WO2007136160A1

WO2007136160A1 - Bio-film filtration using dual perforated plates and compressible synthetic media for secondary effluent reclamation system

Info

Publication number: WO2007136160A1
Application number: PCT/KR2006/005384
Authority: WO
Inventors: Sung Kyu Maeng; Kyu Hong Ahn; Kyung Guen Song
Original assignee: Halla Energy & Environment; Korea Institute of Science and Technology KIST
Current assignee: Halla Energy & Environment; Korea Institute of Science and Technology KIST
Priority date: 2006-05-19
Filing date: 2006-12-11
Publication date: 2007-11-29
Anticipated expiration: 2008-11-19
Also published as: KR100767717B1

Abstract

Disclosed is a bio-film compressible filtration apparatus comprising a filtration tank, a fixed perforated plate, upper and lower porous plates, upper and lower driving shafts, an upper filtering media layer and a lower filtering media layer. According to the invention, it is possible to effectively remove BOD (biochemical oxygen demand) and turbidity inducing materials contained in the effluent and sewage of a sewage treatment plant.

Description

[DESCRIPTION]

[Invention Title]

BIO-FILM FILTRATION USING DUAL PERFORATED PLATES AND COMPRESSIBLE SYNTHETIC MEDIA FOR SECONDARY EFFLUENT RECLAMATION SYSTEM

[Technical Field]

The invention relates to a bio-film compressible filtration apparatus, and more particularly, to a bio-film compressible filtration apparatus and an effluent reclamation system using the same wherein it is possible to effectively remove BOD (biochemical oxygen demand) and turbidity inducing materials contained in the effluent and sewage of a sewage treatment plant.

[Background Art]

A sewage treatment is to remove the contaminants contained in the sewage and is classified into primary, secondary and tertiary treatments depending on the treatment manners thereof. The primary treatment is a method that physically removes suspended solids or sedimentary materials in the sewage. Gravity settling and floatation facilities are used for the treatment and such process from the sewage treatment plant to the first sedimentation location generally corresponds to the treatment. The secondary treatment is to remove the organic materials dissolved in the sewage and the organic solids that are not processed in the primary treatment. A biological process is mainly used. The tertiary treatment is an advanced treatment process of combining the physical, chemical and biological processes to remove nutrient substances such as nitrogen and phosphorus, in addition to the organics having the low biological degradability, which are not removed in the secondary treatment.

Typically, the effluent discharged from the sewage treatment plant is referred to as the water that has passed to the secondary treatment. In case of Korea, on 2003-year end basis, the secondary treated water, which is discharged from the domestic 184 sewage treatment plants, is about average 1.8 ten million tons per day, which means 66 hundred million tons per year. It is expected that the spread percentage of the sewerage will be 81% in 2015 (on a 2005-year material basis of the ministry of environment). However, the secondary treated water, which is reclaimed from the secondary treated water discharged, is about 1.58 hundred million tons. In other words, the reclamation percentage is only 2.4%. When increasing the reclamation percentage of the secondary treated water to 5%, it is acquired an effect of securing a dam having an effective capacity of about 3.3 hundred million tons. Due to this, it has been progressed a variety of attempts to reclaim the secondary treated water of the sewage treatment plant.

The reclamation utilities of the secondary treated water include, for example water for cleaning use, water for spraying use, water for landscaping use, water for maintaining rivers, water for agricultural use and water for cooling use. The treatment standards of the tertiary treatment process that reuses the secondary treated water are somewhat different depending on the above utilities. For example, when the secondary treated water is used as the water for spraying use or water for landscaping use, a chromaticity treatment is not necessary. To the contrary, when the secondary treated water is used as the water for cleaning use, the chromaticity should not exceed 20 degrees.

In the mean time, the method of performing the tertiary treatment process includes an advanced oxidation process, a coagulation sedimentation process, a rapid filtration process, an activated carbon adsorption process, a chlorine treatment process, a reverse osmotic pressure process, a membrane separation process and the like. In the West of U.S.A. where the secondary treated water of the sewage treatment plant is much reclaimed, the coagulation sedimentation process or a disinfection treatment process after filtering with a sand filter is much applied for the purpose of removing the turbidity inducing materials and suspended materials of the secondary treated water to improve the disinfection and oxidation effects. However, in the case of the coagulation sedimentation process, it suffers from the additional slurry. In the case of the sand filtration, it is difficult to cope with a clogging problem resulting from the algae growth in the secondary sedimentation tank due to the nitrogen and phosphorous in the treated water in summer. In particular, the Korean sewage treatment plant performs the advanced sewage treatment, so that the treated water discharged is about 17%, on a 2003-year basis. In addition, under situation that there is lacking in the skilled laborers, the blocking of the sand filter device easily occurs which is due to scum, micro-floc and algae growth.

When disinfecting the secondary treated water with chlorine, there occur disinfection by-products such as tri halo methane (THM), thereby contaminating the water source. As a result, even the chlorine disinfection apparatuses provided in the sewage treatment plant are not used. In addition, when the disinfection method using the chlorine is selected, a dechlorination apparatus should be provided which can solve the THM problem. In order to solve the problem of the disinfection by-products, an ultraviolet disinfection method has been recently suggested. When the ultraviolet disinfection is used, it does not cause the problem of the disinfection byproducts. In addition, when the capacity of the treatment plant is adapted to meet the design factors of the contact and non-contact ways, it is possible to reduce the installation cost and the administrative expense.

In the mean time, although the technologies such as an activated carbon adsorption process, a reverse osmotic pressure process and a membrane separation process have been commercialized due to the high treatment efficiency, the installation cost and the administrative expense are so high, that the economic efficiency thereof is low.

[Disclosure]

[Technical Problem]

The present invention has been made to solve the above problems. An object of the invention is to provide a bio-film compressible filtration apparatus and further an effluent reclamation system using the same wherein it is possible to effectively remove BOD (biochemical oxygen demand) and turbidity inducing materials contained in the effluent and sewage of a sewage treatment plant. [Technical Solution]

In order to achieve the above object, there is provided a bio-film compressible filtration apparatus comprising: a filtration tank having a closed space; a fixed perforated plate that is provided to a lower part in the filtration tank and is closely fixed to an inner wall of the filtration tank; upper and lower porous plates that are sequentially provided at positions spaced from the fixed perforated plate and are closely contacted to the inner wall of the filtration tank to be vertically moveable; upper and lower driving shafts that are connected to one ends of each of the upper and lower porous plates and perform the vertical movements of the upper and lower porous plates respectively; an upper filtering media layer that is filled in a space between the upper and lower porous plates; and a lower filtering media layer that is filled in a space between the lower porous plate and the fixed perforated plate.

Preferably, the fixed perforated plate and the upper and lower porous plates are respectively formed with holes at an interval, thereby having a net shape.

Preferably, the upper and lower filtering media layers comprise a plurality of filtering media pieces, respectively, and the filtering media pieces comprise a sponge-shaped resin.

Preferably, the sponge-shaped resin comprises polyurethane.

Preferably, the bio-film compressible filtration apparatus further comprises a diffuser that is connected to one side of the filtration tank to supply air into the filtration tank, and an air pump that supplies air having a predetermined pressure to the diffuser.

Preferably, the bio-film compressible filtration apparatus further comprises an effluent supply pipe that is provided to one side of the filtration tank to supply effluent into the filtration tank, a filtered water discharge pipe that is provided to one side of the filtration tank to discharge treated water filtered through the filtration tank, and an impurity discharge pipe that is provided to one side of the filtration tank to discharge impurities in the filtration tank.

Preferably, the fixed perforated plate and the upper and lower porous plates are made of metal lath.

Preferably, the bio-film compressible filtration apparatus further comprises a guide shaft that passes through predetermined parts of the upper and lower porous plates, has one end fixed to an upper end of the filtration tank and the other end fixed to the fixed perforated plate and guides the vertical movements of the upper and lower porous plates.

Preferably, the bio-film compressible filtration apparatus for an effluent reclamation system further comprises a flow rate control tank that is provided to a front of the bio-film compressible filtration apparatus and supplies effluent to the bio-film compressible filtration apparatus; and an ultraviolet disinfection apparatus that irradiates ultraviolet to the effluent filtered through the bio-film compressible filtration apparatus in order to disinfect the effluent. [Advantageous Effects]

According to the invention, the upper and lower filtering media layers having different porosities depending on the compression intensity are provided in the filtration tank, and the upper and lower filtering media layers comprise a plurality of filtering material pieces, thereby independently varying the porosities of the upper and lower filtering media layers. To this end, it is possible to efficiently remove the suspended solids and the BOD and turbidity inducing materials contained in the effluent in a single filtration apparatus in biological and physical manners and to maintain the high porosities, thereby securing the high filtering treatment capacity. As well, in the effluent reclamation system provided with the bio- film compressible filtration apparatus having the ultraviolet disinfection apparatus added thereto, it is possible to maximize the ultraviolet irradiation efficiency of the ultraviolet disinfection apparatus.

Furthermore, the bio-film compressible filtration apparatus according to the invention has the higher effluent treatment capacity per unit area than that of the conventional sand filter, so that it can be made small, thereby minimizing the building site area. Contrary to the processes such as an activated carbon adsorption process, a reverse osmotic pressure process, a membrane separation process and the like, the maintenance and installation costs of which are very high, it is possible to easily manage the filtration apparatus, so that the economic efficiency thereof is superior.

In addition, since it is possible to remove the BOD inducing materials through the biological degradation and to remove the suspended solids and the turbidity inducing materials through the physical mechanism in the single filtration apparatus, the contaminant removing range is very high and the structure of the system is very efficient, compared to the conventional process. [Description of Drawings]

FIG. 1 is a perspective view of a bio-film compressible filtration apparatus according to an embodiment of the invention;

FIG. 2 is a front view of a bio-film compressible filtration apparatus according to an embodiment of the invention;

FIGS. 3 to 5 are reference views for illustrating an operation of a bio-film compressible filtration apparatus according to an embodiment of the invent ion;

FIG. 6 shows a structure of an effluent reclamation system to which a bio-film compressible filtration apparatus according to an embodiment of the invention is applied;

FIGS. 7 to 9 are graphs respectively showing BOD, turbidity and amounts of suspended materials in the effluent of a sewage treatment plant, before and after the treatments through a bio-film compressible filtration apparatus according to an embodiment of the invention; and

FIG. 10 is a photograph showing a sponge-shaped resin corresponding to a filtering media piece according to an embodiment of the invention. [Mode for Invention]

As shown in Figs. 1 and 2, a bio-film compressible filtration apparatus 100 according to an embodiment of the invention comprises a filtration tank 101 having a filtering space therein. Three plates are provided in the filtration tank 101. The three plates are closely contacted to an inner wall of the filtration tank 101. The three plates are a fixed perforated plate 102, an upper porous plate 103 and a lower porous plate 104. The fixed perforated plate 102 is fixedly provided to a lower end of the filtration tank 102. The upper and lower porous plates 103, 104 are sequentially provided at positions spaced from the fixed perforated plate 102.

The upper and lower porous plates 103, 104 are designed so that they can be selectively moved in the filtration tank 102 in a vertical direction, contrary to the fixed perforated plate 102. The vertical movements of the upper and lower porous plates 103, 104 can be made by a driving means provided to one end of each of the upper and lower porous plates 103, 104. Specifically, a driving shaft 105 is connected and fixed to each one end of the upper and lower porous plates 103, 104. The driving shaft 105 is adapted to get a driving force using a hydraulic cylinder 106, for example, so that it can selectively move the upper and lower porous plates 103, 104 in a vertical direction. In the mean time, a guide shaft 107 can be further provided so as to smoothly move the upper and lower porous plates 103, 104. The guide shaft 107 is provided to pass through predetermined parts of the upper and lower porous plates 103, 104 and one end thereof is fixed to an upper end of the filtration tank 101 and the other end thereof is fixed to the fixed perforated plate 102. One of more guide shafts 107 can be provided. Since the guide shaft 107 is provided, it is possible to prevent a deflection phenomenon when the upper and lower porous plates 103, 104 are vertically moved.

The fixed perforated plate 102 and the upper and lower porous plates 103, 104 are formed with a plurality of holes at an interval, thereby having a net shape. A preferred size of the hole is about 3-10 mm. The fixed perforated plate 102 and the upper and lower porous plates 103, 104 consist of metal lath, for example.

In the mean time, an upper filtering media layer 120 and a lower filtering media layer 130 are respectively provided in a space between the upper porous plate 103 and the lower porous plate 104 and a space between the lower porous plate 104 and the fixed perforated plate 102. The upper and lower filtering media layers 120, 130 comprise a plurality of filtering material pieces 140 each of which having a predetermined unit size. As the filtering material piece, a sponge-shaped resin such as polyurethane can be used (refer to Fig. 10). In addition, the filtering media piece has preferably a height of about 12-18 mm, a length of about 12-18 mm and a width of about 12-18 mm.

It is preferred that porosities of the upper and lower filtering media layers 120, 130 are different. Specifically, the porosity of the upper filtering media layer 120 is preferably lower than that of the lower filtering media layer 130. For reference, the porosity means, as shown in Fig. 3, a porosity when the filtering media layers are compressed by the fixed perforated plate 102 and the upper and lower porous plates 103, 104. As described above, since the filtering media pieces 140 constituting the upper and lower porous plates 103, 104 are same, the porosities of the upper and lower filtering media layers 120, 130 are highly affected by the compression degrees of the upper and lower porous plates 103, 104.

That is, it is possible to selectively control the porosities of the upper and lower filtering media layers 120, 130 with the compression ratio of the upper and lower porous plates 103, 104. For reference, in case of the prior art, for example, using a complex filtering media such as sand and anthracite, the porosities of the respective filtering media cannot be controlled. However, according to the invention, it is possible to independently control the porosities of the upper and lower filtering media layers 120, 130.

The reason the porosity of the upper filtering media layer 120 is set to be lower than that of the lower filtering media layer 130, i.e., the _g 6 005384

reason the compression ratio for the upper filtering media layer 120 is set to be higher than the that for the lower filtering media layer 130 is as follows.

In the filtration tank 101 that is operated in an upstream direction, the lower filtering media layer 130 serves as a biological filter and the upper filtering media layer 120 serves as a physical filter. In order for the lower filtering media layer 130 to serve as a biological filter, the microbes should form a bio-film and grow on the filtering media piece of the lower filtering media layer 130. For the purpose, the porosity of the lower filtering media pieces should be relatively high. To the contrary, in order for the upper filtering media layer 120 to serve as a physical filter, the ratio of accumulating the suspended solids and the turbidity inducing materials should be increased. For the purpose, the porosity of the upper filtering media pieces should be relatively low.

In addition, since the porosities of the upper and lower filtering media layers 120, 130 are made to be different from each other, as the upstream operation is performed in the filtration, the larger particles are first deposited on the lower filtering media pieces and then the smaller particles are deposited on the upper filtering media pieces, so that the upper or lower filtering media layer 130 is prevented from being easily clogged.

In the mean time, to one side of the filtration tank 102 can be further provided an effluent supply pipe 108 that supplies the effluent into the filtration tank 101, a filtered water discharge pipe 109 that discharges the treated water filtered through the filtration tank 101 and an impurity discharge pipe 110 that discharges the impurities in the filtration tank 101. To one side of the effluent supply pipe 108 can be further provided a flowmeter 113 and a pressure gauge 114 that can respectively control a flow rate and a pressure of the effluent to be supplied into the filtration tank 101. In addition, to one side of the filtered water discharge pipe 109 can be further provided a turbidimeter (not shown) that can measure a turbidity of the effluent. In the mean time, as the bio-film compressible filtration apparatus according to the invention adopts the upstream operation manner, it is preferred that the effluent supply pipe 108 is provided to a lower part of the filtration tank 101, the filtered water discharge pipe 109 is provided to an upper part of the filtration tank 101 and the impurity discharge pipe 110 is provided to upper, center and lower parts of the filtration tank 101.

To one side of the filtration tank 101 is provided an air pump 111 that serves to inject air into the filtration tank 101 through an diffuser 112 and a diffuser hole 112a so that the materials adsorbed to the filtering media pieces are easily detached when cleaning an inside of the filtration tank 101. Meanwhile, a chemical introducing tank (not shown) can be further provided to the bio-film compressible filtration apparatus according to the invention for the purpose of coagulation filtration.

An operation of the bio-film compressible filtration apparatus according to the invention is as follows. The operation of the bio-film compressible filtration apparatus according to the invention can be classified into a filtering step, an aeration and cleaning step and a polishing step. Figs. 3 to 5 are reference views for illustrating an operation of a bio-film compressible filtration apparatus according to an embodiment of the invention.

First, in the filtering step, the BOD and turbidity inducing materials contained in the effluent, i.e., secondary treated water supplied into the filtration tank 101 through the effluent supply pipe 108 are filtered. Herein, as shown in Fig. 3, the lower porous plate 104 is compressed toward the fixed perforated plate 102 and the upper porous plate 103 is compressed toward the lower porous plate 104. In addition, the porosities of the upper and lower filtering media layers 120, 130 can be set to be different from each other depending on the compression degrees of the upper and lower porous plates 103, 104. Preferably, the porosity of the upper filtering media layer 120 is set to be lower than that of the lower filtering media layer 130.

The upper and lower porous plates 103, 104 can be experimentally compressed up to 10-90%, as compared to the normal state. Even when they are compressed by 30% or more, the suspended solids and turbidity inducing materials can be effectively removed. In that case, however, the pressure in the filtration tank 101 is increased. Accordingly, the compression ratio is preferably maintained to be 30% or less.

In the mean time, when the effluent is supplied into the filtration tank 101 through the effluent supply pipe 108, it passes through the upper and lower filtering media layers 120, 130 which are under compressed state. Herein, the BOD inducing organic materials contained in the effluent are degraded through a biological mechanism and the suspended materials and the turbidity inducing materials are adsorbed to the filtering media pieces of the upper filtering media layer 120. The filtered water, from which the BOD inducing materials, the suspended materials and the turbidity inducing materials are removed, is discharged through the filtered water discharge pipe 109, so that a series of filtering processes are completed. The turbidity of the filtered water can be periodically checked through the turbidimeter provided to the filtered water discharge pipe 109, thereby controlling the compression ratio of the upper filtering media layer 120 depending on the turbidity.

The bio-film compressible filtration apparatus according to the invention can realize a high porosity especially by using the sponge-shaped resin as the filtering material, so that the filtration capacity is remarkably higher than that of the conventional filtration apparatus. For reference, the porosities of the conventional sand and anthracite filter are respectively about 40-46% and about 50-56%. A difference in the filtration treatment capacities between the bio-film compressible filtration apparatus according to the invention and the conventional filtration apparatus is as shown in a table 1. [Table 1]

In addition, the BOD, the turbidity and the amount of the suspended solids of the filtered water filtered through the bio-film compressible filtration apparatus according to the invention are maintained to be considerably low, as shown in a table 2. [Table 2]

In addition, the BOD, the turbidity and the amount of the suspended solids of the treated water of the sewage treatment plant, which is filtered through the continuous operation for 72 hours by the bio-film compressible filtration apparatus according to the invention, exhibit the constant treatment efficiency, as shown in Figs.7 to 9.

In the mean time, the aeration and cleaning steps for removing the materials adsorbed to the filtering material pieces are performed under state that a series of filtering processes are completed. In the aeration and cleaning step, as shown in Fig. 4, the compressed state of the upper and lower porous plates 103, 104, which are compressed for the filtration, are released. In addition, the filtered water discharge pipe 109 should be closed and the impurity discharge pipe 110 should be opened. Under such conditions, the cleaning water is supplied into the filtration tank 101 through the effluent supply pipe 108. At the same time, the air is supplied into the filtration tank 101 through the diffuser 112 and the diffuser hole 112a by using the air pump 111. As the air is supplied into the cleaning water, the mobility of the cleaning water is increased, so that the detachment of the materials adsorbed to the filtering material pieces are accelerated.

In the mean time, when progressing the aeration and cleaning step, the cleaning times of the upper and lower filtering media layers 120, 130 are differently applied. In the case of the upper filtering media layer 130, a predetermined staying time is necessary so that the microbes can grow so as to form a bio-film on the filtering media layers. Accordingly, the cleaning times of the lower filtering media layer is relatively smaller, as compared to the upper filtering media layer 120. Even though the cleaning times of the lower filtering media layer 130 is relatively smaller than that of the upper filtering media layer 120, since the compression ratio of the lower filtering media layer 130 is relatively low, a possibility that there will occur a clogging phenomenon is low. As a result, the pressure in the filtering tank 102 is maintained to be constant.

When the aeration and cleaning step is completed, the polishing step is started. In the polishing step (refer to Fig. 5), the upper and lower porous plates 103, 104 are compressed as done so in the filtering step. Thereby, the impurities detached from the filtering media pieces are suspended toward the upper part of the filtration tank 101 and are finally discharged through the impurity discharge pipe 110. When the polishing step is completed, the filtering step is again progressed.

In the mean time, as described in the object paragraph of the invention, the bio-film compressible filtration apparatus according to the invention is an apparatus that is used to efficiently remove the BOD and turbidity inducing materials contained in the effluent of the sewage treatment plant, i.e., secondary treated water. In addition, the bio-film compressible filtration apparatus according to the invention also can be provided to a tertiary treatment system, i.e., effluent reclamation system, thereby maximizing an efficiency thereof. The effluent reclamation system to which the bio-film compressible filtration apparatus according to the invention is applied will be described.

As shown in Fig. 6, the effluent reclamation system of the invention comprises a flow rate control tank 401, a bio-film compressible filtration apparatus 100 and an ultraviolet disinfection apparatus 402. In the prior art, the effluent reclamation system consists of only the ultraviolet disinfection apparatus 402, thereby performing the tertiary treatment of the effluent. As a result, there is a problem that when the BOD and turbidity inducing materials are contained in the effluent, the ultraviolet irradiation efficiency is lowered.

According to the effluent reclamation system according to the invention, the effluent is made to pass through the bio-film compressible filtration apparatus before being introduced into the ultraviolet disinfection apparatus 402. Accordingly, the suspended solids and the turbidity inducing materials contained in the effluent are minimized, so that the ultraviolet irradiation efficiency of the ultraviolet disinfection apparatus 402 can be maximized.

Furthermore, in the effluent reclamation system according to the invention, it is possible to control the staying time of the effluent in the bio-film compressible filtration apparatus and the ultraviolet disinfection apparatus 402 depending on the colon bacilli, smell and chromaticity of the effluent.

The effluent reclamation system according to the invention can remove the BOD inducing materials through the biological degradation using the bio- film, as well as have the functions of removing the suspended solids and the turbidity inducing materials, which the conventional tertiary treatment apparatus has. [Industrial Applicability!

According to the invention, the upper and lower filtering media layers having different porosities depending on the compression intensity are provided in the filtration tank and the upper, and lower filtering media layers omprises a plurality of filtering media pieces, thereby independantly varying the porosities of the upper and lower filtering media layers. Accordingly, it is possible to efficiently remove the suspended solids and the BOD and turbidity inducing materials contained in the effluent in a single filtration apparatus in biological and physical manners and to maintain the high porosities, thereby securing the high filtering treatment capacity. As well, in the effluent reclamation system provided with the bio- film compressible filtration apparatus having the ultraviolet disinfection apparatus added thereto, it is possible to maximize the ultraviolet irradiation efficiency of the ultraviolet disinfection apparatus.

In addition, since it is possible to remove the BOD inducing materials through the biological degradation and to remove the suspended solids and the turbidity inducing materials through the physical mechanism in the single filtration apparatus, the contaminant removing range is very high and the structure of the system is very efficient, compared to the conventional process.

Claims

[CLAIMS] [Claim 1]

A bio-film compressible filtration apparatus comprising: a filtration tank having a closed space; a fixed perforated plate that is provided to a lower part in the filtration tank and is closely fixed to an inner wall of the filtration tank; upper and lower porous plates that are sequentially provided at positions spaced from the fixed perforated plate and are closely contacted to the inner wall of the filtration tank to be vertically moveable; upper and lower driving shafts that are connected to one ends of each of the upper and lower porous plates and perform the vertical movements of the upper and lower porous plates respectively; an upper filtering media layer that is filled in a space between the upper and lower porous plates; and a lower filtering media layer that is filled in a space between the lower porous plate and the fixed perforated plate.

[Claim 2]

The bio-film compressible filtration apparatus according to Claim 1, wherein the fixed perforated plate and the upper and lower porous plates are respectively formed with holes at an interval, thereby having a net shape.

[Claim 3]

The bio-film compressible filtration apparatus according to Claim 1, wherein the upper and lower filtering media layers comprise a plurality of filtering media pieces, respectively, and the filtering media pieces comprise a sponge-shaped resin.

[Claim 4]

The bio-film compressible filtration apparatus according to Claim 3, wherein the sponge-shaped resin comprises polyurethane.

[Claim 5]

The bio-film compressible filtration apparatus according to Claim 1, wherein the bio-film compressible filtration apparatus further comprises a diffuser that is connected to one side of the filtration tank to supply air into the filtration tank, and an air pump that supplies air having a predetermined pressure to the diffuser.

[Claim 6]

The bio-film compressible filtration apparatus according to Claim 1, wherein the bio-film compressible filtration apparatus further comprises an effluent supply pipe that is provided to one side of the filtration tank to supply effluent into the filtration tank, a filtered water discharge pipe that is provided to one side of the filtration tank to discharge treated water filtered through the filtration tank, and an impurity discharge pipe that is provided to one side of the filtration tank to discharge impurities in the filtration tank.

[Claim 7]

The bio-film compressible filtration apparatus according to Claim 1, wherein the fixed perforated plate and the upper and lower porous plates are made of metal lath.

[Claim 8]

The bio-film compressible filtration apparatus according to Claim 1, wherein the bio-film compressible filtration apparatus further comprises a guide shaft that passes through predetermined parts of the upper and lower porous plates, has one end fixed to an upper end of the filtration tank and the other end fixed to the fixed perforated plate and guides the vertical movements of the upper and lower porous plates.

[Claim 9]

The bio-film compressible filtration apparatus according to Claim 1, wherein the bio-film compressible filtration apparatus further comprises a flow rate control tank that is provided to a front of the bio-film compressible filtration apparatus and supplies effluent to the bio-film compressible filtration apparatus; and an ultraviolet disinfection apparatus that irradiates ultraviolet to the effluent filtered through the bio-film compressible filtration apparatus in order to disinfect the effluent.