JPS6125689A - Purification treatment of waste water containing surfactant, oil, and fluorine - Google Patents

Abstract

PURPOSE:To remove effectively contaminants by adding bentonite and a cationic high molecular flocculant to waste water contg. surfactants and oil, adding an Al salt, then adding an alkaline agent to regulate the pH, and separating solid from liquid. CONSTITUTION:Waste water 1 is introduced into a reaction vessel A, and bentonite 2 and a cationic high molecular flocculant 3 are added to decompose the emulsion. The treated water is introduced into a mixing vessel B, and an Al salt 4 and an alkaline agent 5 are added to carry out flocculation. Then flocs are separated in a settling pond C. The treated water is introduced into an oxidation stage D wherein hydrogen peroxide 6 and a ferrous salt 7 are added, then introduced into a neutralization vessel E wherein an alkaline agent 8 is added, and neutralized. The formed flocs are separated in a settling pond F, and clear water 9 is obtained.

Description

[Detailed Description of the Invention] This invention relates to a method for purifying wastewater, and in particular to a method for purifying wastewater using surfactants discharged from surface treatment processes in the aluminum iron industry.
This article relates to a method for purifying wastewater containing oil and fluorine.

[Prior art]

Surfactant, oil, and fluorine-containing wastewater is discharged from the surface treatment process of the aluminum iron industry. Conventionally, this type of wastewater treatment method involves adding a mineral acid to the wastewater to adjust the pH to around 4, and then sequentially adding activated carbon, a cationic polymer flocculant, and an aluminum salt.

Furthermore, after neutralizing the wastewater with an alkali and removing the resulting precipitate, AA salt was added to the resulting clear water.

Furthermore, it has been carried out by adjusting the pH to 6 to 8 with an alkali and removing the formed precipitate. However, the above-mentioned conventional method has the disadvantage that the ability to remove organic pollutants containing surfactants, oil, and fluorine is insufficient.

[Purpose of the invention]

The object of the present invention is to overcome the drawbacks of the prior art.

The object of the present invention is to provide a treatment method that can effectively remove pollutants from wastewater containing surfactants, oil, and fluorine.

[Key points of the invention]

In order to achieve the above object, the present invention provides a surfactant.

Bentonite in wastewater containing oil and fluorine.

After adding a cationic polymer flocculant and adding primary KA4 salt, adding an alkali agent to adjust the pH to 7 and separating the post-liquid (first step) 9 Next, hydrogen peroxide was added to the resulting treated water,
After adding the ferrous salt, the system includes a step (second step) of adjusting the pH to 7 with an alkaline agent and performing solid-liquid separation to obtain treated water.

One embodiment of the present invention will be described with reference to FIG. 1. Emulsion decomposition is carried out by adding 2 tons of bentonite and 3 tons of cationic polymer flocculant to wastewater 1 in a reaction tank AK.

This treated water is further led to mixing tank B with Al salt4. After adding alkaline agent 5 to perform a flocculation reaction, the flocs were separated in sedimentation tank C.

The treated water is led to an oxidation process, after which hydrogen peroxide (6°) and ferrous salt (7) are added, it is led to a neutralization tank (E) and an alkali agent (8) is added to neutralize it, and the flocs are separated in a sedimentation tank (F). , Kiyomizu 9
This is what you get. In the oxidation treatment, residual organic matter is removed, and residual fluorine is also coagulated and removed by the coprecipitation effect of ferric ions. Next, examples will be shown.

[Embodiments of the invention]

To wastewater containing surfactants, oil, and fluorine discharged from the surface treatment process of Aluminum Steel Industry, bentonite "k3000~/" was added and rapidly stirred for 5 minutes, followed by a cationic polymer flocculant. 126q/ was added and stirred rapidly for 5 minutes.Next, 1620η/ of PAC was added, and after rapid stirring for 5 minutes, it was neutralized to pH 7 with Cα(OH)2, and the anionic polymer flocculant was added lη/. After addition, the mixture was slowly stirred for 10 minutes and then allowed to stand for 30 minutes.Next, hydrogen peroxide was added to the supernatant water at a concentration of 468~
/ was added and stirred rapidly for 5 minutes.Next, 3300 cape/ of ferrous sulfate (heptahydrate) was added and stirred rapidly for 5 minutes.

The mixture was neutralized to pH 7 with sodium chloride soda, and then 1*/ of an anionic polymer flocculant was added, stirred slowly for 10 minutes, and then left to stand for 30 minutes. The quality of the wastewater and the quality of the obtained supernatant water are shown in Table 1.

Table 1 [Effects of the Invention] As explained above, according to the present invention, wastewater containing surfactants, oil, and fluorine can be efficiently purified.

[Brief explanation of the drawing]

FIG. 1 is a system explanatory diagram showing one embodiment 51t of the present invention. l...waste water 2...bentonite 3.
...Cationic polymer flocculant 4...Al salt 5...Alkaline agent 6...
・Hydrogen peroxide 7... Ferrous salt 8... Alkali agent 9... Clear water A... Reaction tank B
... Mixing tank C... Sedimentation tank D... Oxidation tank E... Neutralization tank F... Sedimentation tank.

Claims (1)

[Claims] A step of adding bentonite and a cationic polymer flocculant to wastewater containing surfactants, oil, and fluorine, and then adding Al salt, neutralizing the pH to 7 with an alkaline agent, and performing solid-liquid separation to obtain treated water (first step). step) and a step (second step) of adding hydrogen peroxide to the treated water, further adding ferrous salt, neutralizing it to pH 7 with an alkaline agent, and performing solid-liquid separation to obtain treated water. A method for purifying wastewater containing surfactants, oil, and fluorine.