I’m interested in separating and collecting suspended stream sediments for SEM and XRD analysis.  There’s lots published on measuring concentrations (i.e., mg/L), but little on sediment recovery for futher analysis.

I’ve attempted recovery from 0.45 micron filters (cellulose nitrate) by placing the membranes in an ultrasonic bath.  I can recover enough sediment to ID the minerals by XRD, but the filters clog quite readily and the ultrasonic bath always produces a significant amorphous cellulose background as the membrane breaks apart.

Settling times for the clays will be enormous, but I will have access in the field to a nearby lab with standard centrifuges.

However, has anyone tried using one of the centrifuges used for separating soilds from oil?  They are set up to allow continuous flow of oil (water in my case) and rather than using bottles or tubes the sediment is deposited on the inside of a “bowl”.   While spinning, the sediment doesn’t have far to “fall.”

Any thoughts or other suggestions (offline) would be greatly appreciated.

Steve Nelson
Professor of Geochemistry
Dept. Geological Sciences
S-389 ESC
Brigham Young University
Provo, UT  84602
DISCLAIMER FOR THE FEEBLE MINDED:  It should be painfully obvious, but my affiliation with Brigham Young University does NOT imply that the University endorses any political or otherwise partisan content of this message.

"The normal incompetent person flails and stammers and is embarrassed about it. But the true genius at incompetence like our president flails and founders and is too incompetent to recognize his own incompetence. He mistakes his catastrophes for successes and so accelerates his pace toward oblivion. Those who ignore history are condemned to retweet it.”  David Brooks