SU802191A1 - Method of solution purification from active chlorine - Google Patents

Description

(54) METHOD FOR CLEANING SOLUTIONS FROM ACTIVE CHLORINE

one

The invention relates to the purification of waste waters and solutions from active chlorine CP and can be used in the chemical industry in the production of chlorine and caustic soda, organic compounds.

Methods are known for the reduction of active chlorine by chemical reagents — liquid or gaseous, reinforcing or aliphatic-1Ul-W12 hydrocarbons by various inorganic compounds, for example, sulfides, sulfates, sulfur dioxide. The process of dechlorination by these methods requires a necessary excess of the reducing agent and under the conditions of varying volumes of chlorine-containing solutions and the content of active chlorine in them does not exclude its breakthrough,

The closest to the invention to the technical essence and the achieved result is the method of purification of chlorine salt solution 3 from chlorine, which is carried out on activated carbon of marks АP-3 or KAD-iodine with a particle size of 2г5 mm at a linear solution rate of 11.1-22, 3 m / h This method reduces the concentration of active chlorine.

from 30-90 mg / l to a value less than 1 mg / l. However, to obtain such an effect, the contact time of the treated solution with active carbon is not less than 3-6 minutes, which makes it difficult to process large volumes of solutions and requires an increase in the size of the apparatus.

The aim of the invention is to achieve effective removal of solutions with less contact time.

The goal is achieved by the described method by contacting 5 of the treated solutions with activated carbon.

A distinctive feature of the method is the implementation of this contact in the presence of chlorine-containing hydrocarbons, preferably carbon tetrachloride or dichloroethane at a concentration of 10-30 mg / l.

The process technology consists in introducing chlorine-containing hydrocarbon into the solution to be dried. Then this solution is passed through an activated carbon layer.

Example 1. A solution having a pH of 3 and containing 100 mg / l of active

0 chlorine in terms of CE / j, 10 g / l of sodium chloride, 0.1 g / l of calcium chloride and 1 g / l of magnesium sulphate were mixed with dichloroethane, creating its concentration in a solution of 10 mg / l. The resulting mixture was brought into contact with activated carbon AP-3. At a contact time of 2 minutes, the concentration of active chlorine decreased to 0.1 mg / l in terms of Sb.

Example 2. The solution of the composition according to the example was mixed with carbon tetrachloride, creating its concentration in a solution of 30 mg / L. The resulting mixture was put in contact with activated carbon. At a contact time of 0.3 min, the concentration of active chlorine decreased to 0.1 mg / l in terms of CErj.

When using carbon tetrachloride and dichloroethane, the effect of cleaning the solution from active chlorine is observed starting from their concentration of 10 mg / l.,; It is impractical to introduce THESE compounds into the solution in an amount in excess of 30 mg / l, since the effect achieved in this case does not become higher than at their co-concentration of 30 mg / l.

. Dichloroethane and carbon tetrachloride were used as α-chlorine-containing hydrocarbons in the process of purifying solutions from active chlorine when contacting the carbon-containing sorbent, since both of these compounds are readily available, their production almost always accompanies the production of chlorine and caustic soda, one of large consumers of chlorine. In addition, they dissolve in water and dissolve active chlorine; they do not chlorinate during solution cleaning.

These compounds are in liquid form in a wide range of temperatures and are convenient in operation.

Unlike carbon tetrachloride and dichloroethane, other known chlorine solvents, such as heptane, perfluoroethylene, benzene, cyclohexane, methyl chloride or methylene chloride, can be chlorinated to form hardly separable chlorine-containing hydrocarbons, contaminating the treated solutions and are less convenient to use. for higher volatility.

The method of dechlorination of wastewater in the presence of organochlorine hydrocarbons allows a cleaning process 5-10 times faster than the known one. Dechlorinated drains can be returned to recycling.

According to a preliminary calculation, the economic effect due to the intensification of the cleaning process from active chlorine, reducing the size of the process equipment and returning the purified solutions to production will amount to about 100 thousand rubles per year in the production of chlorine caustic soda and organic products of average power.

Claims (3)

1. Method of cleaning solutions from active chlorine by their contact with activated carbon, characterized in that, in order to intensify the process, the solutions are contacted with a sorbent in the presence of chlorine-containing hydrocarbons. 2. The method according to claim 1, characterized in that carbon tetrachloride or dichloroethane is used as chlorine-containing hydrocarbons in an amount of 10-30 mg / l. Sources of information taken into account in the examination 1. USSR author's certificate NM6932, cl. C 02 C 5/02, 1935. 2. Authors certificate USSR fl92704, cl. C 01 D 1/28, 1967. 3. Authors certificate of the USSR 327784, cl. C 02 C 5/02, 1972.