JPH04298284A - Polluted water treating device - Google Patents

Abstract

PURPOSE:To consolidate the suspended matter in polluted water without using a flocculant. CONSTITUTION:A flow passage part 1 which allows the passage of the polluted water is provided. Anode electrode plates 5 and cathode electrode plates 6 respectively connected to the anode 3 and cathode 4 of a DC power source 2 are alternately arranged to form an electrode plate group 7. This electrode plate group 7 is held by a supporting material 8. The above-mentioned anode electrode plates made of aluminum and the cathode electrode plates made of a stainless steel are included.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a turbid water treatment system, and more particularly to a system for continuously purifying construction wastewater.

0002

2. Description of the Related Art Generally, as a method for purifying construction wastewater such as cement-based turbid water, it is known to add a polymer coagulant to turbid water to aggregate and precipitate suspended substances.

To explain the outline with reference to FIG. 5, raw water is pumped up from a construction wastewater reservoir 50 and a rainwater reservoir 51, respectively, and the raw water is treated with polyaluminum chloride (PA).
C) Add 52 solution. And raw water is reaction tank 53,5
4, and a polymer flocculant 55 is added here. Then, the reaction proceeds in the reaction channels 56 and 57, and the suspended solids are aggregated and precipitated in the settling tank 59. The flocculated sludge 58 is then concentrated by a pump in a thickened sludge treatment pond 60. On the other hand, the water after the solid matter has been precipitated in the settling tank 59 is sent to the carbon dioxide gas neutralization device 61 and is sent to the neutralization reaction tank 62.
It is neutralized in After neutralization, the water is discharged into the discharge pit 6.
3 and are discharged into rivers.

0004

[Problems to be Solved by the Invention] However, the above-mentioned conventional method requires a large amount of polyaluminum chloride and carbon dioxide, resulting in high costs, and there are concerns about the environmental impact of using chemicals. has been done. In particular, since cement-based wastewater has a high pH value, a large amount of chemicals are required for neutralization, and it has been pointed out that there is a risk of secondary pollution.

[0005] The aeration method and the activated sludge method are known for purifying organic polluted water, but these methods have limitations in the properties of the turbid water and have problems such as slow processing speed and difficulty in purifying large quantities. There is.

[0006] The present invention has been made in view of the above-mentioned matters, and provides a turbid water treatment device that can process muddy water efficiently at low cost and can significantly reduce the impact on the environment. This is a technical issue.

[0007]

[Means for Solving the Problems] In order to solve the above-mentioned technical problems, the present invention has the following configuration. That is, a channel section 1 through which turbid water passes is provided, and electrode plates 5 and 6 connected to the anode 3 and cathode 4 of a DC power source 2, respectively, are arranged alternately along the water flow direction of the channel section 1. As a practical means.

The electrode plate 5 on the anode side can be made of aluminum, and the electrode plate 6 on the cathode side can be made of stainless steel.

[0009]

[Operation] When a DC voltage is applied to the metal electrode plates 5 and 6,
Metal ions are generated from the anode. Suspended substances in turbid water usually have a negative surface charge, so they are neutralized by contact with metal ions, which are cations, and the neutralized particles are attracted to each other and bonded together. It is thought that this causes the suspended solids in the turbid water to aggregate and precipitate.

In addition, physical effects associated with this include oxygen generated from the electrode plate 5 on the anode side due to electrolysis and hydrogen bubbles generated from the electrode plate 6 on the cathode side, and suspended solids floating in the water. combine to cause these suspended substances to rise rapidly. Therefore, it is possible to expect a kind of aeration effect or deaeration effect.

[0011] In addition, a channel section for passing turbid water is provided, and an anode electrode plate and a cathode electrode plate are arranged alternately in this channel section to form an electrode plate group, so installation is easy and it can be installed as desired, such as a drainage port. It can be installed at any location.

[0012] In addition to the above-mentioned cement-based wastewater, the present invention can be applied to pre-treatment of filtration equipment for waterworks and sewerage systems, purification of turbid water caused by sediment runoff due to rainfall, and all kinds of wastewater associated with construction work.

[0013]

Embodiment An embodiment of the present invention will be explained based on FIGS. 1 to 4.

As shown in FIG. 3, the device A of the present invention is installed in a reservoir 30 of turbid water and a waterway 31 separated by a weir.
It is dammed up by a pump P and discharged by a pump P.

In device A, as shown in FIG. 1, a channel section 1 through which turbid water passes is formed of an insulating material, and has side wall sections 1a and 1b on both sides of a bottom plate to form a U-shaped cross section. be. This flow path section 1 is arranged across the entire width of the waterway 31, so that all of the turbid water in the reservoir 30 passes through the inside of the flow path section 1.

In the flow path section 1, anode electrode plates 5 and cathode electrode plates 6 connected to the anode 3 and cathode 4 of the DC power source 2, respectively, are arranged alternately along the water flow direction. As shown in FIG. 1, the DC power supply 2 includes a commercial power supply P, a slider S
, and a rectifier circuit D using a thyristor. The output of this DC power supply 2 is an anode 3 and a cathode 4.
It is connected to the. As shown in FIG. 2, the anode 3 and cathode 4 are formed of rod-shaped conductors, and an anode electrode plate 5 and a cathode electrode plate 6 are attached to the anode 3 and cathode 4, respectively.

The anode electrode plate 5 and the cathode electrode plate 6 constitute an electrode plate group 7, and at the front end and rear end of the flow path section 1,
It is supported by supporting members 8 installed to bridge the side wall portions 1a and 1b. Since these anode electrode plate 5 and cathode electrode plate 6 are worn out with use, they can be easily replaced.

In the above embodiment, the anode electrode 5 is made of aluminum, but iron can also be used, and the cathode can be made of stainless steel, aluminum, or carbon.

The operation will be explained below. Metal electrode plate 5
, 6, metal ions are generated from the anode. Suspended substances in turbid water usually have a negative surface charge, so they are neutralized by contact with metal ions, which are cations, and the neutralized particles are attracted to each other and bonded together. As a result, the suspended matter in the turbid water aggregates and precipitates.

In addition, physical effects associated with this include oxygen generated from the electrode plate 5 on the anode side due to electrolysis and hydrogen bubbles generated from the electrode plate 6 on the cathode side, and suspended matter floating in the water. combine to cause these suspended substances to rise rapidly. Therefore, it is considered possible to expect a kind of aeration effect or deaeration effect.

[0021] Below, the treatment amount is 1500 m3 (pH of turbid water
11.5) and compare the costs per day. In this experiment, as shown in FIG.
were mixed to complete the neutralization reaction and stored in the neutralization reaction pond 36. (Conventional method) Treatment was performed by adding 30 ppm of polyaluminum chloride, 1 ppm of polymer flocculant, and 330 g/m3 of carbon dioxide. ■Cost of polyaluminum chloride 1500m3 x 30ppm x 10-6 x 103 x 55 yen (approximate price per kg) = 2475 yen ■Cost of polymer flocculant 1500m3 x 1ppm x 10-6 x 103 x 1600
Yen (approximate price per kg) = 2400 yen ■Cost of carbon dioxide 1500 m3 x 0.33 kg/m3 x 220 yen (approximate price per kg) = 108,900 yen or more, total 113,775 yen (75.85 yen/m3) Become. (Method using the device of the present invention) ■Electricity bill secondary output 4.5V 30A, AC primary input 1
100V x 7A x 10-3 x 24h from 00V 7A
r x 27/kwhr = 453.6 yen ■ Aluminum electrode wear and tear cost If you replace the positive electrode (10 pieces) once per month 10 pieces x 1 time x 2,350 yen (unit price per piece) / 30 days = 78
3.3 yen ■Cost of carbon dioxide 1500 m3 x 0.180 kg/m3 x 220 yen (kg
Approximate price) = 59,400 yen or more, totaling 60,637 yen (40.42 yen/m3).

[0022] Thus, it can be seen that the running cost of the present invention is reduced by about half compared to the conventional method.

Note that depending on the pH value of the turbid water to be treated, the use of carbon dioxide can be significantly reduced. Therefore, when comparing the costs excluding the cost of carbon dioxide, the conventional method was 2.75 yen/m3, and the present invention was 0.82 yen/m3, which was a significant cost reduction. In particular, when the method was applied to turbid red clay water, strong agglomeration was observed, and precipitation could be achieved efficiently in a short period of time.

[0024]

According to the present invention, suspended matter in turbid water can be continuously aggregated and settled without using a flocculant. Therefore, processing costs can be significantly reduced, and since there is no need to add a flocculant, there is no risk of adverse effects on the environment, and this method is extremely effective in protecting the environment compared to conventional methods.

[Brief explanation of the drawing]

FIG. 1 is an overall circuit diagram showing an embodiment of the present invention.

FIG. 2 is a perspective view showing an embodiment of the present invention.

FIG. 3 is a side view showing one embodiment of the present invention.

FIG. 4 is an overall system diagram showing an embodiment of the present invention.

FIG. 5 is an overall system diagram showing a conventional device.

[Explanation of symbols]

1...Flow path section, 2. DC power supply, 3. Anode, 4. Cathode, 5. Anode electrode plate, 6. Cathode electrode plate, 7. Electrode plate group, 8. Supporting material.

Claims (2)

[Claims] Claim 1: A channel section through which turbid water passes is provided, and within the channel section, anode electrode plates and cathode electrode plates connected to the anode and cathode of a DC power source are arranged alternately along the water flow direction. A turbid water treatment device comprising an electrode plate group and a support material holding the electrode plate group. 2. The anode electrode plate is made of aluminum;
A turbid water treatment device characterized in that the cathode electrode plate is made of stainless steel.