Behavior of UV-absorbing metal oxide nanoparticles in porous media and their influence on soil bacteria
Contact Person: Manuela Vielkind
Engineered nanoparticles are applied in more and more daily life products. Increasing manufacturing and application of nanoparticle-containing products causes an increased release of these synthesized particles into the environment, especially the soil. The ensuing fate and behavior of these ultrasmall particles still remains mostly unexplained. A central question is, whether these particles agglomerate or persist in their particulate state. In soils, particles interact with soil substances and edaphic microorganisms. These interactions as well as the agglomeration tendency during soil passage are to be investigated within this project.
The pictured experimental setup is used to investigate the agglomeration tendency of engineered nanoparticles during soil passage. Thereby a so-called breakthrough curve is obtained, which enables a prediction about the particle-soil-interaction.
Several parameters, e.g.:
– Particle material and stabilization
– Agglomerate size and con-centration
– Composition and grain size of soil
are varied and their influence on the soil passage is analyzed.
Influence of nanoparticles on soil bacteria
Due to the increasing release of engineered nanoparticles, more and more soil-living bacteria are exposed to them. The influence of this contact on the growth and metabolic efficiency has not yet been adequately explained.
Within this project soil bacteria are cultivated in presence of varied nanoparticle concentrations to distinguish growth inhibition. Cultivation in 96-well-plates increases the confidence level due to nine parallel series of measurement.
The assessment of nanoparticulate toxicity requires the stability of particles to be investigated.
Fig left: Pseudomonas putida in presence of zinc oxide nanoparticles Fig right: 96-well-plate for the assessment of nanoparticulate toxicity