JP3577663B2 - Water purification method and apparatus - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a method and an apparatus for purifying water, and more particularly to a method and apparatus for purifying water by using a narrow and closed water channel to increase purification efficiency and facilitate maintenance.
[0002]
[Prior art]
Conventional basic systems for purifying water from domestic wastewater and fish tanks are as follows: (1) first physically remove solids with a screen (filter); It is common to employ a method of oxidatively decomposing (nitrifying) the generated ammonia to nitrite and further to nitrate by the action of an aerobic microorganism such as activated sludge.
[0003]
In addition, since nitrate in water alone increases the acidity of water and causes eutrophication, as a third step, nitrogen components are removed (denitrified) in the form of nitrogen gas by the action of anaerobic microorganisms. Attempts have been made to pursue more advanced purification.
[0004]
[Problems to be solved by the invention]
However, in the process of nitrification using aerobic microorganisms, a considerable amount of oxygen is required to increase the activity of the microorganisms. In some cases, oxygen is actively supplied using means such as flow and stirring. In the process of denitrification using anaerobic microorganisms, it was necessary to shut off oxygen by closing the denitrification tank or temporarily stopping the flow of water.
It is extremely difficult to continuously and contradict the conditions of the nitrification and denitrification processes in the same facility, which has been a bottleneck for the practical use (miniaturization) of the apparatus.
[0005]
[Means to solve the problem]
In the present invention, a nutrient for promoting the growth of anaerobic microorganisms is disposed at the latter stage where aerobic microorganisms are propagated and nitrification is performed in the front stage of an elongated closed waterway and oxygen is almost consumed by the aerobic microorganisms. Then, nitrification and denitrification are continuously performed while a fixed amount of water is continuously flown in the same channel.
[0006]
In addition, by using a narrow and long water channel, the so-called channel phenomenon in which water selectively flows through a specific part of the filter medium can be prevented, the filter medium can be used effectively, and aerobic microorganisms and anaerobic microorganisms change places in the same water channel. It is possible to coexist, and almost purified water can be obtained, and at the same time, the size of the entire apparatus can be reduced.
[0007]
BEST MODE FOR CARRYING OUT THE INVENTION
FIG. 1 is a diagram showing the most basic embodiment of the present invention.
In FIG. 1, the water to be purified is pumped up from the water tank to be purified by a pump as shown by an arrow “from a water tank” at the upper left, and is supplied to a cylindrical “filter medium container” at the left end. A plurality of “filter media containers” (eight in the illustrated example) are alternately connected in a vertical manner in a stream of water, and follow a path shown by an arrow to reach the “filter media container” at the right end, and from there, the original. To be returned to the aquarium.
[0008]
The eight "filter medium containers" constitute a narrow and long closed water channel as a whole.
The filter material container at the left end constitutes a “physical filtration unit” for removing solid matter, and the subsequent six filter material containers constitute a “biological filtration unit for aerobic bacteria”.
The "filter medium container" on the right end is a "biological filtration unit for anaerobic bacteria".
[0009]
The water to be purified contains enough oxygen for the propagation of aerobic microorganisms together with organic matter when supplied to the filter medium container at the left end from the pump, but oxygen is consumed by the aerobic microorganisms as it goes to the right. When the content decreases and reaches the "filter medium container" on the right end, it hardly exists. Generally, the oxygen concentration in water for anaerobic microorganisms to propagate is said to be 2 mg / l or less, but at this stage, the oxygen concentration in water almost reaches that value.
[0010]
During this time, the organic matter in the water to be purified is nitrified and the concentration of nitrate increases accordingly.This nitrate component is denitrified by the anaerobic microorganisms in the "filter medium container" on the far right and returned to the water tank as purified water. become.
[0011]
FIG. 2 is a cross-sectional view showing an example of the internal structure of each cylindrical “filter medium container”.
FIG. 3 shows an inner cylinder for storing the filter medium stored in the cylindrical “filter medium container” in FIG. 2.
An inner cylinder 1 shown in FIG. 3 is filled with a filter medium 2 (FIG. 2), and a center shaft 1a of the inner cylinder 1 is provided to extend from upper and lower ends of the inner cylinder. Further, a lid 3 having a large number of small holes 3a through which water passes is fitted into the upper end of the inner cylinder 1 after the filter medium 2 is filled therein. A small hole 1c is also provided at the bottom of the inner cylinder 1.
The inner cylinder 1 shown in FIG. 3 is housed in the cylinder 5 shown in FIG. The cylindrical body 5 shown in FIG. 2 is provided with a pair of communicating portions 5a and 5b with lids 6a and 6b at positions facing the upper end of the side surface. The cylindrical body 5 is also provided with a pair of communicating portions 5c and 5d with lids 7a and 7b at positions facing the lower end of the side surface.
[0012]
The communicating portion 5b at the upper end of one cylindrical body 5 has a structure that can be fitted to the communicating portion 5a at the upper end of the cylindrical body 5 (not shown) adjacent to the right side. A continuous water channel is formed between the two cylinders 5,5. Similarly, a water channel can be formed by fitting between the communicating portions 5c and 5d between the lower ends of two adjacent cylinders 5 and 5. Even when they are not directly fitted, they can be connected by a rubber or plastic pipe.
A connection method is also possible in which a communication portion 5d at the lower end of the cylindrical body 5 and a communication portion 5a at the upper end of the cylindrical body 5 (not shown) adjacent to the right side thereof are connected by a pipe.
[0013]
If small holes with lids 5f, 5g, 5h, 5i are formed on the side surfaces outside the upper and lower communication portions 5a to 5d of the cylindrical body 5, they can be used as vent holes or drain holes as needed.
For example, when an abnormal gas is generated inside the cylindrical body 5, the gas can be removed by opening the lids of the upper small holes 5f and 5g at that portion. Further, when there is a sediment or the like, the lids of the lower small holes 5h and 5i can be opened and discharged.
[0014]
Further, by utilizing the small holes, a part of the water in the cylinder 5 in the nitrification area by the aerobic microorganisms is taken out at a stage before entering the cylinder in the denitrification area by the anaerobic microorganisms, and this is returned to the water tank. It can also be used to regulate water quality and growth of anaerobic microorganisms.
That is, if the total length of the cylinders constituting the nitrification area is too short, the amount of water is too large, or the amount of the filter medium is too small compared to the amount of water, the oxygen of the water flowing into the anaerobic area is reduced. It is necessary to take out some of the water before entering the anaerobic area while monitoring the water quality, since the residual amount may become excessive and affect the growth of anaerobic microorganisms in the anaerobic area. It can be used as an outlet of the bypass path in the case.
[0015]
Although the bottom of the cylinder 5 is closed, the top is an opening for taking the inner cylinder 1 in and out, and the lid 8 is provided so that it can be opened and closed.
As described above, since the cylindrical body storing the filter medium 2 is a unit formed into a cartridge of the same standard, not only can it be manufactured at low cost, but also by connecting an appropriate number of cylindrical bodies 5, a purification device of a required length can be obtained. Can be assembled.
In assembling, the cylinders 5 are arranged in parallel so that the longitudinal direction is directed to the vertical direction, and the upper and lower communication portions 5a to 5d are sequentially connected alternately, and unnecessary communication portions are closed by lids. As a whole, a long zigzag channel can be formed as shown by the arrow in FIG.
A similar long zigzag water channel can also be made by connecting the lower communication portion 5d and the upper communication portion 5a of the cylindrical body adjacent to the right with a pipe and repeating the connection.
In addition, it is also possible to make a block in which a plurality of cylinders 5 are combined in advance, and use these blocks connected.
[0016]
In actual use, the water to be purified is introduced into the communicating portion 5a of the state-of-the-art cylinder 5, and a filter medium suitable for physical filtration is sealed in the inner cylinder 1.
Further, a filter medium suitable for propagation of anaerobic microorganisms is sealed in the final-stage cylinder 5, and purified water is drained from the communication section 5b.
[0017]
【Example】
Taking the case where the present invention is applied to an aquarium fish purifying apparatus as an example, the following is obtained.
Each cylinder 5 has a diameter of about 3 cm and a length of about 30 cm.
In a 60 cm wide square water tank generally called a 60 type, eight of these are connected and used, and in that case, the effective total length of the cylindrical body is about 2 m28 cm. In the case of a water tank with a width of 120 cm, the total length is about 4 m56 cm by connecting eight more.
[0018]
FIG. 4 and FIG. 5 show the results of a comparison experiment with the most common purification device on the market when the device of the present invention was used in a 60-type water tank. (Experimenter: Masamichi Tsuji, Associate Professor, Tokyo Institute of Technology) The experiment was carried out using the same amount of water in the same aquarium and releasing 20 healthy angelfish each.
For the water tank for comparison, a 2426 type filter manufactured by Eheim Co. was used. For this, 2.5 l of Ehi Substrut and 1.5 l of Eheimmech recommended by the company were used. On the other hand, in the apparatus of the present invention, a sponge filter and a wool mat were used for the first stage physical filtration, and 0.88 l of a power house M type and 0.88 l of an S type were used in the aerobic filtration area. In the anaerobic filtration zone at the last stage, 100 g of Deniball (trade name) which is an organic carbon preparation was used.
[0019]
As a result, as shown in FIG. 4, the nitrate concentration of the filtered water started to increase in both devices 15 to 18 days after the start of the experiment, but in the device of the present invention, it gradually started to decrease from around 23 to 24 days, and after 60 days. While it remained almost constant, it still continued to rise in the comparison tank. As shown in FIG. 5, the pH of the apparatus of the present invention was almost stable at 7.0, while the pH of the comparative water tank continued to drop sharply. And the experiment had to be stopped.
[0020]
It should be noted that the device of the present invention continues to grow healthy even after 9 months. In other words, it means that there is no need to change the water at a normal level of ornamental fish breeding, and it can be said that the inconvenience of water changing, which was the biggest problem in breeding, was eliminated.
In addition, in the apparatus of the present invention, although nitrate increased in the same manner as the comparative water tank at first, it eventually turned to decrease, although initially there was almost no anaerobic microorganisms in the waterway, It is presumed that cultivation of anaerobic microorganisms was promoted by the cultivation of anaerobic environment and the action of organic carbon, and the original functions began to work.
[0021]
In the above embodiment, the purification of the ornamental fish tank has been described. However, the present invention can be similarly applied to a case where the water to be purified is sewage, human waste, river water, or the like. Depending on the quality of the water to be purified, the content of organic matter that is a nutrient source for the propagation of anaerobic microorganisms may be low from the beginning. By arranging organic plastic, organic carbon, and the like, which are the nutrient sources of the water, it is possible to cope with the water to be purified of any property.
[0022]
[Effects of the present invention]
As described above, the present invention uses an elongated closed waterway to create a favorable environment for anaerobic microorganism growth at the final stage, and to purify water almost neutrally by the denitrification effect brought by the anaerobic microorganism. And a device capable of continuously performing the same for a long period of time with a single device.
In addition, by forming the elongated water channel in a zigzag shape by connecting the cylindrical bodies, there is an advantage that the occurrence of the channel phenomenon is minimized, the filter medium can be easily replaced, and the apparatus can be downsized.
[Brief description of the drawings]
FIG. 1 is a view for explaining a basic principle of the present invention; FIG. 2 is a view showing a structure of a cylinder used as a water channel of the present invention; FIG. 3 is an inner cylinder inserted into the inside of the cylinder; FIG. FIG. 5 is a graph showing an experimental result of the apparatus of the present invention. FIG. 5 is a graph showing an experimental result of the apparatus of the present invention.
1 ... inner cylinder, 1a ... central axis of inner cylinder, 1c ... small hole,
2 ... filter medium, 3 ... lid of inner cylinder, 3a ... small hole, 5 ... cylindrical body, 5a to 5d ... communication part, 5f to 5i ... small hole,
6a-6b ... lid of upper communication part, 7a-7b ... lid of lower communication part,
8 ... Cylinder lid

Claims (3)

Several cylinders,
It is arranged in parallel so that the longitudinal direction goes to the vertical direction,
The upper and lower parts are alternately connected in a stream,
Form an elongated closed water channel in a zigzag shape,
Enclose physical filtration material in the inlet side cylinder of the wastewater to be purified,
The final stage cylinder is used as a biofiltration part by anaerobic bacteria,
Water purification device with the middle part as biological filtration part by aerobic bacteria. Several cylinders,
It is arranged in parallel so that the longitudinal direction goes to the vertical direction,
The upper and lower parts are alternately connected in a stream,
Form an elongated closed water channel in a zigzag shape,
In the cylindrical body, an inner cylinder provided with a number of small holes through which water passes on a lid and a bottom portion is housed,
The inner cylinder of the cylinder close to the inlet side of the wastewater to be purified is used as a biological filtration unit for aerobic bacteria,
A water purification device in which the inner cylinder of the portion near the outlet side of the wastewater to be purified has a biological filtration unit for anaerobic bacteria. Several cylinders,
It is arranged in parallel so that the longitudinal direction goes to the vertical direction,
The upper and lower parts are alternately connected in a stream,
Form an elongated closed water channel in a zigzag shape,
In the cylindrical body, an inner cylinder provided with a number of small holes through which water passes on a lid and a bottom portion is housed,
A physical filtration material is sealed in the inner cylinder in the cylinder on the inlet side of the wastewater to be purified, and the inner cylinder of the final stage cylinder is used as a biofiltration unit using anaerobic bacteria.
A water purifier that uses the inner cylinder of the middle cylinder as a biological filtration unit for aerobic bacteria.

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