JPH0471679A - Method for purifying water - Google Patents

Abstract

PURPOSE:To efficiently purify water without causing environmental disruption by irradiating the whole of a water region to be purified with light from a light source for a specified time or more per one day so that the illuminance of the whole of the water region is regulated to specified luxes or more. CONSTITUTION:The whole of a water region to be purified is irradiated with light from a light source set on or in the water for >=2hr/day so that the illuminance of the whole of the water region is regulated to >=50 luxes. The wavelength of the light is made close to the wavelength range of sunbeams and is preferably 500-800nm. The metabolic activity of organisms is accelerated, the amt. of dissolved oxygen in the water is increased, org. matter is actively degraded by aerobic bacteria and the purification of the water proceeds furthermore. This method does not cause environmental disruption and is efficient and economical.

Description

[Detailed description of the invention] [Industrial application field] The present invention is a water purification method for reservoirs, dams, etc.

[Conventional technology] In water bodies such as reservoirs and dams where water turnover is low, especially in the deep layers, oxygen is deficient in the water, the ability of aerobic bacteria to decompose organic matter decreases, and attributeization progresses, resulting in a decline in water quality. ing.

The above deterioration in water quality is a sanitary problem and also has a bad appearance. Therefore, treatments such as pumping up and removing the attributes, replacing the water, and spraying chemicals are performed.

[Problems to be solved by the invention] However, the amount of water stored in reservoirs and dams is enormous, making it virtually impossible to replace the entire water, and when using water for drinking, it is impossible to add chemicals, etc. Due to these problems, there is currently no effective purification method.

[Means for Solving the Problems] The present invention is a purification method that can also be used for large-scale water bodies such as reservoirs and dams.

The structural feature of the present invention is that the entire targeted purified water area is
It is to irradiate light so that it is 0 lux or more.

The present invention will be explained in detail below.

Water areas to which the water purification method of the present invention is applied include water areas where the addition of chemicals or the like is prohibited or restricted due to the purpose of drinking water, agriculture, or fishing, particularly reservoirs and dams with an average water volume of 3,000 tons or more. It is suitably used for.

In the present invention, a purified water area refers to a water area where the illuminance of natural light, that is, sunlight, is always less than 50 lux, or where the illuminance of 50 lux or more is less than 2 hours a day.

In the water purification method of the present invention, the entire purified water area is illuminated by light sources installed above and below the water for at least 2 hours/day and 50
Irradiate light so that the light is lux or higher - Normal - Since the water near the water surface receives 50 lux or higher during the daytime due to sunlight, it is efficient to install the light source underwater, preferably in purified water. Furthermore, the intensity of the light source is not particularly limited, but
In order to maintain the illuminance of the entire purified water area at 50 lux or more,
It is more efficient to use a large number of light sources with a certain level of intensity than an extremely strong light source.

The wavelength of the light from the light source used in the water purification method of the present invention is preferably as close to sunlight as possible, preferably 500 to 800 nm.
m, more preferably a wide range of 3oo to 900nm.

In the present invention, the light irradiation time from the light source is the total time when the illumination intensity is 50 lux or more including sunlight, 2 times a day.
The time should be adjusted to be at least 5 hours, preferably 5 to 6 hours.

[Function] Bacteria such as photosynthetic bacteria, single-celled organisms such as blue-green algae, protozoa, diatoms, and green algae that generally live in water actively carry out their daily activities during the day when there is light, and their metabolic activities purify water. is progressing naturally.

On the other hand, in places where sunlight is difficult to reach even during the day, or in areas where water quality has deteriorated and water transparency is low, and where sunlight does not reach easily,
Even in the daytime, metabolic activity weakens and purification does not proceed.Furthermore, photosynthetic bacteria, single-celled organisms such as blue-green algae, and green algae do not perform photosynthesis.As a result, oxygen is not generated and pollutants are not decomposed or removed. Without progress, the amount of dissolved oxygen in the water continues to decline, making it even harder for sunlight to reach them, creating a vicious cycle.

The present invention promotes the metabolic activity of the organisms described above by artificially irradiating light onto water areas that are difficult for sunlight to reach. As a result, the amount of dissolved oxygen in the water increases, the decomposition of organic matter by aerobic bacteria becomes active, and water purification further progresses.

Attributes often accumulate at the bottom of water bodies where water has become highly polluted, but as water purification progresses according to the present invention, these attributes will eventually disappear as decomposition progresses from the top of the attributes.

[Example] Specific examples of the present invention will be shown below, but the present invention is not limited thereto.

The water purification method of the present invention was carried out on a reservoir with an average water volume of 5,000 m and a depth of 5 m at its deepest point.

This reservoir has about 20cm of attributes at the bottom.
The purified water area has a volume of 30 ln from 1 m below the water surface to the upper surface of the attribute.
5 light sources were installed, and the entire purified water area was illuminated for 10 hours a day.
Light was irradiated at 50 lux or more. Immediately after irradiation, the illumination intensity was 100 to 150 lux because the water transparency was low, but after three weeks, the transparency increased, so the light source was reduced and irradiation was carried out at a constant range of 150 to 200 lux.

As a result, after 6 weeks, the water clarity further increased, and
Due to this purification operation, the attributes that had accumulated at the bottom of the water were almost completely gone.

After that, when they left the light source only in areas near the bottom of the water that are hard for sunlight to reach, and maintained an illuminance of 50 lux or higher, the water quality did not deteriorate.

[Effects of the Invention] As explained above, the water purification method of the present invention purifies water by simply installing a light source, so there is no danger like using chemicals, and the light source can be installed as is. There is no need to worry about water quality deteriorating over time, so there is no need to worry about destroying the natural environment, and it is extremely efficient and economical.

Applicant: Yoshida Research Institute Co., Ltd.

Claims (1)

[Claims] (1) A water purification method characterized by irradiating light from a light source so that the illuminance of the entire purified water area is 50 lux or more for 2 hours/day or more.