Sorption water treatment in Ukraine
One of the urgent problems of water treatment in recent decades is the need for deodorization (improvement of taste) of drinking water.
The deterioration of the drinking quality of water is due to their mineral and, especially, organic composition.
Deodorization of water in some cases is achieved by coagulation of impurities and their flocculation followed by filtration, but often the use of special technologies is required to eliminate unwanted odors and tastes.
There are several methods of water deodorization: oxidative, aeration, sorption, etc.
The most reliable and economical is the sorption method. As sorbents, activated carbons are most often used, as well as non-carbon sorbents (clinoptilolites, zeolites).
The sorption method of deodorization is much more reliable than the others, because. it is based not on the transformation of pollutants, but on their extraction from water.
Filters loaded with activated carbon, regardless of fluctuations in the level of water pollution, are a permanent barrier in relation to sorbed substances. One of the disadvantages of this method is the low absorption capacity of the coal, which necessitates frequent replacement or regeneration.
The most widely used are granular activated carbons, which can be used in pressure filters. Usually carbon filters in water treatment schemes are placed after clarification. Sorption filters are periodically washed with water.
The disadvantage of using carbon sorption filters is the need for active carbon regeneration, which can be carried out by thermal and chemical methods.
The chemical method involves the preliminary treatment of coal with live steam, and then with alkali. The method is complex, time-consuming and not effective enough, because does not completely restore the sorption capacity of the material.
The thermal method consists in burning out adsorbed organic substances in special furnaces at a temperature of 800 – 900 C. In this case, losses of up to 10-12% of coal during firing are inevitable.
Due to the low efficiency of activated carbon regeneration processes, it is usually replaced.