KR100425522B1 - Wastewater Reusing System Using High Efficiency Sandfilter - Google Patents

Abstract

The present invention relates to a heavy water system using a high rate sand filter, comprising a high rate sand filter, a flow control aeration tank and a chemical aggregating reactor, which are biological pretreatment units, in series, so that the overall process can be made simple and efficient. It is about a water system.

The heavy water system using the high-rate sand filter of the present invention, the microbial contact medium while mitigating the inflow load of the raw water from which the foreign matter is removed in the sedimentation screening step, the sedimentation screening step to remove foreign substances or contaminants contained in the raw water by sedimentation and screening And a flow regulating aeration step of removing organic matter by proliferating microorganisms by supplying air necessary for microbial metabolism, a flocculation step of agglomerating the suspended solids and colloidal material of the effluent from which organic matter is removed in the flow regulating aeration step into larger chunks; A high rate sand filtration step to clean the aggregated particulate matter and a sterilization step to sterilize the harmful bacteria contained in the effluent passed through the high rate sand filtration step with chlorine compounds.

Description

Wastewater Reusing System Using High Efficiency Sandfilter

The present invention relates to a heavy water system using a high rate sand filter, and specifically, a high rate sand filter and a high flow rate aeration tank and a chemical aggregating reactor, which are biological pretreatment units, are configured in series so that the overall process can be made simple and efficient. It relates to a heavy water system using a filter.

Recently, the demand for water is increasing rapidly due to the rapid industrialization and urbanization, while the shortage of water due to the depletion of water resources and extreme water pollution in some regions is intensifying. In addition, in response to the increasing public awareness of water pollution, the government is making efforts to reduce pollution loads in public waters by stepping up the emission allowance standards and implementing water quality regulation for some water systems. . However, the increase in water purification costs due to severe water pollution causes the increase in water tax, and accordingly, the government provides benefits such as tax support and water tax exemption for the dissemination of heavy water which reuses used water. .

In this regard, since a lot of effort and investment have been made to improve the quality of the water and secure the quantity of water, the water reclamation reusing system of the present invention has been proposed to maximize water saving and reuse. Specifically, it is as follows.

As shown in FIG. 1, the water system is used for cleaning, landscaping, toilets, toilets, and toilets that do not require the same level of cleanliness as drinking water. As a system that purifies waste water and reuses it in the system itself, such a water system does not require high cleanliness such as non-drinking flush toilet water, cooling water, cleaning water, fire fighting water, landscaping water and car wash water. The amount of water not used is based on current water consumption, which accounts for a large portion of the tap water.

The general water-based water system, as shown in Figure 2, the settling tank (1) for sedimentation and removal of foreign matter, such as sand, and the screen tank for screening and removing heavy large contaminants contained in the effluent of the settling tank (1) (2), a flow control tank for mitigating contaminant load fluctuations for effective biological treatment of sewage that has passed through the screen tank 2 and storing sewage in order to keep the amount of sewage treated even when excessive raw water is generated. (3), the aeration tank (4) for removing the contaminants of the effluent flowing out of the flow rate adjustment tank (3) by the oxidation and decomposition action by the microorganism, the organic material of the treated water flowing out of the aeration tank (4) is decomposed and propagated The purified supernatant by sedimenting sludge, which is a group of microorganisms, is transferred to the next process, and the sludge settled at the bottom is returned to the aeration tank 4 for biological treatment. The sedimentation tank (5), which is separated, concentrated, and dehydrated, is passed through a buffer tank (6) and a buffer tank (6), which collect the treated water separated from the sedimentation tank (5) for performing a filtration process. Filter tank (7) for filtering and removing suspended solids in treated water, activated carbon adsorption tank (8) for adsorbing and removing undecomposed organic matter, color, odor, etc. of the filtered water by passing through the filter tank (7), activated carbon adsorption tank (8) Backwashing tank (9) for storing a predetermined amount for backwashing of the filtration tank (7) and activated carbon adsorption tank (8) in water from which undecomposed organic matter, color, odor, etc. are removed, and in the backwash tank (9). It is composed of a disinfection tank 10 for sterilizing the harmful bacteria, such as harmful bacteria, Escherichia coli group by disinfecting the flow of treated water with a chlorine compound, which will be described in more detail as follows.

The flow rate adjusting tank 3 is equipped with a pump (P) for transferring the stored sewage to the post-treatment process, and aeration is carried out to prevent the sedimentation of suspended solids and the decay of the sewage. It is about 1 m 3 air / hour per 1 m 3 of the flow regulating tank 3.

In addition, the aeration tank (4) is continuously mixed with the microorganisms and contaminants by the aeration at the same time is supplied with oxygen necessary for the growth of microorganisms, the organic contaminants in the water are decomposed by the action of the oxidation, adsorption, assimilation, etc. of the microorganisms It is consumed by energy and the rest is used for self-proliferation of microorganisms. The treatment efficiency of the aeration tank 4 is affected by the design operation conditions such as the load of organic matter, the aeration time, the air amount, and the conditions of the growing environment such as the water temperature and pH. In the aeration tank 4, activated sludge containing turbidly mixed contaminants and microorganisms is cultivated. When activated sludge is cultured in a good state, microorganisms decompose organic matter and finely molecularly, while oxidizing power and sedimentation separability are achieved. This creates an excellent floc.

In the filtration tank 7, the suspended solids are filtered using the filter medium, and backwashing is performed periodically (once to twice a day) according to pressure or time. At this time, the backwashing using the filtered treated water, the filter medium washed by backwashing performs the filtration function again.

Activated carbon adsorption tank (8) has a porous pores, using activated carbon (Activated Carbon) having a unique adsorption function to absorb and remove undecomposed organic matter, color, odor and the like in the water. The activated carbon adsorption tank 8 is also subjected to backwashing similarly to the filtration tank 7, which is for restoring the function of the water flow and has a different meaning from the filtration tank 7. That is, while the filtration tank 7 is used semi-permanently through washing by backwashing, activated carbon has to be replaced periodically (six months to one year) because the titer of adsorption gradually decreases even when backwashing is performed.

On the other hand, the residual chlorine of the effluent sterilized in the disinfection tank 10 is 0.5mg / L or more, the contact time is 15 minutes or more.

The water system as described above allows the reuse of water once used many times in any form, so that the facility costs required when installing new water pipes from distant water sources to secure necessary water when expanding facilities such as industrial complexes and factories. In addition to savings, it can bring about an effect of reducing the demand for water, and also reduces the amount of sewage discharged, thereby reducing the environmental pollution caused by pollutants.

If the above water supply system can be installed to reduce the amount of water required, the surplus benefits will be overcome, as well as the limitations of water supply caused by the increase in water-intensive large buildings and large-scale facilities. Can be invested in facility investment costs for the production of clean tap water, and can effectively cope with the water shortage in the case of water shortage.

For this purpose, Korean Patent Laid-Open Publication No. 1997-65438 has already disclosed a sewage treatment system consisting of sewage treatment water as a raw water treatment, and a series of floc forming sites, sedimentation basins, and stabilization tanks. Patent registration No. 164580 discloses a heavy water system using a catalytic oxidation tank and an ultrafiltration membrane, and Korean Patent Publication No. 1999-83743 discloses a filter for heavy water using the principle of capillary and siphon tubes.

However, the conventional water-based water system configured as described above is a method of performing filtration or adsorption after biological treatment, and the treatment water quality varies depending on the treatment state of the biological treatment unit, which is the main treatment process, and thus, stable treatment water quality cannot be expected. In addition, the cladding material is not easily removed, so that the suspended solids and colloidal materials are removed to interfere with the adsorption process of the activated carbon adsorption tank, so that the titer of the activated carbon is rapidly dropped.

Therefore, in order to solve the above problems of the general water system, by removing the suspended substances and colloidal substances separately after the biological treatment, not only can obtain stable treated water quality but also increase the efficiency of the biological treatment unit by preventing microbial outflow. A water-based system using ultra filtration (ultra filtration) can be proposed and used, which will be described in more detail as follows.

As shown in FIG. 3, the sewage tank 11 and the screen tank 12, the settling tank 11, and the screen tank 12 which remove the contaminants and sand contained in the influent water are shown in FIG. 3. Effluent from the flow regulating tank 13 and the flow regulating tank 13 to reduce the pollutant load fluctuation for the efficiency of the sewage biological treatment passed in turn and to maintain the amount of sewage to be treated even when excessive raw water is generated. The supernatant water purified by sedimenting sludge, which is a group of microorganisms grown by decomposing organic matter in the treated water flowing out from the aeration tank 14, which removes contaminants of the sewage by using microorganism oxidation and decomposition, is transferred to the next process. Part of the sludge settled at the lower part is returned to the aeration tank for the activity of the aeration tank, and the remainder is separated from the sedimentation tank (15) and the sedimentation tank (15) for disposal by separation, concentration and dehydration. A buffer tank 16 for collecting the treated water for the next filtration process, and a micro filter 17 having a cartridge shape of about 20 to 50 μm for removing suspended substances contained in the effluent of the buffer tank 16. In order to backwash the ultrafiltration unit 18 and the ultrafiltration unit 18 to remove all contaminants above the colloidal substance except the dissolved organic matter in the effluent from which the suspended solids are removed from the micro filter 17, It consists of a backwash tank 19 for storing, and a disinfection tank 20 for sterilizing harmful bacteria, such as colon bacillus, by disinfecting the treated water overflowed in the backwash tank 19 with chlorine compounds, This will be described in more detail as follows.

In the aeration tank 14, microorganisms and contaminants are continuously mixed by the aeration, and oxygen necessary for the growth of the microorganisms is supplied. The organic contaminants in the water are decomposed by the action of oxidation, adsorption, assimilation, etc. It is consumed and the remainder is used for self-growth of microorganisms. The treatment efficiency of the aeration tank 14 is affected by the design operation conditions such as the load of organic matter, the aeration time, the amount of air, and the conditions of growth environment such as water temperature and pH. In the aeration tank 14, activated sludge in which contaminants and microorganisms are turbidly mixed is cultivated. When activated sludge is cultured in a good state, microorganisms decompose organic matter and finely molecularly, while oxidizing power and sedimentation separability are prevented. This creates an excellent floc.

The buffer tank 16 is an intermediate collection tank for ultrafiltration membrane filtration of biologically treated water, and has a built-in level sensor to control the ultrafiltration membrane device (ultrafiltration) according to the inflow of raw water.

The micro filter 17 is a device for removing suspended solids for smooth operation of the ultrafiltration process and protection of the UF membrane. The micro filter 17 is periodically replaced (once to 1 to 2 weeks in the case of sewage treatment) according to the degree of contamination.

The ultrafiltration unit 18 is very precise to remove all contaminants above colloidal materials except for dissolved organic matter, and may use a spiral, hollow fiber, plate-type, or tubular module. same.

Spiral wound modules are sandwiched and rolled into square flat membranes spaced apart and the surfaces of the active layers of the membranes opposite each other. In the actual process, usually two to six modules are placed in one pressure vessel. It is connected in series and used in a pressure vessel.

Hollow fiber module is a type that arranges thousands to tens of thousands of hollow fibers inside a cylindrical pressure vessel. Pressurized raw water is supplied through a central tube to flow in the direction of the hollow fiber normal, and only permeate flows inside the hollow fiber. It is filtered out and exits. The main difference from the spiral module is that the hollow fiber modules cannot be connected in series in a single container. Hollow fiber modules have the advantage of having the largest membrane surface area per unit volume due to their high packing density, but are more susceptible to contamination than other modules and therefore require more rigorous pretreatment.

The plate frame module is formed by sandwiching the inert layer portions of two flat sheets facing each other at a predetermined interval, and then sandwiching a circular or uniform film formed by bonding the ends under and above a plate serving as a mechanical support. It is mounted on the frame. This plate-shaped module is suitable for high concentration solution and simple structure, easy to assemble and disassemble, and only replace the flat membrane itself. The small effective membrane area makes the system bulky.

The tubular module is a device in which up to 30 tubular membranes formed in a cylindrical shape are connected to each other by being mounted in a stainless metal tube. The tubular module can be operated by simple pretreatment, and the flow velocity is increased, so that the formation of scale on the membrane surface is prevented. On the other hand, it requires more space and consumes more energy than the membrane area. Tubular modules are widely used in the food industry because of the ease of cleaning and disinfection of the system.

In the above water system, the dissolved organic substance that can just pass through the ultrafiltration unit 18 is removed in the aeration tank 14, which is a biological treatment unit, and the suspended particles having a relatively large particle are removed by the micro filter 17. Other contaminants are removed by the ultrafiltration unit 18.

Since the ultrafiltration unit 18 does not penetrate microorganisms such as bacteria, the microfiltration unit also prevents the microorganisms from flowing out together with the treated water, thereby further increasing the efficiency of the biological treatment unit. In addition, the water system using the ultrafiltration membrane can obtain a good treated water quality without significantly affecting the efficiency change of the biological treatment unit in the previous step. Therefore, the heavy water system using the ultrafiltration membrane can be said to have a stable treatment water quality and has the advantage of increasing the efficiency of the biological treatment.

However, the conventional water filtration system using the ultrafiltration membrane configured as described above simply comprises a biological treatment and the ultrafiltration membrane without considering the characteristics of raw water, so that the system complexity is required and the occupancy area is large. Had a problem. In addition, the conventional water filtration system using an ultrafiltration membrane has a problem in that maintenance and management costs are high because the micro filter for removing suspended solids must be periodically replaced.

In order to overcome such drawbacks, a process for simplifying the water treatment system by effectively constructing a biological treatment unit and an ultrafiltration device through a thorough analysis of raw water has been filed by the applicant (Korean Patent Registration No. 247380). Briefly, the process is as follows.

Here, as shown in FIG. 4, raw water passing through the immersion tank 21 and the screen tank 22 is collected in the flow regulating aeration tank 23 to remove the contaminants and sand, which is the flow regulating aeration tank 23. In the post-treatment process, the wastewater is stored so that a certain amount of water can be continuously processed, and at the same time, the microorganism contact medium 230 is filled to oxidatively decompose dissolved organic substances by the action of microorganisms. The water in which the dissolved organic matter is decomposed is passed through the pretreatment filtration device 24 by a predetermined amount through the PUMP to remove the tank and the large suspended solids, and then collect in the intermediate collection tank 25. The water in the middle sump passes through the ultrafiltration unit 26 to completely remove the suspended and colloidal material, and the treated water is stored in some backwash tanks 27 to perform a backwashing process to recover the resolution of the UF. After the rest, it is overflowed and transferred to the disinfection tank 28 to kill harmful bacteria and E. coli by chlorine compounds and reuse them as heavy water. The ultrafiltration membrane water system is relatively simple compared to the conventional water system using the ultrafiltration membrane is simply configured.

However, these compact water-based systems also have difficulties in economical system operation due to the following problems.

1) The price of ultrafiltration membranes is high and the initial investment costs are high, resulting in a long payback period.

2) The lifespan of UF Module is about 2 years.

3) When the UF Module is damaged, the water quality deteriorates rapidly and it is very difficult to find the damaged part.

4) Economic feasibility is low due to high maintenance costs such as UF replacement cost and high operating pressure.

The present invention solves problems such as the complexity of the process, difficulty in maintenance, high cost of heavy water production, etc. in constructing the water system, and the high initial investment cost of the ultrafiltration membrane type water system, UF By solving problems such as high operation cost due to module breakage and replacement, the process configuration is simple, and the initial investment cost is low, so the payback period is short, maintenance cost is low, and the cost is also economical It is to provide.

In order to achieve the above object, the present invention is composed of a series of sedimentation, screen tank, flow rate adjustment aeration tank, high rate sand filter, and disinfection tank, high rate sand filter, high rate sand filter is configured to put the chemicals for flocculation in front of the high rate sand filter It is to provide a water-based system using.

1 is an exemplary view showing the application of a general water system.

Figure 2 is a schematic diagram showing the configuration of a general water system.

Figure 3 is a schematic diagram showing the structure of the water system using a conventional ultrafiltration membrane.

Figure 4 is a schematic diagram showing a compact type ultrafiltration membrane configuration previously developed at the head office.

5 is a process flow chart of the water-based system to which the present invention is applied.

Figure 6 is a schematic diagram showing the configuration of the water supply system to which the present invention is applied

<Explanation of symbols for the main parts of the drawings>

31: Tide Tank 32: Screen Tank

33: Flow regulating aeration tank 34: High rate sand filter

35: disinfection tank 36: chemical flocculation reactor

330: microorganism contact medium 360: drug injection device

Hereinafter, with reference to the drawings according to the technical idea will be described in detail the heavy water system using the present invention high rate sand filtration method.

Figure 5 is a process flow chart of the water system to which the present invention is applied, Figure 6 is a schematic diagram showing the configuration of the water system to which the present invention is applied.

In the heavy water system using the high-rate sand filtration method of the present invention, as shown in Figure 5, in the sedimentation screening step (ST100) and the sedimentation screening step (ST100) to remove foreign substances or contaminants contained in raw water by precipitation and screening Organic matters in the flow regulating aeration step (ST200) and in the flow regulating aeration step (ST200) to reduce the inflow load of the raw water from which foreign substances have been removed and to remove the organic material by proliferating microorganisms by supplying air for microbial contact media and microbial metabolism. The flocculation step (ST300) for agglomeration of the suspended effluent suspended solids and colloidal material into a larger mass, a high rate sand filtration step (ST400) for filtering the aggregated particulate matter clean, and the sand filtration step (ST400) It consists of a disinfection step (ST500) to sterilize the harmful bacteria contained in the effluent passed by chlorine compounds.

As shown in FIG. 6, the sewage tank 31, the screen tank 32, the flow regulating aeration tank 33, the high rate sand filter 34, and the disinfection tank 35 are shown in FIG. 6. And chemical coagulation reactor 36 is to be configured in series, which will be described in more detail as follows.

The flow regulating aeration tank 33 is filled with a microorganism contact medium 330 capable of attaching and growing microorganisms to oxidatively decompose organic matters, and the drug aggregation reactor 36 bundles some dissolved substances and colloidal substances in water into large particles. Drug injection device 360 for injecting drugs to make it is mounted.

Next will be described in more detail with reference to the embodiment of the present invention configured as described above. These examples are intended to illustrate the present invention, and it is obvious to those skilled in the art that the scope of the present invention is not limited to these examples.

The immersion tank 31 and the screen tank 32 are pretreatment processes for protecting mechanical devices such as pipes and pumps in a post process, and in the immersion tank 31, the foreign matter such as sand is precipitated and removed, and the screen tank 32 is removed. Removes heavy contaminants.

The flow regulating aeration tank 33 is a device that performs the functions of the flow control tank and the aeration tank of the prior art, and stores the inflow of raw water to mitigate the load fluctuations of the influent so that effective biological treatment can be contained, and contained in the raw water By using the metabolism of the microorganisms attached to the contact medium to be consumed in the energy source for the microbial life activity or proliferation, the dissolved organic BOD as described in more detail as follows.

The flow regulating aeration tank 33 has an effective depth of 1/2 or less so as to quickly remove dissolved BOD which cannot be removed in a high-rate sand filter except for colloidal material which can be removed through cohesion and filtration in a high-rate sand filter. The microbial contact medium 330 is filled at the point and the air necessary for the microbial metabolism is aerated. At this time, the upper half or more of the flow regulating aeration tank 33 serves to adjust the flow rate, buffering unspecified raw water through variable water level fluctuations and alleviating the change in concentration, so that a certain amount is processed in a subsequent process. To do it. On the other hand, the lower side of the lower half serves as the aeration tank, which is a biological oxidative decomposition tank, wherein the air supplied to the flow regulating aeration tank performs the role of stirring the raw water and supplying the oxygen of the microorganism at the same time.

The high rate sand filter 34 and the chemical coagulation reactor 36 separate the suspended solids and colloidal substances in water from the water. The high rate sand filter 34 cannot remove the low molecular colloidal material because the filtration performance is lower than that of the original ultrafiltration membrane. However, in the present invention, the low molecular colloidal material is aggregated by using the drug agglomeration reactor 36 to encapsulate the large molecular colloidal material. By molecularization, it was configured to achieve the separation effect corresponding to the ultrafiltration membrane.

The drug agglomeration reactor 36 is equipped with a drug injection device 360 to agglomerate some dissolved matter and colloidal material in water to form a large floc, wherein the drug used to induce agglomeration reaction Examples of the flocculant include metal salts such as aluminum salts and iron salts, and poly aluminum chloride (PAC) .As a flocculation aid for agglomeration of fine flocs aggregated by a caustic soda and a flocculant into a larger mass, a polymer is used. .

Such agglomeration reactor 36 may be configured as a Line-Mixer that allows the drug to be stirred, contacted, and reacted in the pump line transferred from the flow regulating aeration tank 33 to the high rate sand filter 34, and has a constant residence time. It can also be configured to form a reaction vessel having a stirring, contact, reaction.

The sterilization tank 35 sterilizes harmful bacteria and E. coli groups by administering a chlorine compound of liquid, powder, or tablet to the effluent passing through the high rate sand filter 34, wherein the contact time in the sterilization tank 35 is It should be at least 15 minutes, and the residual chlorine in the effluent discharged after disinfection should be at least 0.5 mg / L.

Looking at the overall water system of the present invention as described above, the dissolved organic matter is removed in the flow control aeration tank 33, the relatively large suspended solids are removed in the high rate sand filter 34, the other contaminants through the chemical flocculation It can be summed up as being removed in high rate sand filter 34 after the macromolecularization.

The following table 1 shows the results of testing the water quality of raw water of 'L' department store heavy water treatment plant in Bucheon, Gyeonggi-do and the treated water of high rate sand filtration and coagulation high rate sand filtration directly without biological treatment.

Water Quality Changes of Influent Water and High-Rate Sand Filtration in Heavy Water Pause division BOD SS enemy High Rate Sand Filtration Cohesive, high rate sand filtration enemy High Rate Sand Filtration Cohesive, high rate sand filtration '98. August maximum 134.6 81.6 26.8 172.2 68.4 5.2 lowest 42.5 24.4 12.2 101.7 38.9 1.0 Average 80.6 46.4 22.7 142.7 49.4 2.3 September maximum 152.6 92.6 31.9 186.7 70.4 4.6 lowest 66.3 31.6 14.8 111.7 39.5 0.2 Average 102.2 54.7 25.7 158.4 50.6 1.1 October maximum 98.7 58.5 24.3 169.6 52.8 7.1 lowest 52.9 32.1 11.3 89.4 33.7 0.8 Average 68.0 40.3 19.2 121.2 40.8 3.4 November maximum 99.8 58.9 20.6 153.8 54.7 6.7 lowest 33.4 20.8 8.2 66.2 22.5 1.2 Average 62.3 35.0 16.2 104.7 31.7 2.5 December maximum 145.5 74.2 29.9 166.5 58.4 4.9 lowest 76.1 41.1 21.6 127.4 42.5 0.4 Average 89.6 52.5 25.4 139.5 43.4 2.2

When coagulating raw water and high rate sand filtration, as shown in Table 1, SS (Suspended Solid) is almost completely removed, whereas dissolved BOD (Biochemical Oxygen Demand) is It slightly exceeds the water quality standard of 10 ppm. Therefore, once the process of removing the dissolved BOD to below the appropriate value in advance as in the present invention, it is possible to maintain the required water quality as a heavy water.

In the case of the general biological treatment, as shown in FIG. 3, the flow control tank 13 is provided at the front end of the system in order to minimize the flow rate, the inflow concentration, and the load fluctuation of the aeration tank 14, which is a microbial reaction tank, and settles at the bottom thereof. And aeration for stirring to prevent rot. At this time, the aeration performed in the flow adjustment tank is not intended for oxygen supply for the microorganisms, but is simply used for stirring.

In the case of the present invention, as shown in Table 1, since the dissolved BOD concentration of the incoming heavy water is relatively low, and the dissolved BOD is rapidly decomposed in the flow regulating aeration tank 33 which is a biological treatment part, The biodegradation function was added to the flow control tank 13 to allow the air supplied for stirring to be used together for microbial decomposition.

The water treatment method as described above is enabled by the chemical coagulation reactor 36 and high-rate sand filter 34 provided at the rear end to effectively remove the contaminants or more than the colloid material to produce a constant treatment water, which is the aggregation It can be said that the flow rate adjusting aeration tank 33, which is a biological treatment part, is optimized in accordance with the separation characteristics of the high-rate sand filter 34. In conclusion, the microbial contact medium is filled in the lower portion of the flow regulating aeration tank 33 and the microorganisms are attached to the contact medium to perform the biological treatment for the optimization of the biological treatment part. The removal can be done at the same time.

Table 2 shows the results of the effect test of the present invention water system.

Effect test result of the present invention water system Pause division BOD SS enemy Treated water enemy Treated water '99. February maximum 100.4 6.2 158.7 4.2 lowest 32.7 1.3 68.6 0.2 Average 66.5 2.2 100.7 1.2 In March maximum 132.4 8.2 162.3 5.3 lowest 75.8 2.7 128.2 0.6 Average 94.5 5.4 142.6 1.5 April maximum 126.5 6.8 159.8 3.2 lowest 51.3 1.5 90.9 0.7 Average 72.4 3.8 111.4 2.1 In May maximum 142.6 7.9 184.5 4.8 lowest 62.3 1.6 99.3 0.3 Average 97.5 4.8 124.7 2.8

The high-rate sand filter 34 used in the present invention is a continuous fluidized-bed sand filter which is a device in which filtration of contaminants and washing of sand, which is a filter medium, are carried out simultaneously.

Conventional sand filter is described as a pressure filter as follows. Fill the pressure vessel with sand, which is a filter material, and filter the raw water by injecting it with a pump. As contaminants accumulate on the surface and inside of the packed sand, water permeation resistance is generated, thereby increasing the filtration pressure. When the filtration pressure is above a certain pressure, backwashing is performed. Water is injected in the direction opposite to the filtration direction to separate and discharge contaminants.

This pressure sand filter has the following problems.

First, the treatment result is unstable because the treatment efficiency varies depending on the degree of contamination of the filter media, cleaning time, and cycle.

Second, since backwashing is incomplete, foreign substances are not removed smoothly, and as the use time increases, the filter medium is gradually contaminated, causing a closing phenomenon.

Third, when the water flow is biased to one side due to the partial closure of the filter medium, the water load is increased and the removal efficiency is lowered.

Fourth, there is a risk of damage to the filter medium due to pressure, closure due to contamination, etc., and the filter medium should be replaced frequently during long-term operation.

On the contrary, the high rate sand filter 34 used in the present invention is a sand filter that solves the problems of the conventional pressure filter, and includes a sand filtration layer, a sand transport device, a washing device, and a refilling device inside the filter. Is provided. At the same time the filtration occurs in the sand filtration layer at the same time the contaminated sand is transported by the sand transfer device is washed and refilled by the washing device, which will be described in detail as follows.

A certain amount of sand is provided as a filtration layer inside the filter, and the filter media layer gradually moves downward in the process of filtration. The lower part of the filter is formed in a cone type so that the sand is collected in one place. The contaminated sand collected by the filtration is transferred to the washing device located at the upper part of the filter by the sand transport device. In the washing apparatus, the sand is washed, the washed sand is transferred to the upper part of the filtration layer through the refilling apparatus, and the washed dirty water is discharged through the drain port. As such, the washing process is continuously performed simultaneously with the filtration process.

High rate sand filter 34 is divided into upflow and downflow according to the direction of injection and filtration of raw water, the upflow is filtration in the process of the raw water flows through the sand layer to the top through the bottom of the filter, downward On the contrary, filtration is performed while raw water is transferred to the upper part of the filter and passed through the sand filtration layer to the lower part.

As described above, since the processes of filtration and washing are continuously performed at the same time, the pollution degree of the sand layer is maintained at a constant level, and the washing efficiency of the filter medium is excellent, and thus, the problem of the conventional pressure sand filter can be solved. Therefore, the method of direct filtering without sedimentation tank after chemical coagulation, which failed or did not attempt in the conventional pressure filter, caused many problems, can be applied without problems in this high-rate sand filter.

Table 3, which is shown next, shows a comparison of the treated water quality of the present invention with the Japan's water quality standards (water level utilization survey for housing complexes, Japan, 1972).

The treated water of the present invention, as shown in Table 3, is very suitable as water, the present invention can significantly reduce the facility cost and maintenance costs compared to the conventional water system, because the following Same as

First, the size of the facility was reduced by about 40% by impregnating the flow regulating tank 3 and the aeration tank 4, which are biological treatments of the conventional water supply system, into the flow regulating aeration tank 33, which is one reaction tank.

Second, in the conventional water supply system, the air is supplied to the flow regulating tank 3 for agitation and the aeration tank 4 is supplied with separate air for the treatment of microorganisms, whereas the present invention provides aeration in one process, that is, in the flow regulating aeration tank. By carrying out the aeration for the control of the flow rate and uniformity of the load and the aeration for the decomposition of microorganisms at once, the capacity of the blower, the air supply pump, is reduced by half, thus reducing the initial investment and maintenance costs.

Third, the ultrafiltration membrane for precision separation is largely dependent on imports, and since the cost of the filtration membrane itself is high, the initial cost and the replacement cost are high, but the high rate continuous sand filter 34 of the present invention is used semi-permanently and is also inexpensive. Do.

Fourth, there is no sedimentation tank according to the inherent separation characteristics of the flocculation and high rate sand filter 34, and the operation and management of the biological treatment part for the purpose of removing the dissolved BOD is very easy, and thus, the active agent, the spawning agent, the bulking inhibitor, etc. There is no cost.

As the present invention has been completed as described above, a heavy water system having a simple configuration and a large effect and high practical applicability can be provided.

In the water-based water system using the high-rate sand filtration method of the present invention, by unifying the flow control tank and the aeration tank into the flow control aeration tank, the configuration of the water supply system can be simplified to reduce the required area and facility cost of the system required for installation, and semi-permanently. The use of available high-rate sand filters for the removal of suspended solids from raw water discharged from the flow-controlled aeration tanks has resulted in cost savings for the maintenance and management of the system.

By completing the water supply system of the present invention and by reusing the water, it is possible to significantly reduce the demand of water supply, thereby creating economic benefits to the demand destinations of apartments, buildings, hotels, hospitals, etc., and furthermore, reducing national pollution by reducing water pollution. It is possible to play a part in improving the environment.

Claims (7)

delete In the deuterium device, A sedimentation tank 31 and a screen tank 32 for removing impurities and sand contained in raw water; In order to mitigate contaminant load fluctuations, the raw water flowing from the sedimentation tank 31 and the screen tank 32 is stored so that effective biological treatment can be carried out, and the dissolved BOD contained in the raw water using the metabolism of microorganisms. As to remove, the upper side is more than 1/2 is to perform the flow adjustment role, the effective depth 1/2 or less lower side is filled with the microbial contact medium 330, the stirring is carried out and the air flow for the microbial metabolism aeration Adjusting aeration tank 33; A chemical agglomeration reactor (36) for injecting a chemical into the effluent flowing out of the flow regulating aeration tank to aggregate contaminants of colloidal substances other than dissolved organic substances into large chunks; A high rate sand filter 34 for filtering the aggregated particulate matter; And a disinfection tank (35) for sterilizing bacteria contained in the effluent flowing out of the high rate sand filter (34). delete delete delete The method of claim 2, Chemical agglomeration reactor 36 is a water-line device, characterized in that the Line-Mixer that allows the drug to be stirred, contacted, and reacted in the pump line transferred from the flow rate adjustment aeration tank (33) to high-rate sand filter (34). The method of claim 2, High rate sand filter is equipped with sand filter layer, sand conveying device, washing device, and refilling device inside the filter to continuously filter the sand in the sand filter layer, while contaminated sand is transferred to the upper part by sand conveying device. And a continuous fluidized bed high rate sand filter, being washed and refilled by the washing device.