Deakin University
Browse

File(s) under permanent embargo

Swelling properties of microbially reduced ferruginous smectite

Version 2 2024-06-04, 08:42
Version 1 2016-10-12, 12:37
journal contribution
posted on 2024-06-04, 08:42 authored by Will GatesWill Gates, HT Wilkinson, JW Stucki
Structural Fe in ferruginous smectite (sample SWa-1, Source Clays Repository of the Clay Minerals Society) was reduced by a mixture of five Pseudomonas species of bacteria in a defined Fe-free medium to determine the effect of microbial reduction on clay swelling. Iron(II), total Fe, and gravimetric water content (m w /m c ) were determined in clay gels equilibrated at applied pressures of 0.1, 0.3, and 0.5 MPa. The water content of microbially reduced SWa-1 decreased at all three applied pressures as the Fe(II) content approached about 0.8 mmol Fe(II)/g-clay. As Fe(II) increased from 0.8 mmol/g-clay, however, further change in m w /m c was negligible. Concurrent with microbial reduction of structural Fe was a significant decrease in the swelling pressure (PI) of SWa-1: for example, when m w /m c = 1.2 (g/g), PI changed from 0.47 MPa at Fe(II) = 0.2, to 0.19 MPa at Fe(II) = 0.9 mmol/g-clay. Both biologically and chemically reduced smectites displayed lower values of m w /m c and a concurrent decrease in II as Fe(II) content increased, but the effect of Fe(II) on m w /m c was greater for the microbially reduced smectites at all applied pressures.

History

Journal

Clays and clay minerals

Volume

41

Pagination

360-364

Location

Chantilly, Va.

ISSN

0009-8604

eISSN

1552-8367

Language

eng

Publication classification

C1.1 Refereed article in a scholarly journal

Copyright notice

1993, The Clay Minerals Society

Issue

3

Publisher

The Clay Minerals Society

Usage metrics

    Research Publications

    Exports

    RefWorks
    BibTeX
    Ref. manager
    Endnote
    DataCite
    NLM
    DC