CN115947501A - A kind of strong flocculation ultrafiltration membrane water purification treatment method of natural flowing water - Google Patents

Abstract

The present invention relates to a natural flowing water strong flocculation ultrafiltration membrane water purification treatment method, which is characterized in that the following steps are adopted: S1, adding natural flowing water and flocculant into a circulation flocculation box, the bottom of the circulation flocculation box is provided with a mud discharge pipe, There is a guide tube in the middle, and a lifting agitator is arranged in the guide tube; the flocculation liquid outlet pipe is set in the middle of the circulation flocculation box; the natural flowing water and the flocculant are fully mixed in the circulation flocculation box to form a flocculation liquid; S2, The flocculant enters the self-cleaning filter after being boosted by the booster pump, and then enters the ultrafiltration membrane purifier from the top of the ultrafiltration membrane purifier, and the purified water obtained after filtration flows out from the water purification pipe in the middle of the ultrafiltration membrane purifier; The concentrated liquid formed before the ultrafiltration membrane enters the return pipe at the bottom of the ultrafiltration membrane purifier; the return pipe is connected to the circulation flocculation box, and the concentrated liquid enters the circulation flocculation box through the return pipe. The invention has the beneficial effects of short technological process, strong anti-fouling ability, simple and reliable operation, and the like.

Description

A kind of strong flocculation ultrafiltration membrane water purification treatment method of natural flowing water

technical field

The invention relates to the technical field of water purification treatment, in particular to a water purification treatment method of natural flowing water strong flocculation ultrafiltration membrane.

Background technique

The Hygienic Standard for Drinking Water (GB5749-2022) was released in March 2022 and will be implemented on April 1, 2023. The standard deletes the provisional provisions on water quality indicators and limit values for small-scale centralized and decentralized water supply, which means that the water quality requirements for urban and rural water supply are homogeneous. Higher requirements are put forward for the water quality of small centralized and decentralized water supply. Small-scale centralized and decentralized water supply is mainly distributed in rural areas, pastoral areas, mining areas, and factories far away from urban municipal pipe networks. Natural conditions often have the characteristics of poor water quality and large seasonal changes, and there is a lack of professional management personnel in management. It makes it difficult for the traditional coagulation, sedimentation, and sand filtration processes to meet the standards stably. The water purification treatment method of ultrafiltration membrane treatment has the advantages of low turbidity of purified water effluent and good water quality, which has attracted attention. However, the conventional full-flow ultrafiltration membrane water purification process requires high pretreatment of raw water, otherwise the membrane pores are easily blocked and affect normal use. Cross-flow filtration can solve the problem of membrane pore clogging, but its high energy consumption and high operating costs also make it difficult to promote its use. The self-cleaning filter is a precision device that uses the filter to directly intercept impurities, floating objects, particles, etc. in the liquid, while reducing the turbidity of the water, reducing dirt, and at the same time ensuring the normal operation and service life of the subsequent equipment. It has automatic The characteristics of sewage.

Contents of the invention

The technical problem to be solved by the present invention is to provide an ultrafiltration membrane water purification process with short process flow, strong anti-fouling ability, and simple and reliable operation.

In order to solve the above-mentioned technical problems, the present invention adopts the following technical scheme, a kind of strong flocculation ultrafiltration membrane water purification treatment method of natural flowing water, it is characterized in that adopting following steps:

S1. Add natural flowing water and flocculant into the circulation flocculation box, the bottom of the circulation flocculation box is provided with a mud discharge pipe, and a guide tube is provided in the middle, and a lifting agitator is provided in the guide tube; the middle part of the circulation flocculation box is set Flocculant liquid outlet pipe; natural flowing water and flocculant are fully mixed in the circulation flocculation box to form flocculant liquid;

S2. The flocculated liquid enters the self-cleaning filter after being pressurized by the booster pump, and then enters the ultrafiltration membrane purifier from the top of the ultrafiltration membrane purifier, and the purified water obtained after filtration passes through the water purification pipe in the middle of the ultrafiltration membrane purifier Outflow; the concentrated solution formed before the ultrafiltration membrane enters the return pipe at the bottom of the ultrafiltration membrane purifier; the return pipe is connected to the circulation flocculation box, and the concentrated solution enters the circulation flocculation box through the return pipe.

Further, a cleaning liquid discharge pipe is provided at the bottom of the self-cleaning filter, and the cleaning liquid discharge pipe is connected to a circulation flocculation box, and the turbid liquid containing larger flocculation particles generated by the self-cleaning filter enters the circulation flocculation box through the cleaning liquid discharge pipe or directly out.

A disinfectant is added to the flocculant when it is pressurized by a booster pump.

The ultrafiltration membrane is a ceramic ultrafiltration membrane, a silicon carbide ultrafiltration membrane, a PTFE ultrafiltration membrane or a PVDF ultrafiltration membrane.

In the present invention, a self-cleaning filter is arranged at the front end of the ultrafiltration membrane purifier, and the turbid liquid of flocs with larger particles is retained to flow back to the circulating flocculation box, thereby strengthening the flocculation effect, and utilizing the disinfectant in the turbid liquid for pre-oxidation treatment.

The invention adopts a booster pump to add disinfectant while boosting the flocculation liquid, so as to ensure the disinfection of the water body, slow down the pollution of the membrane surface and prolong the service life.

As shown in Fig. 1, Fig. 2 and Fig. 3, the present invention firstly adds natural flowing water and flocculant into the circulation flocculation tank 1, and forms a mixed liquid under the action of the lifting agitator 4, and the mixed liquid is formed in the circulation flocculation tank circulation. The turbid liquid containing larger flocculation particles produced by the self-cleaning filter 6 flows back into the circulating flocculation tank 1 to mix with natural flowing water and flocculant and continuously circulates and stirs to form coarse particles and discharge them from the mud discharge pipe 7 at the bottom, and some of the lighter ones float The waste is discharged from the upper slag discharge pipe 8. The flocculation liquid is pumped from the central outlet pipe 9 to the ultrafiltration membrane purifier 10 through the self-cleaning filter 6 under the suction of the booster pump 5 .

After the flocs of fine particles are mixed with the disinfectant, they enter the ultrafiltration membrane purification channel 11 from the top of the ultrafiltration membrane purifier 10 . The filtered clean water flows out from the clean water pipe 12, and the concentrated liquid intercepted by the ultrafiltration membrane washes along the surface of the membrane, gathers in the return pipe 13, and returns to the circulation flocculation tank 1.

The invention adds disinfectant to the front end of the membrane purifier, utilizes the strong oxidizing ability of the disinfectant and the scouring effect of the cross-flow formed by backflow on the surface of the membrane, and slows down the problem of fouling and fouling on the surface of the ultrafiltration membrane.

Returning the concentrated solution produced by the interception of the ultrafiltration membrane to the circulation flocculation box 1 can make full use of the fine, incompletely reacted and adsorbed flocculants to provide flocculation nuclei and promote rapid flocculation. Returning the large-particle flocs produced by the self-cleaning filter 6 to the circulation flocculation box can promote the alum flowers to sink to the sludge discharge pipe 7 for discharge, which strengthens the pretreatment effect at the front end of the membrane and improves the membrane purification efficiency.

The invention adopts a simple and easy-to-operate self-cleaning filter to replace the complex traditional sand filter pretreatment and simplifies system control.

In summary, the present invention has the beneficial effects of short process flow, strong anti-fouling ability, simple and reliable operation, and the like.

Description of drawings

Fig. 1 is a schematic diagram of the process flow of the present invention.

Figure 2 is a schematic diagram of the structure of the circulating flocculation box.

Fig. 3 is a schematic structural diagram of an ultrafiltration membrane purifier.

Implementation

The present invention will be further described in conjunction with accompanying drawing, and the present invention will be described in further detail below in conjunction with embodiment:

Example 1: It is a rural water supply system, the water source is river water, the raw water turbidity is 5~200NTU, the daily water supply is 100m3/d, and the treatment is 5.0m3/hr. The quality of water supply shall meet the standard of "Drinking Water Hygienic Standard (GB5749-2022)". As shown in Figure 1, Figure 2, and Figure 3, the water purification steps are as follows: the river water is used as raw water (natural flow water) at a flow rate of 5.0m3/h, and naturally flows into the circulation flocculation tank, and the raw water, flocculant, and return concentrate (flow rate: 1.00 m3/h) into the circulation flocculation tank 1 and mix evenly inside. The water inlet pipe 2 guides the mixed liquid to the bottom of the diversion tube 3, and under the action of the lifting agitator 4, the mixed liquid forms a circulation in the circulation flocculation tank, and the raw water, flocculant, reflux concentrate, and self-cleaning discharge liquid are continuously circulated and stirred. The formed coarse particles are discharged from the bottom mud discharge pipe 7, and part of the lighter floating matter is discharged from the upper slag discharge pipe 8, and the floc is sucked by the booster pump 5 from the middle outlet pipe 9 (flow: 7.00m3/h )) pumping, through the self-cleaning filter 6 to the ultrafiltration membrane purifier 10. During the suction process of the booster pump 5, the disinfectant is mixed evenly in the flocculation liquid. The self-cleaning filter 6 continuously discharges the intercepted large particles back to the circulation flocculation tank 1 (flow rate: 1.00m3/h). After the flocculation liquid is mixed with the disinfectant, it enters the ultrafiltration membrane purification channel 11 from the top of the ultrafiltration membrane purifier 10 . The ultrafiltration membrane adopts a ceramic membrane, and the purified water flows out from the water purification pipe 12 through the ceramic membrane under pressure (flow rate: 5.00m3/h). The concentrated liquid retained by the membrane washes along the membrane surface, gathers in the return pipe 13, and returns to the loop flocculator 1 (flow rate: 1.00m3/h). After purification, the turbidity of the effluent water is below 1NTU, meeting the requirements of the Sanitary Standard for Drinking Water (GB5749-2022).

Claims (4)

1. a strong flocculation ultrafiltration membrane water purification treatment method of natural flowing water, characterized in that the following steps are adopted: S1. Add natural flowing water and flocculant into the circulation flocculation box, the bottom of the circulation flocculation box is provided with a mud discharge pipe, and a guide tube is provided in the middle, and a lifting agitator is provided in the guide tube; the middle part of the circulation flocculation box is set Flocculant liquid outlet pipe; natural flowing water and flocculant are fully mixed in the circulation flocculation box to form flocculant liquid; S2. The flocculated liquid enters the self-cleaning filter after being pressurized by the booster pump, and then enters the ultrafiltration membrane purifier from the top of the ultrafiltration membrane purifier, and the purified water obtained after filtration passes through the water purification pipe in the middle of the ultrafiltration membrane purifier Outflow; the concentrated solution formed before the ultrafiltration membrane enters the return pipe at the bottom of the ultrafiltration membrane purifier; the return pipe is connected to the circulation flocculation box, and the concentrated solution enters the circulation flocculation box through the return pipe. 2. The strong flocculation ultrafiltration membrane water purification treatment method of natural flowing water according to claim 1, characterized in that: the bottom of the self-cleaning filter is provided with a cleaning liquid discharge pipe, and the cleaning liquid discharge pipe is connected to a circulation flocculation box, The turbid liquid containing larger flocculated particles generated by the self-cleaning filter enters the circulation flocculation tank through the cleaning liquid discharge pipe or is directly discharged outside. 3. The natural flowing water strong flocculation ultrafiltration membrane water purification treatment method according to claim 1, characterized in that a disinfectant is added to the flocculation liquid when it is boosted by a booster pump. 4. according to claim 1, the strong flocculation ultrafiltration membrane water purification treatment method of natural flowing water is characterized in that: the ultrafiltration membrane is a ceramic ultrafiltration membrane or a silicon carbide ultrafiltration membrane or a PTFE ultrafiltration membrane or a PVDF ultrafiltration membrane membrane.

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