CS242324B1 - A method for removing heavy metal ions from their aqueous solutions - Google Patents

Abstract

The invention relates to a method for removing heavy metal ions, such as Hg2+, Pb2+, Cdz+, UO22+ from their aqueous solutions with a concentration of 1 to 500 mg. I-1 using a sorbent. The essence of the method according to the invention lies in the fact that crushed needles, preferably spruce needles with a particle size of 0.2 to 0.5 mm, are used as a sorbent in an amount of 0.5 to 2.5 wt. %, while the sorption takes place with stirring at a temperature of 10 to 30 °C for 30 to 120 minutes at a pH of 3 to 8. The method can be used to capture heavy metal ions from aqueous solutions waste from some chemical and metallurgical production.

Description

242324

The invention relates to a process for removing heavy metal ions such as Hg2 +, Pb2 +, Cd2 +, and UO22 + from their aqueous solutions.

Different species of needles do not need to be used in logging and remain unused. Attempts have been made to utilize this mass and additive to animal feed, but the results have not been successful with a low nutritional value and high levels of toxic substances.

It is known that plants are taken from the air, but especially from aqueous solutions by strips, roots and other parts of the rosin, among them heavy metals in the form of compounds. Barbecue vegetables bioaccumulate, for example, cadmium, zinc, nickel, lead arsenic (Rentschler L ·., Gesunde Pfl. 30, 253, 1978; Galvánkové E., Poláčková Š., Suk V., Čsl. Hyg. 24, 131, 1979; Mitchel GA, Bingham FT, Page AL, J. Environ Qual. Cadmium, zinc, copper and lead accumulated in the conifers depending on the content of these elements in the exhales (Nishi-moto T. et al., Bull. Gov. For. Exp. State. 298,1, 1977; Szczbialka Z., Zesp, Probl., Post, Nauk, Roln, 179, 351, 1976). The lead content increased significantly in the leaves of raspberries growing near the pathway (Paukert J., Martis M., OperaConcortica 14, 155, 1977).

The high accumulation capacity of some metals (lead, cadmium and uranium) and their compounds has also been found in microorganisms (Macaskie LE, Dean ACR, Environ.Tech. Lett. 3, 49, 1981; Aickin RM et al., Microbios Lett. 5 , 129, 1977. Horikoshi, T., Nakajima, A., Sakaguchi, T., Eur., J. Appl., Microl., Biotechnol., 12, 90, 1981). Metals linked to functionally functional groups of proteins, amino acids present in both cell membranes and nucleic acids in both native and de-natured form. As a result of the accumulation of heavy metals in inorganic organisms, habitats of lower and higher animal habitats and, ultimately, man are discarded.

For the removal of heavy metal ions from the aquatic environment, a large number of metals are known, for example, metal adsorption to active carbon, ion exchange methods, selective precipitation and flocculation, etc. The disadvantage of these methods is that they are costly.

This disadvantage is substantially obviated by the method according to the invention by means of a sorbent, which consists in using as a sorbent crushed needles, preferably spruce having a particle size of 0.2-0.5 mm in an amount of 0.5-2.5% by weight. wherein the sorption takes place with stirring at a temperature of 10 to 30 ° C for 30 to 120 minutes, for example 3 to 8.

Absorption is pH dependent and independent of the type of compound used. The sorption proceeds rapidly, the equilibrium is already established in the first 30 minutes, and is virtually unchanged in the next 3 hours. The sorbent has proved to be in a wide range of concentrations from 1 to 500 mg. Γ1. Its ability to sorb, for example, mercury from industrial waste streams was affected by the presence of salts. The presence of sodium chloride in a concentration of 0.01 to 0.1 mg. 11 to reduce the absorption ability by 10 to 20 ° / o.

The absorption ability of spruce and boron needle was verified in various mercury, lead, cadmium and uranium compounds at a concentration of 1 to 500 mg. I-1. The details of the method of the invention are evident from the examples. Přikladl

Add 20 ml of mercuric chloride solution, pH 4.5, containing 200 mg of Hg2 + .1 'to a 100 ml Erlenmeyer flask. To the solution is added 1% of spruce cone adjusted to a particle size in the range of 0.2 to 0.4 mm. The sorption is continued with stirring on a reciprocating shaker with a swirl rate of 120 rpm at room temperature. After adsorption for 60 minutes, the sorbent was separated and the mercury content was determined spectrophotometrically by a spectrophotometer. The average residual concentration from the three experiments was 4.1 mg. 1_1. Example 2

As in Example 1, however, the mercury concentration in the sorbent solution was 1 mg. I-1. The sorption solution contained 0.3 mg. 1_1 mercury. Example 3

The procedure as in Example 1, but for the sorption, was adjusted to 1% pine needles. The initial concentration of mercury in the solution was 100 mg / l, the final concentration after sorption was 15 mg. 1_1. Example 4

To a 100 ml Erlenmeyer flask was charged 20 ml of lead chloride solution containing 100 mg. 1_1 lead. The pH of the solution was adjusted to 5.5 and stirred with 1% spruce needles for 60 minutes as in Example 1. The resulting lead concentration after sorption in the solution was 11 mg. I "1. Example 5

The procedure as in Example 4 was used in the form of tetraethylol in a concentration of 100 mg.l -1 Pb. The resulting concentration of lead in solution after sorption was 16 mg. I-1. Example 6

The 100 ml Erlenmeyer flask was

Claims (1)

SUBJECT Method of removing heavy metal ions from their aqueous solutions at a concentration of 1 to 500 mg. I- ¹ by means of a sorbent, characterized in that crushed needles, preferably spruces of a particle size of 0.2 to 0.5 mm in an amount of 0.5 to 2.5% by weight, are used as sorbent, the sorption being carried out with stirring at at a temperature of 10 to 30 ° C for 30 to 120 minutes at a pH of 3 to 8.