JPH07983A - Water treatment device - Google Patents

Abstract

PURPOSE:To provide a water treatment device where polluted water in a contam inant load state as in the case of little rivers into which domestic miscellaneous waste water is discharged as it is biologically given high-degree purifying treat ment. CONSTITUTION:There are provided a preliminary treatment tank 6 packed with a filter medium for removing floating solid matter, etc., a denitrification tank 7 which is provided with an aiding material bed packed with aiding materials for bacteria and also which is provided with an adsorbent bed packed with an adsorbent for adsorbing nitrogen in a state of ammonia successively to the aiding material bed, a chitosan charcoal tank 10 packed with charcoal which has been subjected to chitosan treatment, a dephosphrization tank 14 packed with an adsorbent for adsorbing phosphor, and a finish tank 15 packed with charcoal.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water treatment device, and more particularly to a water treatment device suitable for advanced purification treatment of polluted water in a pollutant load state such as in a small river where household wastewater is drained as it is.

[0002]

2. Description of the Related Art The applicant of the present invention has previously filed Japanese Patent Application No. 4-59177.
I proposed a charcoal-made micro habitat as the No. 4, and proposed a denitrification method as Japanese Patent Application No. 4-296533. The charcoal micro habitat of Japanese Patent Application No. 4-59177 has an excellent ability to fix microorganisms, and by using this as a "base material", improvement of purification efficiency by biological treatment can be expected. Further, the denitrification method of Japanese Patent Application No. 4-296533 is different from the conventional method in which nitrate nitrogen in water is simply removed as nitrogen gas by denitrifying bacteria. It is a method that incorporates a process of converting it to high-ammonia nitrogen and adsorbing and removing this ammonia nitrogen with an adsorbent. It has the feature that it can perform high denitrification treatment with a simple equipment structure.

However, all of these are new materials and methods, and there is still no water treatment apparatus which effectively utilizes these materials to comprehensively perform advanced water treatment, and its development is desired.

[0004]

Accordingly, the object of the present invention is to combine the novel methods as described above,
It is to provide a water treatment device that can perform advanced water treatment.

[0005]

A water treatment apparatus according to the present invention comprises a pretreatment tank filled with a filter medium for removing suspended solids,
A denitrification tank with an assimilation layer filled with bacteria assimilation, an adsorbent layer filled with an adsorbent capable of adsorbing ammonia nitrogen, and a charcoal treated with chitosan were provided. It is equipped with a filled chitosan charcoal tank, a dephosphorization tank filled with an adsorbent capable of adsorbing phosphorus, and a finishing tank filled with charcoal.

In this water treatment device, suspended solids (SS) are mainly removed in the pretreatment tank, and BOD
The components (organic substances) are also decomposed, denitrification is performed in the denitrification tank, BOD components are decomposed in the chitosan charcoal tank, dephosphorization is performed in the dephosphorization tank, and further decolorization and deodorization are performed in the finishing tank along with finishing SS. Removal and BOD
The components are decomposed, and any of these can realize advanced water treatment by a complex combination of treatments which are biological treatments.

In the water treatment device as described above, nothing is filled so as not to prevent the air supplied by the aeration tank, that is, the air supplied by the air supply means from diffusing into the water to be treated. It is more preferable to add a tank. That is, by efficiently increasing the dissolved oxygen in the aeration tank, it is possible to improve the processing efficiency in the processing tank downstream thereof.

Various combinations are possible for the arrangement order of each tank in the water treatment apparatus as described above. For example, from the upstream side to the downstream side, a pretreatment tank, a denitrification tank, a chitosan charcoal tank, and aeration. Arranging in order of a dedicated tank, a dephosphorization tank, and a finishing tank is a preferable example from the viewpoint of each treatment. When a tank for exclusive use of aeration is added, it is a preferable example to install it just before the dephosphorization tank or just before the denitrification tank.

Further, dephosphorization in the water treatment apparatus as described above has a relatively low correlation with other treatments and the degree of freedom in the treatment sequence is high. Therefore, the dephosphorization adsorbent is used as a filler for another tank. When the dephosphorization tank is combined with another tank, it is structurally simple to combine it with the chitosan charcoal tank, which is preferable in terms of overall processing efficiency. .

Regarding the water treatment device as described above,
A pair of two tanks are provided for both tanks, and a sludge pit is commonly provided for both tanks, and the water to be treated, which has flowed into one tank from above, flows into the other tank from below through the sludge pits. This is more preferable because it is possible to generate a forcible descending flow and an ascending flow in both tanks, so that the contact efficiency of the water to be treated with the filler can be increased.

When the descending flow and the ascending flow are generated in this way, a partition plate for partitioning two tanks forming a pair is formed so as to project sufficiently higher than a normal water level, and the tank is filled. It is more preferable that the water level in the upstream tank be higher than the water level in the downstream tank when the water permeability of the object is reduced. That is, the lowering and lowering pressure and the rising flow pressure can be increased by the water level difference between the upstream side and the downstream side, so that the water resistance due to the sludge (biological film or adhered matter) accumulated on the surface of the packing material or in the gap can be countered. As a result, it is possible to prevent a decrease in water permeability, and it is also possible to remove the sludge by appropriately peeling it by this high-pressure water flow, so that periodic sludge removal work such as backwashing becomes unnecessary. It is also possible to do.

[0012]

EXAMPLES Examples of the present invention will be described below. The water treatment device in this embodiment is an example designed to have a treatment capacity of about 25 m ³ / day, and as shown in FIGS. 1 to 3,
The inside of a rectangular parallelepiped concrete casing having a total length of about 11 m, a width of about 3.5 m, and a height of about 2.2 m is almost evenly divided by the main partition wall W into five blocks Ba to Be.
It has a structure in which necessary blocks are set in each of the blocks Ba to Be.

The first block Ba is entirely used as the settling tank 1. This settling tank 1 is for removing sediments of relatively large suspended matter from the water to be treated, and has an inflow rectifying cylinder 2 at the upstream end and an outflow rectifying cylinder 3 at the downstream end. Others are perplexed. In other words, this settling tank 1
The water to be treated that has flowed in from the inflow path P into the inflow passage P is made a downward flow by the inflow rectifying cylinder 2, flows toward the bottom of the settling tank 1 and gently moves in the tank, and then flows into the outflow rectifying cylinder 3. It flows out from the outlet 3t to the second block Bb. And
During this period, the residence time of the water to be treated in the sedimentation tank 1 is about 1 hour, and during this residence, a relatively large amount of suspended matter is removed by sedimentation.

In the second block Bb, a perforated bottom plate 4b is provided so as to form a sludge pit Db having a predetermined depth so as to float above the bottom of the casing, and a partition plate 5b is provided upright at the center of the perforated bottom plate 4b. A pretreatment tank 6 and a denitrification tank 7 are formed by partitioning. Therefore, both tanks 6 and 7 communicate with each other through the sludge pit Db, and the water to be treated flows down into the denitrification tank 7 through the sludge pit Db after flowing down in the pretreatment tank 6. become.

The pretreatment tank 6 is filled with a plastic porous filter medium (not shown).
While the S is filtered, the BOD component is decomposed and removed by the microorganisms that have settled on the filter medium.

The denitrification tank 7 is for removing nitrogen dissolved in nitric acid state in the water to be treated, and as shown in FIG. 4, an assimilation layer 8 and an adsorbent layer 9 are provided in a laminated state. ing. The assimilation layer 8 is formed by filling the dead bodies of plants, which serve as a nutrient source for the bacteria and also provide a favorable place for the bacteria, to a density at which an appropriate water permeability is obtained. Specifically, for example, a core layer 8c is obtained by crushing old tatami cores, dead branches, or scallops of shiitake mushrooms into an appropriate size between the epidermal layers 8s using a straw-like structure. It is formed by filling. The assimilation layer 8 is highly anaerobicized by being immersed in the water to be treated, and under this anaerobic condition, the conversion of nitrate nitrogen to ammonia nitrogen and nitrogen gas is carried out by the following three kinds of coexisting processes. The generated ammonia nitrogen is adsorbed and removed by the adsorbent layer 9, while the nitrogen gas is released into the air.

The conversion to ammonia nitrogen is carried out in the assimilation layer based on the anaerobic conditions and the reduction based on the biological activity of the bacteria capable of reducing nitrate, which propagates by utilizing the assimilation layer, and the highly anoxic condition in the assimilation layer. In other words, it proceeds by pure chemical reduction at a high reduction level. These reduction processes are indicated as NO ₃ ⁻ → NO ₂ ⁻ → N ₂ O → NH ₄ ⁻ . On the other hand, conversion to nitrogen gas (N ₂ ) is performed by denitrifying bacteria that similarly propagate in the assimilation layer using the anaerobic condition and assimilation, and NO ₃ ⁻ + 5H (hydrogen donor) → 0.5 N ₂
Shown as + 2H ₂ O + OH ⁻ .

The adsorbent layer 9 is formed by filling a gravel-like adsorbent of a mineral material having a high adsorption capacity for ammonia nitrogen such as zeolite (zeolite) or vermiculite. It has a two-layer structure of a layer 9m made of an adsorbent having a large size and a layer 9n made of an adsorbent having a small size.

The third block Bc is the first chitosan charcoal tank 10 for decomposing BOD components by aerobic biological treatment as a whole, and the sludge pit D is also provided at the bottom thereof.
A perforated bottom plate 4c for forming c is provided, and chitosan-treated chitosan charcoal (not shown) is crushed and laminated on the perforated bottom plate 4c, and the chitosan charcoal layer further has an air supply means 11c. Is designed to supply oxygen. Since chitosan charcoal floats on water, an adsorbent for adsorbing ammoniacal nitrogen is placed as a weight on it.

Chitosan charcoal has chitosan attached to the pore walls of the pores of charcoal. By covering the spines, which are disliked by microorganisms, with chitosan, one of the factors inhibiting the colonization of microorganisms is eliminated. By eliminating the polarity of the pore wall by non-polarity, one other factor inhibiting fixation is also eliminated. In other words, chitosan charcoal is designed to maximize the ability of charcoal to retain microorganisms due to its microporous structure.
By using this as a base material for biological treatment, excellent treatment efficiency can be obtained. Such chitosan treatment is
This is done by immersing the charcoal in the chitosan solution for a certain period of time, or by spraying or spraying the charcoal with the chitosan solution (Japanese Patent Application No. 4-59177).

The fourth block Bd is divided into approximately equal parts by a partition plate 5d standing from the bottom of the casing, and the upstream side is the second block.
The chitosan charcoal tank 12 and the aeration exclusive tank 13 on the downstream side. The second chitosan charcoal tank 12 is basically the same as the first chitosan charcoal tank 10 except that its size is about half. On the other hand, the dedicated aeration tank 13 is for supplying oxygen into the water to be treated, and it is complicated like the settling tank 1 so that the air supplied by the air supply means 11d easily diffuses into the water to be treated. Has been

A dephosphorization tank 14 and a finishing tank 15 are provided in the fifth block Be in the same structure as the second block Bb. The dephosphorization tank 14 is mainly for the purpose of adsorbing and removing phosphorus and also for adsorbing and removing ammonia nitrogen, and it is an adsorbent (not shown) for adsorbing phosphorus and an adsorbent for adsorbing ammonia nitrogen. Materials (not shown) are stacked and filled in layers. On the other hand, the finishing tank 15 is filled with normal charcoal (not shown), which is used for decolorization and deodorization, and for fine SS filtration and final biological treatment.

Here, each partition plate 5 in the second block Bb, the fourth block Bd, and the fifth block Be.
b, 5d, and 5e are formed so as to project sufficiently higher than a normal water level state (state of FIG. 1). this is,
This is intended to allow the water level in the upstream tank to be higher than the water level in the downstream tank in response to the increase in water resistance caused by the accumulation of sludge in the filter media and chitosan charcoal in each tank. As described above, it is possible to prevent the deterioration of water permeability and to achieve a constant backwash effect.

As shown in FIG. 2, a sludge recovery pipe 16 is provided along the casing.
The sludge can be collected at any time through the branch pipes facing the blocks from 6. Although not shown, each block is entirely covered with a lid in order to prevent rainwater from entering and irradiation of sunlight.

[0025]

As described above, the water treatment apparatus according to the present invention is a combination of a denitrification tank and a chitosan charcoal tank having high treatment efficiency as a core, a pretreatment tank, a dephosphorization tank, and a finishing tank. Therefore, all advanced water treatment including denitrification and dephosphorization can be efficiently performed by biological treatment. Therefore, for example, by using this for purification treatment of a small river in a basin where household wastewater is drained as it is, it can greatly contribute to conservation of water quality environment in harmony with nature.

[Brief description of drawings]

FIG. 1 is a sectional view of a water treatment device according to the present invention.

FIG. 2 is a plan view of the water treatment device of FIG.

3 is a cross-sectional view taken along the arrow SA ₃ -SA ₃ in FIG.

FIG. 4 is a sectional view of a denitrification tank.

[Explanation of symbols]

 4b, 4e Sludge pit 5b, 5e Partition plate 6 Pretreatment tank 7 Denitrification tank 8 Nitrate layer 9 Adsorbent layer 10 Chitosan charcoal tank 11d Air supply means 13 Aeration tank 14 Dephosphorization tank 15 Finishing tank

Claims (7)

[Claims] 1. A pretreatment tank filled with a filter medium for removing suspended solids and the like, and an adsorbent layer filled with an adsorbent capable of adsorbing ammonia nitrogen as well as provided with an assimilation layer filled with bacterial assimilation. It is equipped with a denitrification tank that is continuously provided in the assimilation layer, a chitosan charcoal tank that is filled with charcoal that has been subjected to chitosan treatment, a dephosphorization tank that is filled with an adsorbent that can adsorb phosphorus, and a finishing tank that is filled with charcoal. Water treatment equipment. 2. The water treatment device according to claim 1, wherein the dephosphorization tank is combined with a chitosan charcoal tank. 3. The water treatment apparatus according to claim 1, further comprising an aeration tank for facilitating diffusion of the air supplied by the air supply means into the water to be treated. 4. The water treatment device according to claim 3, wherein a pretreatment tank, a denitrification tank, a chitosan charcoal tank, an aeration exclusive tank, a dephosphorization tank, and a finishing tank are arranged in this order from the upstream side to the downstream side. . 5. The water treatment device according to claim 3, wherein a pretreatment tank, an aeration tank, a denitrification tank, a chitosan charcoal tank, a dephosphorization tank, and a finishing tank are arranged in this order from the upstream side to the downstream side. . 6. One of the two tanks is paired, and a sludge pit is commonly provided for both tanks, and the water to be treated that has flowed into one tank from above is passed through the sludge pit to the other tank. 1 to allow the gas to flow in from below.
The water treatment device according to claim 5. 7. A partition plate for partitioning two tanks forming a pair is formed so as to project sufficiently higher than a normal water level state,
The water treatment device according to claim 6, wherein the water level of the upstream tank is higher than the water level of the downstream tank when the water permeability of the filling material in the tank is lowered.