Seminars Archive
Heavy metal release from sulfide minerals: from field evidence to nanoscale studies
Abstract
Friday, February 20, 2004, 11:00
Seminar Room, ground floor, Building "T"
Sincrotrone Trieste, Basovizza
Heavy metal release from sulfide minerals: from field evidence
to nanoscale studies
Pierfranco Lattanzi
( Dipartimento di Scienze della Terra-Universit di Cagliari)
Abstract
Mineral sulfides are the main natural repositories of several toxic
"heavy
metals" such as Pb, Cd, Hg, As, Sb. Many mineral deposits contain abundant
sulfides. Sulfides are intrinsically unstable in the exogenous environment,
and therefore their dissolution/oxidation releases heavy metals in
the
environment. Moreover, many sulfides (most notably, pyrite) produce
acidity
upon oxidation, giving way to the well known, environmentally important
phenomenon of acid mine drainage (AMD). There is a huge body of literature
documenting AMD and the related release of toxic heavy metals. In recent
years, there is an increasing number of studies devoted at understanding
the
mechanism(s) of sulfide dissolution/oxidation and heavy metal release.
These
studies have been conducted at the bulk ("molar") scale, but surface-
and
micro- to nanoscale studies are rapidly expanding. Typical techniques
employed for such studies include X-ray photoelectron spectroscopy
(XPS),
scanning and transmission electron microscopy (SEM-TEM), and scanning
probe
microscopy (SPM). The talk will present examples of both field and
micro- to
nanoscale studies, largely drawing from data collected by a research
group
in the Universit di Cagliari.
