RU1838598C - Method for treatment of polluted underground water - Google Patents

Abstract

Usage: mining, methods for treating contaminated groundwater after underground leaching, as well as groundwater contaminated by industrial enterprises. SUBSTANCE: treatment of contaminated groundwater is carried out by injection through wells located along the contour of the source of contamination of a culture fluid containing an organic food source and an accumulative culture of sulfate-reducing bacteria. Higher carbohydrate polymers are used as an organic food source. The ratio of the volume of culture fluid to the volume of polluted groundwater is

Description

The invention relates to the mining industry, and in particular, to methods for treating contaminated groundwater after underground leaching, as well as groundwater contaminated by industrial enterprises (tailings, etc.).

The purpose of the invention is to increase the cleaning efficiency by reducing costs, the degree of cleaning, speeding up the cleaning process and expanding functionality.

This object is achieved in that in a method for purifying contaminated groundwater, including treating contaminated groundwater by pumping through a well a culture fluid containing an organic feed and an accumulative culture of sulfate-reducing bacteria, treating the contaminated groundwater is carried out along the contour of the contamination center. in this case, higher carbohydrate polymers are used as an organic food source.

The ratio of the volume of the culture fluid to the volume of polluted groundwater is (0.5-2): 100,

As higher carbohydrate polymers, plant residues are used.

Sawdust is used as higher carbohydrate polymers.

A method for treating contaminated groundwater is as follows.

EXAMPLE 1. Residual underground leaching solutions were subjected to purification. Cultural fluid was pumped into the wells. As a culture fluid, organic food was used - higher carbohydrate polymers (plant residues) and an accumulative culture of SRV at a ratio of

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volumes (0.1-1}: 100. The cultivation of microorganisms was carried out in a simplified nutrient medium, g / 1000 ml: (MNFZO 0.25 g; KN2P04 0.02 g. The ratio of the volume of culture fluid to the volume of contaminated residual solutions was 0.5-100 Flax liquid culture (SRV biomass solution) was supplied to the extreme wells of the contamination center. Based on the ore mass with a capacity of 15 m, volume 189 m, the total amount of biomass solution was 0.94 m3. The results are shown in Table 1 .

EXAMPLE 2. The contaminated groundwater of a hydrometallurgical plant was cleaned. Cultural fluid was pumped into the wells, which was used as organic food - sawdust and cumulative culture of CRP. The cultivation of microorganisms was carried out in a simplified nutrient medium, g / 1000 ml: (0.25 g; 0.02 g. The ratio of the volume of the culture fluid to the volume of polluted groundwater was 0.5: 100. The culture fluid (biomass solution of CRP) The total amount of the biomass solution was 0.210 m3, based on the mining rock mass with a capacity of 30 m and a volume of 420 m, and the results are shown in Table 1.

The supply of culture fluid to wells located along the contour of the source of contamination (extreme wells) is determined by the fact that, in the presence of a concentration gradient, intensive accumulation of biomass occurs, which eliminates the long stage of adaptation of microorganisms to environmental conditions. The source of CRP is natural eco-labels.

The supply to the wells of a culture fluid containing higher carbohydrate polymers and an accumulating CRP culture allows one to increase the degree of purification from contaminants, reduce costs, and speed up the cleaning process. As a result of the difference in the concentrations of the elements, the microorganisms themselves propagate into the contaminated volume, changing the geochemical environment. As a result of the interaction of sulfate-reducing bacteria with sulfates, the following transformations occur: reduction of the ISI to HaS;

precipitation of ... formed chalcophilic hydrogen sulfide and elements close to them (Ke / Gu, hn, Pb, Mo, Hg, H1, Co, Cd) in a sulfide (disulfide) insoluble form;

a decrease in the redox potential leads to the reduction (precipitation) of selenium, arsenic, vanadium, radionuclides, and nitrates are reduced to molecular nitrogen;

alkalization of the medium: S042 + 6НгО + + 8ё-ЖаЗ + ЮОН,

as a result, the pH rises and

precipitation of elements - hydrolysates:

Al, Be, Cr, MP.

Thus, the effect of sulfate-reducing bacteria on contaminated groundwater has a comprehensive 5 positive effect with the transfer to the insoluble phase of a large spectrum of contaminant elements regulated by GOST standards. At the same time, a decrease in total mineralization occurs0

tion solutions.

The results confirming the choice of the ratio of the volume of the culture fluid to the volume of polluted groundwater are given in Table 2.

5 It can be seen from Table 2 that when the lower limit is exceeded, the degree of purification of the main polluting elements decreases, which is explained by the lack of bacterial cells in the medium involved in the purification process.

Going beyond the upper limit, the degree of purification also decreases, since an excess of cells is introduced, which leads to a deficiency of organic nutrition, which reduces

5 activity and vitality of CRP; In addition, the introduction of large volumes of biomass is not economically viable.

The results of comparative tests of the prototype method and the proposed method are shown in table 3.

From table 3 it is seen that when cleaning contaminated groundwater according to the proposed method, the degree of purification of the main pollution elements increases.

5 The proposed method allows for environmental cleaning of residual solutions of underground metal leaching, industrial effluents of mining and hydrometallurgical enterprises without

0 special movement of the source of pollution, does not require expensive and energy-intensive equipment, meets the requirements of environmental protection.

Formulas of the invention

5 The method of purifying contaminated groundwater, which involves injecting culture fluid through wells with sulphated bacteria and organic food sources, is distinguished by the fact that

liquids into the contaminated water are carried out along the contour of the source of contamination in a volume ratio (0.5-2); 100, respectively, with higher carbohydrate polymers being used as an organic food source.

Table 1

table 2

Table 3