Researchers at the Basque Institute of Agricultural Research and Development Neiker-Tecnalia are working on a strategy to cure soils polluted by organic compounds containing chlorine (organochlorine compounds). The novel process involves integrating zero-iron nanoparticles in bioremediation methods. The companies Ekotek and Dinam, Gaiker-IK4 and the UPV/EHU-University of the Basque Country are also taking part in this project called as NANOBIOR.
It is very difficult to decontaminate soils affected by organochlorine compounds. These organochlorine compounds contain some insecticides chiefly used to control insect pests, such as aldrin, dieldrin, DDT, hexachlorocyclohexane, toxaphene, endosulfan, chlordecone, and mirex.
The application of several of these insecticides is currently banned due to their environmental impact and potential danger to human health. The organizations taking part in the project to degrade organochlorine compounds are keen to use a method where zero-iron nanoparticles are initially applied to aid in the removal of the chlorine atoms in these compounds.
When these atoms have been removed, bioremediation is performed. The bioremediation procedure in progress by Neiker-Tecnalia is made up of two key strategies - bioaugmentation and biostimulation.
The first strategy is made up of stimulating the bacteria that already exists in the soil by adding nutrients, oxygen, humidity and others. Bioaugmentation relies on using bacteria with the preferred degrading capability to the soil. Neiker-Tecnalia also gathers soil samples contaminated by organochlorine compounds. Then the researchers isolate the species of bacteria that exhibit superior capacity to degrade these contaminants. When the highly attractive strains have been isolated, the amount of these bacteria is then increased in the laboratory. The soil, which needs to be decontaminated, is subsequently inoculated with them.
Bank of Effective Strains to Combat Organochlorines
Neiker-Tecnalia’s primary step is to classify bacterial species that can degrade organochlorine compounds and create a collection of species of interest for use in bioremediation. This collection will consist of strains chosen from the Basque Country and will permit bacteria, which can be applied as a decontaminating element of soils, to be readily available.
The integration of bioremediation and application of zero-iron nanoparticles comprises an important step in the progress of soil decontamination. It provides the extra benefit of potentially being able to use them in situ. This methodology is still in the exploratory phase, but has the potential to substitute other methods such as the excavation of contaminated soils. Furthermore, the blending of two methods has made it possible to decrease the time taken to decontaminate, which would take a lot longer if only bioremediation is used.