RU2315003C1 - Method of purification of the water from the organic compounds stipulating its colority - Google Patents

Abstract

FIELD: natural gas industry; other industries; methods of the water purification for the economic, drinking and technological purposes.

SUBSTANCE: the invention is pertaining to the field of the water purification for the economic, drinking and technological purposes and may be used for purification of the natural (ground waters, surface waters) and technogenic waters from the organic compounds - the humic and fulvic acids stipulating the coloring of the water. The method of purification of the waters includes the contact of the polluted water with the sorbent. At that, in the capacity of the sorbent they use brucite. In the preferential version of realization of the method the sorption is exercised by filtration through the brucite layer. The invention also provides for realization of the method by addition of the brucite with the coarseness less than 0.1 mm in the purified water with the subsequent separation of the sediment. The invention ensures the high quality of the water purification and price reduction of the production process at the expense of usage of the natural sorbent.

EFFECT: the invention ensures the high quality of the water purification and price reduction of the production process at the expense of usage of the natural sorbent.

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Description

The technical solution relates to the field of water purification for domestic, drinking and technological purposes and can find application for the purification of natural (underground and surface) and industrial waters from organic compounds that determine the color of water.

A known method of purification of natural water from organic compounds by ed. St. USSR No. 590261, C 02 V 1/14, publ. in BI No. 4 for 1978, by contact with a sorbent containing alumina modified with cadmium sulfide.

The disadvantage of this method is the need to prepare the sorbent using chemical reagents (cadmium salt, sulfuric acid, ammonia solution, sodium sulfide or thioacetamide), which requires additional costs directly on chemical reagents and on the disposal of waste or effluents containing them.

The closest in technical essence and the totality of essential features to the proposed technical solution is a method of purifying water from humic and fulvic acids by sorption on ion exchangers, mainly highly basic (Mamchenko A.V. Sorption of humic compounds by ion exchangers // Chemistry and Water Technology. - 1993 - 15 - No. 4 - S.270-294). This technology can be applied only to certain types of industries in order to obtain highly purified water in view of the high cost of synthetic ion exchangers.

The technical task of the proposed method is to reduce the cost of the process by using cheap natural sorbent while ensuring high quality water purification.

This is achieved by the fact that water is purified from organic compounds that determine its color, carried out by sorption, using, according to the technical solution, brucite as a sorbent.

Brucite is a widespread natural mineral of the class of hydroxides, the chemical formula of which is Mg (OH) ₂ , you can use thermally modified. The effect of using natural or thermally modified brucite is the same: there is a cheaper process.

The use of brucite as a sorbent in the process of water purification allows to obtain high-quality water, including satisfactory maximum concentration limit for drinking water by the “color” indicator (20 degrees), with a simultaneous decrease in the “permanganate oxidation” indicator by 1.5–2.0 times .

Sorption can be carried out by filtration through a layer of brucite or adding it with a particle size of less than 0.1 mm in the treated water, followed by separation of the precipitate.

The essence of the technical solution is illustrated by examples of a specific implementation of the method and the table.

Example 1. In samples of a model solution with a color of 88 degrees, in which the color is due to the presence of humic acids, add portions of natural or thermally modified brucite. Samples of the solution with the indicated brucite are mixed for 15 min on a mechanical stirrer, then the indicated brucite is separated by filtration with humic acids sorbed on it. The filtrates determine the residual color of water and permanganate oxidation.

Example 2. In samples of a model solution with a color of 87 degrees, in which the color is due to the presence of fulvic acids, add portions of natural or thermally modified brucite and then the method is carried out as in example 1.

Example 3. In samples of river water containing humic and fulvic acids in a ratio of ~ 1: 2, with a color of 100 degrees, add portions of natural or thermally modified brucite and then the method is carried out as in example 1.

The cleaning results in examples 1, 2, 3 are presented in the table.

The data in the table show that the decrease in the color of the model solution containing humic acids from 88 to 20 degrees occurs with the consumption of natural brucite - 0.75 g / l; thermally modified brucite - 0.05 g / l. Decrease in color to 20 degrees of a model solution containing fulvic acids occurs at a higher consumption of brucite: 3.0 g / l - natural or 0.5 g / l - thermally modified. For the purification of river water, with a color of 100 degrees to 20 degrees, the consumption of brucite was: 2.0 g / l - natural or 0.75 g / l - thermally modified. Thermal modification of natural brucite increases its cost, but this is offset by a decrease in its consumption by 3 ÷ 10 times compared with natural.

Example 4. A sorption column with a diameter of 20 mm is filled with thermally modified brucite with a particle size of 0.5 ÷ 3.0 mm. The volume of loading is 80 cm ³ . River water with a color of 100 degrees, containing humic and fulvic acids, is passed through the column at a speed of 5 m / h. 12,000 ml of water was purified, which is 150 loading volumes. The residual color did not exceed 20 degrees. Permanganate oxidation decreased from 9.2 to 4.8–5.0 mg O ₂ / L.

Thus, the proposed method is simple and cheap. The use of cheap natural or thermally modified brucite as a sorbent for removal from natural and man-made waters, organic compounds that determine the color of water (humic and fulvic acids), allows to obtain water of guaranteed high quality, including satisfactory maximum concentration limit for drinking water in terms of "color" (20 degrees), with a simultaneous decrease in the indicator "permanganate oxidation" by 1.5 ÷ 2.0 times.

Table Sample number Color, hail. Consumption of natural brucite, g / l Consumption of thermally modified brucite, g / l Permanganate oxidation, mg O ₂ / l Humic acids source 88 - - 8.0 one 28 0.5 - 4.8 2 twenty 0.75 - 4.3 3 fifteen 1,0 - 4.0 four twenty - 0.05 4.6 5 10 - 0.25 3.9 6 2 - 0.5 3,7 Fulvic Acids source 87 - - 9.2 one 34 1,5 - 6.0 2 26 2,5 - 5.8 3 19 3.0 - 5.7 four 25 - 0.25 5.8 5 eighteen - 0.5 5,6 6 fifteen - 0.75 5,4 Humic + Fulvic Acids source one hundred - - 14.8 one 28 1,5 - 7.8 2 25 1.75 - 6.0 3 twenty 2.0 - 5.8 four 22 - 0.5 6.0 5 16 - 0.75 5.8 6 fourteen - 1,0 5,4

Claims (3)

1. A method of purifying water from humic and fulvic acids, causing its color, by sorption, characterized in that brucite is used as a sorbent. 2. The method according to claim 1, characterized in that the sorption is carried out by filtration through a layer of brucite. 3. The method according to claim 1, characterized in that the sorption is carried out by adding brucite with a particle size of less than 0.1 mm in the treated water, followed by separation of the precipitate.