JPS5918112B2 - How to treat organic waste liquid - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for treating organic wastewater such as water and sewage wastewater treatment.

In the conventional method for treating organic waste liquid using activated carbon, especially when organic substances consisting of multiple components rather than a single organic substance are contained, such as sewage wastewater and human waste, the adsorption zone formed is long and the entire organic substance adsorption capacity of activated carbon is limited. Because the quality of the water to be treated exceeded the target water quality while the adsorption tower was not in use, the activated carbon had to be extracted from the adsorption tower and transferred to the regeneration process as a deactivation layer.

Therefore, the effective use of activated carbon is insufficient because activated carbon, which is an expensive material, has to be regenerated without using its entire adsorption capacity. This was an expensive removal method in terms of both cost and running costs.

The present invention solves these problems by adsorbing organic wastewater in an activated carbon bed in a fluidized bed, subjecting the treated water to biological treatment, and then further adsorbing it in an activated carbon bed in a moving bed. In this treatment method, activated carbon in a moving bed state is returned to an activated carbon bed in a fluidized bed state, the activated carbon in a fluidized bed state is regenerated, and an organic waste liquid is supplied to the activated carbon bed in a moving bed state. Therefore, the used post-process activated carbon that mainly adsorbs low-concentration organic matter is returned and used as pre-process activated carbon, and high-concentration organic matter is adsorbed and then discharged as deactivated carbon for regeneration treatment. An object of the present invention is to provide a method for treating organic waste liquid using activated carbon, which fully and effectively utilizes the adsorption capacity of activated carbon.

The method for treating organic waste liquid using activated carbon of the present invention includes industrial water, sewage,
It is applied to human waste treatment, industrial wastewater treatment, garbage pit wastewater treatment, etc.

An embodiment of the present invention will be described based on the drawings.

Reference numeral 1 indicates a pretreatment device in a high-level treatment system for sewage, human waste, etc. After performing filtration treatment, the water to be treated is supplied to a fluidized bed adsorption tower 2 that uses activated carbon in the pre-process, and the organic matter in the water to be treated is absorbed by the activated carbon. However, first, organic substances with a relatively large particle size, which are highly concentrated organic substances, are mainly adsorbed.

Next, the water to be treated is subjected to biological treatment using activated sludge bacteria or the like in the biological treatment device 3 and is removed.

The water to be treated, which is the separated liquid after the precipitation process, is supplied to an upflow type moving bed adsorption tower 4 that uses activated carbon in the subsequent process, but the highly concentrated organic matter with large particle size in the water to be treated is fed to the fluidized bed adsorption tower 2. and removed by adsorption or precipitation in the biological treatment device 3,
In the moving bed adsorption tower 4, organic substances of low concentration and relatively small particle size in the water to be treated are adsorbed and removed.

The water to be treated from which organic substances have been removed in this manner is discharged from the moving bed adsorption tower 4, and the desired organic substances are removed.

The adsorption capacity of the downstream activated carbon in the moving bed adsorption tower 4 decreases over time as it is used, so conventionally used downstream activated carbon is activated and regenerated in an activated carbon regeneration device to remove the organic matter to be adsorbed with water vapor. The adsorption ability of activated carbon was recovered by removing it by causing a water gasification reaction in the presence of a hot atmosphere.

The post-process activated carbon mainly adsorbs organic matter with a relatively small particle size (molecular weight) at a low concentration in the water to be treated, and still has the ability to adsorb organic matter with a relatively small particle size (molecular weight) at a high concentration. Therefore, in the method for removing organic matter from activated carbon of the present invention, the used post-process activated carbon is discharged from the moving bed adsorption tower 4 and returned to the fluidized bed adsorption tower 2 to be supplied and used as the pre-process activated carbon. High concentration of organic matter has a relatively large particle size (
It adsorbs organic matter of molecular weight).

The pre-process activated carbon in the fluidized bed adsorption tower 2, whose adsorption capacity has thus decreased, is discharged and supplied to the activated carbon regeneration device 5, where the activated carbon is thermally, chemically, and biologically activated and regenerated.

The activated carbon activated and regenerated in the activated carbon regeneration device 5 is supplied to the moving bed adsorption tower 4, where it is used as post-process activated carbon to adsorb organic matter in the water to be treated again.

Therefore, the activated carbon is transferred from the moving bed adsorption tower 4 to the fluidized bed adsorption tower 2,
One circulation circuit is formed which passes through the activated carbon regenerator 5 and reaches the moving bed adsorption tower 4 again, and is used repeatedly.

FIG. 2 is a characteristic diagram showing the organic matter adsorption capacity of activated carbon supplied to each adsorption tower, where a is fresh activated carbon, b is discharged carbon from moving bed adsorption tower 4, and C is discharged carbon from fluidized bed adsorption tower 2. d is the regenerated carbon after activation and regeneration in the activated carbon regeneration device 5, and represents the organic matter adsorption capacity Q with respect to the organic matter concentration N;
o indicates the reference concentration flowing into the moving bed adsorption tower 4, Ni indicates the organic matter concentration lower than No, and Ni' indicates the reference concentration flowing into the fluidized bed adsorption tower 2.

Note that the concentration level is N i < No < Ni2.

The discharged carbon is produced by adsorbing a low concentration of organic matter called Ni in the moving bed adsorption tower 4, and the adsorption capacity is approximately half that of the Ni adsorption capacity Q of new activated carbon a and recycled carbon d. With respect to the standard concentration No of the water to be treated flowing into the fluidized bed adsorption tower 2, it has approximately the same adsorption capacity as the new activated carbon a and the recycled carbon d. Organic matter adsorption can be carried out by supplying organic matter.

The deactivated carbon C that has adsorbed a high concentration of organic matter in the fluidized bed adsorption tower 2 contains Ni and N.

The adsorption capacity at low and high concentrations decreases, and if the water is continued to be used, the organic matter concentration of the treated water discharged from the fluidized bed adsorption tower 2 will exceed the standard value, so it is removed from the fluidized bed adsorption tower 2. The activated carbon is activated and regenerated by the activated carbon regeneration device 5.

Since the adsorption capacity of the activated and regenerated activated carbon d is almost the same as that of the new activated carbon a, it is supplied to the moving bed adsorption tower 4 to perform the desired adsorption action.

The newly activated carbon a is appropriately supplied to the moving bed adsorption tower 4.

In a fluidized bed adsorption device that uses activated carbon, the water to be treated is supplied from the bottom of the adsorption device, and the activated carbon on the perforated support is made to flow, and the flowing activated carbon adsorbs organic matter in the water to be treated. Water flows out from the top of the device.

Therefore, since the activated carbon is fluidized in the fluidized bed type adsorption device, the water flow resistance is small and the amount of water to be treated is small, and the device has excellent adsorption ability, but on the other hand, the ability to capture suspended solids (SS) is low. It is small.

Therefore, the fluidized bed type adsorption device is not an appropriate adsorption device for adsorbing relatively small particle size of low concentration organic matter among the organic matter in the water to be treated. It is desirable to use it as the fluidized bed adsorption tower 2 in the previous step.

In an upflow type moving bed adsorption device, water to be treated is supplied from the bottom of the adsorption device, flows upward through the activated carbon layer in the device, receives the adsorption action of the activated carbon, and then flows out from the top of the device.

On the other hand, the activated carbon forms layers inside the device, and the activated carbon in the lower part of the device whose adsorption capacity has decreased is sequentially discharged by the activated carbon transfer device and supplied to the regeneration treatment device. will be resupplied.

Therefore, the activated carbon descends in the device one after another, but as a whole forms one layer, the flow resistance to the water to be treated is relatively large.Therefore, the amount of water passing through is small, and the adsorption capacity of the device as a whole is that of a fluidized bed type. Although the size is smaller than that of an adsorption device, on the other hand, it has a superior ability to capture suspended solids (SS), and is excellent in adsorbing organic matter with a relatively small particle size of low concentration organic matter. It is useful as the moving bed adsorption tower 4 in the downstream process of the biological treatment device 3 in the method for removing organic matter from activated carbon.

The moving bed adsorption tower 4 used in the subsequent process is not limited to a moving bed type adsorption device, but may have an adsorption capacity characteristic that has an adsorption capacity for high concentration organic matter, such as discharged coal from the moving bed adsorption tower 4. The method of the present invention can be applied to any adsorption apparatus having a structure capable of drawing out activated carbon; for example, it can be applied to a fixed bed type adsorption apparatus of an up-and-down counterflow type.

In addition, in the expanded bed adsorption device, the water to be treated is supplied from the bottom of the tower.
It is discharged from the top of the tower, but the activated carbon inside the tower is layered.
As the water to be treated is supplied, the activated carbon layer expands under the pressure and reduces the water flow resistance of the water to be treated, causing suspended solids (
Both the trapping ability and organic matter adsorption capacity of SS) are intermediate between those of a fluidized bed adsorption tower and a moving bed adsorption tower. It is used in the pre-process of the processing device 3.

This method can be applied by installing a rapid filtration device in place of the biological treatment device 3, which is the post-process of the counterfluidized bed adsorption tower 2, and performing separation treatment by filtration to remove relatively high concentration of organic matter. I can do it.

In the activated carbon treatment method for organic waste liquid of the present invention, the water to be treated is first subjected to adsorption treatment using activated carbon in the pre-processing step, and then separation treatment such as precipitation and filtration is performed, so that high-concentration organic substances in the water to be treated are adsorbed and removed and precipitated. Since the organic matter in the water to be treated is subjected to treatment such as removal or filtration, the organic matter that is processed into activated carbon in the post-process is mainly organic matter with a relatively low concentration, and the adsorption treatment of activated carbon in the post-process is the adsorption by high-concentration high-molecular organic matter. Treated water with a reduced organic matter load is supplied to the new activated carbon or recycled carbon, which does not cause alienation or competitive adsorption and has a high adsorption capacity, making it possible to reliably obtain treated water of the desired quality. Furthermore, the quality of treated water can be improved, and the used post-process activated carbon that has already adsorbed low-concentration organic matter but still has the ability to adsorb high-concentration organic matter is supplied to the adsorption tower in the previous process. Furthermore, as the pre-process activated carbon primarily adsorbs organic matter at a high concentration, the adsorption capacity of the activated carbon can be fully and effectively utilized, and it also has the effect of reducing running costs as a method for removing organic matter from activated carbon.

[Brief explanation of drawings]

FIG. 1 is a flow sheet showing one embodiment of the present invention. FIG. 2 is a graph showing the organic matter adsorption capacity of activated carbon. 1... Pretreatment device, 2... Fluidized bed adsorption tower, 3... Biological treatment device, 4... Moving bed adsorption tower, 5... ...Activated carbon regeneration device.

Claims (1)

[Claims] 1 After adsorption treatment of organic wastewater in an activated carbon layer in a fluidized bed state,
In a treatment method in which the treated water is biologically treated and then adsorbed in an activated carbon layer in a moving bed state, the activated carbon in the moving bed state is returned to the activated carbon bed in a fluidized bed state, and the activated carbon in the fluidized bed state is 1. A method for treating organic waste liquid, which comprises regenerating the organic waste liquid and supplying the recycled activated carbon to the activated carbon layer in a moving bed state.