Development of novel, composite nanomaterials for water filtration
Approximately 1/3 of the world’s population lacks access to safe drinking water. Human exposures to drinking water contaminants, such as arsenic, have been linked to cancer, neurological, cardiovascular and pulmonary health problems. In a recent survey of private wells in Iowa, 48% were found to contain arsenic and 8% were determined to have arsenic levels greater than the EPA’s drinking water standard of 10 ppb. It is critical, both globally and locally, to develop improved methods for removing groundwater contaminants. Investigators in this study will design, fabricate and evaluate mesoporous silica-coated electrospun iron oxide nanofibers for arsenic adsorption from water. The Larsen Lab is developing functionalized mesoporous silica materials for adsorption of radioactive contaminants; these materials are also promising for application as arsenic adsorbents. The Cwiertny/Parkin Lab is developing electrospun nanofibers for use as chemically active filtration materials. CHEEC funds will allow the two Labs to work collaboratively to develop and evaluate these novel composite adsorbents.
This work produced materials of benefit for point of use treatment systems. Many Iowans are subject to drinking water contaminated by chromium and copper as a result of degradation in their water distribution system. Because these pollutants are generated during distribution, the only option for removal of these metals is through treatment devices installed at the point of use. By harnessing nanomaterials, we've produced a platform technology ideally suited for point of use treatment as a result of its small footprint and high capacity for metal uptake. Accordingly, outcomes of this work may one day help to improve drinking water quality for Iowans and others impacted by distribution system derived metal contaminants.
The key results of the study are as follows.
- This work produced novel composites of silica and iron oxides for removal of metal from drinking water supplies.
- Composite materials were effective for uptake of copper and chromium, providing uptake capacity that was greater than expected from the performance of individual silica and iron oxides.
- The composites were also more mechanically robust and thus hold practical advantages over more traditional sorbent materials.
S. Egodawatte, K.E. Greenstein, I. Vance, E. Rivera, N.V. Myung, G.F. Parkin, D.M. Cwiertny, S.C. Larsen (2016). Electrospun Hematite Nanofiber/Mesoporous Silica Core/Shell Nanomaterials as an Efficient Adsorbent for Heavy Metals. RSC Advances, 6, 90516-90525.