Three Stage Biotechnology for the Rehabilitation of Soils Polluted with Explosives

Abstract

Screening of plants according to their potential to assimilate TNT and RDX was carried out. As a result, 3 plant species (soybean, alfalfa and ryegrass), 41 bacterial cultures, 14 strains of microscopic fungi, 3 strains of yeast were selected. Two bacterial consortia for bioconversion of TNT were composed. Selected cultures of microorganisms and consortia were tested in conditions of submerge cultivation on the areas containing 0.5 mM TNT. Optimum conditions of submerge cultivation (pH, temperature, duration of incubation) for selected active strains has been established. As a result of the experiments performed for water cleaning, it has been established that 12-days-old soybean seedlings effectively absorb [1-¹⁴ C] TNT from the polluted water and after 8 days approximately 80% of clearing effect is reached. It has been shown that that during destruction of biomass of plants by microscopic fungi Aspergillus niger J 3-5 the release of part of labeled TNT and its metabolites from plant biomass and the release of radioactive CO₂ takes place.