A method of processing wastewater containing alkali metal permanganates

 

(57) Abstract:

The invention relates to the processing of liquid radioactive waste (LRW), generated during decontamination of equipment, vehicles, etc. the essence of the invention lies in the fact that before mixing alkaline wastes containing alkali metal permanganates and acidic wastes containing organic complexing substances, they also add surface-active substances (surfactants) in an amount of 0.1-10 g surfactant per 1 g of manganese in the waste mixture, incubated for 0.25 to 72 hours at a temperature of 10-40oC, and the mixture alkaline and acidic waste is carried out in the ratio required to establish the pH of the mixture in the range of 6-9. Increases the efficiency of the process increases the degree of deposition of radionuclides and transition metal ions. 4 C.p. f-crystals, 1 table.

The invention relates to the treatment of wastewater, in particular to methods for refining alkaline wastewater containing permanganates metals, radionuclides and heavy metal ions. The invention can be used for recycling waste generated during decontamination of equipment, vehicles, clothing and so on, solutions containing alkaline permanganates metalcase destruction of organic compounds by potassium permanganate with the formation of manganese dioxide and precipitation of impurities with the help of a specific connection. The disadvantage of this method is its use only for processing low-salt solutions (FR 2451617, CL G21F 9/16, 1980)

The closest to the technical essence and the achieved effect is a method of processing radioactive alkaline wastewater, comprising the introduction into them of oxalic acid to precipitate the manganese in the form of dioxide, acidification of the solution and neutralize it to a pH of 7-8 [2, prototype]. As a result of mixing, a precipitate of manganese dioxide, containing the main part of the nuclides in liquid radioactive waste (LRW). The obtained precipitate was separated from the liquid phase and is sent to the curing method of cementing or bitumirovannaya (JP 3-5560 B4 class. G21F 9/06, 22.05.85).

The disadvantages of this method include: incomplete precipitation of manganese from decontamination solutions; inability to removal from a solution of organic impurities; high consumption of reagents.

The objective of the invention is to increase the degree of concentration LRW, including high salinity, to ensure the safety of the environment and their further utilization.

The problem is solved is described by way of LRW processing, including mixing alkaline and they also add surface-active substances (surfactants), mainly anionic and/or nonionic type in an amount of 0.1-10 g surfactant per 1 g of manganese in the waste mixture, incubated for 0.25 to 72 hours at a temperature of 10-40oC, and the mixture alkaline and acidic waste is carried out in the ratio required to establish the pH of the mixture in the range of 6-9, followed by the separation and disposal of the resulting sludge.

It was experimentally found that the introduction of surfactants in alkaline and acidic waste containing complexing substances, followed by mixing with sediment manganese dioxide observed an unexpected effect - increases the degree of deposition of radionuclides from the precipitate of manganese dioxide: reduce the amount of time defending and volume of sediment. When this waste is mainly contribute anionic (AS) and/or neionogennye (nonionic surfactants) surfactant in an amount of 0.1-10 g/g Mn in a mixture of waste solutions after making surfactant was incubated for 0.25 to 72 hours at a temperature of 10-40oC, and the mixture of waste is carried out in the ratio required to establish the pH of the mixture in the range of 6-9.

When the exposure time is less than 0.25 hours, a pH of less than 6, a temperature of less than 10oC, the surfactant concentration is less than 0.1 g per 1 g Mn sharp reduction act the Mn increase the amount of sludge and time of sludge, and in the process of evaporation is their denaturation in the presence of an electrolyte with the selection in a separate phase. Increasing the exposure time of more than 72 hours and temperature exposure over 40oC does not increase process efficiency and cost necelesobrazno.

The introduction of waste other types of surfactants, such as cationic, less effective. Introduction to waste coagulants, for example, polyacrylamide, does not lead to the same positive effect.

Thus, the phenomenon is new, not obvious, and the totality of the features of the invention satisfies the criteria of "novelty" and "inventive step".

The method is illustrated by the following examples.

Example 1 (prototype). Recycled alkaline and acidic decontamination solutions of the following composition. The alkaline solution, g/l: NaOH 50; KMnO45 (Mn 1,74); U(Vl) 0,1; TBP 0.1; waxes of 0.1; Fe 0,2; Ni 0,1; Al of 0.2; Cu of 0.07. Acidic solution, g/l; HNO350; N2WITH2ABOUT42; NaF 2; U(Vl) 0,1; TBP 0.1; waxes of 0.1; Mn 003; Fe 0,015; Cr 0,02; 0,005 Ni; Al of 0.03; Cu 0,01.

Specific beta activity of alkaline and acidic solution is 9,0107Bq/l and is determined by the presence of radionuclides125Sb;106EN; 137Cs;134

Examples 2-6 illustrate the inventive method.

Example 2. Recycle alkaline and acid decontamination solution composition shown in example 1, in alkaline solution make neinogennye surfactants (nonionic surfactants) type OP-10 in the amount of 0.17 g/l, while in acidic solution anionic surfactants (AS) - sultanol in the amount of 0.003 g/l and incubated for 72 hours at a temperature of 10oC. Then mix alkaline and acid solutions in the ratio 1: 1,39 - 1:1,150 in the mixture, respectively, to achieve a pH of the mixture to 6.0. The amount of surfactant 0.1 g to 1 g Mn in a mixture of waste. The mixture is stirred for 10 minutes and transferred into a measuring cylinder. The rate of sludge sediment and the degree of deposition of metal ions and radionuclides is determined analogously to example 1.

Example 3. The method is carried out analogously to example 2, with the difference that in alkaline and acidic solution make the nonionic surfactants of the type About which to achieve a pH of the mixture to 8.0. The amount of surfactant 10 g per 1 g of Mn in the mixture of waste.

Example 4. The method is carried out analogously to example 2 with the difference that in alkaline and acid solutions make ASAS - sultanol in the number of 3.48 and 0.96 g/l, respectively, was incubated for 1 hour at a temperature of 25oC and mix to achieve a pH of the mixture of 7.8. The amount of surfactant 2 g per 1 g of Mn in the mixture of waste.

Example 5. The method is carried out analogously to example 2 with the difference that in alkaline and acid solutions contribute AS type contact Petrova (mixture of sulfonic acids obtained by sulfonation of kerosene or gas oil distillate) in an amount of 0.6 g of surfactant per 1 g of Mn in waste mixture, maintained at a temperature of 10oC for 72 hours and mixed to achieve a pH of the mixture to 6.0.

Example 6. The method is carried out analogously to example 2 with the difference that in alkaline solution make waste water from Laundry, containing nonionic surfactants of the type OP-7 and OP-10, and in acidic solution - ASAS - sultanol, maintained at a temperature of 40oC for 0.25 hour and mix to achieve a pH of the mixture to 9.0. The amount of surfactant is 0.1 g to 1 g Mn in a mixture of waste.

The results obtained in examples 1-6 in table.

The advantages of the proposed method mererani sludge and to increase the degree of concentration of waste by reducing the volume of sludge while increasing the degree of deposition of radionuclides and transition metal ions. A high degree of deposition of radionuclides and transition metals allows processing of LRW with high salt concentration, with subsequent recycling of the liquid phase, after separation of the precipitate, for example, by the method of parki. An additional advantage of the proposed method is the possibility of associated disposal of another type LRW - water Laundry or other types of LRW, contain surfactants.

1. A method of processing wastewater containing alkali metal permanganates, including their mixture with an acidic solution containing oxalic acid, separation and disposal of the resulting sludge, characterized in that before mixing in the alkaline waste water and in acidic solution further contribute surfactants, stand up and mixing them in the ratio required to establish the pH of the mixture in the range of 6-9.

2. The method according to p. 1, characterized in that the alkaline waste water and acid solution using liquid radioactive waste.

3. The method according to p. 1 or 2, characterized in that the alkaline waste water and acidic solution contribute anionic and/or neionogennye surfactants.

4. The method according to any of paragraphs.1-3, otlichaya">

5. The method according to any of paragraphs.1-4, characterized in that the extract of the waste before mixing is carried out at a temperature of 10-40oC for 0.25 to 72 hours

 

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SUBSTANCE: the invention is dealt with devices for purification of household and industrial sewage and intended for electrical and cavitational treatment of sewage containing a large quantity of organic compounds. The device for purification of sewage consists of a body made out of a dielectric material partitioned by diaphragms for two electrode chambers and one working chamber, that contains a filtering material. The electrode chambers have cavitational field sources installed and the working chamber is supplied with a the bubbler installed in it. The technical result consists in an increase of recuperation of the filtering material at the expense of application of a cavitational field to it, decrease of the microbiological semination, and an increase of cavitational effect on particles.

EFFECT: the invention ensures an increase of the filtering material recuperation, decreased microbiological semination and increased the cavitational effect on particles.

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FIELD: devices for purification of household and industrial sewage.

SUBSTANCE: the invention is dealt with devices for purification of household and industrial sewage and intended for electrical and cavitational treatment of sewage containing a large quantity of organic compounds. The device for purification of sewage consists of a body made out of a dielectric material partitioned by diaphragms for two electrode chambers and one working chamber, that contains a filtering material. The electrode chambers have cavitational field sources installed and the working chamber is supplied with a the bubbler installed in it. The technical result consists in an increase of recuperation of the filtering material at the expense of application of a cavitational field to it, decrease of the microbiological semination, and an increase of cavitational effect on particles.

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