A Caltech Library Service

Hydrous Manganese Oxide Doped Gel Probe Sampler for Measuring In Situ Reductive Dissolution Rates. 1. Laboratory Development

Farnsworth, Claire E. and Hering, Janet G. (2010) Hydrous Manganese Oxide Doped Gel Probe Sampler for Measuring In Situ Reductive Dissolution Rates. 1. Laboratory Development. Environmental Science and Technology, 44 (1). pp. 34-40. ISSN 0013-936X.

PDF - Supplemental Material
See Usage Policy.


Use this Persistent URL to link to this item:


Reductive dissolution of redox-sensitive minerals such as manganese (Mn) oxides in natural sediments is an important mechanism for trace element mobilization into groundwater. A gel probe sampler has been constructed to study in situ reductive dissolution of Mn oxides. The gel consists of a polyacrylamide polymer matrix doped with hydrous Mn oxide (HMO). Gel slabs are mounted into a probe, which is designed to be inserted into the sediments. The amount of Mn released from the gel by reductive dissolution is determined by comparing the amount of Mn initially embedded into the gel with the amount remaining in the gel after exposure to conditions in the sediments or, in laboratory studies, to reducing agents. In this laboratory study, the performance of the gel probes was examined using the model reductant ascorbate and the Mn-reducing bacteria Shewanella oneidensis strain MR-1. In addition, a 1-D model was used to relate the reaction rates observed for HMO embedded in gels to those for HMO in suspension. One limitation of the HMO-doped gels for assessing microbial reduction rates is that the gels prevent direct contact between the microbes and the HMO and hence preclude enzymatic reduction at the cell surface. Nonetheless, the HMO-doped gel probes offer the possibility to establish a lower bound for Mn-reduction capacity in sediments.

Item Type:Article
Related URLs:
Additional Information:© 2009 American Chemical Society. Received May 29, 2009. Revised manuscript received October 10, 2009. Accepted October 22, 2009. Publication Date (Web): November 4, 2009. We thank Dianne Newman, Doug Lies, Tracy Teal, and Alexa Price-Whelan for help in the selection, cultivation, and fluorescence microscopy of S. oneidensis MR-1. Peter Reichert’s assistance in working with AQUASIM is also appreciated. We gratefully acknowledge funding from an NSF Graduate Research Fellowship and NSF EAR-0525387, as well as from Eawag.
Funding AgencyGrant Number
Issue or Number:1
Record Number:CaltechAUTHORS:20100129-094247179
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:17350
Deposited By: Tony Diaz
Deposited On:01 Feb 2010 03:19
Last Modified:03 Oct 2019 01:26

Repository Staff Only: item control page