CN102329022A - Drinking water treatment device based on ultrafiltration device - Google Patents

Abstract

The invention discloses a drinking water treatment device based on an ultrafiltration device, which includes a first-stage lifting pump, a coagulation sedimentation tank, an ultrafiltration device and a clear water tank, and the huge sand filter tank in the traditional water production process is subtracted. The water outlet of the first-stage lifting pump is connected to the coagulation-settling tank, the water outlet of the coagulation-settling tank is connected to the adsorption reaction tank through a pipeline, and the water outlet of the adsorption reaction tank is connected to the water inlet of the ultrafiltration device through the ultrafiltration water pump, and the ultrafiltration The water outlet of the device is connected to the water inlet of the clear water pool. The drinking water treatment device based on the ultrafiltration device proposed by the present invention has high filtration accuracy, low turbidity of effluent water, and significantly improved effluent water quality; it can remove various pollutants such as dissolved organic matter, bacteria, and viruses from water; it can reduce the amount of chlorine added , prevent the formation of chlorinated by-products, ensure the safety of drinking water, and further improve the taste of water to meet the requirements of drinking water standards. The equipment investment cost of the drinking water treatment device based on the ultrafiltration device is lower than that of the traditional drinking water treatment process.

Description

A drinking water treatment device based on an ultrafiltration device

technical field

The invention relates to drinking water treatment technology, in particular to a drinking water treatment device based on an ultrafiltration device.

Background technique

At present, domestic conventional water production processes are traditional processes, namely coagulation, sedimentation, filtration (sand filtration), and disinfection. With the continuous deterioration of surface water quality and the improvement of drinking water quality standards, traditional water production processes have gradually found it difficult to fully meet the requirements of drinking water quality standards.

In the traditional water production process, the sand filtration process occupies a large area, has high requirements on the water distribution system, and has low filtration accuracy, and the turbidity of the effluent is about 1NTU. In engineering applications, in addition to ensuring strict design and installation conditions, regular maintenance and repairs are also required, otherwise it is difficult to ensure the normal water purification effect of the sand filter system.

On the other hand, with the rapid development of industrial and agricultural production, a large amount of pollutants are discharged into the surface water system, causing water pollution. The water treatment capacity of the traditional process is limited, and it has been unable to effectively remove trace pollutants in the water, and it is difficult to meet the growing requirements of my country's drinking water quality.

In view of this, in order to deal with micro-polluted water sources and sudden pollution, the "ozone-biological activated carbon" (O ₃ -BAC) process is currently the most researched in China. The COD _mn removal rate of this process is only 15-25%, and it is almost impossible to remove refractory organic matter (AOC); the effluent of this process will inevitably entrain activated carbon particles, which contain a large number of bacteria and cannot be thoroughly disinfected In addition, the construction cost of this process is high, and the operation technology is complicated, so it is not suitable for large-scale promotion. Therefore, it is necessary to develop a new drinking water treatment process suitable for the existing water quality conditions to ensure the health of drinking water for residents.

Ultrafiltration (hereinafter referred to as UF) is a rapidly developing new water treatment technology, which has been widely used in many fields. The main application characteristics of ultrafiltration in the field of drinking water treatment are:

(1) It can remove most of the turbidity, and the turbidity of the effluent can be kept within 0.1NTU;

(2) It can remove almost all bacteria and most viruses;

(3) It has a partial removal rate for low-molecular-weight soluble organic matter;

(4) The project occupies a small area and is convenient for installation and maintenance.

At present, there are many single or combined research results on the advanced treatment of water by activated carbon and ultrafiltration technology in China, but most of them are applied to the traditional drinking water treatment process as a link to improve and guarantee water quality. On the one hand, the investment cost is increased, and on the other hand On the one hand, it also brings higher operating costs, which makes the development of ultrafiltration technology in the field of drinking water treatment slow, and affects the application of ultrafiltration technology in this field.

Contents of the invention

Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a drinking water treatment device based on an ultrafiltration device, which replaces the sand filtration process of traditional water production by the ultrafiltration device, reduces investment costs, and improves water quality. And reduce the amount of chlorine added to drinking water, prevent the production of chlorinated by-products, increase the safety of drinking water, and improve the taste of drinking water.

Technical scheme: in order to achieve the above object, the technical scheme adopted in the present invention is:

A drinking water treatment device based on an ultrafiltration device, including a primary lift pump, a coagulation sedimentation tank, an ultrafiltration device and a clear water tank, minus the huge filter tank in the traditional water production process, the primary lift pump The water outlet is connected to the water inlet of the coagulation sedimentation tank, the water outlet of the coagulation sedimentation tank is connected to the water inlet of the ultrafiltration device through the ultrafiltration water pump, and the water outlet of the ultrafiltration device is connected to the clear water tank.

The device does not use the sand filtration process. After the raw water is coagulated in the coagulation tank and settled in the inclined plate sedimentation tank, it directly enters the ultrafiltration device for filtration, and finally completes the interception and separation of particulate matter. The filtered water directly enters the clear water tank, that is, The pipe network can be used for water supply; the ultrafiltration device can effectively remove bacteria and viruses in raw water, reduce the amount of chlorine added in the subsequent system, reduce the production of chlorinated by-products, and make drinking water safer and taste better.

The device also includes an adsorption reaction tank connected between the coagulation sedimentation tank and the ultrafiltration device.

When dealing with slightly polluted source water or when sudden pollution occurs in the water source, an appropriate amount of powdered activated carbon can be added to the raw water after coagulation and precipitation, so that the raw water after coagulation and precipitation undergoes adsorption reaction first, and then enters the ultrafiltration device; At this time, the device should also include a powdered activated carbon dosing device for adding powdered activated carbon to the adsorption reaction tank, and a stirring device is installed in the adsorption reaction tank, so that the powdered activated carbon thrown into the adsorption reaction tank is stirred by the stirring device and completely mixed with water. Mixing, complete the adsorption reaction process under certain hydraulic conditions, transfer the pollutants in the water from the liquid phase to the solid phase, and then remove them through the ultrafiltration device to achieve the purpose of water purification; the residence time of the adsorption reaction tank in the adsorption reaction tank can be determined according to Water quality and water quantity are set, generally 20min--30min.

The above-mentioned powdered activated carbon dosing device can be connected with an activated carbon dosage control device, which can control the dosage of activated carbon according to water quality and water quantity; the activated carbon dosage control device can be realized by PLC.

When there is no need to add powdered activated carbon, the adsorption reaction tank is used as an intermediate tank; when powdered activated carbon needs to be added, the necessary hydraulic gradient and sufficient reaction time for the adsorption reaction must be ensured in the adsorption reaction tank to ensure the adsorption effect; ultrafiltration device It can ensure the interception of powdered activated carbon after the adsorption is completed, and remove the pollution factors in water.

The ultrafiltration device adopts an external pressure PVDF hollow fiber ultrafiltration membrane module with an average cut-off pore size of 0.03 μm (much smaller than the average particle size of powdered activated carbon), large single-membrane flux, high filtration accuracy, and long service life. , Utilizing the precise filtration performance of the external pressure PVDF hollow fiber ultrafiltration membrane module, it can filter out bacteria, viruses, particles, macromolecules and powdered activated carbon in water, and has a good effect on pollutant interception.

According to the operation of the external pressure PVDF hollow fiber ultrafiltration membrane module, the ultrafiltration device can be designed as full-flow filtration or cross-flow filtration (in the case of normal water production, full-flow filtration can be used; to treat slightly polluted water sources or to deal with emergencies When powdered activated carbon is added to prevent serious pollution, the filtration method adopts cross-flow filtration method); the external pressure PVDF hollow fiber ultrafiltration membrane module can filter almost all bacteria and viruses, and the effluent water quality has been greatly improved compared with sand filtration technology, which can stably reach National "Drinking Water Hygienic Standards" (GB5749-2006) requirements.

The device also includes a forward washing device and a backwashing device for flushing the ultrafiltration device, the backwashing device includes a backwashing water pump and a bag filter, and the water inlet of the backwashing water pump is connected to the backwashing water supply port of the clear water tank , the backwash water pump is connected to the water outlet of the ultrafiltration device through the bag filter, and the backwash water outlet is arranged at the water inlet end of the ultrafiltration device; .

In each cycle of the operation of the ultrafiltration device, it is necessary to flush the intercepted matter and powdered activated carbon attached to the ultrafiltration membrane out of the ultrafiltration device through the set positive flushing-backwashing-secondary positive flushing effect, so as to achieve the removal of water The purpose of impurities, its flushing time, flushing cycle, operating membrane flux, working pressure and other parameters can be determined according to the specific water quality. Therefore, after the filtration cycle is over, the ultrafiltration device uses the raw water as the water for the ultrafiltration membrane to be flushed, and the produced water as the water for the backwash of the ultrafiltration membrane to wash out the retentate attached to the ultrafiltration membrane and the expired powdered activated carbon. Ultrafiltration device, so that the ultrafiltration device enters the next operation cycle. The backwash water pump is the water supply pump for the backwash of the ultrafiltration device, and the bag filter is the security filter for the backwash of the ultrafiltration device, which can effectively prevent particulate matter from entering the ultrafiltration device, clogging or scratching the ultrafiltration membrane.

The device can also include a PLC system control device, and an electromagnetic flowmeter is also provided between the water outlet of the ultrafiltration device and the water inlet of the clear water tank; between the ultrafiltration water pump and the water inlet of the ultrafiltration device, the washing outlet Pneumatic valves are respectively provided at the backwash outlet, between the outlet of the ultrafiltration device and the water inlet of the clean water tank, the outlet of the ultrafiltration device and the bag filter; the electromagnetic flowmeter and all pneumatic valves The data transmission end is connected to the PLC system control device.

The activated carbon dosage control device and the relevant parameters of positive flushing-backwashing-secondary positive flushing can be designed directly through the above-mentioned PLC system control device.

The water inlet of the ultrafiltration device and the water outlet of the ultrafiltration device are all provided with a remote pressure gauge and an on-site pressure gauge; the water outlet of the ultrafiltration device is provided with a remote flowmeter and an in-situ flowmeter; The data transmission ends of the remote pressure gauge and the local pressure gauge, the remote flowmeter and the local flowmeter can also be connected to the above-mentioned PLC system control device.

Beneficial effects: the drinking water treatment device based on the ultrafiltration device improved by the present invention has the following advantages compared with the prior art: 1. The sand filter device in the traditional process is replaced by the ultrafiltration device, which has high filtration accuracy and turbid water 2. The use of powdered activated carbon has a developed microporous structure and a huge specific surface area for adsorption, combined with the micropores of the ultrafiltration membrane for efficient retention of fine particles. Compared with The traditional water supply advanced treatment process has greatly improved the efficiency of removing low molecular substances; the "powder activated carbon-ultrafiltration membrane" combined process is applied to the advanced treatment of drinking water, which can remove dissolved organic compounds (COD _mn , UV ₂₅₄ , DOC, etc.), bacteria, viruses and other pollutants can reduce the amount of chlorine added, reduce the generation of chlorinated by-products, ensure the safety of drinking water, and further improve the taste of water, which can meet the hygienic requirements of drinking water; 3. Simple disassembly and installation of the ultrafiltration membrane unit, high mobility, and convenient maintenance; 4. Fast start-up and operation of the device, high degree of automation of equipment operation, simple operation and management, and low operating costs; 5. Economic and technical indicators: cancel sand filtration technology, so that the construction cost of water plants can be saved by about 100-150 yuan/ton (calculated based on the construction cost of sand filtration system 400-450 yuan/ton and the construction cost of ultrafiltration system 280-300 yuan/ton); when there is no need to add powdered activated carbon , while improving the water quality of the effluent, the device will increase the operating energy consumption by about 0.008 yuan/ton; when treating slightly polluted water sources, when adding powdered activated carbon below 4-6mg/L, the operating cost will increase by about 0.028-0.038 yuan/ton; When the water source is suddenly polluted, both the traditional device and this device need to add powdered activated carbon to ensure the quality of the effluent water. The amount of powdered activated carbon added is generally below 30mg/L. The operating cost of the device will increase the cost of powdered activated carbon and operating electricity by a total of 0.028 to 0.038 yuan / ton (the cost of powdered activated carbon increases by about 0.02-0.03 yuan/ton, and the operating electricity fee increases by about 0.008 yuan/ton).

Description of drawings

Fig. 2 is the structural representation of ultrafiltration device of the present invention;

Figure 1 is a schematic diagram of the raw water treatment process of the ultrafiltration device.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings.

As shown in Figure 1, it is a drinking water treatment device based on an ultrafiltration device, including a first-stage lift pump, a coagulation sedimentation tank 1, an adsorption reaction tank 2, an ultrafiltration device 3, a clear water tank 4, and an ultrafiltration device 3. The washing device, the backwashing device, and the PLC system control device, the water outlet of the first-stage lift pump is connected to the water inlet of the coagulation sedimentation tank 1, and the water outlet of the coagulation sedimentation tank 1 is connected to the inlet of the adsorption reaction tank 2. The water outlet, the water outlet of the adsorption reaction tank 2 is connected to the water inlet of the ultrafiltration device 3 through the ultrafiltration water pump 5, and the water outlet of the ultrafiltration device 3 is connected to the clear water pool 4; A powdered activated carbon dosing device is provided above the reaction tank 2, and an activated carbon dosage control device is connected to the powdered activated carbon dosing device; the ultrafiltration device 3 adopts an external pressure type PVDF hollow fiber ultrafiltration membrane module; The washing device comprises a backwash water pump 6 and a bag filter 7, the water inlet of the backwash water pump 6 is connected to the backwash water supply port of the clear water tank 4, and the backwash water pump 6 is connected to the outlet of the ultrafiltration device 3 through the bag filter 7. The water outlet, the backwash water outlet is arranged on the water inlet end of the ultrafiltration device 3; An electromagnetic flowmeter is also provided between the water inlets; between the ultrafiltration water pump 5 and the water inlet of the ultrafiltration device 3, the water outlet of the positive washing, the backwash water outlet, the water outlet of the ultrafiltration device 3 and the clear water pool 4, the water outlet of the ultrafiltration device 3 and the bag filter 7 are respectively provided with pneumatic valves; the water inlet of the ultrafiltration device 3 and the outlet of the ultrafiltration device 3 are provided with remote pressure gauges and In-situ pressure gauge; the water outlet of the ultrafiltration device 3 is provided with a remote flowmeter and an in-situ flowmeter; the data of the electromagnetic flowmeter, the data transmission end of all pneumatic valves, the remote pressure gauge and the in-situ pressure gauge The transmission end, the remote flowmeter and the data transmission end of the local flowmeter are connected to the PLC system control device; the activated carbon dosage control device is also designed through the PLC system control device, and the relevant parameters of the positive flushing device and the backwashing device are also passed The design of the PLC system control device; the flow of water and powdered activated carbon in the ultrafiltration device is shown in Figure 2.

The above-mentioned device is suitable for the advanced treatment of micro-polluted water and the field of sudden pollution treatment of water sources, and removes bulk dissolved organic matter and sudden pollutants in water source water. The PLC system control device controls the automatic periodic operation of the device. The relevant process parameters are as follows:

(1) When using "Ultrafiltration" single process to treat the effluent of the coagulation sedimentation tank, the turbidity removal rate can reach more than 99%, and can be maintained below 0.1NTU;

(2) When the single process of "ultrafiltration" is used to treat the effluent of the coagulation sedimentation tank, the removal rate of major pollutants such as COD _mn , DOC, UV ₂₅₄ gradually decreases with the increase of the membrane flux. When the flux of the ultrafiltration membrane is selected to be 75 ～85L/m ² ·h, COD _mn , DOC, UV ₂₅₄ and other major micro-pollutants can achieve a high removal rate;

(3) When the "powder activated carbon-ultrafiltration" combined process is used to treat the effluent of the coagulation sedimentation tank, the higher the mesh number of the powder activated carbon, the better the adsorption effect, and the higher the removal rate of major micro-pollutants such as COD _mn , DOC, and UV ₂₅₄ . It is recommended to use 200 mesh powdered activated carbon. Under normal operating conditions, the dosage can be selected from 4 to 12mg/L, and the specific value depends on the water quality.

The specific working process of the above-mentioned device is as follows:

1. Powdered activated carbon adsorption (when needed)

Dosing method: directly add to the adsorption reaction tank 2;

Adsorption time: According to the influent water quality and water quantity, it is determined by the process parameters, and it can be 20-30 minutes.

2. Ultrafiltration membrane filtration

Turn on the water pump: ultrafiltration water pump 5;

Valve opening and closing: open the production water valve 9, the water intake valve 8, and the cross-flow valve 10 (when necessary);

Duration: determined according to water quality;

Filtration method: full-flow filtration/cross-flow filtration;

Membrane flux: determined according to water quality;

Process description: The water to be filtered in the adsorption reaction pool 2 is pressurized by the ultrafiltration water pump 5 and enters the ultrafiltration device 3. The outlet pipe connected to the outlet of the ultrafiltration membrane module is sent to the clear water tank.

3. Rinse

The flushing sequence is: forward flushing - upper recoil - lower recoil - secondary forward flushing.

a. is rushing

Opening equipment: ultrafiltration water pump 5;

Valve opening and closing: open the positive flushing valve (water inlet valve) 8, the upper sewage valve 11;

Duration: 10-20s;

Process description: The raw water enters from the bottom of the membrane module, washes the membrane wall inside the membrane filament, and discharges the pollutants inside the membrane filament through the positive washing discharge port of the membrane module.

b. Up recoil

Opening equipment: backwash water pump 6;

Valve opening and closing: open the backwash valve 12, the positive wash discharge valve (upper blowdown valve) 11;

Duration: 10-30s;

Process description: Backwashing is the inverse process of filtration. The filtered water passes through the backwashing water pump 6, and reversely passes through the ultrafiltration membrane wall from the clean water side of the membrane module, taking out the pollutants in the membrane pores, and forward washing through the membrane module. exhaust port.

c. Lower recoil

Opening equipment: backwash water pump 6;

Valve opening and closing: open the backwash valve 12 and the backwash discharge valve 13;

Duration: 10-30s;

Process description: The filtered water passes through the backwashing water pump 6, and reversely passes through the ultrafiltration membrane wall from the clean water side of the membrane module, takes out the pollutants in the membrane pores, and discharges through the backwashing outlet of the membrane module.

d.Secondary positive impact

Opening equipment: primary lift pump;

Valve opening and closing: open the flushing valve 8 and the flushing discharge valve 11;

Duration: 10-20s;

Process description: The raw water enters from the bottom of the membrane module, washes the membrane wall inside the membrane filament, and discharges the pollutants inside the membrane filament through the positive washing discharge port of the membrane module.

The above is only a preferred embodiment of the present invention, it should be pointed out that for those of ordinary skill in the art, without departing from the principle of the present invention, some improvements and modifications can also be made, and these improvements and modifications are also possible. It should be regarded as the protection scope of the present invention.

Claims (9)

1. a drinking water treatment device based on an ultrafiltration device, characterized in that: the device includes a first-stage lift pump, a coagulation sedimentation tank (1), an ultrafiltration device (3) and a clear water tank (4), the one The water outlet of the stage lift pump is connected to the water inlet of the coagulation sedimentation tank (1), and the water outlet of the coagulation sedimentation tank (1) is connected to the water inlet of the ultrafiltration device (3) through the ultrafiltration water pump (5), and the ultrafiltration device ( 3) The water outlet is connected to the clear water pool (4). 2. The drinking water treatment device based on the ultrafiltration device according to claim 1, characterized in that: the device also includes an adsorption reaction tank (2), and the adsorption reaction tank (2) is connected to the coagulation sedimentation tank (1 ) and the ultrafiltration device (3). 3. The drinking water treatment device based on the ultrafiltration device according to claim 2, characterized in that: the device also includes a powdered activated carbon dosing device for adding powdered activated carbon to the adsorption reaction tank (2), and in the adsorption reaction tank (2) There is also a stirring device inside. 4. The drinking water treatment device based on the ultrafiltration device according to claim 3, characterized in that: the device also includes an activated carbon dosage control device for controlling the dosage of activated carbon according to water quality and water quantity, and the dosage of activated carbon is The control device is connected with the powder activated carbon dosing device. 5. The drinking water treatment device based on an ultrafiltration device according to claim 1, characterized in that: the ultrafiltration device (3) adopts an external pressure PVDF hollow fiber ultrafiltration membrane module. 6. The drinking water treatment device based on the ultrafiltration device according to claim 1, characterized in that: the device also includes a forward washing device and a backwashing device for flushing the ultrafiltration device (3), and the backwashing device It includes a backwash water pump (6) and a bag filter (7), the water inlet of the backwash water pump (6) is connected to the backwash water supply port of the clean water tank (4), and the backwash water pump (6) passes through the bag filter (7) Connect the water outlet of the ultrafiltration device (3), the backwash water outlet is arranged on the water inlet end of the ultrafiltration device (3); Wash the water outlet. 7. The drinking water treatment device based on the ultrafiltration device according to claim 7, characterized in that: the device also includes a PLC system control device, at the water outlet of the ultrafiltration device (3) and the inlet of the clear water pool (4) An electromagnetic flowmeter is also arranged between the water ports; between the water inlet of the ultrafiltration water pump (5) and the ultrafiltration device (3), at the water outlet of the forward washing, at the water outlet of the backwash, at the outlet of the ultrafiltration device (3) Between the water outlet and the water inlet of the clear water pool (4), the water outlet of the ultrafiltration device (3) and the bag filter (7) are respectively provided with pneumatic valves; the data transmission ends of the electromagnetic flowmeter and all pneumatic valves Connected to the PLC system control device. 8. The drinking water treatment device based on the ultrafiltration device according to claim 1, characterized in that: the water inlet of the ultrafiltration device (3) and the water outlet of the ultrafiltration device (3) are all provided with a remote pressure gauge and local pressure gauges. 9. The drinking water treatment device based on the ultrafiltration device according to claim 1, characterized in that: a remote flowmeter and an in-situ flowmeter are arranged at the water outlet of the ultrafiltration device (3).

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