BIOMEDY
Applications BIOREM
Prj 9406 - Field Test for bioremediation of underground water contaminated by uranium mining operations
BIOREM was tested on bedded waters contaminated from mining operation consisting in the in-situ leaching of uranium by sulfuric acid. The test was performed using the existing technological wells and comprised several variants. For simplicity it is reported the solution using two wells, one for injection and one for monitoring.
676 m

4.1 m3

660-670 m

23.4 m

10 m

10 m/day

0.2

2 m

125 m3

25 m3

40° C
Well depth

Well volume

BIOREM injection depth

Water-carring horizon thickness

Bioactive water-carrying horizon thickness

Water-carrying filtration factor

Porosity

Bioactive radius

Bioactive volume

Bioactive pore volume

Stratum temperature
Appropriate volume of BIOREM biomass was grown to its critical concentration and injected in the near-filter zone by free pouring. Because the depth of the headwater water-bearing horizon, the biomass was injected under pressure generated by a further injection of polluted water which volume was identical to the well volume (4.1 m3).

Samplings were started after a period of bacterial adaptation to the environmental conditions.

Water corresponding to the well volume (4.1 m3) was first pumped out by airlifting into a temporary reservoir then samples taken and water re-injected into the well. In fact, depending on the pumping intensity, airlifting method generates zone of aeration bringing to saturation of solution with oxygen highly damaging anaerobic processes making useless any direct sampling.

BIOREM process was monitored after 80 days from injection and the detailed, comparative analysis of results are indicated in the table.

A control drilling was performed after the termination of the remediation process with the aim to analyze the geological composition around the purification zone. In the sand, under electronic microscope, were found association of minerals and aggregates with fine dispersed pyrite like: coffinite, pitchblende, needle crystals of native selenium, native gold, forming dentritic crystals, gypsum, calcite and layered aluminosilicates.