JPS60261837A - Method of separating floatable substance in water area - Google Patents

Abstract

PURPOSE:To improve working efficiency, by a method wherein air bubbles are produced by blowing a pressurized air against the sea bottom of a sea area, and floatable substances on the sea bottom, forced to float by means of the bubbles, are raised for separation. CONSTITUTION:After flocculating agent is scattered over an area where sludge (a) is intended to be separated, when, with a pump 2 on a pump ship 1 driven, a pressurized air is injected through an air feed pipe 3 toward the sludge (a) on the sea bottom to blow up the floatable substances and produce air bubbles. Sludge particles, adhered to the air bubbles, are raised in water, and the particles are flocculated through the action of the flocculating agent to produce floating floc which float on a water surface in the form of scum C. The scum C is then removed by a proper means.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for separating floating substances in a water body, and particularly to a method for separating filth and soft sludge on the bottom of a water body in a natural or artificial water area, purifying the bottom of the water, and purifying a floating substance free of filth and sludge. Relates to dredging that allows only gravel to be dredged.

BACKGROUND OF THE INVENTION A sedimentary layer is formed on the bottom of natural or artificial water bodies such as oceans, rivers, lakes, dams, etc. This sedimentary layer contains many things like gravel that do not deteriorate water quality, but it also contains impurities such as plants and soft mud made of silt, clay, colloid particles, etc., and these impurities and soft mud are rotten. There are things that worsen water quality.

These substances that deteriorate water quality adhere to the gravel surface,
Furthermore, over time, it accumulates and forms a sapropel layer, which promotes the formation of water rings and the like, deteriorating water quality and making it impossible for living organisms to live.

In order to purify waters where the water quality has deteriorated in this way, conventional methods have been to dredge with a pump boat or remove the sapropel layer with a grab boat. However, since this type of equipment removes sacrificial sludge from all parts of the water bottom individually, it is inefficient and also removes gravel along with mud, which also removes things that do not deteriorate water quality. I don't like it.

In addition, when reclamation of a certain body of water or when collecting gravel, the above-mentioned pump boat or grab vessel may be used to dredge another body of water. Particularly in the process of depositing mud, if soft mud is mixed in with the collected material, it can pollute the landfill water area, and the mud particles may be suspended in the water and do not settle easily. This may cause problems such as the time it takes, and it is also preferable that there is no mud mixed in when collecting gravel.

As described above, the present invention has the following advantages: Conventionally, the removal of filth from the bottom of water such as the seabed is carried out using a pump boat or a grab boat, and as a result, the working efficiency of removing the filth is poor, and only the filth is not removed. In order to improve the problem of unavoidable attachment of soft mud even when dredging gravel, pressurized air is blown into the bottom of the water, thereby raising floating dirt, soft mud, etc., and making it float in the water. To provide a method for separating floatable substances in a water body, which enables better purification of the water bottom and dredging of gravel by separating non-floating substances such as gravel.

Next, one embodiment of the present invention will be described based on the drawings.

The figure shows the case where saproplastic sludge A accumulated on the bottom of a dam is separated by gravel. A coagulant is sprayed on the area where the saproulic sludge is to be separated, and then pump 2 of pump ship 1 is activated. Then, pressurized air is blown out from the air pipe 3 toward the sludge at the bottom of the water. As a result, the floatable sludge and the like are blown up, and air bubbles are generated, to which the individual blown up mud particles adhere. As the bubbles rise, the mud also rises in the water, and the particles attached to each bubble are coagulated by the action of the flocculant and become floating lumps.
This is floated and separated on the water surface as scum C. In this way, the gravel that does not float even if air bubbles are attached to it is separated from the floating filth that separates due to the attachment of air bubbles, and if the floating scum is removed by an appropriate means, the water body can be Purification can be performed.

Although such floatable materials can be separated using pressurized air,
Pressurized air can be ejected very easily from one location to another, resulting in good workability, and since only dirt can be separated, the separation efficiency is also good.

In addition, as the above-mentioned flocculant, sulfuric acid band, puncture, polymer flocculant, etc. can be used.

The above explanation was about dams, but the same can be done for separating mud at the bottom of the ocean floor, lakes, and rivers.

The above was a case of purifying the water bottom, but as shown in FIG. 2, an air supply pipe 6 is installed near the grab 5 of the grab vessel 4,
Pressurized air is sent from the pump 7 to this, which causes the soft mud a
'' in the same way as in Figure 1, leaving only the gravel type b'' on the bottom of the water and dredging this with grab 5, it is possible to collect only the gravel type that does not float due to air bubbles. Note that even if a pump boat is used instead of a grab boat and the air pipe 6 is installed near the hender, only gravel-based materials can be dredged in the same way.

As explained above, according to the present invention, floating substances such as saproulic sludge on the water bottom are separated from non-floating substances such as gravel using pressurized air. Efficiency can also be improved. Additionally, if the gravel-based non-floating materials are dredged after the floating materials have been separated in this way, dredging can be performed without soft mud, making it easier to use this dredged material for reclamation, etc. can.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of an apparatus used in a method according to one embodiment of the present invention, and FIG. 2 is an explanatory diagram of an apparatus used in a method according to another embodiment. In the figure, ■ is a pump ship, 4 is a grab ship, 5 is a grab ship, 2.
7 is a pump, and 3.6 is an air pipe. June 6, 1980 Patent applicant Tadashi Sano, Patent attorney representing Nippon Solid Co., Ltd.

Claims (1)

[Claims] (1) A method for separating floatable objects in a water body, which comprises blowing pressurized air into the bottom of a water body to generate air bubbles, and using the bubbles to lift and separate the floatable objects on the bottom of the water body.