RSI Research Seminar

Join us every other Monday at noon for lunch and a 30-minute research talk, presented by Resnick Sustainability Institute Graduate Fellows and Caltech researchers funded by the Resnick Sustainability Institute. To see the full schedule of speakers, visit the RSI Research Seminar web page. Seminars currently take place in a hybrid format, both in-person (in the new Resnick Sustainability Center building!) and via Zoom. For more information and to get the Zoom login info, please reach out to [email protected]

Immobilization of Heavy Metals from Solution by Novel Biogenic Manganese Oxides

Heavy metals in drinking water distribution systems and industrial discharge streams pose a concern to human and environmental health. There is significant interest in developing and exploiting mechanisms that draw down soluble heavy metals from various surface and subsurface waters. A diversity of different technologies that accomplish this are being investigated, among them the use of manganese oxides as sorption agents. Many recent studies have synthesized manganese oxides through chemical and hydrothermal processes and studied their properties, while others have harvested oxides generated by heterotrophic bacteria in small quantities during metabolic side reactions. We focus on recently identified lithoautotrophic bacteria that produce a large amount of manganese oxide as their major metabolic product. The high yield of oxides per microbial culture, as well as their structural and catalytic properties make them of interest for examining heavy metal sorption. We have thus pursued three avenues of study: a) resistances of the culture to inhibition by different soluble heavy metals, development and adsorptive capacity of the oxides under b) static incubation and c) flow-through conditions. In this presentation we will report on our recent findings, as well as our ongoing and planned future experimental lines of inquiry.