CN204162533U - The device of coagulation-microfiltration membrane integral system process villages and small towns tap water - Google Patents

Abstract

The utility model relates to a device for treating drinking water in villages and towns with coagulation-microfiltration membrane combined with integrated equipment, which comprises a coagulation reaction system, a permeation circuit and a retention area. The coagulation reaction system comprises a water inlet, a water outlet and a dosing port , agitator and coagulation reaction tank, the retention area includes diaphragm pump, flow meter, backwash water inlet and return pipe, the permeation circuit includes membrane module water inlet, membrane module outlet and hollow fiber membrane external pressure module, hollow fiber The water inlet of the membrane module is provided at the bottom of the membrane external pressure module, and the water outlet of the membrane module is provided on one side. The water port is connected to the top of the hollow fiber membrane external pressure module through the return pipe; the water inlet at the bottom of the hollow fiber membrane external pressure module is connected to the backwash water inlet. The utility model can effectively remove pollutants such as heavy metals, organic matter, fluorine and arsenic, reduce investment costs, and has stable water output and is easy to maintain.

Description

Coagulation-microfiltration membrane integrated system for treating drinking water in villages and towns

technical field

The utility model belongs to the field of environmental protection technology, and relates to the purification technology of water containing organic matter, high fluorine and arsenic, in particular to a device for treating drinking water in villages and towns with an integrated system of coagulation-microfiltration membrane.

Background technique

With the development of society and the improvement of living standards, people's requirements for drinking water quality are becoming more and more stringent. However, the current pollution of surface water sources is very serious, conventional water treatment methods can no longer meet the requirements, and new water treatment technologies must be developed. With the advancement of membrane technology, it has been found that membrane separation processes operated at low pressure, including microfiltration and ultrafiltration, can meet the requirements. Membrane technology is called "the water treatment technology of the 21st century" and has broad application prospects in water purification treatment. The characteristic of membrane separation technology is that it can provide stable and reliable water quality. This is because the main principle of membrane separation of impurities in water is mechanical screening, so the quality of effluent water is only based on the size of the membrane pore size, and has nothing to do with the quality of raw water and operating conditions. In addition, membrane separation will greatly reduce the land use of the water plant and automate the operation, making the water plant a real "water factory".

In membrane water treatment, there are four main types of commonly used membranes: microfiltration membrane (MF), ultrafiltration membrane (UF), nanofiltration membrane (NF), and reverse osmosis membrane (RO). Microfiltration is a membrane process very similar to conventional coarse filtration. The microporous membrane has a relatively neat and uniform porous structure with a pore size of 0.05~10μm, which makes the filtration transition from a relatively rough relative property to a precise absolute property, and is mainly used for intercepting suspensions and emulsions. Ultrafiltration is a process between microfiltration and nanofiltration. The membrane pore size ranges from 0.05 μm (close to microfiltration) to 1 nm (close to nanofiltration). The typical application of ultrafiltration is to separate macromolecular substances and colloid. Nanofiltration is a membrane separation technology between ultrafiltration and reverse osmosis, which can separate small molecular organic matter from water and inorganic salts, and at the same time satisfy desalination and concentration; Based on the fact that other substances cannot pass through the semi-permeable membrane to separate these substances from water, it can effectively remove dissolved salts in water. The most practical applications are reverse osmosis membrane and nanofiltration membrane, but reverse osmosis is a process for seawater purification and ultra-pure water preparation. In addition to high operating pressure and high energy consumption, the "purity" of the treated water is too high, which makes the total water The minerals and ions beneficial to the human body cannot be retained, so whether it is appropriate to use this method to purify water has become a topic of debate. Compared with reverse osmosis, ultrafiltration and microfiltration methods have low operating pressure and low energy consumption. In recent years, there have been more and more researches and applications abroad as alternative methods for conventional water treatment. Because the effluent quality of microfiltration is closer to the standard of urban water, its application research has attracted more attention.

As an indispensable pre-link in the water treatment process, the coagulation process often determines the treatment effect, operating conditions, final water quality and water production cost of the subsequent process, so it is very important in water treatment. The field of research and development is a hot spot in current research. Organic matter in natural water can be divided into three types: suspended state, colloidal state and dissolved state. The suspended state and colloidal part are usually the parts with larger molecular weight and lower solubility, which can be adsorbed by tiny solid particles. Their removal mechanism is similar to that of particulate matter, that is, they are removed through electrical neutralization, adsorption bridging, and net capture and precipitation. This part of organic matter is easily removed through conventional water treatment processes.

To sum up, microfiltration and ultrafiltration in membrane technology are mainly used to remove solid particles; nanofiltration has a good removal effect on small molecular weight organic matter and salts; reverse osmosis can only remove salt in water, but not Organic matter cannot be removed, and some high-priced ions and organic matter will also pollute the membrane, resulting in the fact that wastewater treatment with membrane technology alone cannot meet the water quality requirements. Because organic matter with small molecular weight and high solubility in water has good hydrophilicity and is not easily absorbed by the hydrolyzate of coagulant, the removal rate is very low under general coagulation conditions. Therefore, a combined treatment process is urgently needed.

Contents of the invention

In view of the above shortcomings, the purpose of this utility model is to provide a device for treating drinking water in villages and towns with an integrated coagulation-microfiltration membrane system. Because the hollow fiber membrane does not need a support body, it has a large packing density and can accommodate a lot of membrane area per unit volume. Therefore, the utility model uses HQM series polypropylene hollow fiber membranes and HQM series modified polysulfone hollow fiber membranes. The device can not only effectively remove pollutants such as heavy metals, organic matter, fluorine and arsenic, and reduce pollution to receiving water bodies, but also facilitates the intensification of the device and reduces investment costs.

The coagulation-microfiltration membrane combined system proposed in this utility model is a device for treating drinking water in villages and towns, including a coagulation reaction system, a permeation circuit and a retention area, wherein: the coagulation reaction system includes a water inlet 1, a water outlet 2, a water inlet Drug inlet 4, agitator 5 and coagulation reaction tank body 3, the upper part of one side of the coagulation reaction tank body 3 is provided with a drug feeding port 4, and the two sides of the bottom are respectively provided with a water inlet 1 and a water outlet 2, and a stirring tank is provided inside it. device 5; the retention area includes a diaphragm pump 6, a flow meter 7, a backwash water inlet 11 and a return pipeline 12, and the permeation circuit includes a membrane module water inlet 8, a membrane module water outlet 10 and a hollow fiber membrane external pressure module 9, and the hollow fiber The bottom of the membrane external pressure module 9 is provided with a membrane module water inlet 8, and one side is provided with a membrane module water outlet 10, and the membrane module water inlet 8 is connected to the water outlet 2 of the coagulation reaction system through the flow meter 7 and the diaphragm pump 6 in sequence , the water inlet 1 of the coagulation reaction system is connected to the top of the hollow fiber membrane external pressure module 9 through the return pipe 12; the bottom water inlet of the hollow fiber membrane external pressure module 9 is connected to the backwash water inlet 11.

In the present utility model, the agitator 5 is a variable speed agitator. the

The operation method of the device for treating drinking water in villages and towns in the coagulation-microfiltration membrane combined system proposed by the utility model, the specific steps are as follows:

The pretreated drinking water in the villages and towns flows into the coagulation area for pretreatment through the water inlet, and the coagulation compound agent is put into the dosing port, mixed evenly with a variable speed agitator, and the water sample fully reacts with the coagulant. Mechanisms such as electrical neutralization, net capture and sweeping, and adsorption bridging make colloids and suspended particles in water form flocs, change the size distribution of suspended particles in raw water, and effectively remove organic matter and other macromolecular substances, while removing fluorine and arsenic. The mechanism is:

(1) Adsorption, the process of high-efficiency coagulant flocculation and precipitation to remove fluorine and arsenic is electrostatic adsorption. Due to the adsorption of charged fluorine and arsenic ions on fluorine-containing arsenic flocs, the positive charge is partially neutralized, and sodium ions and hydrogen ions are used as charge balance ions Adsorbed to the above to form molecular adsorption;

(2) Ion exchange. The radii of fluoride ion and hydroxide charge are similar, and OH- and F-are exchanged, which is an important mode of action of high-efficiency defluoridation agent; 

(3) Complex precipitation. Fluoride and arsenic ions can form fluorine and arsenic complex ion groups with aluminum, calcium, magnesium, iron and other ions. During the flocculation process, a variety of complexes will be formed and settle down. A small amount of coagulant can reliably remove fluorine and arsenic in water. .

The pretreated water sample flows through the hollow fiber microfiltration membrane through the diaphragm pump, and the diaphragm pump promotes its circulation in the device. After the water sample flows through the microfiltration membrane, part of the permeate enters the next processing device, and the other part The concentrated water is returned to the coagulation area, and the microfiltration membrane is backwashed regularly to prolong its service life, and the backwash water is returned to the coagulation area. The whole process realizes the adjustment of the operating condition through the pressure control system. The small particles and dissolved pollutants removed by the coagulant mainly sink to the bottom of the coagulation zone. After the coagulant in the reactor is saturated, the gate at the bottom is opened, collected and treated separately.

In the utility model, the pretreatment of the water sample refers to: filtering and settling to remove suspended impurities in the waste water.

In the present invention, the pollutant refers to at least one of heavy metals, organic matter and fluorine and arsenic.

The beneficial effects of the utility model are:

Compared with the prior art, the utility model has the remarkable advantages that: the combination of membrane technology and coagulation process is used to reduce the processing load of the membrane, improve the removal effect of heavy metals, organic matter and soluble substances in water, and effectively control the effluent Turbidity, ensuring the biological safety of the effluent, has huge technical and economic advantages.

Description of drawings

Figure 1 is a schematic diagram of the device of the present utility model.

Numbers in the figure: 1 is the water inlet, 2 is the water outlet, 3 is the coagulation reaction tank, 4 is the dosing port, 5 is the variable speed agitator, 6 is the diaphragm pump, 7 is the flow meter, 8 is the water inlet of the membrane module , 9 is the hollow fiber membrane external pressure module, 10 is the water outlet of the membrane module, 11 is the backwash water inlet, and 12 is the return pipe.

Detailed ways

Below further illustrate the utility model by embodiment.

Embodiment 1: as shown in Figure 1, described device is made up of coagulation reaction system, permeation circuit and retention zone, wherein: coagulation reaction system comprises water inlet 1, water outlet 2, dosing port 4, agitator 5 and The coagulation reaction tank body 3 is used for mixing the reaction liquid. The retention area includes a diaphragm pump 6, a flow meter 7, and the permeation area includes a membrane water inlet 8, a membrane outlet 10, a hollow fiber membrane external pressure module 9 for separating pollutants, a backwash water inlet 11, and a return pipeline 12. The whole system needs to be adjusted by the pressure control system when it is running.

Add village and town drinking water to the above reaction device:

The drinking water in villages and towns enters the coagulation reaction tank 3 from the water inlet 1. At the same time, the coagulation compound agent is put into the dosing port 4. The main components are calcium, magnesium, iron and aluminum. Turn on the variable speed agitator 5 to mix the water sample evenly. According to the reaction under the optimal coagulation conditions (mixing time 60S, mixing speed 250 r/min, flocculation time 15 min, flocculation stirring speed 60 r/min), the coagulant passed through the compression double layer, electrical neutralization, network Mechanisms such as trapping and sweeping, adsorption and bridging make colloids and suspended particles in water form flocs, change the size distribution of suspended particles in raw water, and effectively remove macromolecular substances such as organic matter, while the mechanism of fluorine and arsenic removal is adsorption and ion exchange. And complex precipitation, precipitation for 30 minutes, suspended particles, small molecular organic matter, heavy metals, high fluorine and arsenic, etc. form flocs and sink to the bottom, regularly open the bottom cover for cleaning, then open the outlet valve and diaphragm pump 6, and push the device through the diaphragm pump The water sample enters the hollow fiber membrane external pressure module 9 through the flow meter 7, and the water sample enters the water from the hollow fiber membrane external pressure module water inlet 8 through the central nozzle containing 6 channels, and the water sample enters the hollow fiber membrane The inside of the pressure module 9 is advective and cross-flows through the membrane surface, and the filterable material penetrates the hollow fiber membrane wall and enters the inner hole of the fiber under the push of the pressure difference to become an ultrafiltrate, and then flows out from the water outlet 10 into the next The treatment device and the rest are concentrated into concentrated liquid, which flows out through the return pipe 12 at the confluence port of the central distribution pipe at the other end of the module housing, and enters the coagulation reaction zone. Due to the regular natural bundles of the fibers, when the raw liquid flows between the fibers, it is in a highly cross-flow state at a relatively high flow rate, which is more beneficial to overcome the concentration polarization of the stagnant layer on the membrane surface, and the pollution resistance (fouling resistance space) Larger, able to adapt to wider water quality or feed conditions, reduce pretreatment process and cost, and have no dead ends for microfiltration permeate. And in order to solve the difficulty of blockage and backwashing in this device, a fully automatic backwashing device is designed. The left valve is closed at the membrane water inlet 8, and the clean water flows from the bottom to the top at the right backwashing inlet and outlet 11. , the backwash water flows into the coagulation reaction zone through the return pipe 12 from the upper water outlet to complete a cycle.

Claims (2)

1. A device for treating drinking water in villages and towns with a coagulation-microfiltration membrane system, including a coagulation reaction system, a permeation circuit and a retention zone, characterized in that the coagulation reaction system includes a water inlet (1) and a water outlet (2) , the dosing port (4), the agitator (5) and the coagulation reaction tank (3), the coagulation reaction tank (3) is provided with a dosing port (4) on the upper part of one side, and the bottom two sides are respectively provided with the inlet The water inlet (1) and the water outlet (2) are provided with an agitator (5); the retention area includes a diaphragm pump (6), a flow meter (7), a backwash water inlet (11) and a return pipe (12), The permeation loop includes a membrane module water inlet (8), a membrane module water outlet (10) and a hollow fiber membrane external pressure module (9), and the bottom of the hollow fiber membrane external pressure module (9) is provided with a membrane module water inlet (8) , one side is provided with membrane module water outlet (10), and described membrane module water inlet (8) connects the water outlet (2) of coagulation reaction system through flow meter (7), diaphragm pump (6) successively, coagulation reaction The water inlet (1) of the system is connected to the top of the hollow fiber membrane external pressure module (9) through the return pipe (12); the water inlet at the bottom of the hollow fiber membrane external pressure module (9) is connected to the backwash water inlet (11). 2. The device for treating drinking water in villages and towns according to claim 1, wherein the agitator (5) is a variable speed agitator.