Center-wide Mesocosm Experiment Has Begun

By Nick Geitner

Beginning in January of 2016, CEINT is conducting a center-wide mesocosm experiment in order gain a deeper understanding of nanoparticle effects and transport in a realistic wetland environment. While the mesocosm facilities are located at and managed by Duke University, experimental planning and efforts are spread across all CEINT institutions. We hope to answer several key questions, including:

• How does the nutrient level in the environment influence nanomaterial movement through the environment and biological or ecological effects?
• How are these effects influenced by nanoparticle size?
• Can we design functional assays for laboratory studies that are capable of predicting these realistic environmental responses?

This ambitious, yearlong experiment will utilize a set of 25 mesocosm boxes receiving a variety of different weekly small nanoparticle treatments. While half are enhanced with extra nutrients, every box contains the same water and soil, land and aquatic plant life, and variety of aquatic life forms. There are however several different nanomaterials used independently:

• An agricultural fungicide that utilizes copper nanoparticles
• Small ceria nanoparticles particles, similar to those used in the electronics industry for polishing or industrial catalysis
• Large ceria nanoparticles, similar to those from diesel exhaust when ceria nanoparticle fuel additives are used, which are growing in popularity in Europe
• Gold nanoparticles, while they rarely find their way into the environment, are used as a model nanoparticle that does not change over time and can easily be traced through entire ecosystems

In contrast to previous, more individually-centered mesocosm efforts, nearly every CEINT-affiliated lab will be closely involved in this massive undertaking, and planned experiments span all 3 Themes and Cores of the Center. These experiments range from weekly monitoring of the environmental health and chemistry of each mesocosm to more intensive quarterly sampling of water and soil chemistry and whole organism analysis across the ecosystems. Further information and updates can be found at CEINT mesocosm facility.

Points of contact for all mesocosm information and planning are, for Themes 1 and 2 Nick Geitner (nicholas.geitner@duke.edu) and for Theme 3 Steve Anderson (sa165@duke.edu).