Abstract:

Microogranisms found in the environment play an essential role in cleaning and recycling wastes generated by humans, animals and plants. Antimicrobial pollutants can seriously hinder the functionality of native microbial populations, leading to ineffective removal of biological and chemical wastes in the environment. Recently, carbon-based nanomaterials, such as carbon nanotubes and graphene oxides, have been attracting a lot of interest since they have unique properties that make them very valuable materials for materials science, high-energy physics and a wide range of technological applications. In fact, the market for carbon-based nanomaterial products is projected to reach nearly $675 million by 2020, hence it is expected that large quantities of environment through human activities, wastewater discharge and landfill disposal. Landfills and wastewaters are expected to be the ultimate repositories for these wastes. Therefore, it is essential to understand the effect of these graphene-based nanomaterials on microbial populations responsible for maintaining the environment balanced in these environments. The theme of this research is to understand the effects of graphene oxide and single walled carbon nanotubes in microbial communities found in landfills and wastewater and determine the toxic concentrations that affect the functionality of these microbial communities.Additionally, my research group investigates alternative solutions to reduce the use of these nanomaterials, and therefore reduce their release into the environment. Our approach is to combine these nanomaterials with polymers, such as polyvinyl-N-carbazole (PVK), to develop nanocomposites. These nanocomposites contain small amounts of carbon-based nanomaterials as fillers within the polymer matrix. The PVK polymer was selected to generate carbon-based nanocomposites since it stabilizes the dispersion of the nanomaterials in any solution chemistry due to p-p interaction of the PVK carbazole group with the aromatic rings of the carbon-based nanomaterials. The well-dispersed nanocomposite can, then, be easily used to modify membranes for water purification. These modified membranes are much more efficient in the inactivation and removal of viruses and bacteria from water than unmodified ones. In this study, we also demonstrate that it is possible to reduce the amount of nanomaterials within a polymer matrix and still produce more efficient water purification systems.

Biography:

Debora F. Rodrigues received her BS and MS in Biology and Microbiology, respectively, from the University of Sao Paulo, Brazil, and her PhD in Microbiology and Molecular Genetics from Michigan State University in 2007 under the supervision of Prof. James Tiedje. In her MS research she demonstrated the presence of genes involved in the degradation of polychlorinated biphenyls (PCBs) and hydrocarbons in Brazilian estuaries. Her PhD work focused on the physiology and diversity of microorganisms in the Siberian permafrost. She was a postdoctoral associate in the Environmental Engineering Program at Yale University in the group of Prof. Menachem Elimelech from 2007 to June 2010. Her research at Yale dealt with toxicity of carbon nanotubes to microorganisms as well as the effect of bacterial surface structures on bacterial adhesion and biofilm formation and maturation. She is currently an Assistant Professor at the University of Houston in the Department of Civil and Environmental Engineering. Her research interests involve investigation of the toxicological effects of carbon-based nanomaterials and polymer nanocomposites to wastewater microbial communities and their potential applications for water treatment and corrosion prevention.