JPH0351479B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <<Field of Industrial Application>> The present invention relates to a method for purifying sewage that comprehensively utilizes the natural ecosystem in specific water surfaces such as lakes, inner bays, reservoirs, park moats, and ponds.

≪Conventional technology≫ Conventionally, wastewater was purified at sewage treatment plants, human waste treatment plants,
Sewage purification methods found in factory wastewater treatment plants, housing complex septic tanks, etc. were common.

However, the reality is that such sewage treatment facilities are not sufficient and pollution of rivers and other areas is progressing.

Therefore, in recent years, proposals have been made to purify sewage by comprehensively utilizing the natural ecosystem of large and small animals and plants on specific water surfaces such as lakes, inner bays, reservoirs, park moats, and ponds. For example, by attaching a floating body to the periphery and mooring a container with suitable plants inside floating on the water surface, it is possible to repeatedly cultivate the plants by harvesting and replanting them. A plant-based water purification device for rivers, etc. that can constantly purify the water quality (Utility Model Application No. 52-32162), which blows air or oxygen into contaminated water of rivers, etc. to pollute it to the extent necessary for stocking freshwater fish. Pollution characterized by increasing the oxygen content of the water and purifying the contaminated water by stocking the water area with gutspie or tapminnow, which are freshwater fish that collect garbage as nutrients, and letting them eat the garbage in the water. Water purification method (Tokuko 1970-
23228) etc.

However, none of the above proposals actively utilizes the bottom layer, which has a high concentration of nutrients for plants and microorganisms, and does not purify nitrogen content sufficiently, so there is a limit to the purification of sewage and sludge. . Furthermore, there was also the disadvantage that the cost would be high if it was carried out over a wide area.

≪Problem to be solved by the invention≫ While conducting intensive studies to solve the above-mentioned drawbacks, the present inventors realized that a population of floating algae plays a very useful role in the proliferation of fish. A careful study of this shows that when floating algae gather, it is due to convergence of surface flow (conditions for downward flow to occur).
Particularly in shallow waters, converging water currents are always combined with rising water currents in the bottom layer, and the conditions in which nutrients in the bottom layer circulate provide a favorable environment for the growth of fish eggs and fry. We estimate that floating plants are floating in specific areas on the water surface, allowing various large and small animals and plants to live around them, and actively supplying high concentrations of nutrients for plants and microorganisms from the bottom layer to the water surface. The present inventors have discovered that this can significantly activate the activities of floating plants and fish, and can also promote the purification of wastewater more efficiently than ever before, leading to the present invention.

Therefore, an object of the present invention is to provide a method for purifying wastewater that can comprehensively utilize the natural ecosystem and efficiently purify a wide range of wastewater.

≪Means for Solving the Problems≫ The above-mentioned object of the present invention is to float floating plants as floating filter media in a specific area of the water surface, to allow various large and small animals and plants to live around them, and to A natural ecology at a specific water surface characterized by supplying nutrients to the various large and small plants and animals by spouting sewage from the bottom layer like sprinkling on a specific water surface area, thereby allowing the large and small plants to reproduce and at the same time purifying the sewage. This was achieved through a wastewater purification method that comprehensively utilizes the system.

The present invention will be explained in detail below based on examples.

FIG. 1 is a sectional view showing the method of purifying wastewater that comprehensively utilizes the natural ecosystem at a specific water surface according to the present invention.

In the figure, reference numeral 1 is a submersible fountain pump, and 2 is a nozzle, which is fixedly connected to a float 3 on the water surface.

Reference numeral 4 indicates the soil part at the bottom of the water, where nitrogen and phosphorus, which usually cause eutrophication, are accumulated.

Reference numeral 5 refers to bottom water, which is sewage, and when it becomes anoxic, the above nitrogen and phosphorus are eluted by anaerobic microorganisms, and the concentration may be several times higher than in surface water 6. .

An aquatic plant 7 is floating around the nozzle 2, and its leaf diameter and roots constitute a filter medium to which microorganisms and small animals adhere, and also provide a suitable habitat for fish.

A floating fence 8 is provided around the aquatic animal 7, forming a specific water surface. fence 8
can be omitted if the fluctuation of the water surface is small.

Reference numeral 9 is the land portion.

<<Operation>> With the above configuration, when the submersible pump 1 is operated, the bottom layer wastewater 5 containing nutrients such as nitrogen and phosphorus is spouted up from the nozzle 2 in the form of a fountain, and various plankton and microorganisms are collected using the aquatic plants 7 as a contact filter medium. and forcibly cultivating aquatic animals, etc.

Nutrients such as phosphorus supplied as described above are recovered by plants or fish, but nitrogen is also released into the atmosphere through denitrification from the anaerobic bottom layer, which is much more than before. Sewage will be purified efficiently.

<<Effects of the Invention>> As described above, by using the wastewater purification method of the present invention, the purification of pollution in rivers, etc. can be promoted more than ever.

By the way, in the case of lakes and marshes with a water depth of 10 meters or more, they are considered temperate lakes, with the bottom water temperature being 10°C lower than the summer bottom water temperature.
It is possible to combine the sewage purification method of the present invention with improving the temperature of lakes and marshes, and with cooling systems for inns and the like.

In addition, in the case of sea areas, there are very few aquatic plants to target, but if you target large algae such as blue algae and cultivate it in a fence, it is easy to collect and use it, and it can be used for methane fermentation and composting. When combined with this, it becomes possible to solve problems within a complete material circulation system.

Furthermore, by installing the wastewater purification method of the present invention not in the center of a lake or sea area but in parallel to an estuary, beach, or seawall where pollution flows into, an artificial long-channel contact oxidation pond method purification system or floating A fish shore-like system is also possible using only a combination of a floating net and a submersible pump.

The scope of application of the sewage purification method of the present invention is as follows.

(b) By transporting the decomposed products of organic matter thrown as feed to the water surface as a measure to prevent water pollution in aquaculture and fishing grounds, it is possible to propagate useful plants and general fish, and also purify the water area.

(b) It can be applied as a water quality and environmental improvement measure in sewage treatment plants, human waste treatment plants, factory wastewater treatment plants, housing complex septic tanks, etc.

(c) By creating a system that combines beautification measures for lakes, reservoirs, creeks, park viewing ponds, etc. and water pollution control measures, aquatic plants can be used as contact filter media, making it the optimal facility for maintaining water transparency.
In addition, it is even more efficient if it is combined with irrigation of green areas and soil purification systems.

(d) Since the reduction of NH ₄ and sterilization using a plant chain are combined, it can be applied to a system that solves the problem of carcinogenic trihalomethanes generated by chlorine disinfection of wastewater.

(e) Out of the 300,000 agricultural reservoirs in Japan, those that are no longer needed can be used for purifying sewage and for small parks.

(f) It can be applied as a simple water surface mobile sewage treatment method to purify pollutants from upstream at the inlet part of an artificial lake where the water level fluctuates.

[Brief explanation of drawings]

FIG. 1 is a sectional view showing the method for purifying wastewater of the present invention. 1... Submersible pump, 2... Nozzle, 3... Float, 4... Soil portion, 5... Bottom water, 6... Surface water, 7... Aquatic plant, 8... Floating fence, 9...
...The athletics part.

Claims (1)

[Claims] 1. Floating plants as flotation filter media are placed in a specific area of the water surface, and various large and small animals and plants are made to live around them, and sewage from the bottom layer is spouted out in the manner of sprinkling water onto the specific water surface area. A sewage purification method that comprehensively utilizes the natural ecosystem at a specific water surface, which is characterized by supplying nutrients to various large and small animals and plants, allowing them to propagate, and purifying the sewage at the same time.