JP2619201B2 - Water treatment equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art The present applicant has previously filed Japanese Patent Application No. 4-59177.
A micro-habitat made of charcoal was proposed as No. 4, and a denitrification method was proposed as Japanese Patent Application No. 4-296533. The charcoal microhabitat of Japanese Patent Application No. 4-59177 is excellent in microbial fixation, and by using this as a "base material", improvement in purification efficiency by biological treatment can be expected. The denitrification method disclosed in 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. This is a method that incorporates a process of converting to high ammonia nitrogen and removing this ammonia nitrogen by adsorption with an adsorbent.As a result of simultaneous use of multiple types of coexisting biological treatments, The feature is that high denitrification treatment can be performed with a simple equipment structure.

[0003] However, these are all new materials and methods, and there is still no water treatment apparatus for effectively utilizing them to perform advanced water treatment comprehensively, and development thereof is desired.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to combine the above-mentioned novel methods,
An object of the present invention is to provide a water treatment device capable of performing 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 and the like.
A denitrification tank provided with an adsorbent layer filled with an adsorbent capable of adsorbing ammonia-nitrogen and a denitrification tank provided with an adsorbent layer filled with bacterial assimilates and a charcoal treated with chitosan is provided. It has a filled chitosan charcoal tank, a dephosphorization tank filled with an adsorbent capable of adsorbing phosphorus, and a finishing tank filled with charcoal.

[0006] In this water treatment apparatus, suspended solids (SS) are mainly removed in a pretreatment tank and BOD is removed.
The components (organic substances) are also decomposed, the denitrification is performed in the denitrification tank, the BOD component is decomposed in the chitosan charcoal tank, the dephosphorization is performed in the dephosphorization tank, and the finishing SS is also decolorized and deodorized. Removal and BOD
The components are decomposed, and advanced water treatment can be realized by complex combinations of treatments, all of which are biological treatments.

[0007] In the above water treatment apparatus, 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, the processing efficiency in the downstream processing tank can be improved.

Various arrangements are possible for the arrangement order of the tanks in the water treatment apparatus as described above. For example, from an upstream side to a downstream side, a pretreatment tank, a denitrification tank, a chitosan charcoal tank, an aeration tank, Arranging in the order of a dedicated tank, a dephosphorization tank, and a finishing tank is a preferable example from the viewpoint of each processing. In addition, when a dedicated aeration tank is added, it is preferable that the tank be provided immediately before the dephosphorization tank or immediately before the denitrification tank.

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

[0010] Further, regarding the water treatment apparatus as described above,
Two tanks are paired for either tank, and a sludge pit is provided in common for both tanks, and the water to be treated, which has flowed into one tank from above, flows into the other tank from below via the sludge pit. In this case, a forced downward flow and an upward flow can be generated in both tanks, so that the contact efficiency of the water to be treated with the filler can be increased, which is more preferable.

When a downward flow and an upward flow are generated as described above, a partition plate for partitioning the two tanks to be paired is formed so as to protrude sufficiently high with respect to a normal water level state. 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 down pressure and the ascending flow pressure can be increased by the water level difference between the upstream side and the downstream side. As a result, a decrease in water permeability can be prevented, and sludge can be appropriately peeled and removed by the high-pressure water flow, so that periodic sludge removal work by backwashing or the like becomes unnecessary. It is also possible to do.

[0012]

Embodiments of the present invention will be described below. The water treatment apparatus in this embodiment is an example designed to have a treatment capacity of about 25 m ³ / day, as shown in FIGS.
The inside of a casing formed of concrete in a rectangular parallelepiped shape 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 a main partition wall W into first to fifth five blocks Ba to Be.
And the tanks required for each of the blocks Ba to Be are set.

The entire first block Ba is a sedimentation tank 1. The sedimentation tank 1 is for sedimentation and removal of relatively large suspended matter from the water to be treated, and has an inflow rectification cylinder 2 at an upstream end and an outflow rectification cylinder 3 at a downstream end. The others are empty. In other words, this sedimentation tank 1
The water to be treated, which flows from the inflow passage P into the flow rectification cylinder 2, is made to flow downward by the inflow rectification cylinder 2, flows toward the bottom of the sedimentation tank 1, and moves slowly in the tank. It flows out from the outlet 3t to the second block Bb. And
The residence time of the water to be treated in the sedimentation tank 1 during this period is about one hour, and a relatively large suspended matter is settled and removed during the residence.

In the second block Bb, a perforated bottom plate 4b is provided so as to float from the bottom of the casing so as to form a sludge pit Db of a predetermined depth, and a partition plate 5b provided upright at the center of the perforated bottom plate 4b. And a pretreatment tank 6 and a denitrification tank 7 are formed. Therefore, the two tanks 6 and 7 communicate with each other through the sludge pit Db, and the water to be treated flows down the pretreatment tank 6 and then flows upward through the sludge pit Db into the denitrification tank 7. become.

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

The denitrification tank 7 is for removing nitrogen dissolved in the water to be treated in the form of nitric acid. As shown in FIG. 4, an assimilate layer 8 and an adsorbent layer 9 are provided in a laminated state. ing. The assimilable material layer 8 is formed by filling a dead body of a plant, which serves as a nutrient source for bacteria and provides a favorable place for bacteria, with a density that allows appropriate water permeability. Specifically, for example, the core layer 8c is obtained by crushing an old tatami mat core or dead branch or shiitake mushroom firewood into an appropriate size between the skin layers 8s using straw as a straw-like structure. It is formed by filling. This assimilate layer 8 is highly anaerobic by being immersed in the water to be treated, and under these anaerobic conditions, the conversion of nitrate nitrogen to ammonia nitrogen and nitrogen gas is performed by the following three coexisting processes. The resulting 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 by reducing the anaerobic conditions in the assimilate layer and the biological activity of the bacteria having a nitrate reducing ability which propagates by utilizing the assimilates, and under the high anoxic conditions in the assimilate layer. That is, it proceeds by pure chemical reduction at a high reduction level. These reduction process is _{^{NO 3 - → NO 2 - →}} N 2 O → NH 4 - shown as. On the other hand, the conversion to nitrogen gas (N ₂ ) is carried out by denitrifying bacteria that also propagate in the assimilate layer using the anaerobic conditions and assimilates, and NO ₃ ⁻ + 5H (hydrogen donor) → 0.5 N ₂
Indicated as + 2H ₂ O + OH ⁻ .

The adsorbent layer 9 is formed by filling an adsorbent made of a mineral substance such as zeolite (zeolites) or vermiculite, which has a high ability to adsorb ammonia nitrogen, into a pebble shape. It has a two-layer structure of a layer 9m made of a large size adsorbent and a layer 9n made of a small size adsorbent.

The third block Bc is a first chitosan charcoal tank 10 for decomposing BOD components by aerobic biological treatment, and has a sludge pit D at its bottom.
A perforated bottom plate 4c for forming c is provided, and chitosan charcoal (not shown) treated with chitosan is crushed and laminated on the perforated bottom plate 4c, and the chitosan charcoal layer is supplied with air supply means 11c. To supply oxygen. Since chitosan charcoal floats on water, an adsorbent for ammonia nitrogen adsorption is placed thereon as a weight.

Chitosan charcoal is charcoal in which chitosan is attached to the pore walls of pores of the charcoal. One of the factors inhibiting the colonization of microorganisms is removed by covering the spicules which the microorganisms dislike with chitosan. Eliminating the polarity of the pore pore walls by non-polarity also eliminates one other anchoring inhibition factor. In other words, chitosan charcoal makes the most of the microporous microbial colonization suitability of charcoal,
By using this as a substrate for biological treatment, excellent treatment efficiency can be obtained. Such a chitosan treatment,
This is performed by immersing the charcoal in the chitosan solution for a certain period of time, or by spraying or spraying the chitosan solution on the charcoal (Japanese Patent Application No. 4-59177).

The fourth block Bd is substantially equally divided by a partition plate 5d erected from the bottom of the casing.
The chitosan charcoal tank 12 and the downstream side are dedicated aeration tanks 13. The second chitosan charcoal tank 12 is basically the same as the first chitosan charcoal tank 10 except that the size is about half. On the other hand, the aeration-dedicated tank 13 is for supplying oxygen to the water to be treated, and is provided similarly to the sedimentation tank 1 so that the air supplied by the air supply means 11d is easily diffused into the water to be treated. Has been.

The fifth block Be has a dephosphorization tank 14 and a finishing tank 15 having the same structure as the second block Bb. The dephosphorization tank 14 has a main purpose of adsorbing and removing phosphorus and also performs an auxiliary adsorption and removal of ammonia nitrogen. An adsorbent (not shown) for adsorbing phosphorus and an adsorbent for adsorbing ammonia nitrogen are used. Materials (not shown) are filled in layers. On the other hand, the finishing tank 15 is filled with ordinary charcoal (not shown), and the charcoal is used for decolorization and deodorization, and also for filtering fine SS and final biological treatment.

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

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

[0025]

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

[Brief description of the drawings]

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

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

FIG. ₃ is a sectional view taken along arrows SA ₃ -SA ₃ in FIG. 2;

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 Utilization layer 9 Adsorbent layer 10 Chitosan charcoal tank 11d Air supply means 13 Aeration dedicated tank 14 Dephosphorization tank 15 Finishing tank

Claims (7)

(57) [Claims] 1. A pretreatment tank filled with a filter medium for removing suspended solids and the like, an assimilate layer filled with assimilable bacteria, and an adsorbent layer filled with an adsorbent capable of adsorbing ammonia nitrogen. It is equipped with a denitrification tank provided in a continuous state in the material layer, a chitosan charcoal tank filled with charcoal treated with chitosan, a dephosphorization tank filled with an adsorbent capable of adsorbing phosphorus, and a finishing tank filled with charcoal. Become a water treatment device. 2. The water treatment apparatus 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 a dedicated aeration tank for facilitating diffusion of the air supplied by the air supply means into the water to be treated. 4. The water treatment apparatus according to claim 3, wherein a pretreatment tank, a denitrification tank, a chitosan charcoal tank, a dedicated aeration 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 apparatus according to claim 3, wherein a pretreatment tank, a dedicated 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. A pair of two tanks is provided for any one of the tanks, and a sludge pit is provided in common for both tanks, and water to be treated which has flowed into one of the tanks from above is supplied to the other tank via a sludge pit. Claim 1 to make it flow from below
The water treatment device according to claim 5. 7. A partition plate for partitioning two tanks to be paired is formed so as to project sufficiently high with respect to a normal water level state,
7. The water treatment apparatus 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 filler in the tank decreases.