Multi-stage membrane filtration deep purification water treatment system integration

Abstract

The invention relates to the field of multi-stage membrane filtration deep purification water, in particular to a multi-stage membrane filtration deep purification water treatment system integration, which comprises a water pretreatment module, a reverse osmosis desalination module, a deep desalination module, a dosing module, a wastewater neutralization and discharge module and a control module, according to the system, a water source enters the pretreatment module to remove impurities such as large suspended matters and particulate matters, then enters the reverse osmosis desalination module and the deep desalination module to remove impurities such as dissolved salt, organic matters and bacteria in water, the EDI device is used for further desalting water in the reverse osmosis water production tank to improve the purity of the water, and in the process, the water in the reverse osmosis water production tank is recycled. The coagulant and sodium hypochlorite are successively added to improve the water quality and improve the treatment efficiency, and the scale inhibitor and the reducing agent are added to prolong the service life of the reverse osmosis membrane and reduce the maintenance cost.

Description

Technical Field

[0001] The system relates to the field of multi-stage membrane filtration deep water purification, and in particular to the integration of multi-stage membrane filtration deep water purification treatment systems. Background Art

[0002] The existing water sources basically come from outdoor water supply pipes. Although this supply method is convenient, the water temperature and water quality of the source water often lack clear information and guarantees. Therefore, before this part of the water source is put into use, the raw water needs to be properly treated.

[0003] Source water may contain various impurities, microorganisms, heavy metals and other harmful substances. The water treatment process includes coagulation, sedimentation, filtration and other steps. By adding coagulants to the water, the suspended particles and colloidal substances in the water are condensed into larger flocs, which are convenient for subsequent sedimentation and removal. Gravity is then used to make the flocs formed after coagulation and other heavy substances in the water settle to the bottom to form sludge and be discharged from the system. Finally, the interception effect of the filter medium, which includes sand and activated carbon, is used to further remove suspended matter and tiny particles in the water to ensure the safety of the water quality. However, the above-mentioned method of treating and purifying water takes a relatively long time to process, and the water quality of the effluent is unstable.

[0004] Therefore, in order to solve the problem that the treatment time is relatively long and the water quality of the effluent is unstable during the water treatment process of the above-mentioned water treatment process, a multi-stage membrane filtration deep purification water treatment system integration can be designed.

[0005] System Contents

[0006] In order to overcome the problems of long treatment time and unstable water quality in traditional water treatment processes.

[0007] The technical solution of this system is: multi-stage membrane filtration deep purification water treatment system integration, the system includes water pretreatment module, reverse osmosis desalination module, deep desalination module, dosing module, wastewater neutralization and discharge module, control module; characterized in that,

[0008] The pretreatment module includes a laminated self-cleaning filter that can realize automatic cleaning of multiple filter units and an ultrafiltration device for purifying source water; the reverse osmosis desalination module includes a primary reverse osmosis device and a secondary reverse osmosis device; the deep desalination module includes an EDI electric desalination device; the dosing module includes a coagulant dosing device, a reducing agent dosing device, and an antiscalant dosing device; the wastewater neutralization and discharge module includes a wastewater neutralization tank and a wastewater discharge pump; the control module adopts a microcomputer-PLC control system, with two upper industrial computers as the human-machine interface, and the lower computer adopts a programmable controller. The system has functions such as water treatment system data acquisition, system flow, monitoring key operation, data acquisition, alarm system, report printing, etc. The PLC system completes program control, data conversion and other functions.

[0009] As a preferred embodiment, the coagulant dosing device is mainly used to reduce the SDI and turbidity of the raw water. The coagulant needs to be added before the raw water enters the laminated self-cleaning filter. The coagulant solution is prepared manually, and the solution is added automatically. The dosage is automatically controlled by the water inlet flow rate. The two solution tanks are operated in reverse order. The dosing point is set at the pipeline mixer of the self-cleaning filter inlet pipe, and the position of the pipeline mixer is set.

[0010] As a preferred embodiment, the sodium hypochlorite dosing device is added to the inlet water of the ultrafiltration device through the raw water sodium hypochlorite dosing metering pump through the pipeline mixer to inhibit the growth of microorganisms and prevent the clogging of the filter and the ultrafiltration membrane. The sodium hypochlorite is automatically added through the metering pump, and the dosage is automatically adjusted according to the inlet water flow rate;

[0011] Sodium hypochlorite is added to the ultrafiltration and primary reverse osmosis chemical cleaning water tanks and the secondary reverse osmosis and EDI chemical cleaning water tanks through the chemical cleaning sodium hypochlorite dosing pump to provide chemical cleaning agents for the ultrafiltration device, primary reverse osmosis device, secondary reverse osmosis device, and EDI device.

[0012] Preferably, the reducing agent dosing device mainly functions to prevent oxidizing substances such as residual chlorine in the water from destroying the structure of the reverse osmosis membrane and reducing the life of the reverse osmosis membrane. The reducing agent is added before the water enters the reverse osmosis device to reduce the oxidizing property of the reverse osmosis inlet water, so that the redox potential of the water reaches the requirements of ≤200mV and residual chlorine <0.1mg / L. The reducing agent solution is prepared manually, and the solution addition is automatically controlled. The reducing agent is automatically added by a metering pump. The dosage is automatically adjusted according to the water inlet flow rate of the first-stage reverse osmosis device and the solution tank is switched. The dosing point is set on the water inlet pipe of the first-stage reverse osmosis device.

[0013] Preferably, the antiscalant dosing device is mainly used to prevent the surface of the primary reverse osmosis membrane from scaling, affecting its water production capacity or the chemical cleaning effect after scaling of the membrane surface. It is necessary to reduce the possibility of precipitation of scaling substances in the reverse osmosis device. Therefore, the antiscalant needs to be added before the influent enters the primary reverse osmosis device to change the existence form of calcium, magnesium and other ions in the primary reverse osmosis influent, thereby greatly reducing the possibility of scaling during the concentration process and achieving the Langelier index LSI <0. The scale inhibitor solution is prepared manually, and the solution addition is automatically controlled. The scale inhibitor is automatically added through a metering pump, and the dosage is automatically adjusted according to the influent flow rate of the primary reverse osmosis device. The two solution tanks are operated in reverse order, and the dosing point is set on the inlet pipe of the primary reverse osmosis device.

[0014] Preferably, a wastewater neutralization tank is set up in the wastewater neutralization and discharge module, which is divided into two compartments. The acid and alkaline wastewater from the deionization room, the chemical cleaning and dosing room, the acid and alkali metering room, etc. is discharged into one compartment of the wastewater neutralization tank through the drainage ditch. When one compartment of the water tank is full, the water inlet valve is closed, and the wastewater is introduced into another compartment of the water tank. The water tank filled with wastewater begins to be neutralized, and the wastewater is stirred by the agitator to test whether the pH is qualified. The pH standard is 6.0-9.0. After meeting the national emission standards, it is discharged to the production wastewater system. If the pH is unqualified after detection, alkali is added if it is acidic, and acid is added if it is alkaline. Then it is stirred again to test whether the pH is qualified. After repeated tests, it is discharged after meeting the national emission standards.

[0015] Beneficial effects of this system:

[0016] This system sets a heater in the clean water tank that stores source water. When the raw water temperature is lower than 10℃, the heater starts to heat the raw water to 10℃. The designed water temperature of this system is 10℃, which maintains the constant temperature of the water entering the system. The water source enters the pretreatment module to remove larger suspended matter, particulate matter and other impurities, and then enters the reverse osmosis desalination module and deep desalination module to remove dissolved salts, organic matter, bacteria and other impurities in the water. The EDI device further desalinates the water in the reverse osmosis water production tank to improve the purity of the water. In this process, the addition of coagulants and sodium hypochlorite helps to improve water quality and improve treatment efficiency. The addition of scale inhibitors and reducing agents can extend the service life of the reverse osmosis membrane and reduce maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 What is shown is the schematic diagram of the water treatment process of this system;

[0018] Figure 2 Shown is a schematic diagram of the water treatment integrated system of this system. DETAILED DESCRIPTION

[0019] The system is further described below in conjunction with embodiments.

[0020] See also Figure 1 , This system provides an embodiment: a multi-stage membrane filtration deep purification water treatment system integration, the system includes a water pretreatment module, a reverse osmosis desalination module, a deep desalination module, a dosing module, a wastewater neutralization and discharge module, and a control module; it is characterized in that,

[0021] The pretreatment module includes a laminated self-cleaning filter that can realize automatic cleaning of multiple filter units and an ultrafiltration device for purifying source water; the reverse osmosis desalination module includes a primary reverse osmosis device and a secondary reverse osmosis device; the deep desalination module includes an EDI electric desalination device; the dosing module includes a coagulant dosing device, a reducing agent dosing device, and an antiscalant dosing device; the wastewater neutralization and discharge module includes a wastewater neutralization tank and a wastewater discharge pump.

[0022] The main function of the coagulant dosing device is to reduce the SDI and turbidity of the raw water. The coagulant needs to be added before the raw water enters the laminated self-cleaning filter. The coagulant solution is prepared manually, and the solution is added automatically. The dosage is automatically controlled by the water inlet flow rate. The two solution tanks operate in reverse. The dosing point is set at the pipeline mixer of the self-cleaning filter inlet pipe, and the position of the pipeline mixer is set.

[0023] The sodium hypochlorite dosing device uses the raw water sodium hypochlorite dosing pump to add the sodium hypochlorite to the inlet water of the ultrafiltration device through the pipeline mixer to inhibit the growth of microorganisms and prevent the clogging of the filter and ultrafiltration membrane. Sodium hypochlorite is automatically added through the metering pump, and the dosage is automatically adjusted according to the inlet water flow rate;

[0024] Sodium hypochlorite is added to the ultrafiltration and primary reverse osmosis chemical cleaning water tanks and the secondary reverse osmosis and EDI chemical cleaning water tanks through the chemical cleaning sodium hypochlorite dosing pump to provide chemical cleaning agents for the ultrafiltration device, primary reverse osmosis device, secondary reverse osmosis device, and EDI device.

[0025] The main function of the reducing agent dosing device is to prevent oxidizing substances such as residual chlorine in the water from destroying the structure of the reverse osmosis membrane and reducing the life of the reverse osmosis membrane. The reducing agent is added before the water enters the reverse osmosis device to reduce the oxidizing property of the reverse osmosis water, so that the water's redox potential reaches the requirements of ≤200mV and residual chlorine <0.1mg / L. The reducing agent solution is prepared manually, and the solution addition is automatically controlled. The reducing agent is automatically added through a metering pump. The dosage is automatically adjusted according to the water inlet flow of the first-stage reverse osmosis device and the solution tank is switched. The dosing point is set on the water inlet pipe of the first-stage reverse osmosis device.

[0026] The main function of the scale inhibitor dosing device is to prevent the surface scaling of the primary reverse osmosis membrane and affect its water production capacity or the chemical cleaning effect after scaling of the membrane surface. It is necessary to reduce the possibility of scaling substances precipitating in the reverse osmosis device. Therefore, it is necessary to add scale inhibitors before the influent enters the primary reverse osmosis device to change the existence form of calcium, magnesium and other ions in the primary reverse osmosis influent, thereby greatly reducing the possibility of scaling during the concentration process and achieving the Langelier index LSI <0. The scale inhibitor solution is prepared manually, and the solution addition is automatically controlled. The scale inhibitor is automatically added through a metering pump. The dosage is automatically adjusted according to the influent flow of the primary reverse osmosis device. The two solution tanks are operated in reverse order, and the dosing point is set on the inlet pipe of the primary reverse osmosis device.

[0027] The wastewater neutralization and discharge module is provided with a wastewater neutralization tank, which is divided into two compartments. The acid and alkaline wastewater from the deionization room, chemical cleaning and dosing room, acid and alkali metering room, etc. is discharged into one compartment of the wastewater neutralization tank through the drainage ditch. When one compartment of the water tank is full, the water inlet valve is closed and the wastewater is introduced into another compartment of the water tank. The water tank filled with wastewater begins to be neutralized, and the wastewater is stirred by the agitator to test whether the pH is qualified. The pH standard is 6.0-9.0. It is discharged to the production wastewater system after meeting the national emission standards. If the pH is unqualified after detection, alkali is added if it is acidic, and acid is added if it is alkaline. Then it is stirred again to test whether the pH is qualified. After repeated tests, it is discharged after meeting the national emission standards.

[0028] The control module adopts a microcomputer-PLC control system, with two upper industrial computers as the human-machine interface and a lower computer using a programmable controller. The system has functions such as water treatment system data acquisition, system flow, monitoring key operation, data acquisition, alarm system, report printing, etc. The PLC system completes program control, data conversion and other functions.

[0029] The water quality of the effluent after deep water purification by multi-stage membrane filtration is in compliance with the requirements of the secondary standard GB / T6682-2008 "Specifications and Test Methods for Water Use in Analytical Laboratories" and the relevant provisions of DL 5068-2014 "Chemical Design Specifications for Power Plants":

[0030] Conductivity (at 25℃, mS / m)≤0.10

[0031] Oxidizable matter content (in O, mg / L) ≤ 0.08

[0032] Absorbance (254nm, 1cm pathlength) ≤ 0.01

[0033] Evaporation residue (105±2℃, mg / L)≤1.0

[0034] Soluble silicon (in terms of SiO2, mg / L) ≤ 0.02

[0035] Chloride ion (mg / L) ≤ 0.05

[0036] Fluoride ion (mg / L) ≤ 0.05.

Claims

1. Multi-stage membrane filtration deep purification water treatment system integration, the system includes water pretreatment module, reverse osmosis desalination module, deep desalination module, dosing module, wastewater neutralization and discharge module, control module; characterized in that , The pretreatment module includes a laminated self-cleaning filter capable of automatically cleaning multiple filter units and an ultrafiltration device for purifying source water; The reverse osmosis desalination module includes a primary reverse osmosis device and a secondary reverse osmosis device; The deep desalination module includes an EDI electric desalination device; The dosing module includes a coagulant dosing device, a reducing agent dosing device, and an antiscalant dosing device; The wastewater neutralization and discharge module includes a wastewater neutralization tank and a wastewater discharge pump; The control module adopts a microcomputer-PLC control system, with two upper industrial computers as the human-machine interface and a lower computer using a programmable controller. The system has functions such as water treatment system data acquisition, system flow, monitoring key operation, data acquisition, alarm system, report printing, etc. The PLC system completes program control, data conversion and other functions.

2. The multi-stage membrane filtration deep water purification system integration according to claim 1 is characterized by: The main function of the coagulant dosing device is to reduce the SDI and turbidity of the raw water. The coagulant needs to be added before the raw water enters the laminated self-cleaning filter. The coagulant solution is prepared manually, and the solution is added automatically. The dosage is automatically controlled by the water inlet flow rate. The two solution tanks operate in reverse. The dosing point is set at the pipeline mixer of the self-cleaning filter inlet pipe, and the position of the pipeline mixer is set.

3. The multi-stage membrane filtration deep water purification system integration according to claim 1 is characterized by: The sodium hypochlorite dosing device uses the raw water sodium hypochlorite dosing pump to add the sodium hypochlorite to the inlet water of the ultrafiltration device through the pipeline mixer to inhibit the growth of microorganisms and prevent the clogging of the filter and ultrafiltration membrane. Sodium hypochlorite is automatically added through the metering pump, and the dosage is automatically adjusted according to the inlet water flow rate; Sodium hypochlorite is added to the ultrafiltration and primary reverse osmosis chemical cleaning water tanks and the secondary reverse osmosis and EDI chemical cleaning water tanks through the chemical cleaning sodium hypochlorite dosing pump to provide chemical cleaning agents for the ultrafiltration device, primary reverse osmosis device, secondary reverse osmosis device, and EDI device.

4. The multi-stage membrane filtration deep purification water treatment system integration according to claim 1 is characterized by: The main function of the reducing agent dosing device is to prevent oxidizing substances such as residual chlorine in the water from destroying the structure of the reverse osmosis membrane and reducing the life of the reverse osmosis membrane. The reducing agent is added before the water enters the reverse osmosis device to reduce the oxidizing property of the reverse osmosis water, so that the water's redox potential reaches the requirements of ≤200mV and residual chlorine <0.1mg / L. The reducing agent solution is prepared manually, and the solution addition is automatically controlled. The reducing agent is automatically added through a metering pump. The dosage is automatically adjusted according to the water inlet flow of the first-stage reverse osmosis device and the solution tank is switched. The dosing point is set on the water inlet pipe of the first-stage reverse osmosis device.

5. The multi-stage membrane filtration deep water purification system integration according to claim 1 is characterized by: The main function of the scale inhibitor dosing device is to prevent the surface scaling of the primary reverse osmosis membrane and affect its water production capacity or the chemical cleaning effect after scaling of the membrane surface. It is necessary to reduce the possibility of scaling substances precipitating in the reverse osmosis device. Therefore, it is necessary to add scale inhibitors before the influent enters the primary reverse osmosis device to change the existence form of calcium, magnesium and other ions in the primary reverse osmosis influent, thereby greatly reducing the possibility of scaling during the concentration process and achieving the Langelier index LSI <0. The scale inhibitor solution is prepared manually, and the solution addition is automatically controlled. The scale inhibitor is automatically added through a metering pump. The dosage is automatically adjusted according to the influent flow of the primary reverse osmosis device. The two solution tanks are operated in reverse order, and the dosing point is set on the inlet pipe of the primary reverse osmosis device.

6. The multi-stage membrane filtration deep water purification system integration according to claim 1 is characterized by: The wastewater neutralization and discharge module is provided with a wastewater neutralization tank, which is divided into two compartments. The acid and alkaline wastewater from the deionization room, chemical cleaning and dosing room, acid and alkali metering room, etc. is discharged into one compartment of the wastewater neutralization tank through the drainage ditch. When one compartment of the water tank is full, the water inlet valve is closed and the wastewater is introduced into another compartment of the water tank. The water tank filled with wastewater begins to be neutralized, and the wastewater is stirred by the agitator to test whether the pH is qualified. The pH standard is 6.0-9.

0. It is discharged to the production wastewater system after meeting the national emission standards. If the pH is unqualified after detection, alkali is added if it is acidic, and acid is added if it is alkaline. Then it is stirred again to test whether the pH is qualified. After repeated tests, it is discharged after meeting the national emission standards.

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