This thesis aims at investigating differences in bioavailability of copper from nanoparticles depending on coating and aging of the nanoparticles and differences in bioavailability of copper depending on form (ionic or as nanoparticles). Copper nanoparticles were synthesized with two different coatings (dehydroascorbic acid and PVP 10.000) and aged for 1 year. Then the synthesis was repeated, yielding nanoparticles of the same type, but of different ages. Nanoparticles were characterized to provide information about composition, size and stability. The nanoparticles were then mixed into sediment to achieve a concentration of ~365µg Cu/g dry weight of sediment. Capitella telata from culture were kept in sediment spiked with each of the four categories of nanoparticles or ionic cupper (CuCl). Comparisons were made of the cupper koncentration in the tissue of the worms (whole worms were used). Survival, growth and presence of sulfide were assessed in all treatments. Capitella telata tissue concentration in worms exposed to sediment spiked with copper nanoparticles was significantly (ANOVA p≤0,05) different than in worms exposed to sediment spiked with CuCl after day 7. Comparisons between cupper nanoparticles of different coatings could not be made, as conditions of 'ceteres paribus' (all else equal) could not be met between groups. A significant difference (ANOVA p≤0,05) between copper koncentration in worms exposed to sediment spiked with copper nanoparticles (with dehydroascorbic acid coating) of different ages was observed on day 20. It is concluded that copper concentration in Capitella capitata tissue (whole body) is affected by the form the copper (nano or ionic) and by the ageing of copper nanoparticles with dehydroascorbic acid coating, under the conditions of the experimental setup.
|Uddannelser||Miljøbiologi, (Bachelor/kandidatuddannelse) Kandidat|
|Udgivelsesdato||24 jun. 2014|
|Vejledere||Gary Thomas Banta|