JPS6136997B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a liquid treatment method for treating wastewater, for example, with ozone and an adsorbent. FIG. 1 is a cross-sectional view showing a conventional liquid processing device. In the figure, 1 is an adsorption filtration tank, 2 is a filter material stored in this adsorption filtration tank, and 3 is the adsorption filtration tank 1.
4 is a gas dispersion type gas-liquid contacting device provided in the previous stage of the adsorption filtration tank 1, 5 is an inlet for introducing the water to be treated into this device, and 6 is an inlet to be treated. Water, 7 is a gas dispersion device for discharging and dispersing reactive gas into the water to be treated, 8 is an air pipe for supplying gas to this gas dispersion device, and 9 is treated by the gas-liquid contact device 4. a connecting pipe for guiding the treated water to the adsorption filtration tank 1 at the next stage;
0 is a discharge port for discharging the water treated by the adsorption filtration tank 1, and 11 is the gas-liquid contact device 4.
12 is a waste gas treatment device for treating the gas discharged from the exhaust port, and 13 is a bubble rising in the water to be treated. A conventional liquid processing device is configured as described above.
For example, wastewater is injected as the liquid to be treated from the inlet 5, and inside the gas dispersion type gas-liquid contact device 4,
The pollutants contained in the wastewater are oxidized, decomposed, or sterilized by contact with the bubbles 13 containing, for example, ozone gas, which are released and dispersed in the form of fine bubbles from the gas dispersion device 7 . Next, the wastewater is led to the adsorption filtration tank 1 through the connecting pipe 9, and passes through a layer of activated carbon, which has an adsorption function, as the filter material 2, so that the pollutants in the oxidized and decomposed wastewater are adsorbed and filtered. be done. In this way, if the wastewater is treated with ozone before adsorption and filtration of pollutants in the wastewater using a filter medium such as activated carbon, the load on the adsorption filtration tank is reduced, so wastewater treatment using this combination is recommended. It is done. However, it was necessary to provide an upper space 3 inside the adsorption filtration tank 1 as shown in FIG. In other words, when the filter material 2 becomes clogged, the discharge port 1
The filter medium 2 is backwashed by sending water backwards from zero, but the layer of the filter medium expands at this time, so it is provided to accommodate this expansion, and this space is unnecessary during normal operation. . Therefore, the adsorption filtration tank 1 has to be large in size, and since the gas-liquid contact device 4 and the adsorption filtration tank 1 are separated by function and placed separately, they have the drawbacks of occupying a large space and making the device expensive. . The object of the present invention is to provide a method for processing liquid with an inexpensive liquid processing device that is smaller in size. FIG. 2 is a cross-sectional view showing one embodiment of the present invention, and the reference numerals shown in the figure indicate the same or corresponding parts as those of the conventional device described above. As shown in FIG. 2, the basis of the present invention is that a conventional gas dispersion type gas-liquid contact device 4 is incorporated into the conventional adsorption filtration tank upper space 3 shown in FIG. 1, and these are integrated. is an integrated tank body. In the liquid treatment apparatus configured as described above, a liquid to be treated, such as waste water, is introduced into the tank body 14 from the inlet 5, and is diffused from the gas dispersion device 7 in the upper half of the tank body 14. For example, the pollutants in the wastewater are oxidized and decomposed or sterilized by ozone gas, and then the tank body 14
The above-mentioned oxidation and
Contaminants and the like in the decomposed wastewater are adsorbed and filtered for treatment, and the treated water is taken out from the discharge port 10. Note that the waste gas containing ozone gas is led to the waste gas treatment device 12 through the exhaust port 11 as shown by the broken line arrow. In addition, since the liquid to be treated near the surface of the filter medium 2 and the surface of the filter medium layer are always disturbed by the gas flowing out from the gas dispersion device 7, clogging of the layer of the filter medium 2 is significantly prevented. I will do it. Needless to say, since the size of the device can be made smaller than that of conventional devices, the device can be manufactured at low cost. In the embodiment described above, when the filter medium 2 becomes clogged, a cleaning liquid is injected from the discharge pipe 10 to perform so-called backwashing. FIG. 3 is a sectional view showing the above-mentioned backwashing process, and all the reference numerals shown in the figure are the same as those shown in FIG. 2. As shown in the figure, by injecting the cleaning liquid from the outlet 10 provided at the bottom of the tank body 14, the filter medium 2 is disturbed and pushed upward.
At this time, for example, air is introduced from the air pipe 8 and discharged from the gas dispersion device 7, so that the filter medium 2 is vigorously agitated, so that the filter medium 2 can be efficiently washed. Therefore, the generation of lumps (mud balls), which are formed when particles of the filter medium adhere to each other due to pollutants in wastewater, is also suppressed. Next, the characteristics of the liquid treatment device shown in the above embodiment are compared with those of the conventional device and are shown in the table below.

[Table] In the above table, Sample (1) A _c only...Through only an adsorption filtration tank using activated carbon. Sample (2) O ₃ +A _c ...Through the conventional liquid processing device shown in Figure 1. Sample (3) O ₃ ×A _c ...Through the liquid treatment device of the present invention shown in FIG. 2. TK/K _p =0.5 means the time required for the liquid permeability coefficient K of the filter layer to become half of the initial value K _p , and TOC represents the total organic carbon. In order to keep other conditions constant, the waste liquid, activated carbon, amount of activated carbon used, cross-sectional area of the filter tank, etc. were all the same. As is clear from the table above, it can be seen that the clogging of the filtration layer is particularly improved. Incidentally, in the above description, the present invention is applied to the treatment of waste liquid, but it goes without saying that it can also be applied to other treatments. As explained above, this invention operates a filtration device for liquid purification by injecting cleaning liquid into the tank body from the outlet of the liquid to be treated, especially when air is being fed into the tank body from the gas dispersion device. Since the cleaning solution and air are used for backwashing at the same time, the liquid to be treated near the surface of the filter medium and the surface of the filter layer are constantly disturbed, and clogging of the filter layer is significantly suppressed. Along with
During backwashing of the filter media, the filter media is vigorously stirred together with the cleaning liquid by the air from the gas dispersion device, resulting in the effect that the filter media can be efficiently cleaned.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing a conventional liquid processing device, Fig. 2 is a sectional view showing an embodiment of the present invention, and Fig. 3 is a sectional view showing a state in which the filter medium is backwashed in the above embodiment. It is a diagram. In the figure, 2 is a filter medium, 5 is an inlet, 7 is a gas dispersion device, 10 is an outlet, and 14 is a tank body.
Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A tank body that houses a filter medium and leaves a space at the top;
The liquid to be treated is processed by a liquid processing device equipped with an inlet for the liquid to be treated provided at the top of the tank, an outlet for the liquid to be treated provided at the bottom of the tank, and a gas dispersion device provided at the bottom of the space. When processing a liquid, the gas dispersion device is positioned above the filter medium, and ozone is introduced into the tank body from the gas dispersion device to clean the filter medium. In some cases, the gas dispersion device is located within the filter medium, a cleaning liquid is introduced from the outlet, and air is introduced from the gas dispersion device. Processing method. 2. A liquid treatment method according to claim 1, which uses an adsorbent as a filtering material. 3. A liquid treatment method according to claim 2, using activated carbon as an adsorbent.