JPS6363039B2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention particularly relates to a method for decomposing ammonia nitrogen contained in treated water from a human waste septic tank into nitrogen gas and allowing the treated water to permeate underground. This invention relates to a trench type human waste processing and purification device.

[Technical background of the invention and its problems] A conventional trench-type sewage treatment device has a long and shallow trench groove formed in the form of a gutter, in which a predetermined filter medium is filled and a wastewater pipe is buried. The wastewater is treated by infiltrating as much soil as possible from the wastewater pipe. For example, special public service in 1977-
Trench type sewage treatment equipment related to No. 54193 (No. 6
(see figure), an impermeable tank 1 made of an impermeable material and shaped like a gutter is arranged at the bottom of a trench groove 2, and a sand layer 3 filled with sand to a predetermined thickness is placed inside the impermeable tank 1. A gravel layer 4 and a covering soil layer 5 are laminated on the sand layer 3, and a wastewater pipe 6 and a porous drainage pipe 7 are provided in the gravel layer 4 and the covering soil layer 5, respectively. The boundary between the gravel layer 4 and the covering soil layer 5 is made concave. With the above configuration, a small amount of sewage is transferred to the sewage pipe 6.
If it is supplied from the ground, it permeates by gravity from the gravel layer 4 to the sand layer 3, and from the sand layer 3 to the soil around the trench groove 2 by capillary siphon action, a part of which evaporates from the ground surface, and the rest. It is replenished by seepage into groundwater.

Further, when a large amount of wastewater is supplied from the wastewater pipe 6, when it percolates up from the upper surface of the gravel layer 4 to the drain pipe 7, it is back-filtered through the covering soil layer 5 of approximately the same thickness.

In this way, effective purification treatment is generally possible for wastewater.

However, if the sewage is human waste, the sewage pipe 6 of the sewage treatment device is connected to a human waste septic tank (not shown), and the purified sewage is decomposed by microorganisms in the soil in the trench 2. The treated water will be diffused into the ground, but approximately 97% of organic matter (BOD) (COD) and suspended solids (SS) in the wastewater will be removed. On the other hand, ammonia nitrogen (NH ₃ -N) in sewage is oxidized in the human waste septic tank and changes to nitrite nitrogen (NO ₂ -N), but this nitrite nitrogen is not produced in the sewage treatment equipment mentioned above. There was a problem in that the water seeped into the ground from the trench 2, contaminating the groundwater.

[Object of the invention] The present invention has been made in view of the above problems, and
The treated water from the human waste septic tank is decomposed by aerobic soil microorganisms, and the nitrite nitrogen and nitrate nitrogen oxidized in the septic tank are decomposed into nitrogen gas by anaerobic denitrifying bacteria. This invention relates to a trench type night soil treatment water purification device that reliably prevents contamination of underground water by rendering it harmless.

[Means for Solving the Problems] In order to achieve the above-mentioned problems, the trench type human waste water purification device according to the present invention fills the inner bottom of the trench groove in which the water stop tank is formed with sand, and the sand layer A gravel layer is formed on top of the gravel layer, and a soil layer is further formed on top of the gravel layer, and a sprinkler pipe with a side permeation structure is installed in the gravel layer, and a purification treatment is performed to cover the sprinkler pipes at predetermined intervals. A pipe is provided, and the purification pipe has an aerobic chamber surrounding the outer peripheral surface of the water sprinkler pipe, and an anaerobic chamber formed above the aerobic chamber.

In the above-mentioned aerobic chamber, the filter medium is made more aerobic to activate the reproduction of microorganisms, and the water to be treated is
It is designed to improve the oxidation ability of BOD,
In addition, the denitrifying bacteria generated around the organic matter filled in the anaerobic chamber reduce the oxygen in nitrite nitrogen and nitrate nitrogen, decomposing most of them into nitrogen gas.

[Embodiments of the Invention] Examples of the present invention will be described below with reference to FIGS. 1 to 5.

A trench groove 11 of a predetermined width and depth is formed in the ground, and a sheet 12 made of a waterproof material is stretched in the shape of a cross-sectional box at the bottom of the trench groove 11. Sand (hereinafter referred to as sand layer) 13 is filled up to a height exceeding . In the upper layer of the sand layer 13, sprinkler pipes 15, each having a large number of through holes 14 connected to the side wall and communicating with a human waste treatment device (not shown), are laid over the sprinkler pipes 15 at regular intervals, which will be described later. It is covered with a purification treatment tube 16. In addition, a gravel layer 17 is laid in a mountain shape with a thickness of about 40 cm on the upper layer of the sand layer 13 to the processing pipe 16 and the exposed watering pipe 15, and ventilation is carried out through a net 18 stretched over the upper layer of the gravel layer 17. A soil layer 19 is formed.

Note that the symbol GL in the figure indicates the ground surface.

The purification pipe 16 is a feature of the present invention, and is made of reinforced plastic such as FRP and has an inverted U-shaped cross section with a width of about 100 to 200 mm, a height of 100 to 150 mm, and a length of about 1000 mm. It is formed into a duct shape, and has a plurality of slits 20 longitudinally bored at the top, and a number of square holes 21 at the lower ends of both side walls. Furthermore, the interior is vertically divided into two layers, the upper layer forming an anaerobic chamber 22 and the lower layer forming an aerobic chamber 23. Inside the anaerobic chamber 22, a predetermined organic substance, e.g. It is filled with charcoal 24 such as charcoal or coal, and the inside of the lower aerobic chamber 23 is a cavity, and a desired space (air layer) is maintained around the outer periphery of the water sprinkler pipe 15 that penetrates there. It is designed to do so.

In the configuration described above, when purified wastewater is supplied from the human waste treatment device to the sprinkler pipe 15,
Gravity infiltrates from the gravel layer 19 to the sand layer 13 through the through holes 14, and from the sand layer 13 to the soil around the trench groove 11 by capillary siphon action, while some transpires from the ground surface GL into the atmosphere. The rest is replenished by infiltration into groundwater. Of course, drainage is carried out in the gravel layer 17.
When it penetrates the soil, it is decomposed by soil microorganisms.

At this time, approximately 97% of organic substances (BOD) (COD) and suspended solids (SS) in the wastewater are removed.

In particular, in the purification treatment pipe 16, the gravel layer 17 around the aerobic chamber 23 becomes more aerobic, so microorganisms multiply actively, and the BOD oxidation ability is greatly improved compared to the conventional method. Get results.

In addition, in the anaerobic chamber 22, denitrifying bacteria generated around the charcoal 24 use the carbon C of the charcoal 24 as an energy source to remove nitrite nitrogen (NO ₂ -N) and the necessary oxygen ( _O2 ) in nitrate nitrogen ( _NO3 -N),
Most of the nitrite nitrogen (NO ₂ -N) and nitrate nitrogen (NO ₃ -N) are decomposed into nitrogen gas, which is released into the atmosphere from the gravel layer 17 through the aerated soil layer 19.

[Effects of the Invention] As explained above, according to the present invention, purification treatment pipes each equipped with an aerobic chamber and an anaerobic chamber are arranged at predetermined intervals on top of a watering pipe laid in a trench. , activates the reproduction of aerobic microorganisms and promotes purification by the microorganisms, while promoting the activation of anaerobic denitrifying bacteria, reducing nitrite nitrogen (NO ₂ −
It has the effect of decomposing N) and nitrate nitrogen (NO ₃ -N) into nitrogen gas, reliably preventing groundwater contamination by these harmful nitrogen compounds, and being able to be used at low cost. .

[Brief explanation of drawings]

Figures 1 to 5 relate to one embodiment of the present invention, in which Figure 1 is a partial sectional view of a trench-type human waste treatment water purification device, and Figure 2 is a longitudinal sectional view of the same device as it is used buried. FIG. 3 is a perspective view of the end of the purification tube, which is the main part of the device, FIG. 4 is a front view of the purification tube, and FIG. 5 is a plan view of the purification tube.
FIG. 6 is a longitudinal cross-sectional view showing the cross-sectional structure of a known trench-type sewage treatment device. 11...trench groove, 12...sheet, 13...
...Sand layer, 15...Water pipe, 16...Inverted U-shaped pipe, 1
7... Gravel layer, 19... Covering soil layer, 22... Anaerobic chamber, 24... Charcoal.

Claims (1)

[Claims] 1. Fill the bottom of the trench with sand, and install a perforated watering pipe connected to the human waste septic tank on the top of the sand layer.
The interior was divided into two upper and lower layers with an inverted U-shaped cross section, and the upper layer was an anaerobic chamber filled with charcoal etc. and communicated with the outside, while the lower layer was an aerobic chamber formed in a hollow shape and communicated with the outside. A trench-type human waste treatment and purification device comprising a purification pipe arranged in such a manner that an aerobic chamber covers the porous water sprinkler pipe, and further a gravel layer and an aerated soil layer are sequentially laminated on the purification pipe and the sand layer.