JPS5815040Y2 - Organic nitrogen removal equipment - Google Patents

Description

[Detailed description of the invention] This invention circulates and flows the liquid to be treated, which contains non-organic nitrogen, between a deep aeration tank with a large amount of oxygen gas and a reduction tank with a small amount of oxygen gas, thereby converting the non-organic nitrogen into minerals. The present invention relates to an organic nitrogen removal apparatus constructed as follows.

Generally, organic nitrogen removal equipment aerates the liquid to be treated that contains organic nitrogen, then sends the liquid to a reduction tank for denitrification treatment, and then sends the liquid to a precipitation tank for precipitation treatment. However, in order to increase the processing efficiency by increasing the processing path of the liquid to be treated, the conventional method has the aeration tank and reduction tank configured as relatively deep tanks (about 5 to 6 m). In the organic nitrogen removal equipment, in order to remove the large amount of nitrogen gas generated in the denitrification zone, a special deaeration tank is installed to carry out deaeration treatment at the next stage of the denitrification treatment process using the reduction tank. Although it is possible to improve the processing efficiency as a deep type, it has the drawback that it requires the provision of a special device for degassing.

In addition, in the conventional circulation type denitrification method, a mixed decomposition tank is connected to the starting point of the treatment process by a circulation path, and a pump is specially installed in the circulation path to supply the liquid to be treated to the denitrification zone side. There was a need.

Although this invention can perform efficient treatment using an organic nitrogen removal device in a deep aeration tank, the structure and arrangement of the reduced species itself eliminates the need for a special deaeration device and is effective. Deaeration treatment can be performed, and the liquid to be treated can be supplied to the denitrification zone without the need for a special pump as a drive source.The configuration of the aeration tank and reduction tank can be used to simplify the structure and supply the liquid to the denitrification zone. The aim is to be able to do this without any loss.

The characteristic structure of the organic nitrogen removal device according to the present invention is that an aeration tank is constructed from an inner cylinder with a deep downward flow path formed inside and an outer cylinder with an upward flow path formed between the inner cylinder. , disposing a reduction tank forming an annular flow path at an upper outer circumferential position of the aeration tank, and forming a communication port in the outer cylinder through which overflow liquid from the ascending flow path flows out to the annular flow path side; Furthermore, a partition wall is provided in the reduction tank so as to interrupt the continuous state in the circumferential direction of the annular flow path, and the communication port is located on both sides of the partition wall, and the flow is divided by the partition wall. A supply path for the liquid to be treated and activated sludge is connected near one end of the channel, and a pump is connected near the other end of the channel to circulate and transfer the liquid to be treated toward the downward flow path of the aeration tank. The structure is connected to a circulation flow path in which the flow path is interposed in the middle of the flow path, and this configuration provides the following effects.

In other words, although it is possible to perform aeration processing efficiently using a deep aeration tank, the reduction tank, which serves as the denitrification zone, is constructed with a shallower water depth than the aeration tank, making it difficult to use the aeration tank. Since it is constructed with a long annular flow channel in the circumferential direction surrounding it, the surface area of the water flow is large in the annular flow channel where denitrification is performed, and the flow velocity is also relatively thick. without the need for special stirring means, etc.
Since the degassing process is performed simultaneously with denitrification, there is an advantage that a special device for degassing again after denitrification can be omitted.

In addition, in order to circulate and supply the liquid to be treated after aeration to the denitrification zone, the overflow liquid is supplied through a communication port provided at the upper end of the ascending flow path. It is also advantageous in that a special drive source such as a pump is not required for the means.

Embodiments of the present invention will be described below with reference to the drawings. Inner cylinder 1a and outer cylinder 1 whose horizontal cross section is circular or similar
For example, 100
A descending passage A and an ascending passage B having a level difference of about m are formed, and the outer cylinder 1b
and the lid body 12 constitute a reduction tank 2 having an annular flow path 2A.
A partition wall 3 in the radial direction is provided to break the continuity of the person in the circumferential direction, and a first button and second weirs 4 and 5 are provided on both sides of this partition wall 30, and the level of the first weir 4 is raised. and install it,
A third weir 6 having a higher level than the first weir 4 is provided in a portion of the outer cylinder 1b that extends between the partition wall 3 and the first weir 4, and a third weir 6 that is higher in level than the first weir 4 is provided in a portion of the outer cylinder 1b that extends between the partition wall 3 and the second weir 5. , a fourth weir 7 having a higher level than the second weir 5 and approximately the same level as the third' weir 6 is formed above the third weir 6 button and the fourth weir 7; A communication port 6', ? through which the liquid to be treated overflows the opening portion that is It is configured as '.

Further, in this reduction tank 2, a supply flow path C for a mixed liquid formed by mixing activated sludge into a liquid to be treated containing organic nitrogen is connected to a first weir corresponding to the starting end of the two annular flow paths. 4, and the partition wall 3, the second weir and the fourth weir 5
, 7 from the storage portion 2a at the end of the flow path to the downward flow path A.
A flow path for pumping the mixed liquid by a pump P is provided toward the upper part of the liquid, and the liquid to be treated is made to flow through the downward flow path A and the upward flow path B, and is supersaturated at atmospheric pressure or higher. A device 8 for supplying oxygen gas for aeration is connected to the middle of the downward flow path A, and the oxygen gas is dissolved in the liquid to be treated at the upper part of the downward flow path A toward the aeration tank 1. The liquid to be treated that overflows the third weir 6 of the ascending flow path B is passed from the first weir 4 through the circular path 2A in the annular reduction tank 2 with a long flow path, and from the second weir 5 to the storage at the end of the flow path. While overflowing into the portion 2a, this liquid to be treated and the fourth
repeating a cycle in which the liquid to be treated overflowing the weir 7 is pumped to the upper part of the descending channel A by the pump P;
That is, the aeration tank 1 with a large amount of oxygen gas is used as an oxidation zone, and the reduction tank 2 with a low amount of oxygen gas is used as a denitrification zone, and by circulating the liquid to be treated in both zones, the organic nitrogen content in the liquid to be treated is converted into inorganic nitrogen. For example, the decomposition state of ammonia is as follows: (1) In the oxidation zone, NH'4 +02→NO3+H++H20 (2) In the denitrification zone, N03-)-CH30H→N2+CO2+H20+OH
becomes.

The above CH30H is generally contained in the stock solution as a component that increases BOD (biochemical oxygen demand). For example, if the liquid to be treated is supplied to the aeration tank 1 with a large amount of oxygen gas,
BOD decomposition occurs faster than nitrogen decomposition and the nitrogen decomposition rate decreases, making it necessary to add a large amount of CH30H to denitrify the nitrogen in the denitrification zone. If a configuration is adopted in which nitrogen is supplied to the zone, nitrogen will be decomposed in this zone and BOD will be reduced.
The treated liquid with low organic nitrogen content and BOD can be circulated to the oxidation zone, making it possible to mineralize the organic nitrogen content efficiently and economically while minimizing or eliminating the need for addition of CH30H. .

Furthermore, since H+ is generated in the oxidation zone and OH is generated in the denitrification zone, pH adjustment can be reduced or eliminated.

The liquid to be treated is fed into a small amount separation tank 9 from the ascending channel B side, separated into sludge and cleaning liquid by specific gravity sorting, and the sludge is collected by a conveyor 10, and pump P1 is used as necessary. The cleaning liquid is returned to the supply channel C and taken out from the discharge channel 11.

The aeration tank 1 has a double-tube structure, and the aeration tank 1 is lengthened vertically to reduce its diameter, making the square tank installation site extremely narrow. Even if installed on the ground with height restrictions, the installation site for both tanks 1 and 2 can be made smaller than in the past.

In addition, although the proposed device is mainly applied to sewage treatment, it can also be applied as a treatment device for various kinds of raw solutions containing organic nitrogen, and activated sludge includes various types of activated sludge that have been conventionally used to mineralize organic nitrogen. is applicable.

[Brief explanation of drawings]

The drawings show an embodiment of the organic nitrogen removal device according to the present invention,
FIG. 1 is a flow sheet, FIG. 2 is a cross-sectional view of the first and second tanks, and FIG. 3 is a cross-sectional view taken along the line ■--■ in FIG. 1... Aeration tank, 1a... Inner cylinder, 1b.
...Outer cylinder, 2...Reduction tank, 2A...
...Annular channel, 3...Partition wall, 6', 7'...
...Communication port, A...Descent flow path, B...
・・Rising flow path, C・・Supply path, D・・・・
Circulation channel, P...pump.

Claims (1)

[Scope of utility model registration request] An aeration tank 1 is composed of an inner cylinder 1a in which a deep downward flow path A is formed and an outer cylinder 1b that forms an upward flow path B between the inner cylinder 1a, and the upper outer peripheral position of the aeration tank 1 is A reduction tank 2 forming two annular flow channels is disposed in the outer cylinder 1b, and communication ports 6/, 7/ for allowing the overflow liquid from the upward flow channel B to flow out to the annular flow channel 2A side are provided in the outer cylinder 1b. In addition,
A partition wall 3 is provided in the reduction tank 2 so as to interrupt the continuous state of the two annular channels in the circumferential direction, and with the communication ports 6' and 7' located on both sides thereof, This partition wall 3
A supply path C for the liquid to be treated and activated sludge is connected near one end of the flow path divided by An organic nitrogen removal apparatus characterized in that a circulation flow path is connected to the flow path in which a pump P is interposed in the flow path so as to circulate and transfer the liquid.