TY - JOUR
T1 - Effects of oxidation state on metal ion binding by Medicago sativa
(alfalfa): Atomic and X-ray absorption spectroscopic studies with Fe(II)
and Fe(III)
AU - Tiemann, KJ
AU - Gardea-Torresdey, JL
AU - Gamez Goytia, Gerardo
AU - Dokken, K
AU - Cano-Aguilera, I
AU - Renner, MW
AU - Furenlid, LR
PY - 2000/2
Y1 - 2000/2
N2 - We present here experimental results that investigate the effects of
metal-ion binding on iron-ion sorption to and recovery from alfalfa
biomass. Fe(II)- and Fe(III)-ion binding were measured in order to
ascertain the differences in binding strengths due to changes in
oxidation state. Stronger binding was found for iron(III)-biomass as
compared to iron(II)-biomass. The optimal pH for iron uptake was
determined to be 5. The results of pH binding profile, iron desorption,
and temperature-dependent binding experiments as well as X-ray
spectroscopic (XAS) measurements all suggest that binding of iron by
alfalfa biomass may be occurring through carboxyl ligands. The XAS
experiments further demonstrate that the metal binding proceeds without
an oxidation state change, and both iron(II) and iron(III) have similar
coordination environments. The information presented will assist in
understanding the binding of other metals to alfalfa biomass and in
developing methods for their recovery.
AB - We present here experimental results that investigate the effects of
metal-ion binding on iron-ion sorption to and recovery from alfalfa
biomass. Fe(II)- and Fe(III)-ion binding were measured in order to
ascertain the differences in binding strengths due to changes in
oxidation state. Stronger binding was found for iron(III)-biomass as
compared to iron(II)-biomass. The optimal pH for iron uptake was
determined to be 5. The results of pH binding profile, iron desorption,
and temperature-dependent binding experiments as well as X-ray
spectroscopic (XAS) measurements all suggest that binding of iron by
alfalfa biomass may be occurring through carboxyl ligands. The XAS
experiments further demonstrate that the metal binding proceeds without
an oxidation state change, and both iron(II) and iron(III) have similar
coordination environments. The information presented will assist in
understanding the binding of other metals to alfalfa biomass and in
developing methods for their recovery.
M3 - Article
SP - 693
EP - 698
JO - Environmental Science & Technology
JF - Environmental Science & Technology
ER -