CS244613B1 - Wastewater treatment process - Google Patents

Abstract

The invention relates to a method for treating wastewater containing sulfur compounds by the action of a technical culture of anaerobic microorganisms of the genus Deeulfovibrio in the absence of oxygen. The invention consists in the reaction taking place in a closed stirred reactor with such an intensity of stirring that the liquid velocity at the bottom of the reactor does not fall below 0.1 m/s and does not exceed 1.2 m/s, preferably 0.3 to 0.6 m/s, for a period of 1 to 4 days, preferably 22 to 60 hours, at a temperature of 0 to 65 °C, preferably 25 to 32 °C, at a pH of 5 to 9, preferably 6 to 7.5, with hydrogen sulfide leaving the reactor for further processing.

Description

The invention relates to a process for the treatment of effluents containing humorous compounds in an anaerobic environment by a technical culture followed by treatment of the resulting hydrogen sulphide.

Hitherto known methods for removing sulfur compounds from the aqueous phase, such as ionic training or reverse ozmos, are very costly, others such as precipitation are poorly effective.

The process according to the invention, based on the treatment of sulfur-containing waste water by the action of anaerobic microorganisms of the Desulfovibrio genus with no oxygen, characterized in that the reaction is carried out in a closed agitated phase with agitation intensity such that the liquid velocity at the bottom of the reactor does not fall below 0. 1 m / o and did not proceed 1.2 m / s, preferably 0.3 to 0.6 m / s, for 1 to 4 days, preferably 22 to 60 hours, at a temperature of 0 to 65 ° C, preferably 25 to 60 ° C. 32 ° C at a pH of 5 to 9, preferably 6 to 7.5, wherein the resulting hydrogen sulphide leaves for further processing.

An advantage of the invention is that in addition to the removal of the sulfur compounds from the aqueous phase, hydrogen sulfide is obtained, which can be converted into elemental sulfur by known methods. The whole process is preferably carried out in a continuous manner.

The method described is obvious with the following examples.

Example 1

2,000 ml of waste water containing 30 g / l of sulphate was metered into a 5,000 ml inclined vessel. The vessel was heated to 28 ° C and maintained at this temperature throughout the desulfurization process.

After the vessel had been heated, it was purged with technical nitrogen and 400 ml of Desulfovibrio technical fermentation medium at a concentration of 1.10 ¹⁰ org./ml was added. The resulting pH was adjusted to 6.2.

In the next step, stirring was started at an intensity such that the rate of suspension at the bottom of the vessel was in the range of 0.3 to 0.6 m / s. The resulting sulfide was discharged from the vessel through a gas cap to measure the amount for analytical determination.

After 50 hours of operation, the apparatus was shut down and a residual sulphate content of 1.9 g / l was found in the water.

Example 2

Ds of a closed stirred reactor maintained at a temperature of 32 ° C, the contents of which were stirred at a rate such that the liquid velocity at the bottom of the reactor was 0.3 m / β, continuously supplied waste water from coal desulfurization containing 22 g / l sulfate ions.

From the previous process, this water contained a coal suspension of 50 mg / L. Water was fed into the reactor at a rate such that its average residence time in the reactor was 48 hours. The resulting hydrogen sulfide was continuously discharged from the system through a gas shut-off. ^IN

The sulphate ion content was determined in the outgoing water. During the whole monitored period, ie 45 days, the sulphate content of the outgoing water did not drop below 1.2 g / l and did not exceed the value of

1.9 g / l. The pH of the reaction mixture was maintained in the range of 6.0 to 7.3, the concentration of the organisms of the technical accumulation culture of the genus Dosulfovibrio was maintained at a value of 1.10? to 1.10 ¹¹ org / ml.

Example 3

De-closed stirred tank maintained at temperature. 30 ° C, the contents of which were stirred at a rate such that the liquid velocity at the bottom of the reactor was 0.4 m / s, continuously supplied waste gas from the desulfurization of coal with an average total sulfur content of 8 g / l and its distribution of 14.9 g / l of sulfate ions, 4.3 g / l of thiosulfate ions, 0.22 g of zero-valent sulfur (the remainder of the unidentified form of sulfur).

Furthermore, this water contained a coal slurry with an average amount of 42 mg / l. Water was fed to the reactor at a rate such that its average residence time in the reactor was 48 hours. The resulting hydrogen sulfide was continuously discharged from the system through a gas cap.

Residual sulfur was determined in the outgoing water for its oxidation to sulphates. Throughout the monitored period, ie 28 days, the sulphate content in the leaving group did not decrease. water below 1.2 g / l and did not pass the hednet 1.9 g / l.

The pH of the reaction mixture was maintained in the range of 6.0 to 7.3, the concentration of the organisms by the technical disinfection culture of the Desulfovibrio genus was maintained at a value of 1.10 to 1.10 ¹ org / ml by reflux from the biophase separator.

Claims (1)

A process for the treatment of sulfur-containing effluents by an industrial culture of anaerobic microorganisms of the Desulfovibrio species in the absence of oxygen, characterized in that the reaction takes place in a closed stirred reactor and with stirring intensity so that the liquid velocity at the bottom of the reactor does not fall below 1 m / s; 2 m / s preferably 0.3 to 0.6 m / s for 1 to 4 days, preferably 22 to 60 hours at a temperature of 0 to 65 ° C, preferably 25 to 32 ° C, at a pH of 5 to 9 β, preferably 6 to 7.5, the resulting hydrogen sulfide leaving the reactor for further processing.