SU941319A1 - Process for purifying effluents from vanadium - Google Patents

Description

(54) METHOD FOR CLEANING WASTEWATER FROM VANADIUM

, 1 The invention relates to purification methods

wastewater from metals and can be used for wastewater treatment, in particular, from vanadium. One type of wastewater containing toxic vanadium compounds is wastewater from power plants that use sulfur fuel oil.

A known method of purification of wastewater from vanadium by the adsorption of activated carbon 1.

However, due to the limited resources of activated carbon, a known method is not very suitable for the treatment of industrial effluents.

The closest to the invention to the technical essence and the achieved result is the method of sewage treatment from 6-day spill precipitation with chemical reagents. Vanadium-containing effluent is treated at pH 2–8 and a temperature of 20–40 ° C with iron compounds to obtain a hardly soluble precipitate of iron vanadate 2.

The disadvantages of this method are the high cost of cleaning, the use of significant quantities of reagents, the formation of large amounts of sludge, as well as incomplete

vanadium removal. The residual content of vanadium in the treated effluent is 5-10 mg / l, which is many times higher than the maximum permissible (MAC-0.1 mg / l).

The purpose of the invention is to increase the degree of purification and reduce the cost of wastewater treatment from vanadium.

This goal is achieved by converting vanadium into insoluble compounds when treating wastewater with activated sludge containing sulfate reducing bacteria (SBB) under anaerobic conditions.

Under these conditions, SCB reduced sulfates to hydrogen sulfide, which forms insoluble sulfides with Vanada. The real wastewater generated in the system of oil-fired boilers of the power station contains, besides vanada, iron, copper, nickel, as well as a significant amount of sulphates.

The use of the proposed method of purification ensures that the effluent from metal ions reaches the maximum permissible concentration (MPC) and also partial removal from sulfates.

3941319

Example Biochemical wastewater treatment is carried out in an installation consisting of a tank for the cultivation of microopratrasMOB (biotenk) with a volume of 10 liters, a raw material tank and a sump. The process / activity is continuously for 10 days under anaerobic conditions with constant circulation of active sludge. The flow rate of the liquid is .0.5 l / h, the temperature in the biotank is 22–25 ° C, the rate of stirring is 100 rpm. Nitrogen was used as a carrier gas; as a baseline culture, a culture was taken; SRB isolated from the reservoir waters of the Romashkinskoye oil field. The culture used on the former is pre-adapted to metal ions, from which 15

100

35

80

five

ten

8700

5220

5 3

100

80

five

ten

8700

3500 0.05

100 OD

80

five

ten

8700

1540

believe purify, wastewater, in particular to vanadium. For biochemical purification, the so-called obmigate waters of the oil-fired boilers of power plants are received, having the following composition (pH 5.2), mg / l:

Vanadium100

Iron80

Copper5

Nickel10

Sulfates8500

COD150

The nutrient elements, nitrogen and phosphorus, are added to the watersheds.

The table shows the data on biochemical wastewater treatment.

85

56.3

ten

100

50

25

100

40

95

97.6

ten

100

25

50

100

60

99.95

0.1

99.9

ten

50

100

25 0.1

100

80

The proposed method in comparison with the known method provides a higher degree of wastewater purification from vanadium (residual vanadium concentration is 0.05 mg / l, and in the known method it is 5 mg / l), as well as the simultaneous removal of other contaminants: copper, iron, nickel, and sulfates. The implementation of the wastewater treatment method proposed provides the possibility of cheaper biological wastewater treatment from Vanadium. Preliminary calculations show that at a throughput of 4.5 thousand m3 / day, the cleaning cost is minimal.

Claims (2)

DETAILED DESCRIPTION OF THE INVENTION The invention is a method for purifying wastewater from vanadium by converting it to insoluble compounds, characterized in that, in order to increase the degree of purification and reduce the cost of the process, wastewater is treated under anaerobic conditions with active sludge containing sulfate reducing bacteria. Sources of information taken into account in the examination 1. J. Water Poll. Coutr. Federation, 1976, 48, No. 4, p. 762. 2. Patent of Germany N 26106: 37, cl. C 02 C 5 / 02,1077