Superfund Research Program
Nanoparticle Based Strategies for Remediation of Contaminated Sediments: Implications, Synergies, and Antagonistic Effects with Associated Nano-Bioremediation
- Project Summary
This project investigates and assesses the combination of bio- and nano-remediation strategies. Over the past year, the research team investigated the use of nano-scale zero valent iron (NZVI) to maximize energy production (in the form of methane generation) during the anaerobic degradation of organics. Methane producing bacteria are typically slow growing and sensitive to environmental disturbances and there is great interest in developing methods to boost the methane production through both biological and chemical amendments. Researchers were particularly interested in understanding the microbially-driven processes behind the improvement of biogas production in bioreactors amended with NZVI and performed a characterization of the microbial communities using two molecular approaches. The first employed quantitative PCR (qPCR) to look at the dynamics of specific microbial populations. To that end, qPCR assays targeting 16S rDNA of 4 orders of hydrogenotrophic and acetoclastic methanogens were developed. In the second approach the high throughput Illumina MiSeq sequencing platform was used in order to assess the taxonomic composition of the microbial community. The relative abundance of the hydrogenotrophic methanogens belonging to the order Methanobacteriales and Methanococcales in the reactors amended with 2.5 and 5.0 g/L NZVI were 15 to 20 times more abundant than in the other reactors, suggesting that these methanogens likely used the hydrogen released by nZVI, and were responsible for the increased methane production in the reactors. Our second amplicon based metagenomic approach generated millions of high quality DNA reads; analyses are currently being performed.