Abstract
Several studies have demonstrated that gypsum (CaSO4·2H2O) and calcite (CaCO3) can be important hosts of arsenic in contaminated hydrogeological systems. However, the extent to which microbial reducing processes contribute to the dissolution and transformation of carbonate and sulfate minerals and, thereby, to arsenic mobilization is poorly understood. These processes are likely to have a strong impact on arsenic mobility in iron-poor environments and in reducing aquifers where iron oxyhydroxides become unstable. Anoxic batch bioassays with arsenate (As(V)) coprecipitated with calcite, gypsum, or ferrihydrite (Fe(OH)3) were conducted in the presence of sulfate or molybdate to examine the impact of bioprocesses (i.e. As(V), sulfate, and Fe(III)-reduction) on arsenic dissolution, speciation, and eventual remineralization. Microbial reduction of As(V)-bearing calcite caused an important dissolution of arsenite, As(III), which remained in solution up to the end of the experiment (30 days). The reduction of As(V) from gypsum-As(V) also led to the release of As(III), which was subsequently remineralized, possibly as arsenic sulfides. The presence of sulfate triggered arsenic dissolution in the bioassays with ferrihydrite-As(V). This study showed that although gypsum and calcite have a lower capacity to bind arsenic, compared to iron oxides, they can play a critical role in the biogeochemical cycle of arsenic in natural calcareous and gypsiferous systems depleted of iron since they can be a source of electron acceptors for reducing bioprocesses.
| Original language | English (US) |
|---|---|
| Article number | 124823 |
| Journal | Chemosphere |
| Volume | 239 |
| DOIs | |
| State | Published - Jan 1 2020 |
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Keywords
- Arsenate
- Biogeochemistry
- Bioprocesses
- Mobilization
- Remineralization
- Sulfide
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Chemistry(all)
- Pollution
- Health, Toxicology and Mutagenesis
Cite this
Dissolution and final fate of arsenic associated with gypsum, calcite, and ferrihydrite : Influence of microbial reduction of As(V), sulfate, and Fe(III). / Rios-Valenciana, Erika E.; Briones-Gallardo, Roberto; Chazaro-Ruiz, Luis F.; Lopez-Lozano, Nguyen E.; Sierra Alvarez, Maria Reye; Celis, Lourdes B.
In: Chemosphere, Vol. 239, 124823, 01.01.2020.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Dissolution and final fate of arsenic associated with gypsum, calcite, and ferrihydrite
T2 - Influence of microbial reduction of As(V), sulfate, and Fe(III)
AU - Rios-Valenciana, Erika E.
AU - Briones-Gallardo, Roberto
AU - Chazaro-Ruiz, Luis F.
AU - Lopez-Lozano, Nguyen E.
AU - Sierra Alvarez, Maria Reye
AU - Celis, Lourdes B.
PY - 2020/1/1
Y1 - 2020/1/1
N2 - Several studies have demonstrated that gypsum (CaSO4·2H2O) and calcite (CaCO3) can be important hosts of arsenic in contaminated hydrogeological systems. However, the extent to which microbial reducing processes contribute to the dissolution and transformation of carbonate and sulfate minerals and, thereby, to arsenic mobilization is poorly understood. These processes are likely to have a strong impact on arsenic mobility in iron-poor environments and in reducing aquifers where iron oxyhydroxides become unstable. Anoxic batch bioassays with arsenate (As(V)) coprecipitated with calcite, gypsum, or ferrihydrite (Fe(OH)3) were conducted in the presence of sulfate or molybdate to examine the impact of bioprocesses (i.e. As(V), sulfate, and Fe(III)-reduction) on arsenic dissolution, speciation, and eventual remineralization. Microbial reduction of As(V)-bearing calcite caused an important dissolution of arsenite, As(III), which remained in solution up to the end of the experiment (30 days). The reduction of As(V) from gypsum-As(V) also led to the release of As(III), which was subsequently remineralized, possibly as arsenic sulfides. The presence of sulfate triggered arsenic dissolution in the bioassays with ferrihydrite-As(V). This study showed that although gypsum and calcite have a lower capacity to bind arsenic, compared to iron oxides, they can play a critical role in the biogeochemical cycle of arsenic in natural calcareous and gypsiferous systems depleted of iron since they can be a source of electron acceptors for reducing bioprocesses.
AB - Several studies have demonstrated that gypsum (CaSO4·2H2O) and calcite (CaCO3) can be important hosts of arsenic in contaminated hydrogeological systems. However, the extent to which microbial reducing processes contribute to the dissolution and transformation of carbonate and sulfate minerals and, thereby, to arsenic mobilization is poorly understood. These processes are likely to have a strong impact on arsenic mobility in iron-poor environments and in reducing aquifers where iron oxyhydroxides become unstable. Anoxic batch bioassays with arsenate (As(V)) coprecipitated with calcite, gypsum, or ferrihydrite (Fe(OH)3) were conducted in the presence of sulfate or molybdate to examine the impact of bioprocesses (i.e. As(V), sulfate, and Fe(III)-reduction) on arsenic dissolution, speciation, and eventual remineralization. Microbial reduction of As(V)-bearing calcite caused an important dissolution of arsenite, As(III), which remained in solution up to the end of the experiment (30 days). The reduction of As(V) from gypsum-As(V) also led to the release of As(III), which was subsequently remineralized, possibly as arsenic sulfides. The presence of sulfate triggered arsenic dissolution in the bioassays with ferrihydrite-As(V). This study showed that although gypsum and calcite have a lower capacity to bind arsenic, compared to iron oxides, they can play a critical role in the biogeochemical cycle of arsenic in natural calcareous and gypsiferous systems depleted of iron since they can be a source of electron acceptors for reducing bioprocesses.
KW - Arsenate
KW - Biogeochemistry
KW - Bioprocesses
KW - Mobilization
KW - Remineralization
KW - Sulfide
UR - http://www.scopus.com/inward/record.url?scp=85072248001&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85072248001&partnerID=8YFLogxK
U2 - 10.1016/j.chemosphere.2019.124823
DO - 10.1016/j.chemosphere.2019.124823
M3 - Article
C2 - 31726520
AN - SCOPUS:85072248001
VL - 239
JO - Chemosphere
JF - Chemosphere
SN - 0045-6535
M1 - 124823
ER -