JP2002336604A - Method and apparatus for separating pollutants in polluted water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a separating method and a separating apparatus for rapidly separating pollutants in a large quantity of the abrasive polluted water. SOLUTION: The pollutants in the polluted water are flocculated and separated by passing the polluted water successively from the upstream side to the downstream side while stirring in stirring tanks 31-37, incorporating a plurality of kinds of flocculants in the polluted water by one kind with a certain time difference successively from the upstream to the downstream while stirring to finish the incorporation of full kinds of the flocculants at the downmost stream position.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method and an apparatus for separating pollutants contained in polluted water such as industrial wastewater, domestic wastewater, ponds, rivers, and sewers.

[0002]

BACKGROUND ART Polluted water such as industrial wastewater, domestic wastewater, ponds, rivers, sewers, etc., contains a lot of pollutants (toxic substances, sludge, sludge, food waste, etc.) which adversely affect the environment.
For example, abrasive polluted water of optical components in industrial wastewater contains toxic fine particles such as transition metal elements and rare earth elements. And need to be separated. At present, polluted water naturally precipitates pollutants in a sedimentation tank and separates it from liquid.However, this method requires a considerable amount of time to complete settling, and requires a large amount of polluted water to be treated. It is necessary to increase the size of the sedimentation tank, which requires a great deal of time and equipment.

Recently, a method of shortening the settling time by mixing a flocculant into the polluted water and stirring to condense the pollutant has been attempted. However, even with this method, a large amount of the polluted water is treated. To do so, a large-scale sedimentation tank is required, and it is necessary to prepare a stirrer that can stir the contaminated water in the sedimentation tank on average, which can solve the problem of treating large amounts of contaminated water. is not.

[0004]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a method and apparatus for separating a large amount of contaminants contained in contaminated water quickly and in large quantities. Aim.

[0005]

The technical means adopted by the present invention to achieve the above object is to agitate polluted water containing pollutants by flowing water while flowing from upstream to downstream. In the method of mixing a plurality of types of flocculants in the contaminated water, one by one from upstream to downstream sequentially with a time lag, by stirring with the contaminated water, a method for coagulating and separating contaminants in the contaminated water. is there. (Claim 1)

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS In addition, a plurality of agitation tanks communicating in parallel from upstream to downstream are agitated by a water flow while flowing polluted water containing pollutants in order from upstream to downstream. Multiple types of flocculants are mixed into the contaminated water in the tank from the upstream agitation tank to the downstream agitation tank one by one with a time lag, and stirred with the contaminated water to coagulate the contaminants in the contaminated water. It is more effective to adopt a method of separating by performing the separation. (Claim 2)

In the present invention, the ph value of the polluted water is adjusted because the ph value of the waste water after the pollutant is effectively separated or the effluent after the separated pollutant is separated is about 7. Ph adjuster mixed into the polluted water from the uppermost stream and the lowermost stream,
A method of stirring with contaminated water is used. (Claim 3)

[0008] As an apparatus capable of carrying out the method of claim 1 or 2, a plurality of stirring tanks are arranged in parallel along a piping path of polluted water containing pollutants. Alternatively, a plurality of selected coagulants, which coagulate contaminants in contaminated water, are sequentially mixed from the upstream side to the downstream side with a time difference from one to another by a separation device. it can. (Claim 4)

[0009] Further, all or a selected plurality of the stirring tanks are provided with one storage unit for each of the stirring tanks or a plurality of the selected stirring tanks. In each storage unit, a plurality of flocculants for flocculating pollutants in the polluted water are alternately stored for each kind, and these flocculants are sequentially stirred from the upstream side to the downstream side with a time lag for each kind. This can be achieved by a separation device adapted to be mixed into the water. (Claim 5)

[0010] As a device capable of carrying out the method of claim 3, there is provided a separation device in which a ph adjusting agent for adjusting ph of contaminated water is mixed into at least the agitating layers located at the uppermost stream and the lowermost stream. Claim 6) Alternatively, a ph regulator for adjusting the pH of the contaminated water is stored in at least a storage section provided in the stirring layer located at the uppermost stream portion and the lowermost stream portion.
This can be achieved by a separation device (claim 7) in which the adjusting agent is mixed into the stirring tank from the storage unit.

As the stirring structure in the stirring tank of the present invention, for example, a propeller-like stirring blade driven by a motor can be used. However, in terms of simplification of the apparatus, energy saving and suppression of noise. What stirs by the power of the polluted water blown out into a stirring tank is suitable. (Claim 8)

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. Separation device A includes a polluted water tank 1, a pump 2, and a plurality (seven in the drawing) of stirring tanks 31 to 3 from the upstream (right side in the drawing).
7, the sedimentation sedimentation tank 4 and the drainage tank 5 are arranged in this order, and all the members arranged downstream from the pump 2 are all connected by a pipe 6. The stirring tanks 31 and 37 are provided with storage units 61 and 62 for the ph adjusting agent, and the ph adjusting agent is supplied to the stirring tanks 31 and 37 by the compressor 38 through the pipe 39.
It is made to flow into. In addition, stirring tanks 32, 34, 3
6 is provided with storage units 63 to 65 for flocculants, in which three different flocculants are stored, respectively, and the flocculants are stirred by the compressor 38 through the pipes 39 through the pipes 39, 34, 36. It is made to flow into.

Here, the stirring tanks 31 to 37 will be described.
The stirring tanks 31 to 37 are substantially columnar in a vertically long direction, and
It is tapered from the middle to the lower end.
And the pipe 6 from the upstream is laid on the upper side surface,
At the lower end, a pipe 6 that goes downstream is provided. The stirring structure of the stirring tanks 31 to 37 causes the polluted water sucked up from the pump 2 to flow into the stirring tank 31 vigorously, and a vortex is generated by the flowing water and the tapered portion toward the lower end. The contaminated water is agitated, and the agitated contaminated water is further stirred by the water flow of the contaminated water.
The stirred polluted water in 1 is vigorously flown into the stirring tank 32. The polluted water flowing into the stirring tank 32 is
In the same manner as the stirring in the above, the water of the polluted water continuously flowing into the stirring tank 31 is continuously and vigorously flown into all the stirring tanks below the stirring tank 32, and is stirred.
It is drained to the sedimentation tank 4.

Although not shown in the drawings, for example, a large amount of plastic pieces are put in a stirring tank and stirred with the contaminated water. In addition to the vortex agitation, the plastic pieces moving around in the contaminated water with the vortex flow. By stirring, the effect of stirring the polluted water can be enhanced. In addition, when a plastic piece is put in, a sieve-like partition is preferably provided in the stirring tank so as not to flow down with the contaminated water.

Next, stirring tanks 31, 32, 34, 36, 3
The piping structure between the storage unit 7 and the storage units 61 to 65 will be described. The stirring tanks 31, 32, 34, 36, and 37 and the storage units 61 to 65 are connected by the pipe 39 as described above.
More specifically, the pipes 39 provided at the lower ends of the storage units 61 to 65 are provided with the stirring layers 31, 32, 34, 36, 3.
Split into two on the way to 7 and each split into a pipe 6
Pipes are provided on the side surfaces of the stirring tanks 31, 32, 34, 36, and 37 above. The compressor 38 and the storage units 61 to 61
65 is piped by the air pipe 40, and the compressor 38 sends air to the storage units 61 to 65,
The ph regulator and the flocculant in the storage units 61 to 65 are mixed with the stirring tank 3
1, 32, 34, 36, 37. The operation of the compressor 38 is controlled by a timer (not shown) which is adjustable in time and which is linked to the operation of the pump 2. When the pump 2 is operated, the operation is started and stopped alternately at regular intervals. is there. Reference numeral 41 is a regulator for the injection amount of the ph regulator and the flocculant,
By adjusting this injection amount controller, a required constant amount of a ph regulator and a flocculant is injected.
In the figure, 7 is a drain valve, 8 is a pollutant discharge section, and 9 is a drain section.

The structure of the separation device is not limited to the illustrated structure. For example, the number of stirring tanks may be increased. In addition, the operation of the pump, the mixing timing of the ph regulator and the coagulant, the replenishment and the injection amount adjustment, the drainage treatment, etc.
Unlimited continuous operation can be made possible by centralized control by a computer and fully automated.

Hereinafter, the separation process of the contaminated water and the contaminants in the contaminated water using the separation apparatus A having the above-described configuration will be described step by step. The polluted water in the polluted water tank 1 is stirred by the pump 2 into the stirred tank 3.
1 and vigorously flow into the tank 1 to agitate the polluted water, and a certain amount of a ph regulator is injected from the storage unit 61. The contaminated water stirred with the ph regulator in the stirring tank 31 flows into the stirring tank 32 by the continuously flowing polluted water and is further stirred, and a certain amount of the first flocculant is injected from the storage unit 63. Is done. The contaminated water stirred with the flocculant in the stirring tank 32 is
The contaminated water flowing into the stirring tank 33 is further stirred by the continuously flowing polluted water. The contaminated water stirred by the stirring layer 33 is further fed into the stirring tank 34 by the continuously flowing polluted water and further stirred. At the same time, a predetermined amount of the second flocculant is injected from the storage unit 64. The contaminated water stirred with the flocculant in the stirring tank 34 is
The polluted water continuously flows into the stirring tank 35 to be further stirred. The contaminated water stirred by the stirring layer 35 flows into the stirring tank 36 by the continuously flowing contaminated water, is further stirred, and a certain amount of the third flocculant is injected from the storage unit 65. The polluted water stirred with the flocculant in the stirring tank 36 is
The contaminated water continuously flows into the stirring tank 37 to be further stirred, and a certain amount of the ph regulator is injected from the storage unit 62 and discharged to the sedimentation tank 4. ~
In the contaminated water, which has been stirred, adjusted for pH, and mixed with a flocculant, the liquid and contaminants are gradually separated in the way, and the sedimentation tank 4
Is completely separated at the time of reaching, the wastewater is drained in that state, and the contaminants settle in the sedimentation tank 4. In the sedimentation tank 4, only the clarified liquid is drained to the drainage tank 5 by the sedimentation of the contaminants. As described above, pollutants in the polluted water can be separated.

When a certain amount of the ph regulator and the flocculant is injected, the compressor 38 is temporarily stopped and restarted after a certain period of time. And the time during which the ph value adjustment and the coagulant chemical reaction are effectively performed,
Adjust according to the size of the stirring tank and the number of stirring tanks.

Next, the results of a separation experiment performed using a separation apparatus having the following conditions are shown. Stirring tank: 7 pieces, each having a diameter of 70 mm, a length of 200 mm, a tapered portion, and a plastic piece. Location of storage for ph regulator and flocculant: Same as in the previous example. Ph adjustment value of polluted water: 7 polluted water used: polishing slurry containing abrasives mainly containing transition metal elements and rare earth elements and polishing wastes used flocculant: first flocculant: bentonite solution second flocculant: Sulfuric acid band solution Third flocculant: Polymer flocculant solution Timing of mixing ph regulator and flocculant: Every 30 seconds Amount of flocculant mixed: approximately 1% of the flow rate of polluted water According to this separation experiment, this apparatus is generally used. A capacity of 300 l / h was observed. From the above experimental results, it is considered that more polluted water can be separated per hour by increasing the number and size of the stirring layers. Further, the flocculant is not limited to those used in the experiment, and any flocculant having a flocculant effect can be used. In this experiment, it was recognized that pollutants can be separated in almost the same manner as the abrasive waste liquid, not only from the abrasive waste liquid, but also from other industrial wastewater, domestic wastewater, pond, river, and sewer polluted water. ing.

[0020]

As described above, according to the present invention, a plurality of types of coagulants are added with a time lag while continuously flowing polluted water.
Since it is a method and apparatus for mixing and stirring each type to separate contaminants, a large amount of contaminated water can be rapidly separated without using a large sedimentation tank as in the related art.
Furthermore, since the size of the whole apparatus can be reduced by the arrangement of the stirring tanks and the form of piping, it is possible to separate and treat a large amount of polluted water even though the apparatus is small and does not take up much space. Moreover, according to the invention of claim 8,
This is effective in terms of simplification and energy saving of the separation device and suppression of noise, and enables reduction of operation cost and preservation of the surrounding environment.

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a separation device of the present invention.

[Explanation of symbols]

 A: Separation device 2: Pump 31-37: Stirring tank 38: Compressor 39: Pipe 40: Air pipe 6: Pipe 61, 62: Storage unit (for ph regulator) 63-65: Storage unit (for regulator)

────────────────────────────────────────────────── ─── of the front page continued (51) Int.Cl. ⁷ identification mark FI theme Court Bu (reference) C02F 1/52 C02F 1/52 K F-term (reference) 4D015 BA19 BA21 BA24 BA28 BB13 CA20 DA05 DA32 DB01 DC02 EA03 EA07 EA08 EA14 EA16 EA17 EA32 4G035 AB44 AC12

Claims (8)

[Claims] 1. A method according to claim 1, wherein the contaminated water containing the contaminants is stirred by a water stream while flowing from upstream to downstream, and a plurality of coagulants are added to the contaminated water with a time lag sequentially from upstream to downstream. A method in which the contaminants in the contaminated water are agglomerated and separated by mixing each type and stirring with the contaminated water. 2. A method according to claim 1, wherein said plurality of agitation tanks communicating in parallel from upstream to downstream are stirred by a water flow while flowing contaminated water containing contaminants in order from upstream to downstream. Multiple types of flocculants are mixed into water one by one with a time lag from the upstream agitation tank to the downstream agitation tank, and are stirred with the contaminated water to coagulate and separate contaminants in the contaminated water. Method. 3. The method according to claim 1, wherein a ph regulator for adjusting the pH of the contaminated water is mixed into the contaminated water at least from the uppermost stream and the lowermost stream and stirred with the contaminated water. 4. A plurality of agitation tanks are arranged in parallel along the pipe path of the contaminated water containing the contaminants, and the contaminants in the contaminated water are supplied to all or selected plural of the agitation tanks. An apparatus for aggregating and separating contaminants in contaminated water by allowing a plurality of coagulants to coagulate to be mixed for each type with a time lag from upstream to downstream sequentially. 5. A stirrer or all or a plurality of selected stirrers are provided with one storage unit for each stirrer, and each storage unit is provided with a plurality of types of agglomerated contaminants in polluted water. The flocculants are stored alternately for each type, and these flocculants are mixed into the agitation tank one by one with a time lag from the upstream side to the downstream side in order to coagulate the contaminants in the contaminated water. Device to separate. 6. The apparatus according to claim 4, wherein a ph adjusting agent for adjusting the ph of the contaminated water is mixed into at least the stirring layers located at the uppermost stream and the lowermost stream. . 7. A ph adjuster for adjusting the pH of the contaminated water is stored in at least storage units provided in the agitating layers located at the uppermost stream and the lowermost stream. 6. The apparatus according to claim 5, wherein said apparatus is mixed with said apparatus. 8. The separation apparatus according to claim 4, wherein the stirring tank is stirred by the power of polluted water blown into the stirring tank.