KR20000008079A - Method for disposing sewage and waste water by using absorbing biofilter and apparatus thereof - Google Patents

Abstract

PURPOSE: A method and an apparatus are provided for disposing sewage and waste water in low cost and high efficiency. CONSTITUTION: Sewage and waste water are disposed by passing it through a disposal medium (115) which is a soft, easily-bending and elastic sponge foam material in the form of cells structure connected each other; supplying it with air to release the first disposed water; and treating the first disposed water in an ammonia nitrogen disposing bath (200) by zeolite (202) adsorption to remove ammonia nitrogen. The disposal medium (115), an absorbing bio filter, is a sponge-form material prepared by using a synthetic resin, in the form of a regular hexahedron whose the length of side is about 5 cm, and the mean radius of cells is less than 0.5 mm. A ventilation air is flown in through a large vacant space filled with air (116) between foam pieces filled with water (117) of the medium (115). Microbes live on sewage in the medium (115), and the sewage is held for a long time in the medium (115) to be perfectly disposed.

Description

Wastewater Treatment Method and Apparatus Using Absorbent Biofilter

The present invention relates to the aerobic treatment of household waste water and industrial waste water of a certain type and subsequent treatment, and also to purification of general waste water.

Conventional free drainage filters and sand filters for aerobic wastewater treatment provide means for adsorption of microorganisms on the outer surface of the medium, adequate retention time, and ventilation of the filter media. The intrinsic nature of the filter media determines the loading rate of wastewater (1m3 of waste water per square meter of filter), and determines the increase in loading rate and overall efficiency.

In sand, soil, and other similar solid molecular filters, microorganisms stick to the outer surface and turn into narrow holes between the molecules and the areas where wastewater and venting air enter and exit. When the loading rate is not as low as 0.001 to 0.007 m3 / m2 / day in sand and soil filters, these holes are clogged, so a large capacity filter is required for wastewater treatment. However, low loading rates inhibit the production of large amounts of solids and minimize maintenance.

Water moss peat filters provide more porosity and retention time (absorbency) (US Pat. No. 5,049,265, Boyd, 1991), but the recommended loading rate is only 0.011 m 3 / m 2 / day and larger capacity is still required. At higher load rates, the moss filter expands and stagnates. Sand, soil, and moss are inconsistent because they are inherently changing materials.

Synthetic drip filter media consists of non-absorbent plastic materials with consistent physical properties, including good surface area, large space and light weight. Since the wastewater and air inflow passages are separated, the drip filter can be loaded simultaneously and supplied with air. Higher loading rates without clogging results, but more maintenance costs due to the formation of solids due to aerobic microbial activity. Low holding times require more passage of wastewater through the medium, resulting in more power consumption.

Increased surface area and the use of rigid closed-cells (US Pat. No. 3,293,174 Robjohns 1996), the uneven surface improves the loading rate per cubic meter of the drop filter media, which is mainly due to uneven surface Because of the light weight. However, the retention time is still low because the foam does not absorb water. The outer surface is only used for microbial adsorption and only allows aerobic action and solids production.

Open-cell synthetic foams have been used to treat clear tank water (US Pat. No. 5,164,089 Preston 1992), but the foam has settled down and must be frequently removed and cleaned. The water must pass through the foam pieces, otherwise the water will pass selectively around the foam.

Open-cell flexible foams have been used in sedimented open-air and tanks in groundwater facilities to increase the surface area for microorganisms for aerobic and anaerobic digesters (US Pat. No. 4,566,971 Reimann and Fuchs). 1986, US Pat. No. 4,664,803 Fuchs and Reinman 1987). In this application, the free drainage filter is not used. Flexible foams are preferred in settled environments because foam pieces are easily sticking and easy to clean by compression (US Pat. No. 4,524,139 Fuchs 1985). The flexible foam does not deform because its weight is maintained by the buoyancy of the waste water.

In a free drainage filter, a solid closed cell foam (Robjohns 1966) where wastewater flows only above and around the outer surface of the medium (Robjohns 1966) and the wastewater flow path passes through or around the medium and the airflow is separated like a drop filter. Prefer rigid open cell foam (Europe / German Patent 0 104 525 Reinman and Fuchs 1984) (Flexible open cell foam is recommended for free drain biofilters because it deforms and compresses due to its own weight when wet). It is not used at all, unless a hard brace is used to avoid deformation and compression (Reinman and Fuchs 1984). Free drainage foams are easier to maintain and have advantages in manufacturing and cost compared to milled and perforated foam blocks with hard braces added.

However, in rigid open cell foams (Reimann and Fuchs 1984), there is a disadvantage in that the contact between the foams is inadequate due to the rigidity and lack of deformation of the foams. Because of the small point-like contact area, wind channeling occurs and accelerates through the narrow point contact between pieces, similar to the acceleration between buildings. This undesired channeling is associated with more channeling and underneath the outer foam pieces than the desired flow through the foam pieces for increased retention time, contact with microorganisms, and better anaerobic environments to produce less solids. Only results in a short cycle.

In order to achieve a complete treatment result in a small area, a free drainage biofilter combining the positive external characteristics of the above technology without the disadvantages is required. Ideal filter media include high surface area, ease of microbial adsorption, many interconnected pores for microbial growth and water flow, high retention time (absorbency) of waste water upon contact with microorganisms, protection from microbial flushing, and very high loading rates. It requires conditions such as separation of air and sewage flow passages for the purpose, prevention of low solids or any solids formation, light weight for transport, ease of cleaning media, and continuous treatment.

Rigid, rigid, flexible foams provide the characteristics of this ideal filter and form the basis of the present invention. The deformation of the flexible foam is actually an advantage because the wide contact of the foam pieces makes it easier to move through the piece while minimizing the acceleration between pieces. Channeling and short circulation are therefore minimized, and air paths continue to exist between the foam pieces, maintaining a balance between anaerobic and aerobic environments.

In view of the above drawbacks of this prior art, the inventors of the present invention have already disclosed a patent for providing aerobic treatment facilities and methods in one direction for various wastewaters such as small amounts of sewage and landfill effluents. Applied Application No. 97-47774, entitled "Method and Apparatus." However, since the prior application does not disclose wastewater treatment and apparatus for the removal of nitrogen components, the present invention has been improved by applying the conventional patent application by improving the apparatus and method for the removal of such nitrogen components.

The present invention includes a high efficiency biofiltration module that provides a relatively small volume of complete sewage treatment due to the characteristic physical properties of the flexible open cell foam mediator. Deformation of the flexible foam is considered desirable to obtain the preferred flow paths and speeds through the filter media and to obtain a good combination of anaerobic and aerobic action without generating a minimum amount of solids or solids.

Sewage containing biodegradable materials is fed to a free drainage aerobic module containing absorbent biofilter media. Aerobic filter media is a material with excellent moisture retention and air permeability characteristics, such as polyurethane foam. Foam fragments have an open cell interior to allow sewage to pass through the foam interior, and the large space between the fragments prevents clogging by the biomat composition and allows both sewage loading and air ventilation simultaneously. In contrast, solid molecular media have much less potential loading since they cannot be loaded and vented at the same time. The combination of water retention and gout in the present invention shows a much higher loading rate (10 times or more) compared to solid molecular media such as sand.

In natural water systems, nitrogen exists in various forms, contributing to water pollution. For the removal of nitrogen, physicochemical and biological treatment methods can be used. The main purpose of the physicochemical treatment is to remove ammonia nitrogen rather than to remove total nitrogen.

In general, biological nitrogen removal is more efficient, but physicochemical treatment is sometimes more economical, and a typical method is selective ion exchange. Ammonia removal process by ion exchange utilizes natural zeolite and clinopolite to selectively substitute ammonia. In order to remove ammonia by ion exchange, it is possible to remove up to 90-97% by filtration to avoid the influence of solid matter.

In the present invention, most of the contaminants and solids are removed by the absorbent biofilter, and the nitrogen component which has an adverse effect on the eutrophication of the lake by adsorption and removal of ammonia nitrogen, which accounts for 60% of the nitrogen concentration contained in domestic wastewater, by zeolite. It is a method and apparatus for the complete treatment of waste water by removal.

1 is a cross-sectional view of a modular treatment invention that replaces a conventional tile bed with an aerobic biofilter.

2 shows the invention in a vertical arrangement for ground installation. Ventilated pipes enhance aerobic treatment to provide complete nitrogenization, especially at low temperatures.

3 is a perspective view of a low side unsaturated aerobic module designed specifically for landfill applications. Wastewater and draft airflow paths through the treatment media are indicated.

4 is a cross-sectional view showing a prior art medium such as sand.

5 is a cross-sectional view showing an example of the mediator of the present invention.

6 is a crystal structure of zeolite used to adsorb and remove nitrogen components.

7 is a view showing the configuration of a zeolite treatment tank for adsorption and removal of nitrogen components.

※ Explanation of drawing code

100 container 105 wastewater insertion hole

110: distribution management 115: treatment medium

116: space filled with air 117: a piece of foam filled with water

125: primary treatment water outlet 155: air collection header

165: air ventilation blower 170: air outlet

175: air ventilation means 200: ammonia nitrogen treatment tank

201: primary treatment water injector 202: zeolite

203: nitrogen treatment tank support 204: final treated water outlet

The present invention is a device for treating the waste water through the treatment medium 115 and the ammonia nitrogen treatment tank 200 in the container 100, the waste water introduced into the waste water insertion port 105, sponge-like through the distribution pipe 110 The foam material is connected to a plurality of cell structures, the foam material is passed through the treatment medium 115 composed of a plurality of block types that are soft, flexible, and elastic, and aerobic treatment by the air ventilation means 175, thereby providing a primary treatment. The waste water is discharged through the outlet 125, and the first treatment water is removed from the ammonia nitrogen treatment tank 200 through the zeolite 202 adsorption to remove the ammonia nitrogen component to provide a waste water treatment apparatus, characterized in that will be.

In more detail, the present invention provides a means for aerobic treatment of small and transportable amount of sewage contained in a container in one direction with a high loading rate by means of flow and ventilation means separated from a particular absorbent filter mediator and means for adsorbing and removing nitrogen components. To provide. The present invention is independent of the natural environment and does not require high mechanical maintenance. The sewage of an anaerobic sewage purification tank can be treated with any obvious sewage source of the invention, including any undesired biochemically degradable material such as water on contaminated surfaces. The device can be installed above or below the surface and is effective in drainage, soil conditions, rock conditions, or even under conditions not suitable for conventional tile beds or supervised tile beds.

Therefore, the advantages of the present invention will be that the following.

The sewage treatment system of the present invention completely and flexibly treats household sewage, certain industrial sewage, including aerobic treatment and subsequent treatment in a continuous module regardless of soil type, precipitation and drainage conditions; To dispose of the contaminated ground or ground water or to recycle it continuously; Treating sewage in a small volume of aerobic modules by using absorbent materials instead of solid molecular materials; It does not require large land, so if it is reclaimed, the land is low; It can be easily installed by workers with easy skills, low maintenance effort, some skills and can include mechanical devices or chemical additives, but does not depend on them; Regardless of the specific tank shape and size, and the special configuration for the treatment module, it is acceptable to use ordinary, consistently inexpensive materials for the modules and aerobic saturation treatment media; Special treatment modules can be added or modules can be connected together to treat special types of sewage or special amounts of sewage; Can be directly connected to conventional sewage septic tanks to easily retrofit older devices and does not require special piping in the house or building; For predictable work, standard type goods manufactured at the factory can be used and inspected and approved easily and transported easily; Can be installed above ground or underground, can be covered by panel and wall covering, can be easily hidden from the sun and can be easily insulated and heated in permafrost areas; It is also possible to remove nitrogen, a factor that causes eutrophication of the appeal.

It should be appreciated that all of the above advantages will necessarily be achieved simultaneously in any given plant.

The phenomenon in which the foam of the present invention was not clogged was shown in the laboratory and field experiments after 10 months and 18 months of continuous use at 80 cm / daily loading rate. On-site installations show three years of loading at 55 cm / day of wastewater without the removal of 95-99% of the filtered solids and BOD and without signs of blockage (Table 1). During the operation, a surge of 205 cm / day was shown for several days with no results. Sand and peat filters, on the other hand, were clogged prior to one month of use at this high loading rate. In the present invention, excellent physical properties such as high surface area, high moisture retention and air permeability allow a small amount of treatment in one direction.

Average results of on-site facilities treating clarifier wastewater (T = 5 ~ 14 ℃), flow rate average 2000L / day, very high loading rate 54cm / day n Inflow Outflow Removal rate BOD ₇ (mg / L) 9 123 2.6 97-99 TSS (mg / L) 10 82 2.8 96-98 Ammonia nitrogen 7 5.9 1.1 - Nitrate Nitrogen 10 0.2 5.5 - Total coliform bacteria (CFU / 100ml) 10 1.6e7 7.1e4 99.3-99.7 E. coli 10 5.6e6 3.4e4 99.5-99.7

Waste water is purified by microbial activity by slowly filtration down through the unsaturated filter media. Natural air convection through the exhaust windows of container walls generally provides adequate treatment of organics, solids and pathogens. In order to perform ammonia removal which was not completely removed, adsorption is carried out through a zeolite mediator. If the waste water contains adequate oxygen for the treatment, a simple vent in the container provides adequate ventilation by natural convection.

Water treated with oxygen is collected under the aerobic module, passed to a continuous nitrogen treatment module, and disinfected and reused.

The present invention works effectively in unsuitable drainage and soil conditions in conventional tile beds, supervised tile beds, or peat tile beds. The module can be placed on or under the surface and continued by additional modules for nutrient removal, disinfection and further aerobic treatment.

The present invention provides a highly efficient one-way aerobic biofilter for major wastewater treatment, which has low maintenance requirements and can be prefabricated outside the treatment plant and transported to the treatment area for continued operation. have. The present invention has been improved by replacing tile beds and sand filters and has less maintenance requirements than mechanized ventilation systems.

The additional features of the present invention will be described in detail with reference to the accompanying drawings.

Best way for carrying out the invention

The best method for carrying out the invention and the details of the modifications are as follows.

Basic Structure of Aerobic Module

The aerobic module 100 (shown schematically in FIGS. 1 and 2 and detailed in FIG. 3) is the most important element in the process and preferably the container 100, the dispensing supervisor 110 and the treatment medium ( 115 and ventilation means 175. The structure of the container 100 includes a wastewater insertion port 105, a discharge outlet 125 of treated water, and a selective inspection or access window 150. As shown in Figure 1, if the water surface is low enough, it may be buried or installed on the ground surface.

The dispensing main 110 is fitted directly near the top of the treatment medium 115 and is connected to the sewage insertion port 105. The dispensing main may include a spray stopper directed upward or downward.

The air venting means 175 includes an air collecting header 155, an air inlet 105, an air outlet 170, and an air ventilating blower 165 that are fitted just below the bottom of the medium 115. . Air collection header 155 is maintained by any suitable means.

In another embodiment where adequate ventilation can be provided by natural convection, the air vent means 175 comprises an air inlet 150 or an air outlet 170. In another embodiment, the vented air is injected through the distribution main 110 together with the sewage by a pump using compressed air as the power transmission means. In another embodiment where the sewage contains adequate oxygen or does not require aerobic treatment, forced ventilation is not required in the module. The treatment medium 115 actually fills the module 100.

Function / Process of Aerobic Module

Sewage 130 is introduced into the aerobic module 100 through the insertion port 105, and then to the distribution main pipe 110. Water is slowly filtered downwards through the absorbent medium 115 being treated and discharged through the outlet to another treatment module, such as the water saturation module 200, as shown in FIG. 1 and FIG. Go back.

The venting air 145 enters through the inlet 150 and is collected through the permeable medium 115 to the collection header 155 and discharged through the outlet 170. Alternatively, the air may be introduced together with the sewage by a blower or by a pump through which the air transmits power.

Detailed description of aerobic module elements-containers

The container used for the aerobic module 100 is made of a suitable material such as plastic, concrete, which is hermetically sealed, impermeable, non-responsive, rigid and structurally strong.

The container can be of any suitable shape and the size of the container is traditionally about 3-5 cubic meters for a flow of 2000 liters of sewage. Larger or more modules can be used for more water flow.

The sewage and air inlets and outlets 105, 125, 150 and 170 are assembling devices that penetrate walls of rigid material such as plastic and are of suitable size and connected by suitable means.

Insertion port 105 is located right next to the top of the module and outlet 125 is located right next to the bottom of the module, both of which ensure free drainage of sewage through the module 100. When the pump is turned on, although the dispensing main is still right next to the top, the insert 105 may be near the bottom for convenience or to prevent freezing.

Access window 150 allows for inspection and maintenance and may double the air for vent air 145.

Detailed description of aerobic module elements-distribution mains

As shown in FIG. 3, the distribution main 110 is a means for evenly and directly distributing sewage to the top of the medium 115. Main pipe 110 is a perforated tube of rigid plastic, such as PVC, of suitable size and connected and maintained by suitable means. If the dosing is done by a pump or siphon surge, the main pipe 110 can be a series of spray plugs, discharged over a frying plate (not shown), or otherwise sewage to the top of the biofilter media. To be distributed.

The distribution main 110 is shaped so that the sewage can be evenly distributed over the medium 115, and is shaped and positioned so that the holes therein can be evenly distributed. In another embodiment, the spray stopper and splash plate in the main conduit 110 are arranged to be evenly sprayed onto the medium 115.

Detailed description of aerobic module elements-structure of ventilation means

The air vent means 175 includes a vent air inlet 150 (described above), an air collection header 155, a blower 165, and an air outlet 170 (described above).

The air collection header 155 is made of a perforated plastic tube of appropriate size and is connected and maintained by suitable means. Suitable perforations are made along the tube, for example, every 10-20 cm. A rigid screen surrounds the perforated tube to prevent it from being blocked by the media 115 surrounding the header 155.

The air collection header 155 is shaped so that the ventilation air is distributed as evenly as possible through the medium 115. For example, field experiments of the batches shown in FIG. 2 show that long, narrow rectangular rings of perforated tubes are effective for venting long, narrow tanks.

In one embodiment, the blower 165 is located directly next to the air outlet 170 to facilitate ventilation of the module 100. The blower 165 may be electric power or wind power.

In another embodiment, the air vent 175 includes an air inlet 150 or outlet 170.

In another embodiment, the air venting means 175 includes a pump through which air is powered and an air outlet 170.

Air flow through the media and the function of the ventilation system

Ventilated air is introduced into module 100 to maintain aerobic biological activity in media 115 and circulate water.

The flow can be done upwards or downwards through the medium 115, but the odor of the vented air 148 is minimized if the airflow follows the path of the sewage. Odor removal may be carried out by passing the air 148 discharged through a deodorant medium such as natural peat or activated carbon (not shown).

Detailed description of aerobic module elements-the structure of the media

The treatment medium 115 is a means for slowly sending sewage down through the aerobic module 100 and promoting air circulation. Sewage treatment in a module of the appropriate size is possible only when using the medium 115 having excellent moisture retention and air permeation characteristics. Preferred materials for the vehicle include open cell synthetic foams such as flexible polyurethane foams, modified synthetic foams, sponges or other similar materials. This absorbent material transfers water through them by open cells and also has high water retention. These foams are in water saturation, but airflow occurs simultaneously through the open voids between the foams. For example, by placing polyurethane foams of various sizes, typically between 0.5 and 5 cm, excellent aerobic treatment was obtained in laboratory and field experiments. Placing narrow and large pieces provides more open space between the pieces for ease of ventilation, while placing smaller and wide pieces will result in less empty space and limited air flow.

The medium material should be strong enough to retain good properties over the expected lifespan of the system (20-30 years).

Function of media

Unsaturated aerobic module 100 regenerates the processing of conventional tile beds in small aerobic containers 100 (e.g. 3-5 m 3 in typical dwellings).

The mediator 115 maintains a beneficial biomass population by protecting it from being washed away by drying, extreme temperatures, and increased sewage flow. As shown in FIG. 6, the mediator 115 provides nutrient-rich sewage to allow inflow of vented air through the large void 116 filled with water between the foam pieces 117 filled with water and to maintain biological populations. And hold long enough for complete processing in the biofilter. In Figure 6, the large arrow shows the air inflow through the space and the small arrow shows the sewage movement through the foam pieces.

In contrast, as shown in FIG. 5 (prior art), the ventilation air cannot flow because the space between the solid material molecules is filled with sewage.

The above description has described embodiments by way of example. Many variations of the invention will be readily apparent to those skilled in the art. Such intelligible variations are within the scope of the invention as described and claimed, whether expressly disclosed or not.

For example, although the above description refers to an aerobic saturation module defined by a container, under certain soil conditions, a pit of container volume size defined by the pit wall is dug up, providing a suitable lid or cover, and within the excavated volume. It is also possible to place and support various elements in.

Although the embodiments of the present invention are intended to combine the aerobic step and the resulting treatment step, it should also be appreciated that in certain applications, the aerobic step may be sufficient.

As described, modules containing a treatment medium serve as an aerobic treatment site. Wastewater treatment systems work by sending wastewater from a septic tank to an aerobic treatment site. Waste water is contaminated with ammonia, organics and other substances; This pollutant is transformed into a harmless or relatively harmless substance by oxidation, and it is a function of aerobic treatment sites to perform such oxidation in a way to reduce costs.

In a preferred form of aerobic treatment system, the treatment medium comprises a foam material of the type such as a soft sponge. That is, the material should be elastic, flexible, soft and elastically deformable material.

The soft foam material has an open cell structure and the cells are interconnected. The size of the cell is important; The cell is so small that moisture present inside the cell is retained inside the cell by sponge action-that is, moisture is retained inside the cell by surface tension and spreads from the cell to the low cell by capillary action.

The cells are so small that water does not drain even in cells where the foam material is practically constantly saturated with water. The larger the cell of the foam, the greater the chance of water draining out of the cell, especially when a small amount of water is introduced into the foam material.

The foam should have an internal interconnect cell with an average diameter of 0.5 mm or less and the upper part is limited to an average diameter of 1 mm. When the cell is of this small size, the foam's sponge action is effective for water to spread through the foam and keep the foam saturated. The foam material of the small cell acts to draw water from side to side and even up from this cell to that cell.

In general, it is known that when a cell is 2 mm or more in width, it cannot support itself in the cell or other spaces, and is likely to drain out of such a large cell.

In order to properly perform the aerobic treatment action, the foam includes a space and an open space between the foam pieces. These spaces are interconnected, through which air can freely circulate between spaces.

Soft foam piles are not flat lines, but rather piles of soft foam pieces. Foam blocks don't matter what form they are, as long as they are stacked so that there is a lot of space between them. Cuboid-shaped blocks will form a good space in a randomly stacked state (but they will not form a satisfactory space when the cubic blocks are neatly laid out in regular rows). The designer should try to make the void space 30% or 40% of the foam material volume. Such proportions are obtained, for example, when the block is in the form of a sphere (though spherical forms are difficult to manufacture), or in the form of an angular form that is easy to cut, such as a cuboid.

Stacking the blocks automatically provides space with the desired openness and interconnection, so it is desirable to stack them rather than flatten the foam. It is difficult to provide adequate space in such a state that the soft foams are aligned flat and the cost increases from the manufacturing point of view.

Soft foam blocks are preferably the same size. If they are of different sizes, smaller blocks tend to fill the space between them.

Even if the space is open and free, if air simply passes through the entire foam material, there will be less air circulation through the foam material. Therefore, the position of the foam material should be set so that the circulation air moves through the foam material. This method involves placing the foam material in a container and aligning the air to move downwards (or upwards) through the foam. This action requires placing the sides of the foam material essentially tight to the container.

In a form in which the foam material is piled up into individual blocks, the blocks will naturally fit tightly on both sides of the container and will be arranged to satisfactorily fit. ; That is, the air will pass between the sides of the foam material and the sides of the container so that it will not just pass through the space.

Rigid foams do not fit tightly on both sides of the container, so rigid foams are not suitable for this reason.

Stacked soft foam blocks bump into each other at the point of contact. Since the block is soft, elastic deformation of the block occurs at the point of contact. In fact, when a block actually deforms at the point of contact, the block is defined as soft; Keep in mind that blocks tend to deform more and more when loaded with water. Hard blocks, on the other hand, tend not to deform at the point of contact.

The elastic deformation of the soft foam block at the contact point means that each contact point occupies a large area. Because the blocks are soft, each soft block has a large area for water transfer between blocks and adjacent blocks. Thus, when a block is a soft elastic foam rather than a rigid foam, water can be transferred from this block to that block. As it is important that air can circulate freely through the foam material, it is also important to be able to move to all the foam blocks that make up the foam material while the water is saturated.

Aerobic treatment of wastewater can be most cost effective when the entire foam material is stacked in separate blocks of soft, elastic foam. The space between the blocks is large enough to ensure that air is fully circulated through the foam material, and all areas of foam material will be able to reach their full potential and contribute to aerobic treatment.

Likewise, because foam material has such small cells and very good water transfer between blocks, all sections of foam material will be saturated with water and will also contribute to their full potential. The large space will ensure that the air circulation is evenly distributed throughout the foam and the small cell and good transfer force between the cells will ensure that the sewage is evenly distributed throughout the block.

In other forms of aerobic treatment, aerobic reactions will inevitably occur only in preferred areas, and the 'dead' areas of these treatment stations tend to increase over time. In the treatment plant described, water does not pass or air passes through only the preferred area, but spreads throughout the foam. Therefore, the volume of foam material required to achieve a given processing level is minimal when the foam material is soft and elastically deformable, and the cell size is about 0.5 mm when the entire foam is stacked well with individual blocks of soft material foam.

It should be noted that when blocks are stacked in a container, the space between blocks is automatically created at no cost. No drilling or internal cutting is required to form this space (this is difficult with soft foam). The blocks themselves are created by cutting the soft foam plate into cuboids or by pulling the blocks from the foam plate, and in this way the blocks are not all the same size. It can be noted that the space created by stacking the blocks as much as 30 or 40% of the total volume and that this number is a suitable size proportion to enhance the excellent air circulation characteristics described above. Not only is the space created automatically, the space is automatically created at a reasonable size at no cost.

The designer should pay attention to the size of the soft foam block. If the block is too large, air will not be able to reach the center of the block, so the center of the block will not be able to play a full role in promoting aerobic reactions. The designer must aim to ensure that the foam material at all locations contributes to the response. This is because the efficiency of the aerobic treatment plant is maximized at this time. When air and water are evenly distributed, efficiency is maximized.

If the block is more than 10 cm in diameter, the center of the block begins to lose efficiency. The block is a 5 cm cube. Blocks may be smaller than that, but they have little advantage.

The foam material should always be practically saturated. In this case, during the period when no new wastewater is introduced into the block pile, the moisture is somewhat stagnant in the foam block. When a group of wastewater is introduced into a pile of foam blocks, the moisture already in the pile drains down the pile. As a result, water comes from the bottom of the pile. Water does not actually move in time between sewage inputs; Because of the small cell size (oxidative-causing bacteria live in the cell walls), all water is in close and intimate contact with the bacteria and biochemical processes can continue efficiently.

If the water flows through and flows every day, the residence time for the water in the block pile is constant. The designer should try to set the dwell time of the water in the pile block about a day, or slightly longer if not meant to overuse the system sometimes. In this way, the entire foam should be about 1500 or 2000 liters per 1000 liters of water per day (when the space is 35% of the volume of the block, a volume of 1500 liters of volume corresponds to about 1000 liters of foam volume). do).

It is desirable to drop water over a pile of foam blocks on a regular drip rather than at regular intervals, but there is no difference in the average residence time for water.

The designer should be careful about whether water is evenly sprayed on top of the block pile. Although a soft foam block, as described above, spreads water nicely to the sides, or even upwards, putting all the water in one part can make the water a preferred passage, resulting in inefficiency.

As described, the block is preferably formed by cutting rather than molding. Molding tends to crust on the cast components, which affects the water power and the viability of the aerobic bacteria on which the treatment plant depends.

Soft polyurethane foam is known to be nearly ideal as a growth substrate for aerobic bacteria, especially when the surface is cut (or torn) than when molded.

Not only do bacteria live in cells and have a physically protective environment there, but the organic materials they need, the air they need, are provided directly to the bacteria by making them intimate contact, rather than spilling on them.

In the case of soft polyurethane foams, the surface texture inside the cell is very good; For example, compared to the results of hard cell walls, the surface of the material has a slightly glossy finish that is not ideal for promoting fast and widespread bacterial settlement. Soft polyurethane foam, which has a cell of about 0.5 mm and circulates through open spaces between blocks, is not only effective in retaining water evenly over the foam material, but also highly viable throughout the foam. It is also effective for settling bacteria.

Zeolite adsorption module

The zeolite adsorbent is filled in a column-shaped vessel (Fig. 8), and it is discharged after selectively adsorbing only the ammonia nitrogen component by passing the incoming water by gravity or pump pressure. In addition, the ammonia nitrogen adsorption tank 200 is installed at the rear end of the aerobic module as shown in Figs.

The first treatment water is ejected through the injector 201 in the upper part of the ammonia nitrogen adsorption tank 200, and selectively adsorbs only the ammonia nitrogen component by passing through the zeolite layer, followed by the final treatment water outlet 204 for final treatment. Treated water is discharged.

A typical small household septic tank treatment system handles an average of about 1000 liters of wastewater per day, which requires about 1500 liters of foam blocks. Aerobic treatment plants with 1.5 cubic meters (1,500 liters) of soft foam blocks can be expected to be completely effective at decomposing all oxidizable pollutants present in water. This is equivalent to the relatively large capacity of a traditional aerobic tile bed, sand bed, or aerobic soakaway for the same volume of sewage.

If a sand filter type of a conventional treatment plant is provided, several tons of sand will be loaded into the site, excavated, welded and other costly preparatory work will be required. Soft foam block treatment plants are much less expensive in terms of materials and require no excavation or welding.

An important advantage of the fact that the foam block is soft and elastic is that it can be compressed and transported. Without the need to carry tons of sand, polyurethane foam can be compressed into small packages that can be transported by one or two people over long distances or by plane to remote areas at very low cost. Soft polyurethane foams can be packaged directly from the manufacturing site or vacuum packed. In the case of sand, they must be dug up if they are clogged. Soft foam blocks have a much lower chance of being clogged.

In the case of soft foam blocks, the water pressure is different because of the hydrostatic pressure. If the entire configuration is made without removing the foam, the bottom water pressure is much higher than the top water pressure. However, when the foam is formed into separate blocks and the water transfer between the blocks is good, the hydraulic pressure difference along the vertical height will be reduced. In other words, the pressure difference between the top and bottom will be smaller.

Air circulation between blocks should be assisted by a blower. In the case of a plant using a soft foam block, the following results were found in the comparison of the inflow and outflow. Without natural air circulation or blower;

The BOD concentration dropped to 6.5%.

Total coliform concentration dropped to 0.015%.

The concentration of E. coli dropped to 0.005%.

This result was good, but the result was much better with an artificial blower.

Artificial air circulation and blowers;

The BOD concentration dropped to 1.6%.

Total coliform concentration dropped to 0.002%.

The concentration of E. coli dropped to 0.0001%.

In this experiment, the sewage loading rate in the soft foam block was as high as 80 cm / day (80 cm / day means 80 cubic cm per day per square cm of cross section of the foam block). In experiments with soft foam blocks the loading rate was 150 cm / day without clogging.

Soft foam blocks do not show this loading rate in fat processing, so overuse should be avoided. However, for solid (organic) materials, the result of the blower gives good results.

The temperature of the treatment plant is important in determining the efficiency of biochemical processes. Below about 5 ° C., the biochemical action decreases. Oxidation must take the method of using this heat to produce heat, maintain it, and maintain good temperatures in aerobic treatment plants in cold weather.

To preserve the natural heat generated by the treatment plant, the treatment plant must be sealed and recirculate the air used by blowers or other air circulation means rather than injecting new air frequently. Since oxygen in the air is gradually depleted during biochemical processes, a small amount of fresh air inlet must be provided (but oxygen depletion to affect the action will take several months). Sealing the treatment plant and recirculating spent air is good for cold weather. In hot climates, biochemistry occurs much more quickly and effectively.

Soft foam block aerobic treatment plants are used for lake treatment of domestic septic tanks, but can also be used in industrial treatments and landfills.

The designer must be careful not to let the water overflow into the foam block. Blocks must be saturated, but the space between blocks must always be open. When draining, water should drain out without accumulation. Therefore, the container has an outlet so the effluent must be taken out.

Foam block containers should have a (waterproof) box. The block should touch the sides of the container so that no air can pass around the outside of the pile. Proper racks should be installed at the bottom of the container so that the block does not touch the bottom of the container. An air duct is created under the rack, which controls the air circulation and receives the water falling from the foam block. The water outlet is a pipe that goes out of the room. To recirculate the air, the top of the ventilator should be locked and only a small vent hole should be left to let in the replenishment air.

90% or more of ammonia nitrogen is removed by zeolite adsorption in the ammonia nitrogen processing tank 200. The water outlet controls all runoff from the treatment plant. The outlet port draws out the effluent or is sent elsewhere along the conduit for further continuous treatment.

Claims (5)

In the apparatus for treating wastewater through the treatment medium ( 115 ) and the ammonia nitrogen treatment tank ( 200 ) in the container ( 100 ), the wastewater introduced into the wastewater insertion port ( 105 ) is a sponge-like foam material through the distribution pipe ( 110 ) Connected to the plurality of cell structure and the foam material is passed through the treatment medium ( 115 ) consisting of a plurality of blocks of soft, flexible and elastic, and aerobic treatment by the air vent means 175 , the primary treatment water discharge port ( 125 ), and wastewater treatment apparatus characterized in that the primary treated water is removed from the ammonia nitrogen treatment tank ( 200 ) through the zeolite ( 202 ) adsorption treatment to remove the ammonia nitrogen component. The wastewater treatment apparatus according to claim 1, wherein the distribution main pipe 110 is disposed above the treatment medium 115 to distribute the wastewater evenly. The method of claim 1, wherein the treatment medium 115 is a sponge material made of synthetic resin, the shape is a cube having a side length of about 5cm, the average radius of the cell is less than 0.5mm, between the foam pieces filled with water ( 117 ) Wastewater treatment equipment which allows for the inflow of vented air through a large empty space ( 116 ) filled with air, provides nutrient-rich sewage to maintain biological populations, and retains sewage for a long time in a biofilter. The method according to claim 1, wherein the air vent means 175 in the treatment medium is installed to include an air collecting header 155 , an air inlet port 105 , an air outlet port 170 , and an air ventilating fan 165 at the bottom of the medium. Waste water treatment device The ammonia nitrogen treatment tank 200 is sprayed through the injector 201 at the top of the ammonia nitrogen adsorption tank, and passed through the zeolite layer to selectively adsorb only the ammonia nitrogen component. Waste water treatment apparatus, characterized in that for discharging the final treated water through the final treated water outlet ( 204 )