JPS6228719B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a floatation water treatment method for treating sewage by planting plants on the water surface of water channels (hereinafter referred to as waterways) and forming colonies of rhizosphere microorganisms on the underwater roots of the plants. This invention relates to ditch water treatment equipment.

Propagating floating or floating aquatic plants, such as water hyacinth and water hyacinth, or other vascular plants capable of growing on water, on supports (e.g. drainboards) provided just below the water surface of ephemeral or circulating waterways; In a plant ditch water treatment device that purifies wastewater mainly through the activities of rhizosphere microorganisms that form around underwater roots that have developed between the support and the water surface,
Unless the organic suspended nutrients in the inflowing wastewater are effectively attached to the underwater roots of plants, the treatment effect of the wastewater cannot be enhanced. In other words, if suspended nutrients in sewage are effectively attached to the underwater roots of plants, the activity of rhizosphere organisms will be increased and the absorption of dissolved organic matter in sewage will be promoted, thereby further increasing the treatment effect. It should be possible.

Traditionally, as a method for trapping suspended nutrients in wastewater in the underwater roots of plants, blocking bodies, such as gravel, have been used to create appropriate turbulence in the water body flowing down the bottom of the water channel of a ditch water treatment device. There is a waterway in which a part of the turbulent water flows gently through the underwater root zone of the plants by installing a blocker or a blocking plate. However, this method requires considerable turbulence to be generated in order to improve the uptake rate of suspended nutrients by the roots, and as a result, there is a risk that the already formed rhizosphere microbial colonies will become detached. , there is a limit to its capture rate.

The present invention adsorbs suspended nutrients in wastewater to air bubbles generated by a foaming device installed in a waterway without relying on turbulence in the waterway,
It is an object of the present invention to provide a flotation ditch water treatment device that effectively treats wastewater by floating it to effectively transport it to the underwater roots of plants above.

Next, one embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a cross-sectional view of a water groove showing the basic configuration of the present invention. A support 3 for preventing the propagated plants 2 from being submerged in water is provided at the upper part of the water channel 1, and a bubble outlet 6 is provided at the bottom of the water channel 1 through which air bubbles flow from a bubble generator 4 through a pipe 5. As the plant 2 grows, underwater roots develop between the water surface 7 and the support 3 and directly below the support 3, and suspended matter in the sewage is captured around the roots, and the aquatic rhizosphere microorganisms that purify the sewage develop. A colony is formed. Furthermore, the wastewater flowing down the waterway 1 becomes a fast-flowing part 8 where the flow velocity is high between the support 3 and the bottom of the waterway 1, and the rhizosphere part 9 between the support 3 and the water surface 7 becomes a slow-flowing part where it flows slowly. Become.

In the flotation ditch water treatment device constructed as described above, wastewater is purified by absorption and decomposition of pollutants by the rhizosphere microorganisms and the plants themselves. Therefore, in order to effectively carry out purification, stable and highly active rhizosphere microbial colonies must be developed around the underwater roots of plants. Therefore, a bubble spout 6 is placed at the bottom of the water channel 1.
By providing dissolved oxygen to the rhizosphere 8, the activity of the rhizosphere microorganism colony is increased, and at the same time, the air bubbles transport dissolved and suspended substances in the wastewater, i.e., nutrients, to the roots of the plants. This makes it possible to effectively trap water in the water and to make the function of the flotation ditch water treatment device sufficiently high and stable.

A specific configuration in which the present invention is applied to a sewage treatment plant will be described below with reference to FIGS. 2 and 3.

FIG. 2 is a plan view of the sewage treatment plant, and FIG. 3 is a partial sectional view of FIG. 2. The sewage treatment plant is surrounded by an outer wall 10, the interior is partitioned by a partition wall 11 and earth and sand 12, and a waterway 1 is provided at the bottom with a bubble outlet 6 through which bubbles flow from a bubble generator 4 through a pipe 5. It is something that was given. This waterway 1 is provided with a support 3 having a gap directly below the water surface through which sewage passes, and on top of this support 3 there is a water channel 13.
The growth of this rhizosphere forms a colony of rhizosphere microorganisms. In addition, wastewater flows into the sewage treatment plant from an oxidation pond 14 at one corner and communicates with the inlet of the waterway 1, a water receiving pit 16 provided with a movable weir 15, and the other corner communicates with the outlet of the waterway 1. death,
Each of the treated water pits 18 is provided with a movable weir 17. A well-known measuring device 19 is installed in the treated water pit 18 to monitor dissolved oxygen, pH, turbidity, conductivity, oxidation-reduction potential, water temperature, outside air temperature, solar radiation, etc. of the introduced treated water. In addition, a fish cultivation monitoring pond 22 is provided, which introduces water from the treated water pit 18 of the waterway 1 via a pump 20 and a waterway 21, and a fish culture monitor pond 22 is provided, in which carp, carp, etc.
Fish such as crucian carp, goldfish, and medaka are released.

The treated water according to the present invention includes a sedimentation tank 23 and a disinfection tank 2.
4. In addition to the treated water that passes through the treated water storage tank 25 and is discharged into a river (not shown) or reused, a part of the water is returned to the water receiving pit 16 or the aeration pond 26 by the pump 20, and is used inside the waterway 1. The water is circulated in the aeration pond 2.
In step 6, aeration is performed by an aerator 27 to adjust the nutritional balance, dissolved oxygen, and PH of the sewage in the sewage treatment plant.

In the waterway 1 of the sewage treatment plant to which the present invention is applied, configured as described above, there is a water channel 13 on the water surface, a colony of rhizosphere organisms by this rhizosphere part 9,
Since the bubble outlet 6 is provided at the bottom, a fast flow section 8 with a high flow rate and a slow flow section with a slow flow rate are formed in the rhizosphere section 9 between the bottom and the rhizosphere. The generated air bubbles effectively trap dissolved and suspended substances in the wastewater, that is, nutrient substances at the same time, in the rhizosphere of the watercress 13. Although the biochemical oxygen demand (BOD) and turbidity of influent water to a wastewater treatment plant are high and variable, the present inventors have shown that the BOD of treated water is below 3 ppm and the turbidity is below 2 ppm. , the transparency is extremely low at more than 2 meters, and no toxicity has been detected.
We were able to obtain water where fish such as crucian carp, goldfish, and killifish can normally live. Furthermore, the removal rate of ammonia and phosphorus was 95-100%, and the removal rate of total nitrogen was 50-98% throughout the year. In the present invention, the installation location of the bubble generator 4 and the bubble outlet 6 is not limited to the vicinity of the entrance of the waterway 1, and it goes without saying that they can be installed at multiple locations as necessary.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a water channel of a ditch water treatment device showing the basic configuration of the present invention, FIG. 2 is a plan view showing a specific configuration of an embodiment of the present invention, and FIG. It is a sectional view taken along the - line in the direction of the arrow. 1...Water channel, 2...Plant, 4...Bubble generator, 6...Bubble spout, 9...Underwater rhizosphere.

Claims (1)

[Claims] 1. Floating or floating aquatic plants or other vascular plants are planted on a support provided in the upper part of the water channel through which sewage flows, and the bottom part of the waterway faces the underwater roots through a fast-flowing part in the middle area. A flotation ditch water treatment device, comprising: a bubble ejecting device that generates bubbles that float suspended matter in wastewater.