RU2424193C1 - Method for sorption purification of waste water from phenols - Google Patents

Abstract

FIELD: chemistry.

SUBSTANCE: invention can be used in coke-chemical, oil-refining, chemical and cellulose and paper industry. In order to implement the method of purifying waste water from phenol, the sorbent used is magnesium-containing material consisting of magnesium carbonate (51.62-52.84%) and magnesium hydroxide (46.13-47.28%), crushed to grain size between 5 and 10 mm. The material has high phenol sorption capacity of 32.6 mg/g. The degree of sorption of phenol from waste water reaches 100%, while acidity and salt content of the purified waste water drops. The sorption process takes place at room temperature.

EFFECT: method simplifies conditions for sorption of phenols and desorption thereof while maintaining high degree of purity of phenols.

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Description

The invention relates to the technology of sorption wastewater treatment, can be used for wastewater treatment from phenols in the coke, oil refining, chemical, pulp and paper and other industries.

The phenol group is formed by aromatic hydroxyl-containing compounds in which the hydroxyl groups are in the benzene ring. They are highly toxic substances, therefore, the problems of their removal are an important scientific and technical task.

Known sorption methods of wastewater treatment from phenols using synthetic anion exchangers AB-17 in the OH form. EDE-10P-OH, AN-2F, AN-1 [S.M. Rustamov, F.T. Makhmunov, Z.Z. Bashirov. Local adsorption treatment of industrial wastewater from phenol. J. "Chemistry and water technology", 1994, v.16, No. 1, P.69-71], active charcoal mixed with sand in a ratio of from 1:50 to 1: 100 [Patent No. 2079434, IPC C02F 001 / 28, publ. 05/20/1997], flask with a size of fractions from 2.5 to 5.0 mm, impregnated with a solution of iron salt, semi-synthetic sorbents [V.E. Doroshenko, Yu.I. Tarasovich, G.A. Kozub. Phenol sorption by semi-synthetic and natural sorbents. J. "Chemistry and water technology", 1995, v.17, No. 3, p.248-250, N.M. Alykov, A.S. Resnyanskaya. Water purification by natural sorbent. J. "Ecology of the Industry of Russia", No. 2, 2003, pp. 13-14], products of processing of natural aluminosilicates [N.M. Alykov, A.S. Resnyanskaya. Water purification by natural sorbent. J. "Ecology of the industry of Russia", No. 2, 2003, p.13-14] and others.

The main disadvantage of the known sorbents is the length of the process of obtaining or processing sorbents, the insufficiently high degree of wastewater treatment from phenols.

The closest technical solution and the achieved result to the claimed invention is a method of treating wastewater from phenols by adsorption of carbon fiber material in the form of fabric or felt [Application for invention No. 94028265, IPC C02F 001/28, publ. 05/20/1996].

The disadvantage of the prototype method is the high cost of the used sorbents, the need for heating the purified solutions, as well as the reagents used in the desorption of phenol.

An object of the invention is to simplify the conditions of sorption and desorption while maintaining a high degree of purification.

The technical result is achieved by the fact that as a sorbent of phenols from wastewater a magnesium-containing material is used, consisting of magnesium carbonate (51.62-52.84%) and magnesium hydroxide (46.13-47.28%), which has a high sorption capacity of phenol - up to 32.6 mg per 1 g of sorbent. The sorbent is ground to grains from 5 to 10 mm in size. Phenol wastewater treatment occurs under mild conditions without heating.

The applied magnesium-containing material, consisting of magnesium carbonate (51.62-52.84%) and magnesium hydroxide (46.13-47.28%), according to the research, consists of magnesium carbonate (51.62-52.84%) and magnesium hydroxide (46.13-47.28%).

Concrete example

To implement the method used wastewater CJSC Izoplit (Oboyan, Kursk region), producing chipboard.

Wastewater from Isoplit, containing 122.0 mg / l of phenol, is passed through an adsorption column filled with 40.0 g of magnesium-containing material, consisting of magnesium carbonate (51.62-52.84%) and magnesium hydroxide (46 , 13-47.28%). The flow rate of the solution is 0.250 l / h at a temperature of 20 ° C. The phenol content was monitored in the filtrate by the above method. The degree of phenol adsorption was 100%. Water was passed to a phenol content in the filtrate of 0.001 mg / L (MPC). Under these conditions, the sorbent capacity for phenol is 32.6 mg / L.

The degree of purification was determined by the phenol content found by the titrometric method. It is based on the phenol bromination with excess bromide-bromate mixture, the production of iodine by the interaction of potassium iodide with bromine, and titration of iodine with sodium thiosulfate with starch as an indicator.

The analyzed water with a volume of 20.0 to 50.0 ml is transferred into a 300 ml conical flask equipped with a ground stopper, acidified with 10.0 ml of 2 N. solution of sulfuric acid, add 25.0 ml of bromide-bromate mixture (1.67 g of potassium bromate and 6.0 g of potassium bromide in 1 liter of water), close the flask with a stopper and leave for 30 minutes. Then add 1 g of dry potassium iodide, close the flask with a ground stopper, and after 5 minutes, the released iodine is 0.05 N sodium thiosulfate solution; starch solution is added at the end of the titration.

Under similar conditions, distilled water is titrated after addition of bromide-bromate mixture, sulfuric acid and potassium iodide (blank sample). The calculation is carried out according to the formula

,

,

where b is the volume of the sodium thiosulfate solution consumed in the blank, ml;

a is the volume of the sodium thiosulfate solution used for titration, ml;

0.784 - the amount of phenol equivalent to 1 ml of 0.05 N. solution of sodium thiosulfate, mg;

V is the volume of wastewater taken for analysis, ml.

The oxidation of water was also controlled - COD (chemical oxygen consumption), found by the permanganometric method. The conductivity of the studied waters was measured using a conductivity meter - salimeter - KSL - 101 of the Multitest series. The device is designed to measure the electrical conductivity of liquids (X) and the total salt content in terms of sodium chloride.

As can be seen from the table, when passing wastewater through the sorbent, in addition to purifying it from phenol, there is a decrease in water oxidizability and total salt content, that is, the quality of the water improves.

For phenol desorption, a 10% NaOH solution was used, passing it through an adsorption column at a rate of 0.120 l / h for two hours. In this case, a 9-fold concentration of phenol from wastewater in the form of sodium phenolate is observed.

The advantages of the claimed method:

- achievement of a 100% degree of phenol sorption;

- a simultaneous decrease in oxidizability and total salinity of wastewater;

- the use of cheap natural sorbents;

- the sorption process proceeds at room temperature.

Table - Change in wastewater composition The determined values Solution content Before sorption After sorption MPC The phenol content, mg / l 122.0 0 0.001 COD, mgO ₂ / L 48.0 40,0 3.0 Electrical conductivity, mS / cm 4,196 2,32 Salt content in terms of NaCl, g / l 2.24 1,459 1,0

Literature

1. S.M. Rustamov, F.T. Makhmunov, Z.Z. Bashirov. Local adsorption treatment of industrial wastewater from phenol. J. "Chemistry and water technology", 1994, v.16, No. 1, pp. 69-71.

2. Patent No. 2079434, IPC C02F 001/28, publ. 05/20/1997.

3. V.E. Doroshenko, Yu.I. Tarasevich, G.A. Kozub. Phenol sorption by semi-synthetic and natural sorbents. J. "Chemistry and water technology", 1995, v.17, No. 3, p.248-250.

4. N.M. Alykov, A.S. Resnyanskaya. Water purification by natural sorbent. J. "Ecology of the industry of Russia", No. 2, 2003, p.13-14.

5. Application for invention No. 94028265, IPC C02F 001/28, publ. 05/20/1996.

Claims (1)

The method of sorption wastewater treatment from phenols, characterized in that the sorbent is a magnesium-containing material consisting of magnesium carbonate (51.62-52.84%) and magnesium hydroxide (46.13-47.28%), crushed to grains size from 5 to 10 mm.