Abstract
Despite the number of detailed studies on arsenate adsorption onto synthetic 2-line ferrihydrite carried out during the past few decades, questions remain regarding the fate of adsorbed arsenate during phase transformation of this poorly crystalline iron oxy-hydroxide. We assessed arsenate partitioning during this transformation by aging synthetic 2-line ferrihydrite with adsorbed arsenate (at an As/Fe molar ratio of ~0.017) for 7 days at 75 °C under highly alkaline conditions (pH ~10). X-ray diffraction patterns show that ~55% of the ferrihydrite converted almost entirely to hematite (with traces of goethite) after aging 7 days, accompanied by a ~54% loss of reactive surface area (BET). ICP-MS analyses indicate that despite this conversion and significant loss of surface area, the aqueous arsenate concentration decreased from ~1.48 to ~0.51 mg/L during the course of the experiment. XAS analyses suggest that the concentration of arsenate and its speciation are controlled by its incorporation into the hematite.
© 2014 by Walter de Gruyter Berlin/Boston
Articles in the same Issue
- New data on lunar magmatic processes
- Thermodynamic approach provides insights into the aging process of biological apatite
- Effects of chemical composition and temperature on transport properties of silica-rich glasses and melts
- Speciation of and D/H partitioning between fluids and melts in silicate-D-O-H-C-N systems determined in-situ at upper mantle temperatures, pressures, and redox conditions
- Effect of oxalate and pH on chrysotile dissolution at 25 °C: An experimental study
- Gabbroic Shergottite Northwest Africa 6963: An intrusive sample of Mars
- Césarferreiraite, Fe2+Fe23+(AsO4)2(OH)2·8H2O, from Eduardo mine, Conselheiro Pena, Minas Gerais, Brazil: Second arsenate in the laueite mineral group
- Atomic structure and formation mechanism of (101) rutile twins from Diamantina (Brazil)
- Mathesiusite, K5(UO2)4(SO4)4(VO5)(H2O)4, a new uranyl vanadate-sulfate from Jáchymov, Czech Republic
- Comparison of metal enrichment in pyrite framboids from a metal-enriched and metal-poor estuary
- Chemistry of bone mineral, based on the hypermineralized rostrum of the beaked whale Mesoplodon densirostris
- Allendeite (Sc4Zr3O12) and hexamolybdenum (Mo,Ru,Fe), two new minerals from an ultrarefractory inclusion from the Allende meteorite
- Hutcheonite, Ca3Ti2(SiAl2)O12, a new garnet mineral from the Allende meteorite: An alteration phase in a Ca-Al-rich inclusion
- Infrared absorption spectroscopy of SiO2-moganite
- Kaolinite transformation into dickite during burial diagenesis
- Effect of clays and metal containers in retaining Sm3+ and ZrO2+ and the process of reversibility
- Solid solutions and phase transitions in (Ca,M2+)M2+Si2O6 pyroxenes (M2+ = Co, Fe, Mg)
- Further complexities of the 10 Å phase revealed by infrared spectroscopy and X-ray diffraction
- Solid phases of FeSi to 47 GPa and 2800 K: New data
- In-situ infrared spectra of hydroxyl in wadsleyite and ringwoodite at high pressure and high temperature
- Experimental and infrared characterization of the miscibility gap along the tremoliteglaucophane join
- A calorimetric and thermodynamic investigation of the synthetic analogs of cobaltomenite, CoSeO3·2H2O, and ahlfeldite, NiSeO3·2H2O
- Arsenate partitioning from ferrihydrite to hematite: Spectroscopic evidence
- Pressure-induced phase transitions in coesite
- Qingsongite, natural cubic boron nitride: The first boron mineral from the Earth’s mantle
- Phase relations in the system FeCO3-CaCO3 at 6 GPa and 900–1700 °C and its relation to the system CaCO3-FeCO3-MgCO3
- In-situ high-temperature emissivity spectra and thermal expansion of C2/c pyroxenes: Implications for the surface of Mercury
- Thallium geochemistry in the metamorphic Lengenbach sulfide deposit, Switzerland: Thallium-isotope fractionation in a sulfide melt
- Fluorowardite, NaAl3(PO4)2(OH)2F2·2H2O, the fluorine analog of wardite from the Silver Coin mine, Valmy, Nevada
- Correianevesite, Fe2+Mn22+(PO4)2·3H2O, a new reddingite-group mineral from the Cigana mine, Conselheiro Pena, Minas Gerais, Brazil
- Structural complexity of lead silicates: Crystal structure of Pb21[Si7O22]2[Si4O13] and its comparison to hyttsjöite
- A high-resolution powder neutron diffraction study of the crystal structure of neighborite (NaMgF3) between 9 and 440 K
- Geothermometric study of Cr-spinels of peridotite mantle xenoliths from northern Victoria Land (Antarctica)
- Crystal chemistry of the ulvöspinel-qandilite series
- Quantitative models linking igneous amphibole composition with magma Cl and OH content
- Chromium solubility in perovskite at high pressure: The structure of (Mg1–xCrx)(Si1–xCrx)O3 (with x = 0.07) synthesized at 23 GPa and 1600 °C
- New Mineral Names
- Errata
Articles in the same Issue
- New data on lunar magmatic processes
- Thermodynamic approach provides insights into the aging process of biological apatite
- Effects of chemical composition and temperature on transport properties of silica-rich glasses and melts
- Speciation of and D/H partitioning between fluids and melts in silicate-D-O-H-C-N systems determined in-situ at upper mantle temperatures, pressures, and redox conditions
- Effect of oxalate and pH on chrysotile dissolution at 25 °C: An experimental study
- Gabbroic Shergottite Northwest Africa 6963: An intrusive sample of Mars
- Césarferreiraite, Fe2+Fe23+(AsO4)2(OH)2·8H2O, from Eduardo mine, Conselheiro Pena, Minas Gerais, Brazil: Second arsenate in the laueite mineral group
- Atomic structure and formation mechanism of (101) rutile twins from Diamantina (Brazil)
- Mathesiusite, K5(UO2)4(SO4)4(VO5)(H2O)4, a new uranyl vanadate-sulfate from Jáchymov, Czech Republic
- Comparison of metal enrichment in pyrite framboids from a metal-enriched and metal-poor estuary
- Chemistry of bone mineral, based on the hypermineralized rostrum of the beaked whale Mesoplodon densirostris
- Allendeite (Sc4Zr3O12) and hexamolybdenum (Mo,Ru,Fe), two new minerals from an ultrarefractory inclusion from the Allende meteorite
- Hutcheonite, Ca3Ti2(SiAl2)O12, a new garnet mineral from the Allende meteorite: An alteration phase in a Ca-Al-rich inclusion
- Infrared absorption spectroscopy of SiO2-moganite
- Kaolinite transformation into dickite during burial diagenesis
- Effect of clays and metal containers in retaining Sm3+ and ZrO2+ and the process of reversibility
- Solid solutions and phase transitions in (Ca,M2+)M2+Si2O6 pyroxenes (M2+ = Co, Fe, Mg)
- Further complexities of the 10 Å phase revealed by infrared spectroscopy and X-ray diffraction
- Solid phases of FeSi to 47 GPa and 2800 K: New data
- In-situ infrared spectra of hydroxyl in wadsleyite and ringwoodite at high pressure and high temperature
- Experimental and infrared characterization of the miscibility gap along the tremoliteglaucophane join
- A calorimetric and thermodynamic investigation of the synthetic analogs of cobaltomenite, CoSeO3·2H2O, and ahlfeldite, NiSeO3·2H2O
- Arsenate partitioning from ferrihydrite to hematite: Spectroscopic evidence
- Pressure-induced phase transitions in coesite
- Qingsongite, natural cubic boron nitride: The first boron mineral from the Earth’s mantle
- Phase relations in the system FeCO3-CaCO3 at 6 GPa and 900–1700 °C and its relation to the system CaCO3-FeCO3-MgCO3
- In-situ high-temperature emissivity spectra and thermal expansion of C2/c pyroxenes: Implications for the surface of Mercury
- Thallium geochemistry in the metamorphic Lengenbach sulfide deposit, Switzerland: Thallium-isotope fractionation in a sulfide melt
- Fluorowardite, NaAl3(PO4)2(OH)2F2·2H2O, the fluorine analog of wardite from the Silver Coin mine, Valmy, Nevada
- Correianevesite, Fe2+Mn22+(PO4)2·3H2O, a new reddingite-group mineral from the Cigana mine, Conselheiro Pena, Minas Gerais, Brazil
- Structural complexity of lead silicates: Crystal structure of Pb21[Si7O22]2[Si4O13] and its comparison to hyttsjöite
- A high-resolution powder neutron diffraction study of the crystal structure of neighborite (NaMgF3) between 9 and 440 K
- Geothermometric study of Cr-spinels of peridotite mantle xenoliths from northern Victoria Land (Antarctica)
- Crystal chemistry of the ulvöspinel-qandilite series
- Quantitative models linking igneous amphibole composition with magma Cl and OH content
- Chromium solubility in perovskite at high pressure: The structure of (Mg1–xCrx)(Si1–xCrx)O3 (with x = 0.07) synthesized at 23 GPa and 1600 °C
- New Mineral Names
- Errata