KR101814871B1 - A system for treating organic matter in rare earth compounds extracted waste water and a treating method using the same - Google Patents

Abstract

The present invention relates to a system for treating an organic matter in a rare earth extraction wastewater and a method for treating an organic matter in the rare earth wastewater using the same. In accordance with the present invention, not only the efficiency of oxidation of organic matter in the rare earth extraction wastewater is increased, So that it is possible to solve the contamination and improve the field applicability of the ozone oxidation treatment process.

Description

Technical Field [0001] The present invention relates to an organic matter treatment system in a rare earth extraction wastewater, and a method for treating organic matter in a rare earth wastewater using the same. BACKGROUND ART < RTI ID = 0.0 >

The present invention relates to a system for treating organic matter in rare earth extracted wastewater and a method for treating organic matter in rare earth wastewater using the same.

The Rare Earth Elements are collectively referred to as the 17 elements of lanthanum elements (Sc) 57 and 71, scandium (Sc) 21 and yttrium (Y) 39.

In the process of extracting rare earths, wastewater containing organic matter is generated and many researches have been carried out for the treatment of organic matter contained in such wastewater. Ozone, fenton, ozone / H ₂ O ₂ , ozone / UV, and ozone catalyst have been developed.

Among the advanced oxidation processes, ozone treatment is the most applied process in the field. This ozone treatment process has high oxidation treatment efficiency, but there is a problem of on-site management and secondary contamination due to residual ozone problem.

In order to solve such a problem, there have been many studies to reduce the ozone concentration and to apply it to the processing site in combination with other processes. However, the processing cost is still too high, and there are still many problems such as difficulty in on-site control.

Meanwhile, Korean Patent Laid-Open Publication No. 2001-0044325 discloses a water treatment apparatus by altitude oxidation treatment using ultraviolet rays and ozone, but the above-mentioned problems are still not solved.

Korean Patent Laid-Open Publication No. 2001-0044325

In order to solve the above problems,

The present invention introduces a hydrodynamic cavitation process to an organic matter treatment system of rare earth extraction wastewater, thereby reducing the injection concentration of ozone, increasing the amount of generated OH radicals having strong oxidation power, and further reducing the bubble size of ozone By increasing the solubility of ozone gas, the oxidizing power is increased, It is an object of the present invention to provide a novel organic matter treatment system in a rare earth extraction wastewater that not only increases the efficiency of organic matter oxidation but also can solve the problem of residual ozone and secondary contamination due to ozone.

Another object of the present invention is to provide a method for treating organic matter in a novel rare earth wastewater using the organic matter treatment system.

In order to achieve the above object,

The present invention relates to an ozone reaction unit for treating an organic matter in a rare earth extraction wastewater by reacting rare earth extracted wastewater with ozone;

A supply part connected to the upper part of the ozone reaction part and supplying the rare earth extraction wastewater to the ozone reaction part;

A discharge unit connected to a lower portion of the ozone reaction unit and discharging the rare earth extraction wastewater treated with an organic matter in the ozone reaction unit;

An ozone generating unit generating ozone reacting in the ozone reaction unit;

An inlet for introducing ozone generated in the ozone generator;

A venturi tube and separator for introducing the ozone to generate ozone microbubbles and OH radicals; And

And an outlet for supplying the generated ozone minute bubbles and OH radicals to the ozone reaction unit.

And an organic matter treatment system in the rare earth extraction wastewater.

The present invention also provides a method for treating an organic matter in rare earth extraction wastewater using the organic matter treatment system of the rare earth extraction wastewater.

According to the present invention, the efficiency of oxidation of organic matters in the rare earth-extracted wastewater is increased to increase the treatment efficiency, and secondary contamination due to residual ozone is solved, thereby further enhancing the field applicability of the ozone oxidation treatment process.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is an enlarged schematic view showing a micro-bubble generating portion of an organic matter treatment system in the rare earth extraction wastewater of the present invention.
FIG. 2 is a graph showing the parameters that may affect the organic matter treatment efficiency of the organic matter treatment system in the rare earth extraction wastewater of the present invention.
3 is an enlarged view of the microbubble generator in the organic substance treatment system of the present invention.
4 is a graph showing the consumption of ozone according to the change in pH inside the microbubble generator.
FIG. 5 is a graph showing the amount of reduction of organic matter according to pH change in the micro-bubble generating unit.
6 is a graph showing the consumption of ozone according to the temperature change inside the microbubble generator.
7 is a graph showing the amount of reduction of organic matter according to the temperature change in the micro-bubble generating unit.
8 is a graph showing the concentration of organic substances in the rare earth extraction wastewater with time in the continuous treatment of organic matter in the rare earth extraction wastewater using the organic matter treatment system in the rare earth extraction wastewater.
9 is a schematic diagram of an organic matter treatment system in the rare earth extraction wastewater of the present invention.

According to the present invention,

An ozone reaction unit for treating organic matter in the rare earth extraction wastewater by reacting rare earth extraction wastewater with ozone;

A supply part connected to the upper part of the ozone reaction part and supplying the rare earth extraction wastewater to the ozone reaction part;

A discharge unit connected to a lower portion of the ozone reaction unit and discharging the rare earth extraction wastewater treated with an organic matter in the ozone reaction unit;

An ozone generating unit generating ozone reacting in the ozone reaction unit;

An inlet for introducing ozone generated in the ozone generator;

A venturi tube and separator for introducing the ozone to generate ozone microbubbles and OH radicals; And

And an outlet for supplying the generated ozone minute bubbles and OH radicals to the ozone reaction unit.

And an organic matter treatment system in the rare earth extraction wastewater.

Hereinafter, the present invention will be described in more detail.

Throughout this specification,

&Quot; Rare earth extraction wastewater " is wastewater generated in the process of extracting rare earth elements at high temperature using strong hydrochloric acid or strong sulfuric acid. The rare earth extraction wastewater exhibits a strong acidity below pH 1, Means a wastewater containing chemical-induced organic matter ((C ₈ H ₁₇ ) ₂ HPO ₃ , oxalic acid, etc.).

In one embodiment of the present invention,

(C ₈ H ₁₇ ) ₂ HPO ₃ represented by the following formula ( ₁ ), oxalic acid (C ₂ H ₂ O ₄ ) represented by the following formula ( ₂ ), benzene, But is not limited to, at least one selected from the group consisting of toluene, ethylbenzene, and xylene.

(C ₈ H ₁₇ ) ₂ HPO ₃ (Phosphonic acid (2-ethylhexyl) -mono (2-ethylhexyl) ester) C ₂ H ₂ O ₄ (oxalic acid, oxalic acid)

[Chemical Formula 1]

(2)

The organic matter treatment system of the present invention is used to treat the organic matter in the rare earth extraction wastewater. FIG. 9 shows a system for treating organic matters in rare earth extraction wastewater according to an embodiment of the present invention.

First, the rare earth extraction wastewater is supplied to the ozone reaction unit 10 through the supply unit 20.

In the ozone reacting unit 10, organic matter in the rare earth extraction wastewater is treated by oxidation reaction by ozone, and the ozone is generated in the ozone generating unit 40 connected to the ozone reaction unit 10.

The ozone generating unit 40 is not limited as long as it includes an apparatus capable of generating ozone.

The ozone generated in the ozone generator 40 is supplied to the minute bubble generator 50.

In one embodiment of the present invention,

In the microbubble generator 50, fine bubbles of ozone are generated. The ozone microbubbles contain ozone in fine bubbles having an average particle size of 50 nm or less, and preferably have an average particle size of 50 nm or less. Do not.

When the average particle size of the fine bubbles of the ozone is within the above range, the OH radical generation amount and the solubility of the ozone are increased to increase the oxidizing power of the ozone, and as a result, the treatment efficiency of the organic substance treatment apparatus in the rare earth extraction wastewater of the present invention is increased .

The microbubble generator 50 includes an inlet 51 for introducing ozone generated in the ozone generator 40, a venturi tube and a separator 52 for generating ozone microbubbles and OH radicals, And an outlet 53 for supplying bubbles and OH radicals to the ozone reaction unit 10.

The minute bubbles of ozone generated in the minute bubble generator 50 can circulate in the minute bubble generator 50.

OH radicals can be generated by the circulation of the minute bubbles of the ozone. Thereafter, the minute bubbles and the OH radicals of the ozone move to the ozone reaction unit 10 to treat the organic matter among the rare earth extracted wastewater.

In one embodiment of the present invention,

In the ozone reacting unit 10, organic matter in the rare earth extraction wastewater can be treated by direct oxidation with ozone and indirect oxidation.

The direct oxidation is characterized in that ozone is dissolved in water to oxidize organic matter. The indirect oxidation is characterized in that ozone is self-decomposed to generate an OH radical (.OH) having a strong oxidizing power to oxidize organic matter.

Mechanisms of direct oxidation and indirect oxidation by ozone are shown in the following Reaction Schemes 1 and 2, respectively.

[Reaction Scheme 1]

[Reaction Scheme 2]

In one embodiment of the present invention,

The expansion angle of the inflow portion of the venturi tube is 20 to 25 and the expansion angle of the outflow portion is preferably 4 to 8, but is not limited thereto.

The reason is that when the expansion angle of the inlet and outlet of the venturi tube is in the above range, an appropriate pressure difference is given to the inside of the venturi tube, and the OH radical generation amount and the solubility of ozone are increased to increase the oxidizing power of ozone, The treatment efficiency of the organic matter treatment apparatus among the rare earth-extracted wastewater is maximized. In addition, since the amount of ozone injected is reduced to prevent secondary contamination due to ozone, there is an advantage that on-site maintenance becomes convenient.

In another embodiment of the present invention,

The hole size of the separator is preferably 0.5 mm to 2 mm, and the number of holes of the separator is preferably 1 to 10, but is not limited thereto.

When the hole size and the number of holes in the separator are within the above range, the OH radical generation amount and the solubility of ozone are increased, thereby increasing the oxidizing power of the ozone and consequently maximizing the treatment efficiency of the organic matter treatment apparatus in the rare earth extraction wastewater of the present invention .

The rare earth extraction wastewater treated with organic matter in the ozone reaction unit 10 is discharged by a discharge unit 30 connected to the lower part of the ozone reaction unit 10.

The present invention also relates to a method for treating organic matter in rare earth extraction wastewater using the organic matter treatment system of the rare earth extraction wastewater.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the embodiments of the present invention described below are illustrative only and the scope of the present invention is not limited to these embodiments. The scope of the present invention is indicated in the claims, and moreover, includes all changes within the meaning and range of equivalency of the claims. In the following Examples and Comparative Examples, "%" and "part" representing the content are based on weight unless otherwise specified.

Example

Example  1. Organic matter treatment system in rare earth extraction wastewater

9 is a diagram showing the configuration of an organic matter treatment system in the rare earth extraction wastewater according to the present invention. As shown in Fig. 9, the organic substance treatment system of the present invention was constructed. In addition, the microbubble generator 50 of the organic substance treatment system of the present invention is constructed as shown in FIG.

Test Example  1. Determination of reaction rate constant of organic matter treatment reaction in rare earth extraction wastewater

The hydrodynamic cavity cavitation ozone process was used to measure the reaction rate constant of the organic material treatment reaction according to the pH and temperature of the micro bubble generator by setting the hole size of the separator to be Φ 1 mm and the number of holes to 5.

The reaction rate constants were measured by measuring the amount of ozone consumption and the amount of organic matter reduction according to pH or temperature change, and calculating the unit time.

The results are shown in Figs. 4 to 7 and Table 2 below.

pH 2 3 5 7 9 The reaction rate constant (10 ^-3 min ^-1 ) 2.4 3.1 3.6 16.3 19.9 Temperature (℃) 15 25 40 55 - The reaction rate constant (10 ^-3 min ^-1 ) 1.9 3.6 4.3 5.4 -

As shown in Table 2 above, the effects of pH and temperature inside the venturi tube were observed. As a result, the dissolved ozone consumption and the rate constant of the organic oxidation reaction rate were increased with increasing pH and temperature.

Test Example  2. Measuring the throughput of organics in rare earth extraction wastewater

As shown in FIG. 8, organic matter was continuously treated for 100 days. As a result, the organic matter concentration in the organic matter treatment system of the present invention was 83 mg / L, the organic matter concentration was 18 mg / L, the organic matter treatment rate was 78.3% Respectively.

10: ozone reaction part
20:
30:
40: ozone generator
50: fine bubble generator 51: introducing part 52: venturi tube and separator 53:

Claims (11)

An ozone reaction unit for treating organic matter in the rare earth extraction wastewater by reacting rare earth extraction wastewater with ozone;
A supply part connected to the upper part of the ozone reaction part and supplying the rare earth extraction wastewater to the ozone reaction part;
A discharge unit connected to a lower portion of the ozone reaction unit and discharging the rare earth extraction wastewater treated with an organic matter in the ozone reaction unit;
An ozone generating unit generating ozone reacting in the ozone reaction unit;
An inlet for introducing ozone generated in the ozone generator;
A venturi tube and separator for introducing the ozone to generate ozone microbubbles and OH radicals; And
And an outlet for supplying the generated ozone minute bubbles and OH radicals to the ozone reaction unit,
Wherein the venturi pipe has a structure in which two venturi pipes are connected in series, the expansion angle of the initial inlet is 20 to 25, the expansion angle of the final outlet is 4 to 8,
The separator is installed at a connection portion between the venturi pipes and has 1 to 10 holes having a diameter of 0.5 mm to 2 mm,
Wherein the ozone microbubbles passed through the venturi tube have an average particle size of 50 nm or less. delete delete delete delete The method according to claim 1,
Wherein the organic matter in the rare earth extraction wastewater is treated by direct oxidation and indirect oxidation by ozone in the ozone reaction part. The method of claim 6,
Wherein the direct oxidation is characterized in that ozone is dissolved in water to oxidize organic matter. The method of claim 6,
Wherein the indirect oxidation comprises autoxidation of ozone to generate OH radicals to oxidize organic matter. The method according to claim 1,
The extraction of the rare earth wastewater organics Phosphonic acid (2-ethylhexyl) -mono (2-ethylhexyl) ester {(C 8 H 17) 2 HPO 3}, (C ₂ H ₂ O ₄ ), benzene, toluene, ethylbenzene, and xylene. Organic matter treatment system in rare earth extraction wastewater. The method according to claim 1,
Wherein the rare earth extraction wastewater is directly introduced into the ozone reaction section. A method for treating organic matter in rare earth extraction wastewater using the organic matter treatment system of the rare earth extraction wastewater of claim 1.

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