JPH0581319B2 - - Google Patents

Description

[Detailed Description of the Invention] In recent years, the water quality of lakes and marshes has become increasingly eutrophic due to the large influx of industrial and domestic wastewater, and the overgrowth of tall plants such as reeds has only worsened the landscape. This is causing serious social problems such as deterioration of water quality, especially in urban areas.

The present invention is one of the measures against eutrophication as described above,
The purpose of this method is to purify water by utilizing the nutrient absorption properties of aquatic plants such as water hyacinth.The purpose of this method is to purify the entire body of water such as rivers, lakes, and marshes that have no waterways, etc., where wastewater from the surrounding area flows in and out. The point is that it provides an effective method for purification.

The circulating water purification method according to the present invention, which was taken to achieve the above object, pumps up raw water from a water body such as a lake, and connects it to a contact oxidation channel and a part of the water body away from where the raw water is pumped. It is characterized by supplying oxygen to the aquatic plant cultivation area divided into sections through water-permeable partition bodies capable of preventing outflow of plants in the order of description, and spouting oxygen into the water of the aquatic plant cultivation area, thereby , we have achieved the following effects.

By supplying raw water pumped from a water area to an aquatic plant cultivation area, a water cycle occurs in which the raw water is purified by the nutrient absorption action of the aquatic plants and returned to the water area. The nutrient concentration of the entire water body gradually decreases, and the water quality can be gradually purified. Moreover, by spouting oxygen into the water of the water area for aquatic plant cultivation, the oxygen is dissolved in the water, and the vertical mixing of the water mass is promoted to supply nutrients in the lower and lower layers of the water area to the surface layer (water surface). Therefore, it is possible to prevent insufficient absorption of nutrients from the surface layer of floating aquatic plants such as water hyacinth, and to efficiently purify the water area where aquatic plants are cultivated. Furthermore, instead of directly supplying the raw water pumped from the water area to the aquatic plant cultivation area, by supplying it to the aquatic plant cultivation area through a contact oxidation channel, the BOD of the raw water can be improved.
This prevents a large amount of microorganisms from adhering to the roots of aquatic plants and inhibiting their ability to absorb nitrogen and phosphorus, even when BOD is high. Absorption capacity can be maintained well.

Therefore, according to the present invention, it is possible to efficiently purify water by utilizing the nutrient absorption action of aquatic plants, especially in closed areas where wastewater flows in from the surrounding area but there are no rivers or waterways flowing out. It is now possible to provide a purification method that is effective for purifying entire bodies of water, such as lakes and marshes, where water tends to stagnate.

Embodiments of the present invention will be described in detail below based on the drawings.

In FIGS. 1 and 2, A is an example of a water area to be purified, such as a lake, and an aquatic plant cultivation area B is equipped with an air ration device E at the entry point of this water area A. It is partitioned through. The water-permeable compartment C is made up of a weir supporting a net with a mesh that prevents aquatic plants from flowing out, and the air ration device E blows air upward into the water via an aeration pipe. By spewing out oxygen, the oxygen in the air is dissolved in the water, and the vertical mixing of the water mass is promoted to supply nutrients in the lower and lower layers of the water body to the surface layer (water surface), which leads to floating substances such as water hyacinth. It has the function of preventing insufficient absorption of nutrients from the surface layer of aquatic plants.

D is a submersible pump d ₁ that pumps raw water from a location sufficiently distant from the aquatic plant cultivation area B in the water area A, and a submersible pump d 1 that pumps raw water from a location sufficiently distant from the aquatic plant cultivation area B in the water area A, and a submersible pump d ₁ that pumps raw water along the edge of the water area A to cultivate the aquatic plants. Cultivation area B
This water transmission equipment consists of a water transmission pipe _d2 for sending the water to the water supply pipe d2, and the raw water sent through this water transmission equipment D is passed through the downstream contact oxidation waterway F to the aquatic plant cultivation area B.
It is caused to flow into the country.

As shown in Fig. 3, the flowing contact oxidation waterway F is a flowing waterway in which various types of contact materials F are arranged in a plane and utilizes the head without using power. This is to prevent a large amount of microorganisms from adhering to the roots of aquatic plants when the water level is high, thereby inhibiting the ability of the roots to absorb nitrogen and phosphorus.

In the purification method of the present invention, raw water is pumped up from the water area A by the water supply equipment D, and supplied to the downstream contact oxidation waterway F and the aquatic plant cultivation area B in the order of description, and the air ration device E is used to cultivate the aquatic plants. This is done by blowing air, that is, oxygen, into the water in water area B.

Next, other examples will be listed.

[] Among the water-permeable partitions C, the portions from the bottom of the aquatic plant cultivation zone B to the mid-depth position are constructed as water-impermeable partitions, and the portions beyond that are constructed as water-permeable partitions. In this case, it is possible to keep the water level in the aquatic plant cultivation area B constant at all times, and the water is always supplied by the pump, so it does not run out. It also has the advantage of allowing floating matter to settle easily.

[] The part of the water-permeable partition C that includes the free liquid surface and extends above and below it is configured as a water-impermeable partition wall or a partition wall that has a large number of very fine water holes, and The lower portion is configured as a water-permeable partition wall. In this case, there is an advantage that aquatic plants such as water hyacinth can be effectively prevented from flowing into the water area A.

[] For example, when using an aquatic plant that has the property of floating widely in water, such as chlorella, the water-permeable partition body C should be designed to prevent the aquatic plant from flowing through and allow water to flow out. It is best to use a thin net (synthetic resin bag net) like this.

Further, as a modification of this embodiment, only the portion of the facultative partition C located between the upper and lower water layers is made of the above-mentioned net or a substance having the same function.

[] It is also possible to provide something that emits ultraviolet rays, such as an ultraviolet lamp, near the aquatic plants in the aquatic plant cultivation area B, thereby making the aquatic plants more active.

[] If there is a channel into which sewage flows into water area A, the sewage in this channel is transferred to water area B for cultivating aquatic plants.
It is constructed and used so that it can be poured into the interior.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; FIG. 1 is a schematic plan view of a water area to be purified, FIG. 2 is a schematic vertical cross-sectional view, and FIG. 3 is a conceptual diagram of a downstream type catalytic oxidation waterway. A...Aquatic areas such as lakes, B...Aquatic plant cultivation areas, C...Water permeable compartments, F...Contact oxidation channels.

Claims (1)

[Claims] 1 Pump up raw water from a water area A such as a lake, and divide it into a contact oxidation waterway F and a water-permeable partition body C that can prevent the outflow of aquatic plants in a part of the water area A that is remote from the area where the raw water was pumped. A circulating water area purification method in which oxygen is supplied to the formed aquatic plant cultivation area B in the order of description, and oxygen is spouted into the water of the aquatic plant cultivation area B.