Metals such as nickel, zinc, arsenic, mercury, iron and, manganese can contaminate soil and groundwater as a result of anthropogenic activities. The multidisciplinary approach used by Biosearch Ambiente makes the successful resolution of this type of contamination possible.

Metals are normally present in the ecosystem at low concentration.  Their presence at  high concentration (above the regulation limits) can be due to a pollution event, particularly frequent in proximity of factories like galvanic or steel plant or to an  accidental leak of organic compound (es hydrocarbons) which would cause the leaching of iron, manganese or arsenic  normally present in soil.

Depending on where a metal contamination occurs (water or soil), the approach for a remediation treatment is different:

  • Groundwater: in situ metal precipitation
  • Soil: soilwashing with natural biosurfactants
Groundwater remediation

Each metal is characterized  by a biogeochemical cycle  which regulates its presence in the environment.

In groundwater, a good strategy to neutralize a toxic metal is to change its oxidation state. This can turn  a dangerous, persistent and mobile  species, into a poorly bioavailable and immobile element that has lost most of its toxic character .

This result can be achieved by controlling parameters in groundwater as the redox potential, the pH, and the dissolved oxygen.

Soil Remediation

The metal contamination of soils and sediments can be considerably decreased by washing the matrix with surfactant solutions obtained with a natural process.

These surfactants exert on the metal a chelating function, carrying it in solution and effectively removing it from the solid matrix.