JP3137326B2 - Water purification method - 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 purification method for purifying water in ponds, lakes, marshes, rivers and the like.

[0002]

2. Description of the Related Art There are various methods for purifying the water quality of ponds, lakes and the like. For example, constructing a water purification facility that combines chemical methods with filtration and sedimentation next to lakes and marshes,
There is a method of drawing water from a lake into the water purification facility, purifying the water, and then discharging the water to the lake again.

[0003]

SUMMARY OF THE INVENTION
Very expensive and often difficult to implement in practice. On the other hand, it is known that so-called porous concrete has a certain degree of water purification action, and it can be implemented at a relatively low cost, but it is said that the purification action is not so great.

[0004] The present invention provides a water purification method which can be carried out at a relatively low cost by using porous concrete, and which provides a remarkable purification capability compared to the case where conventional porous concrete is used alone. is there.

[0005]

SUMMARY OF THE INVENTION The present invention is a water purification method characterized by installing a porous concrete block and a phosphorus adsorbent block obtained by firing a mixture of volcanic ash and ferrous sulfate in water. .

[0006] Porous concrete is a porous concrete produced by blending an extremely large ratio of coarse aggregate to fine aggregate compared to ordinary concrete. The phosphorus adsorbent is obtained by mixing and firing volcanic ash and ferrous sulfate. This is an extremely excellent phosphorus adsorbent having a large phosphorus adsorption capacity, and a large water purification effect can be obtained by using it together with porous concrete.

[0007] The size and shape of the block are not limited, and the size and shape that are easy to handle can be freely selected. For example, it can be installed underwater or on the waterside as a bed block for riverbed, a block for revetment, or a reef block. It is also possible to integrate the porous concrete block and the phosphorus adsorbent block.

[0008] In order to obtain a sufficient effect in about one month, the amount of the block installed in water is about 1.5 to 5% (volume percentage) of the amount of water in the porous concrete, and the phosphorus adsorbent block is made of the porous concrete. Although it is desirable to set it to about 10% (volume), it is needless to say that the present invention is not limited to this, and may be increased or decreased as needed.

[0009]

The cause of water pollution is mainly organic matter, nitrogen and phosphorus. The present inventors have studied the water purification action of porous concrete. As a result of the action of microorganisms inhabiting the myriad of pores of the porous concrete, the organic matter in the polluted water becomes carbon dioxide and water, and the nitrogen compound becomes nitrogen. They were actively decomposed and removed by gas, respectively, but they found that only the porous concrete had little phosphorus removal effect.

FIG. 1 is a graph showing changes in the concentration of phosphoric acid phosphorus in water when porous concrete is used alone (2) and when porous concrete and a phosphorus adsorbent are used together (1). 23 liters of tap water are put into each of the two containers, and KH2PO4 is added so as to be 1 mgP / l.
Each piece was filled with eight pieces of 10 cm square porous concrete and about 0.81 liter of a phosphorus adsorbent. As is clear from this, the effect of removing phosphoric acid phosphorus by the porous concrete alone is small, but the effect is dramatically increased by using the porous concrete together with the phosphorus adsorbent. When neither the porous concrete nor the phosphorus adsorbent was contained (3), the phosphorus concentration did not decrease at all.

FIG. 2 is a graph showing the change in the concentration of total phosphorus in water in a polluted water existing in nature alone (5) and in the case of using both a porous concrete and a phosphorus adsorbent (4). It is. 23 liters of naturally polluted pond water are placed in two containers, one containing about 1 liter of phosphorus adsorbent and the other containing 8 10 cm square porous concrete and about 1 liter of phosphorus adsorbent. Both were put in, and sampling was performed over time to measure.
As can be seen from this graph, the phosphorus adsorbent alone has a small effect of adsorbing phosphorus in polluted water in nature.
This is considered to be because most of the phosphorus in the polluted water in the natural world is present in organisms such as plankton, so that phosphorus in such organisms cannot be directly adsorbed. However, by using it together with porous concrete,
It is presumed that the microorganisms adhering to the porous concrete surface release phosphorus into the water from living organisms in the water, and the phosphorus adsorbent adsorbs the phosphorus, whereby the phosphorus adsorption effect increases synergistically. In addition, in FIG. 2, (6) shows the change of the total phosphorus concentration in the water when neither the porous concrete nor the phosphorus adsorbent is measured, which is measured simultaneously for reference.

[0012]

[Example] A porous concrete block and a phosphorus adsorbent block were set in water of a pond polluted with plankton and algae having an amount of water of about 70 m3. The porous concrete block is about 200 cylinders with a diameter of about 15 cm and a height of about 30 cm. The phosphorus adsorbent block is a mixture of volcanic ash and ferrous sulfate, which is fired and has a capacity of about 5 liters. About 20 of them were used.

[0013] Water quality is initially 20-30 ppm of total organic matter
(Carbon content), total phosphorus was 0.085 ppm, phosphoric acid phosphorus was 0.01 ppm, and visibility was 10 to 15 cm. After 30 days, total organics are about 10 ppm, total phosphorus is 0.1 ppm.
038 ppm, no phosphoric acid phosphorus was detected, and the visibility was 50
cm or more.

As in this embodiment, in order to obtain a sufficient effect in about 30 days, the amount of the porous concrete should be about 1.5% or more of the water amount, and the amount of the phosphorus adsorbent should be about 10% of the porous concrete ( Volume).

When the amount of water in a river or the like changes, it is desirable to install a porous concrete block and a phosphorus adsorbent block in a place constantly submerged in the riverbed.
Even if installed on a riverbed that is not always underwater, a certain effect can be obtained.

[0016]

According to the water purification method of the present invention, since the porous concrete block and the specific phosphorus adsorbent block are merely installed in water, the method can be carried out relatively inexpensively and easily. A great effect can be obtained by the synergistic action of the phosphorus adsorbent block.

[Brief description of the drawings]

FIG. 1 is a graph showing changes in the concentration of phosphoric acid in water when porous concrete is used alone or when porous concrete and a phosphorus adsorbent are used in combination.

FIG. 2 is a graph showing a change in the concentration of total phosphorus in water when a phosphorus adsorbent is used alone in polluted water existing in nature and when a porous concrete and a phosphorus adsorbent are used in combination.

[Explanation of Signs] 1 Change in phosphoric acid phosphorus concentration in water when porous concrete and phosphorus adsorbent are used together 2 Change in phosphoric acid phosphorus concentration in water when porous concrete is used alone 3 Porous concrete and phosphorus adsorbent Change in phosphoric acid phosphorus concentration in water when neither is contained 4 Change in total phosphorus concentration in water when using porous concrete and phosphorus adsorbent 5 Change in total phosphorus concentration in water when phosphorus adsorbent is used alone 6 Changes in total phosphorus concentration in water when neither porous concrete nor phosphorus adsorbent is included

──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Masayuki Hashimoto 1-6-1, Otemachi, Chiyoda-ku, Tokyo Inside Nippon Cement Co., Ltd. (72) Inventor Kazuto Yoshimori 1-2-23, Kiyosumi, Koto-ku, Tokyo Japan Cement Co., Ltd. Central Research Laboratory (58) Fields investigated (Int. Cl. ⁷ , DB name) C02F 1/28 C02F 3/10 B01D 15/00 E02B 3/00 C02F 1/58

Claims (3)

(57) [Claims] 1. A method for purifying water, comprising installing, in water, a porous concrete block and a phosphorus adsorbent block obtained by firing a mixture of volcanic ash and ferrous sulfate. 2. The water purification method according to claim 1, wherein the amount of the porous concrete block is 1.5% of the treated water amount.
(Volume percentage) or more 3. The water purification method according to claim 1, wherein a ratio of the phosphorus adsorbent block to the porous concrete block is about 10% (percentage by volume).