KR100767717B1 - Bio-film filtration using dual perforated plates and compressible synthetic media for secondary effluent reclamation system - Google Patents

Abstract

A bio-film consolidation filtering apparatus and a system for reusing discharged water using the same are provided to remove effectively a material for increasing BOD(Biochemical Oxygen Demand) and turbidity from discharged water or sewage in a sewage treatment plant. A filtering bath(101) has a closed type predetermined space. A fixing penetration plate(102) is formed within the filtering bath such that the fixing penetration plate is closely fixed to an inside wall of the filtering bath. An upper sealing porous plate(103) and a lower sealing porous plate(104) are sequentially positioned above the fixing penetration plate. The upper sealing porous plate and the lower sealing porous plate is closely attached to the inside wall of the filtering bath such that the sealing porous plates are movable upwardly and downwardly. An upper driving shaft and a lower driving shaft are respectively connected to the upper and lower sealing porous plates to move the upper and lower sealing porous plates independently. A space between an upper sealing porous plate and a lower sealing porous plate is filled with an upper filtering layer(120). A space between the lower sealing porous plate and the fixing penetration plate is filled with a lower filtering layer(130).

Description

Bio-film filtration using dual perforated plates and compressible synthetic media for secondary effluent reclamation system

1 is a perspective view of a biofilm consolidation filtration device according to the present invention.

Figure 2 is a front view of the biofilm consolidation filtration device according to the present invention.

Figure 3a to 3c is a reference diagram for explaining the operation of the biofilm consolidation filtration device according to the present invention.

Figure 4 is a block diagram of a effluent reuse system applying the biofilm consolidation filtration device of the present invention.

5a to 5c are graphs showing the amount of BOD, turbidity and suspended solids of sewage treatment plant effluent before and after treatment through the biofilm consolidation filtration device according to the present invention, respectively.

Figure 6 is a photograph showing the actual substance of the sponge-like resin corresponding to the media of the present invention.

Description of the main parts of the drawing

101: filtration tank 102: fixed through plate

103: upper contact sheet 104: lower contact sheet

105: drive shaft 106: hydraulic cylinder

107: guide shaft 108: effluent supply pipe

109: filtered water discharge pipe 110: impurity discharge pipe

111: air pump 112: diffuser

113: hydraulic system 114: pressure gauge

120: upper filter layer 130: lower filter layer

140: The Media

The present invention relates to a biofilm consolidation filtration device and a effluent reuse system using the same, and more particularly, to biofilm consolidation filtration that can effectively remove biochemical oxygen demand (BOD) and turbidity-inducing substances contained in the effluent or wastewater of a sewage treatment plant. An apparatus and a effluent reuse system using the same.

Sewage treatment aims at the removal of contaminants contained in sewage and is classified into primary treatment, secondary treatment and tertiary treatment according to the treatment method. Primary treatment is a method of physically removing suspended substances or sensitizing substances in sewage, which uses gravity sedimentation and flotation, and usually includes processes from sewage treatment plants to the initial settling basin. Secondary treatment is mainly used for biological treatment for the purpose of removing organic matter dissolved in sewage and organic solids not treated in the first treatment. Tertiary treatment is a highly advanced process that combines physical, chemical, and biological treatments to remove nutrients such as nitrogen and phosphorus in addition to low biodegradable organics that are not removed in secondary treatment.

Normally, the discharged water discharged from the sewage treatment plant has gone through the secondary treatment, and as of the end of 2003, the secondary treated water discharged from 184 domestic sewage treatment plants amounts to about 1.8 billion tons per day, reaching 6.6 billion tons per year. The penetration rate is expected to reach 81% in 2015 (based on Ministry of Environment 2005 data). However, the secondary treated water recycled out of the discharged secondary treated water is about 158 million tons, which is only 2.4% reuse. Increasing the reuse rate of the secondary treated water to 5% has the effect of securing a dam of about 300 million tons effective capacity. Accordingly, various efforts are being made to reuse secondary treatment water in sewage treatment plants.

Reuse of secondary treated water includes washing water, sprinkling water, landscaping water, river maintenance water, agricultural water and cooling water. The treatment criteria of the tertiary treatment process in which the secondary treated water is reused are somewhat different depending on the use. For example, when used as sprinkling water or landscaping water, no chromatic treatment is required, while for washing water the chromaticity should not exceed 20 degrees.

On the other hand, the method of performing the three-treatment process includes advanced oxidation method, coagulation sedimentation method, rapid filtration method, activated carbon adsorption method, chlorine treatment method, reverse osmosis method, membrane separation method and the like. In the western United States, where there are many cases of reuse of secondary treatment water in sewage treatment plants, it is filtered by coagulation sedimentation or filtration to remove turbidity and suspension of secondary treatment water and to enhance the disinfection and oxidation effects. Many methods have been applied. However, in case of flocculation, there is a disadvantage in that additional sludge occurs, and in the case of filtration, it is difficult to cope with clogging due to algae growth in a secondary settling tank due to nitrogen and phosphorus in the treated water during summer. In particular, domestic sewage treatment plants are treated with high sewage treatment as of 2003, and the discharged water is about 17%, and there is a problem that clogging of the filtration device due to scum, micro flocs, and algae growth is difficult when skilled man is lacking. have.

In case of disinfecting secondary treatment water with chlorine, disinfection by-products such as THM (Tri halo methan) are generated to contaminate the water source. Therefore, even chlorine disinfection devices installed in sewage treatment plants are not used. Is the reality. In addition, in the case of selecting a disinfection method by chlorine treatment, there is a disadvantage that a countermeasure should be taken by installing a dechlorination facility that can solve the THM problem. Recently, UV disinfection methods have been proposed to solve the problems with the disinfection byproducts, and disinfection by UV does not cause problems with disinfection byproducts and adopts the treatment plant capacity according to the design factor among the contact method and the non-contact method. City facility costs and management costs can be reduced.

Meanwhile, technologies such as activated carbon, reverse osmosis, and membrane separation methods have been commercialized due to high processing efficiency, but have high installation and maintenance costs.

The present invention has been made to solve the above problems, a biofilm consolidation filtration device that can effectively remove the biochemical oxygen demand (BOD) and turbidity-inducing substances contained in the effluent or waste water of the sewage treatment plant and reused effluent using the same The purpose is to provide a system.

Biomembrane consolidation filtration device according to the present invention for achieving the above object is a filtration tank having a predetermined space of a closed type, and a fixed through-hole plate provided at the lower end in the filtration tank, in close contact and fixed to the inner wall of the filtration tank, the fixed through plate It is sequentially provided at a position spaced apart from the upper by a predetermined distance, the upper contact plate and the lower contact plate and the lower contact plate, which is in close contact with the inner wall of the filtration tank is movable up and down, and connected to one side of the upper and lower contact plate, respectively, The upper drive layer and the lower drive shaft, which independently perform the vertical movement of the upper and lower contact plates, and the upper media layer filled in the space between the upper contact plate and the lower contact plate, and the lower contact plate. It characterized in that it comprises a lower media layer is filled in the space between the through plate.

Preferably, the fixed through-hole plate, the upper and lower close contact plate is formed with a hole at a predetermined interval each has a mesh form.

Preferably, the upper and lower media layers are each composed of a plurality of media pieces, the media pieces are made of a sponge-like resin.

Preferably, the sponge-like resin includes polyurethane.

Preferably, it further comprises a diffuser connected to one side of the filtration tank for supplying air into the filtration tank, and an air pump for supplying air having a predetermined pressure to the diffuser.

Preferably, a discharge water supply pipe provided on one side of the filtration tank for supplying effluent water into the filtration tank, a filtration water discharge pipe provided on one side of the filtration tank for discharging the treated water filtered through the filtration tank, and provided on one side of the filtration tank It further comprises an impurity discharge pipe for discharging the impurities therein.

Preferably, the fixed through plate, the upper and lower close contact plate is composed of a metal lath.

Preferably, it penetrates through a predetermined portion of the upper and lower close contact plate, one end is fixed to the upper end of the filter tank and the other end is fixed to the fixed through plate to guide the vertical movement of the upper and lower close contact plate It further comprises a guide shaft.

The effluent recycling system using the biofilm consolidation filtration device according to the present invention includes a biofilm consolidation filtration device, a flow rate adjusting tank which is provided at the front of the biofilm consolidation filtration device, and supplies effluent water to the biofilm consolidation filtration device, and the biofilm consolidation filtration device. It characterized in that it comprises an ultraviolet disinfection device for disinfecting by irradiating ultraviolet light to the effluent filtered through.

According to a feature of the present invention, in the biofilm consolidation filtration apparatus, the upper and lower media layers having different porosities according to the strength of consolidation in the filtration tank and the upper and lower media layers are composed of a plurality of media pieces, the upper and lower parts. The ability to independently vary the porosity of the media layer allows for effective biological and physical removal in one filtration unit of BOD, suspended matter and turbidity material contained in the effluent, as well as high filtration as it maintains high porosity. Throughput can be secured. In addition, it is possible to maximize the ultraviolet irradiation efficiency of the ultraviolet disinfection device by configuring the effluent reuse system to add the ultraviolet disinfection device to the biofilm consolidation filtration device.

Hereinafter, a biofilm consolidation filtration device and a effluent reuse system using the same will be described in detail with reference to the accompanying drawings. 1 is a perspective view of a biofilm consolidation filtration device according to the present invention, Figure 2 is a front view of a biofilm consolidation filtration device according to the present invention.

1 and 2, the biofilm consolidation filtration device 100 according to the present invention first includes a filtration tank 101 having a predetermined filtration space therein. Three plates are provided inside the filtration tank 101, and the three plates are in close contact with the inner wall of the filtration tank 101. Specifically, the three plates refer to the fixed through plate 102, the upper close contact plate 103, and the lower close contact plate 104. The fixed through plate 102 is installed in a fixed state at the lower end of the filtration tank 101 and the upper and lower tightly perforated plates 103 and 104 at a position spaced a predetermined distance upward from the fixed through plate 102. ) Are provided sequentially.

The upper and lower tight contact plates 103 and 104 are designed to selectively move up and down within the filtration tank 101, unlike the fixed through plate 102. Up and down movement of the upper and lower close contact plates 103 and 104 may be performed by driving means provided on each side of the upper and lower close contact plates 103 and 104. Specifically, the drive shaft 105 is connected and fixed to one side of each of the upper and lower close contact plate 103, 104 and the drive shaft 105 is to receive the driving force by the hydraulic cylinder 106, etc. In addition, the upper and lower close contact plates 103 and 104 can be selectively moved up and down. On the other hand, the guide shaft 107 may be provided for smooth up and down movement of the upper and lower contact plate (103, 104). The guide shaft 107 is provided to pass through a predetermined portion of the upper and lower close contact plate 103, 104, one end is fixed to the upper end of the filter tank 101 and the other end is the fixed through plate 102 It is fixed to). The guide shaft 107 may be provided with one or more, and as the guide shaft 107 is provided, it is possible to prevent the occurrence of bending during the vertical movement of the upper and lower contact plate (103, 104). .

The fixed through-hole plate 102, the upper and lower close contact plate 103, 104 is formed with a plurality of holes at regular intervals to have a mesh form, the preferred size of the hole is about 3 to 10mm. Metal lath and the like may be cited as the specific means for implementing the fixed through plate 102 and the upper and lower close contact plates 103 and 104.

On the other hand, in the space between the upper contact plate 103 and the lower contact plate 104 and between the lower contact plate 104 and the fixed through-hole plate 102, the upper media layer 120 and the lower media layer, respectively 130 is provided. The upper and lower media layers 120 and 130 are composed of a plurality of media pieces 140 having a predetermined unit size, and the media may include a sponge-like resin such as polyurethane (see FIG. 6). ). Moreover, the preferable size of the said media piece is about 12-18 mm in height, 12-18 mm in length, and about 12-18 mm in width.

Preferably, the upper medial layer 120 and the lower medial layer 130 have different porosities. Specifically, the porosity of the upper media layer 120 is preferably smaller than the porosity of the lower media layer 130. For reference, the porosity refers to the porosity when the media layer is consolidated by the fixed through-hole plate 102, the upper and lower tightly perforated plate 103, 104, as shown in FIG. As described above, since the upper piece layer 120 and the lower piece layer constituting the lower filter layer 130 are the same, the porosity of the upper filter layer 120 and the lower filter layer 130 is higher than the upper filter layer 120. Affected by the degree of consolidation of the lower contact plate (103, 104).

That is, the porosity of the upper and lower media layers 120 and 130 may be selectively adjusted by the consolidation ratios of the upper and lower tighter porous plates 103 and 104. For reference, in the conventional method of using a composite filter medium, for example, in the case of using a sand and anthracite (anthracite) as the filter medium can not control the porosity of each filter medium in the present invention, the upper and lower media layers 120 The porosity of 130 may be adjusted independently.

Reasons for setting the porosity of the upper medial layer 120 to be smaller than the porosity of the lower medial layer 130 In other words, the consolidation ratio of the upper medial layer 120 is lower than that of the lower medial layer 130. The reason for setting larger than the consolidation rate is as follows.

In the filtration tank 101 operated in an upflow, the lower media layer 130 plays a role of biodegradation and the upper media layer 120 performs a physical filtration role. In order for the lower medial layer 130 to perform a biodegradation role, microorganisms must form and grow a biofilm on the medial piece of the lower medial layer 130, and for this purpose, the porosity between medial pieces must be relatively large. On the other hand, in order for the upper filter layer 120 to perform a physical filtration role, the accumulation rate of suspended matter and turbidity-inducing material must be increased. For this purpose, the porosity between the filter pieces must be relatively small.

In addition, as the upper and lower media layers 120 and 130 having different porosities, large particles are first deposited on the lower media pieces and then small particles are deposited on the upper media pieces during filtration by the operation of upflow. This prevents the disadvantage that the upper or lower media layer 130 is easily clogged.

On the other hand, one side of the filtration tank 101, the effluent water supply pipe 108 for supplying effluent water into the filtration tank 101, the filtration water discharge pipe 109 for discharging the treated water filtered through the filtration tank 101, the filtration tank 101 The impurity discharge pipe 110 for discharging the impurities therein is further provided. One side of the discharge water supply pipe 108 may be provided with a flow meter 113 and a pressure gauge 114 for adjusting the flow rate and pressure of the discharge water supplied into the filtration tank 101, respectively. In addition, one side of the filtered water discharge pipe 109 may be provided with a turbidimeter (not shown) that can measure the turbidity of the filtered water. On the other hand, as the biofilm consolidation filtration device of the present invention adopts an upflow type, the effluent water supply pipe 108 is preferably provided below the filtration tank 101, and the filtration water discharge pipe 109 is provided above the filtration tank 101. , The impurity discharge pipe 110 is preferably installed at the top, middle and bottom of the filtration tank 101.

One side of the filtration tank 101 is provided with an air pump 111, the air pump 111 is the diffuser pipe 112 and so that the substances adsorbed on the filter medium during the cleaning of the filtration tank 101 is easily removable It serves to inject air into the filtration tank 101 through the acid pores (112a). On the other hand, although not shown in the drawings, the biofilm consolidation filtration apparatus of the present invention may be further provided with a chemical injection tank to enable coagulation filtration.

Looking at the operating principle of the biofilm consolidation filtration device according to the present invention configured as described above are as follows. The operation of the biofilm consolidation filtration apparatus of the present invention can be largely divided into filtration, aeration, washing, and polishing steps. 3A to 3C are reference diagrams for explaining the operation of the biofilm consolidation filtration apparatus according to the present invention.

First, in the filtration step, the discharged water, that is, the secondary treated water is supplied to the inside of the filtration tank 101 through the discharge water supply pipe 108, and the BOD and turbidity substances contained in the secondary treated water are filtered. As described above, the lower tighter perforated plate 104 is consolidated toward the fixed through plate 102, and the upper tighter perforated plate 103 is compacted toward the lower tighter perforated plate 104. In addition, the porosity of the upper filter layer 120 and the lower filter layer 130 may be set differently according to the degree of consolidation of the upper and lower tight porous plates 103 and 104. Preferably, the porosity of the upper media layer 120 is set to be smaller than the porosity of the lower media layer 130.

Consolidation of the upper and lower contact plate (103, 104) is experimentally possible, consolidation up to 10-90% compared to the normal state, even when the consolidation of more than 30% can effectively remove the suspended matter and turbidity material filtration tank ( The problem of an increase in the pressure in 101 occurs, so it is desirable to maintain it within a consolidation rate of 30% or less.

Meanwhile, when the effluent is supplied into the filtration tank 101 through the effluent supply pipe 108, the effluent water passes through the upper and lower media layers 120 and 130 in a consolidated state. Is decomposed through a biological mechanism in the lower media layer 130, and suspended matter and turbidity materials are adsorbed on the media pieces of the upper media layer 120. Filtrate, from which BOD-induced organic matter, suspended matter and turbidity material have been removed, is discharged through the filtrate discharge pipe 109 to complete a series of filtration processes. At this time, the turbidity of the filtered water is periodically checked through a turbidimeter provided in the filtered water discharge pipe 109 to adjust the consolidation ratio of the upper media layer 120 according to the turbidity.

As described above, the biofilm consolidation filtration device of the present invention can realize high porosity using a sponge-like resin as the filter material, so that the filtration throughput is much higher than that of the conventional filtration device. The porosity of the conventional filtration and anthracite coal is about 40 to 46% and 50 to 56%, respectively, and the difference in the filtration throughput through the biofilm consolidation filtration device and the conventional filtration device of the present invention is shown in Table 1 below. .

sand hard coal Sand + anthracite Biofilm Consolidation Filter Filtration throughput (L / m ² · min) 120 160 80-400 800

In addition, the amount of BOD, turbidity, and suspended solids of the filtrate filtered through the biofilm consolidation filtration apparatus of the present invention is maintained at a significantly low level as shown in Table 2 below.

BOD (mg / L) Turbidity (NTU) Suspended solids (mg / L) Initial effluent 13 0.79 4.16 Filtrate according to the present invention 3 0.29 0.78 Processing efficiency (%) 77 64 81

In addition, the amount of BOD, turbidity, and suspended solids in the sewage treatment plant treated by 72 hours of continuous operation using the biofilm consolidation filtration apparatus of the present invention shows a constant treatment efficiency as shown in FIGS. 5A to 5C.

On the other hand, the aeration and washing step to remove the substances adsorbed on the filter medium in a state of complete filtration process is carried out. In the aeration and washing step, as shown in FIG. 3B, the consolidation state of the upper and lower tight porous plates 103 and 104 that have been consolidated for filtration is released. In addition, the filtered water discharge pipe 109 should be locked and the impurity discharge pipe 110 should be opened. In this state, the washing water is supplied into the filtration tank 101 through the discharge water supply pipe 108 and at the same time, through the diffuser 112 and the acid pores 112a using the air pump 111. Air is supplied into the filtration tank 101. As air is injected into the washing water, the mobility of the washing water is increased to accelerate the desorption of substances adsorbed on the media piece.

On the other hand, the number of cleaning of the upper filter layer 120 and the lower filter layer 130 in the aeration and cleaning step is applied differently. In the case of the lower filter layer 130, since a predetermined residence time for growing microorganisms is required for forming the biofilm on the filter piece, it is preferable to apply the number of cleaning operations relatively less than the upper filter layer 120. Although the number of cleaning of the lower filter layer 130 is relatively less than the number of cleaning of the upper filter layer 120, since the consolidation ratio of the lower filter layer 130 is relatively small, there is a small possibility of clogging. Accordingly, the pressure inside the filtration tank 101 is kept constant.

When the aeration and cleaning steps are completed, a polishing step is performed. In the polishing step (see FIG. 3C), the upper and lower tight porous plates 103 and 104 are consolidated as in the filtration step. Accordingly, impurities desorbed from the filter medium are suspended above the filter tank 101 and finally discharged through the impurity discharge pipe 110. After the polishing step is completed, the filtration step is performed again.

Meanwhile, as described in the object of the present invention, the biofilm consolidation filtration apparatus according to the present invention is an apparatus used to effectively remove BOD and turbidity-causing substances contained in sewage treatment plant effluent, that is, secondary treated water, and the biofilm of the present invention. The consolidation filtration device may be included in a tertiary treatment system, ie, effluent reuse system, to maximize its efficiency. Referring to the effluent reuse system using the biofilm consolidation filtration device of the present invention.

As shown in FIG. 4, the effluent recycling system according to the present invention is largely composed of a flow control tank 301, a biofilm consolidation filtration device 100, and an ultraviolet disinfection device 302. In the conventional case, only the ultraviolet disinfection device 302 was configured as the discharge water reuse system alone to perform the third treatment for the discharged water, but when BOD and turbidity material are excessively contained in the discharged water, there is a problem in that ultraviolet irradiation efficiency is lowered.

The effluent recycling system of the present invention passes the biofilm consolidation filtration device of the present invention prior to introducing the effluent to the ultraviolet disinfection device 302 to minimize the suspended substances and turbidity substances contained in the effluent. UV radiation efficiency can be maximized.

In addition, in the effluent reuse system of the present invention, by providing the flow rate adjusting tank 301, the effluent retention time in the biofilm consolidation filtration device and the ultraviolet disinfection device 302 can be adjusted according to the coliform, odor and chromaticity of the effluent. do.

The effluent reuse system according to the present invention can remove BOD through biodegradation using a biofilm, in addition to the function of removing suspended solids and turbidity substances, which are functions of the existing tertiary treatment apparatus.

Biofilm consolidation filtration device and effluent reuse system using the same according to the present invention has the following effects.

In the biofilm consolidation filtration apparatus, the porosity of the upper and lower media layers is independently provided by providing upper and lower media layers having different porosities according to the strength of consolidation in the filter tank, and having the upper and lower media layers composed of a plurality of media pieces. The variability enables effective biological and physical removal in one filtration device of BOD, suspended matter and turbidity material contained in the effluent, as well as ensuring high filtration throughput as it maintains high porosity. In addition, it is possible to maximize the ultraviolet irradiation efficiency of the ultraviolet disinfection device by configuring the effluent reuse system to add the ultraviolet disinfection device to the biofilm consolidation filtration device.

In addition, the biofilm consolidation filtration device of the present invention has excellent effluent treatment capacity per unit area compared to a conventional filtration device, which can be miniaturized and minimizes the land use area, and maintains costs such as activated carbon adsorption, reverse osmosis, and membrane separation. And unlike the expensive installation process, the maintenance is easy and the economy is excellent.

In addition, BOD can be removed through biodegradation and suspended matter and turbidity can be removed through a physical mechanism in one filtration device, and thus the contaminant removal range is wider than existing methods, and the system configuration is very efficient.

Claims (9)

A filtration tank having a predetermined space of a closed type; A fixed through plate provided at a lower end of the filtration tank and tightly fixed to the inner wall of the filtration tank; An upper contact porous plate and a lower contact porous plate which are sequentially provided at positions spaced a predetermined distance upward from the fixed through plate, and which are in close contact with the inner wall of the filtration tank and move up and down; An upper drive shaft and a lower drive shaft connected to one side of each of the upper and lower close contact plates to independently perform vertical movement of the upper and lower close contact plates; An upper media layer filled in a space between the upper and lower contact porous plates; It comprises a lower filter layer which is filled in the space between the lower contact plate and the fixed through plate, The upper and lower media layers are biofilm consolidation filtration device, characterized in that composed of a plurality of media pieces of sponge-like resin each having the same size. The biofilm consolidation filtration apparatus according to claim 1, wherein the fixed through plate, the upper and lower close contact porous plates each have a hole at a predetermined interval to form a mesh. delete The biofilm consolidation filtration device according to claim 1, wherein the sponge-like resin comprises polyurethane. According to claim 1, characterized in that it further comprises a diffuser connected to one side of the filtration tank for supplying air into the filtration tank, and an air pump for supplying air having a predetermined pressure to the diffuser pipe Biofilm Consolidation Filter. The method of claim 1, A discharge water supply pipe provided on one side of the filtration tank and supplying effluent water into the filtration tank; A filtered water discharge pipe provided at one side of the filtration tank and discharging the treated water filtered through the filtration tank; The biofilm consolidation filtration device provided on one side of the filtration tank further comprises an impurity discharge pipe for discharging the impurities in the filtration tank. 2. The biofilm consolidation filtration apparatus according to claim 1, wherein the fixed through plate, the upper and lower close contact plates are made of metal lath. According to claim 1, It penetrates through the predetermined portion of the upper and lower close contact plate, one end is fixed to the upper end of the filter tank and the other end is fixed to the fixed through plate to move the vertical movement of the upper and lower close contact plate Biofilm consolidation filtration device further comprising a guide shaft for guiding. Biofilm consolidation filtration device of claim 1; A flow rate adjustment tank provided at a front end of the biofilm consolidation filtration device to supply effluent water to the biofilm consolidation filtration device; A effluent reuse system using a biofilm consolidation filtration device, comprising an ultraviolet disinfection device for disinfecting the effluent filtered through the biofilm consolidation filtration device.

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