JPS6320091A - Flocculating method - Google Patents

Abstract

PURPOSE:To stably grow flocculated and suspended fine particle groups to huge flocs by passing water to be treated with which a flocculating agent is intimately mixed in a flocculation reaction vessel in which three-dimensional network packing materials are uniformly packed from the bottom thereof in the gentle ascending flow. CONSTITUTION:The water to be treated with which the flocculating agent such as polyaluminum chloride is intimately mixed is passed in the gentle ascending flow into the flocculation reaction vessel 21 uniformly packed therein with the three-dimensional network packing materials 23 which are filamentous and has various large and small gaps (e.g., snake gourd fiber structure-like materials). As a result, the flocculated and suspended fine particle groups are stably grown to the huge flocs and the treated water having the stable quality is obtd.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention produces water by mixing a coagulant with water to be treated in which fine suspended particles are suspended. This invention relates to an agglomeration method for growing coagulum (floc) K.

[Conventional technology]

The aggregated suspended fine particles produced by mixing a flocculant such as polyaluminum chloride or sulfuric acid with treated water containing fine suspended particles are grown into huge heavy flocs, and these flocs are allowed to settle under gravity. , the coagulation-sedimentation method to obtain clear water has been widely adopted. At that time, as a flocculation method to grow the suspended particles that have come into contact with the flocculant and flocculated into huge, heavy flocs, the treated water mixed with the flocculant is introduced into a detour channel with a large number of baffle plates. A method of growing flocs while causing water to flow in a detour (detour method), or a method of growing flocs while gently agitating treated water mixed with a flocculant using a stirring device such as a flocculator (mechanical agitation method) etc. are known.

However, in the former method, if the fluctuation of the leaves is large, the growth of the flocs will not be stable.For example, if the amount of water is small, the frequency of contact between the aggregated particles will decrease, making it difficult to grow into huge flocs; The large flocs that have grown may be destroyed by the water flow.

In the latter method, mechanical agitation tends to cause short-circuit currents, and flocs do not grow sufficiently due to insufficient contact frequency between agglomerated particles, and maintenance is complicated since there are mechanically operating parts. It has the following drawbacks.

[Purpose of the invention]

The purpose of the present invention is to improve the drawbacks of the conventional methods as described above, and to provide a flocculation method that stably grows a group of turbid fine particles flocculated into a huge floc using an extremely simple method. It is something to do.

That is, in the present invention, from the bottom of a large coagulation reaction tank, a three-dimensional network filler having linear and various sized voids is uniformly filled.
The gist of the present invention is a flocculation method characterized in that water to be treated mixed with a flocculant is slowly circulated in an upward flow to cause the growth of flocs.

[44 compositions of invention] Hereinafter, the present invention will be explained in more detail with reference to the drawings.

FIG. 1 is a flowchart showing an embodiment of the present invention. In the figure, // is a storage tank for water to be treated, 1, 2 is a mixing tank for flocculant, and /3 is a flocculation reaction to grow into a huge floc. Tank,
/Hiro is a separation device that separates grown flocs, /Yo is a storage tank for treated water. i, Figure 2 shows the flocculation reaction tank in Figure 1/
This is a schematic cross-sectional view of 1w1 for explaining the configuration of 2. ! is treated water introduction pipe, 13
indicates a three-dimensional network filler with filaments and voids of various sizes.

The water to be treated is stored in storage tanks // which contain fine suspended particles. Therefore, these treated waters are introduced into a mixing N/- having a stirring function, where a flocculant/6 and, if necessary, a pg adjuster/7 are added and mixed vigorously with these. As a result, the suspended fine particles form an aggregated suspended fine particle group near the outlet of the mixing tank/2.

The treated water mixed with a flocculant to form agglomerated fine particles is led to the flocculation reaction tank/3.

The flocculation reaction tank 3 is composed of a flocculation reaction tank main body /, a water introduction pipe λλ to be treated, and a three-dimensional reticulated filler material 3. The water to be treated is introduced in an upward flow.

As shown in Figure 1, the coagulation reaction tank main body 1 is uniformly filled with a three-dimensional network filler 3 which is made of filaments and has voids of various sizes.

Therefore, the water to be treated flows in a detour in a zigzag pattern between the voids of the three-dimensional mesh filler 23, and the flow path is also long). The flocs grow into huge flocs and move upward, overflowing into the separation device ltA together with the water to be treated.

The three-dimensional network filler to be filled in the coagulation reaction tank main body 2 may be any material having a three-dimensional network shape with a large number of voids of various sizes, such as loofah fiber texture, Raschig ring-like filler, etc. Any filling material is fine.

The porosity of the three-dimensional network filler 23 is preferably from 10 to 10 rx, and it is uniformly filled into the main body of the T-coagulation reaction tank, and the filling amount is in the range of 0.2 to 3 m3/g under no load. It is preferable to

The flow rate introduced from the treated water inlet pipe 2 may be a slow flow rate within a range in which the three-dimensional reticular filler 23 does not flow, and the flow rate is usually adjusted to 3 to 1/o yx/hr.

Commercially available three-dimensional network fillers include Hechimaron, Saranrock, Touchlon, and Netring (all trade names).

Next, it is separated with the suspended particles that have grown into huge flocs! Huge flocs of the treated water flowing into /4' are separated by sedimentation, and the upper liquid water is introduced as treated water into storage tank /j and stored therein, or is discharged as is.

By adopting the flocculation method described above, the frequency of contact between the flocculated suspended fine particles generated by mixing the flocculant increases, and the growth into giant flocs is always carried out under stable conditions. In addition, the quality of the treated water obtained is also stable due to the formation of large flocs that tend to settle.

〔Example] The present invention will be specifically explained below using examples.

Examples and Comparative Examples After adding kaolin to river water and adjusting the turbidity, a flocculation test was conducted on all of the treated water.

Polyaluminum chloride is used as the flocculant, and Ic A is used so that the pH of the water to be treated during flocculation is around plJ.
After 115 m, the mixture was introduced into a flocculation reactor to grow flocs.

The flocculation reaction tank has a high porosity as a three-dimensional network filler! % of Hetimaron was filled with /-Oyl''/rrr.

In addition, using the same water to be treated, the conventional mechanical stirring method,
We also want to test the detour method.

The results are as shown in Table 1, and I am very happy.

Table 7 [Effects of the Invention] As described above, the present invention allows the flocculation reaction to occur by passing the treated water mixed with a flocculant through a three-dimensional network of filaments, thereby removing flocs. Compared to the conventional flocculation method, which is an extremely simple method of growing flocs, the growth of flocs is always stable, and the quality of the treated water is also stable.

[Brief explanation of the drawing]

FIG. 1 is a flowchart showing an embodiment of the present invention. In the figure, // is a storage tank, and l is a mixing tank. 13 is a flocculation reaction tank, l≠ is a sedimentation separator % l! indicates a storage tank. FIG. 2 is a schematic vertical cross-sectional view of the flocculation reaction tank, in which 2/ represents the flocculation reaction cylinder main body 1, 22 represents the to-be-treated water inlet pipe, and -3 represents the three-dimensional reticular filler. Junjin Nippon Rensui Co., Ltd. Agent Patent Attorney Necessity - Other 7 people seen 1 A 2nd sister

Claims (1)

[Claims] (1) To grow flocs by flowing the water mixed with a flocculant in a slow upward flow from the bottom of the flocculation reaction tank, which is uniformly filled with a three-dimensional net-like filler having fibrillated voids of various sizes. A flocculation method characterized by: