RU1813745C - Method of treatment of sewage sediments - Google Patents

Abstract

The essence of the method: a sewage sludge with a humidity of 80% or more in a mixture with oil tar is heated to 150-170 ° C and the mixture is kept at this temperature for 0.5-1.0 hours. Under these conditions, partial hydrolysis occurs organic matter, complete disinfection and stabilization of sediment. A stable emulsion is formed due to; d, formation and preservation of cationic and anionic surfactants, suitable for long-term storage. 3 tab.

Description

FIELD OF THE INVENTION This invention relates to the processing of sludge generated during the treatment of domestic and industrial wastewater.

The purpose of the invention is to simplify the method of processing sewage sludge and to obtain a stable deodorized product with a maximum content of cationic surfactants.

Sludge with a water content of 80% or more is loaded into an autoclave with a mixing device and a heat transfer surface. Oil tar or bitumen heated to 200-300 ° C is also fed there. The mixture is heated to 150-170 ° C and held for 0.5-1 hours. After completion of the exposure, the mixture is throttled to atmospheric pressure in another container. In this case, the evaporation of the balance (by heat) amount of water and stripping from the product of odorous substances occurs. Reduced in comparison with the methods previously used, the heating temperature provides energy savings, simplifies the equipment used (since the pressure decreases from 28-100 to 4-6 kg / cm2) and sharply reduces the formation of water-soluble substances. At the recommended temperatures, the product contains almost completely nitrogen-containing substances, the intensive decomposition of which is observed at temperatures above 160 ° C. Their content in the sludge treatment product ensures the formation of a stable emulsion from tar (or bitumen), water, soluble sediment components and solid particles in the organic phase. Such emulsions can be transported as liquid media, which simplifies their further use. The resulting product is quite stable, can be stored at summer temperatures for about 1 month without decay. There is no unpleasant odor of the starting material, which expands the possibilities of its use. The emulsion is used in road construction.

PRI me R. In an autoclave equipped with a mixing device and a heater, 1 kg of sewage sludge with a humidity of 80% is loaded. 0.25 kg of oil tar heated to 150 ° C are also fed here. The autoclave is sealed and heated to 170 ° C. With the stirrer running, heating is continued for 0.5 hours. After completion of the exposure, gas and water vapor are released

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through a refrigerator until 0.12 kg of water is released. Then the temperature in the autoclave is reduced to 90 ° C. The finished product is unloaded.

The material balance is given in table. 1.

Similar experiments are carried out under other conditions x. When optimizing the method, the greatest possible solubility of the organic matter of the precipitate in the tar, the high preservation of cationic surfactants (nitrogen content) and the possibly lower viscosity of the resulting emulsion are taken into account.

The data of such experiments are given in table.2.

The full use of the entire mass of organic and mineral matter of the sediments without their preliminary drying provides a significant environmental and economic effect. An expensive sludge disposal operation is avoided. Exception0

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contamination of soil and water with pathogenic bacteria and viruses, as well as toxic substances. The additional costs of treating the concentrated water effluents generated by known methods are eliminated.

Comparative with the prototype data are given in table. 3 ..

Claims (1)

SUMMARY OF THE INVENTION A method for processing sewage sludge by heating it, characterized in that, in order to simplify the method, to obtain a stable deodorized product with a maximum content of cationic surfactants, the sludge is heated to a temperature not exceeding 150-170 ° C in a mixture with oil tar or bitumen in an amount of 20-30% for 0.5-1 hours. Table 1 table 2 Indicators 180-260 2.8-10.0 50-60 Not stable Less than 25 Not formed Solid residue burial and complex water treatment Necessary increase in biological water treatment capacity Table 3 The claimed method 120-170 0.2-0.6 Do Yu Stable More than 80 Formed Full use of organic and mineral sediment with a positive effect