JPS5855996Y2 - organic sewage treatment equipment - Google Patents

Description

[Detailed description of the invention] The present invention is a sewage treatment system, specifically, a filter bed in a tank filled and fixed with a filter medium having a large specific surface area to which aerobic microorganisms can attach, is used to contain sufficient dissolved oxygen. The present invention relates to an organic sewage treatment system in which organic sewage is repeatedly circulated, filtered and purified while being biochemically oxidized and decomposed by aerobic organisms that grow on the filter medium.

The organic sewage treatment equipment of the above method uses the conventional trickling filter method,
Unlike the long-time bombardment method, standard activated sludge method, etc., this method is a type of contact bombardment method and is extremely useful when secondary-treated sewage is subjected to higher-level treatment by installing a new filter bed. It is a processing device.

Conventional treatment equipment has a high degree of purification performance, but in the treatment of nitrogen contained in organic wastewater, ammonia nitrogen and albuminoid nitrogen are oxidized to nitrite nitrogen or nitrate nitrogen. However, further nitrogen removal, that is, denitrification as nitrogen gas, has not been achieved, and it has been observed that it is difficult to remove nitrogen from sewage, and that sludge flows out due to swelling of activated sludge. The disadvantage is that the sludge easily flows out into the treated water as fine pin flocs that do not easily settle, and there is also a problem in the management of the equipment, as a large amount of surplus sludge is generated.

If the sludge exfoliated as described above flows into the treated water as fine, non-settling pin flocs, a problem arises in that the quality of the treated water deteriorates.

The purpose of this invention is to repeatedly circulate organic wastewater containing sufficient dissolved oxygen through a fixed filter bed filled with a filter medium that has a large specific surface area on which aerobic microorganisms can attach. As a sewage treatment equipment that biochemically oxidizes and decomposes the sewage using epiphytic aerobic microorganisms while filtering and purifying the sewage, the sewage comes into contact with the filter material and is sufficiently decomposed by the microorganisms that have grown on the filter material. It is an object of the present invention to provide a sewage treatment device in which nitrogen bone removal is performed to a high degree, floating matter is almost prevented from flowing into treated water, and surplus sludge is hardly generated.

The above object of the present invention is to repeatedly circulate organic wastewater containing sufficient dissolved oxygen through a fixed filter bed filled with a filter medium having a large specific surface area on which aerobic microorganisms can attach. In sewage treatment equipment that biochemically oxidizes and decomposes wastewater using aerobic organisms that grow on it, it filters and purifies it.
The filter bed consists of an upper filter bed and a lower filter bed, and the upper filter bed has a plurality of surfaces that can guide wastewater diagonally with respect to the vertical direction so that the wastewater can flow down in a turbulent flow. The lower filter bed is composed of filter media arranged in parallel at intervals,
A plurality of corrugated plate-shaped filter media are arranged horizontally in parallel at intervals from top to bottom, and the filter media are arranged in such a way that wastewater can fall from one end of the upper filter media onto the lower corrugated media between the adjacent upper and lower filter media. This is achieved by an organic sewage treatment device characterized in that the end positions are shifted in the horizontal direction.

The filter material in the upper filter bed aerobically treats nitrogen components in wastewater and converts them into nitrate nitrogen or nitrite nitrogen, which strengthens the effect of turbulence and also withstands fluctuations in water volume and water pressure. .

This filter material is a net plate-like filter material that is inclined at an acute angle with respect to the vertical direction, and a plate-like filter material that has wavy surfaces on the front and back surfaces. Examples include those whose portions and valleys are inclined with respect to the vertical direction.

The lower filter bed can be constructed by arranging several corrugated plate-shaped filter media in substantially horizontal parallel from top to bottom, and arranging them in several rows in both length and width. If you have enough, it is a good idea to stack them in several layers.

The material of each filter medium is preferably plastic, but other materials may also be used.The size of the filter medium, the mutual spacing, and when using a net plate filter medium, the net size, etc. will depend on the properties of the treated sewage. , is determined as appropriate depending on the processing scale, processing purpose, etc.

In the treatment device of the present invention, the wastewater supplied from above the upper filter bed and flowing down the filter bed does not become a turbulent flow, and is oxidized by sufficiently repeatedly contacting the aerobic microorganisms that have grown on the filter media of the filter bed. In the lower filter bed, most of the flow of sewage becomes a substantially horizontal flow, so that biofilm or sludge, or microorganisms, that have grown on the filter medium are difficult to peel off. The aerobic microbial layer a and the anaerobic microbial layer overlap, and the aerobic microbial layer a is formed on the lower surface, which improves the ability to capture suspended solids such as pin flocs in the wastewater, and almost no suspended solids flow into the treated water. It disappears.

Nitrate nitrogen in the wastewater is converted to nitrogen gas as the wastewater advances to the lower part where the atmosphere of anaerobic microorganisms that grow in the upper valleys of the corrugated plate filter media in the lower filter bed is strong. minutes are fully removed.

Furthermore, in the treatment apparatus of the present invention, by coexisting aerobic and anaerobic microorganisms, the generation of surplus sludge as a whole is extremely reduced, and sewage is purified to a high degree.

It is also possible to provide a known sedimentation separation tank or a known biological treatment tank, such as a rotating disk method, a trickling filter method, or a long-time perturbation method, in front of the treatment device of the present invention.

Further, a settling tank may be provided after the treatment apparatus of the present invention.

The sewage treatment apparatus of the present invention can treat various types of sewage that have been pretreated, including untreated domestic water.

As described above, according to the sewage treatment apparatus of the present invention, organic sewage can be brought into sufficient contact with the filter medium and sufficiently decomposed by the microorganisms living on the filter medium, and the nitrogen components contained in the organic sewage can be easily converted to nitrogen gas. It can denitrify and highly remove nitrogen components from wastewater, significantly reduce BOD and COD, and the concentration of organic matter in treated water becomes extremely low and stable.It also traps pin flocs in the lower filter bed. The removal rate of suspended solids is high due to its excellent adsorption properties, and the outflow of suspended solids into the treated water is almost prevented, and furthermore, the coexistence of aerobic and anaerobic microorganisms in the lower filter bed reduces the generation of excess sludge as a whole. With this method, a high degree of purification is achieved, and the maintenance of the equipment is also easy.

Embodiments of the present invention will be described below based on the drawings.

FIG. 1 is a schematic cross-sectional view of one embodiment. In this processing apparatus, a filter bed is disposed in the middle part of the processing tank 1, and this filter bed includes an upper filter bed 6 and a lower filter bed 8. I am admonishing you.

An air conduit 3 is installed above the processing tank 1, and a branch pipe 4 branched from this pipe passes through the filter beds 6 and 8 and reaches the bottom of the processing tank 1.

Each branch pipe 4 has another pipe fitted over it to form an air lift pump 5.

As shown in FIG. 2, the upper filter bed 6 has a plurality of units 7 arranged in parallel at intervals with a plurality of net plate-shaped filter media slightly inclined with respect to the vertical direction, arranged in two upper and lower stages. They are piled up.

The lower filter bed 8 is composed of a plurality of units, and each unit has corrugated plate-shaped filter media 9 arranged horizontally in parallel from top to bottom at intervals, and between adjacent upper and lower filter media. The end positions of the filter media are shifted in the horizontal direction so that wastewater can fall from one end of the upper filter media onto the lower filter media.

2 and 10 are advection tubes, respectively.

The wastewater supplied from the advection pipe 2 to the treatment tank 1 first flows down the upper filter bed 6, then flows down the lower filter bed 8 in a horizontal flow in a zigzag pattern, reaching the bottom of the treatment tank, where it is pumped again by the air lift pump 5. The sewage is supplied above the upper filter bed in a state containing sufficient dissolved oxygen, and is thus circulated within the treatment tank where it is biochemically oxidized and decomposed and denitrified by the microorganisms in the filter beds 6 and 8.
The circulated water flows out from the advection pipe 10.

When sewage flows down inside the upper filter bed 6, it tries to fall vertically under its own weight, but it is also guided diagonally to the vertical direction by the slopes that are everywhere, and the sewage mixes with other sewage. They collide and collide, creating a turbulent flow as a whole.

In addition to the above-mentioned net plate-shaped filter media, the filter media constituting the upper filter bed 6 may be a plate-shaped filter media whose front and back surfaces are corrugated, as shown in FIG. The filter medium may have peaks and troughs of the corrugated surface inclined with respect to the vertical direction so as to provide the following.

In the embodiment shown in FIG. 1, there is only one processing tank, but a plurality of such processing tanks can be used in series.

The size, number and direction of inclination of the filter media in the upper stage filter bed, the size and number of filter media in the means filter bed, the area of the opening facing the next stage filter media from the end of one filter media, etc. are shown in the above examples. others,
It can be determined as appropriate depending on the properties of the wastewater to be treated, the purpose of treatment, the amount of treatment, etc.

The purification performance of the device of the present invention will be shown below using Examples.

As is clear from the above examples, it is clear that extremely high level of sewage purification can be achieved by the treatment apparatus of the present invention.

[Brief explanation of drawings]

FIG. 1 is a schematic vertical sectional view of one embodiment of the present invention, and FIGS. 2 and 3 are slope views of a net plate filter medium and a wavy plate filter medium applied to the upper filter bed in the processing apparatus of the present invention, respectively. ,
FIG. 4 is a perspective view showing an example of a filter medium applied to the lower filter bed in the processing apparatus of the present invention, and FIG. 5 is an explanatory diagram showing a microbial layer formed on the wave-shaped forest filter medium of the lower filter bed. . In the figure, 1 is a treatment tank, 2 is an advection pipe, 3 is an air conduit, 4 is an air branch pipe, 5 is an air lift pump pipe, 6 is an upper filter bed, 7 is a filter medium, 8 is a lower filter bed, and 9 is a filter medium , 10 is an advection tube.

Claims (1)

[Scope of utility model registration request] Aerobic microorganisms grow on the filter bed by repeatedly circulating organic sewage containing sufficient dissolved oxygen through a fixed filter bed filled with filter media that has a large specific surface area on which aerobic microorganisms can grow. In a sewage treatment device that performs filtration and purification treatment while being biochemically oxidized and decomposed by A plurality of filter media each having a large number of surfaces capable of guiding wastewater diagonally to the vertical direction are arranged in parallel at intervals so that the wastewater can flow down. The filter media are arranged horizontally in parallel at intervals from top to bottom, and the end positions of the filter media are shifted in the horizontal direction between each adjacent upper and lower filter media so that wastewater can fall from one end of the upper filter media onto the lower filter media. An organic sewage treatment device characterized by being arranged in an array.