasing from j to m; and the deviation dosage of coagulant. D dj This indicates the deviation dosage of coagulant when the turbidity is j in the second deviation relationship curve; D tj This represents the theoretical dosage of coagulant when the turbidity is j.

10. The method as described in claim 9, characterized in that, In Method B's B-S4, the formula for calculating the real-time corrected CO2 aeration rate is: Real-time corrected CO2 aeration rate = Real-time deviation CO2 aeration rate × Average CO2 deviation coefficient. The formula for calculating the real-time correction dosage of coagulant is: Real-time correction dosage of coagulant = Real-time deviation dosage of coagulant × Average deviation coefficient of coagulant.

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