Stratigraphic and geochemical controls on naturally occurring arsenic in groundwater, eastern Wisconsin, USA

Kinetics of sorption and abiotic oxidation of arsenic(III) by aquifer materials

“…Increasing arsenic mobility in groundwater in response to elevated pH values (>10) has been reported (Mariner et al, 1996). In oxic environments, release of sediment-bound arsenic has been observed in response to elevated concentrations of phosphate (Kent and Fox, 2004) and oxidation of sulfide minerals at low pH values (McCreadie et al, 2000;Schreiber et al, 2000). In anoxic environments, sediment-bound arsenic can be mobilized by reductive dissolution or transformation of Fe(III) hydroxide coatings and reduction of arsenate (As(V)) to arsenite (As(III)) (e.g., Belzile and Tessier, 1990;Ahmann et al, 1997;Harrington et al, 1998;Cummings et al, 1999;McArthur et al, 2001;Hö hn et al, 2001;Harvey et al, 2002;Horneman et al, 2004;Kent and Fox, 2004;Swartz et al, 2004;van Geen et al, 2004).…”

Inverse geochemical modeling of groundwater evolution with emphasis on arsenic in the Mississippi River Valley alluvial aquifer, Arkansas (USA)

“…Recently, inverse geochemical modeling has been used to investigate the chemical evolution of groundwater along the flow path by numerous investigators (Plummer et al, 1990;Rosenthal et al, 1998;Perry, 2001;Eary et al, 2002;Guler and Thyne, 2002;Savage and Bird, 2002;Lakshmanan et al, 2003;Lecomte et al, 2005;Dai et al, 2006;Dhiman and Keshari, 2006;Mirecki, 2006;Clark and Journey, 2006). Inverse geochemical modeling has been also used in several As studies (Schreiber et al, 2000;Carrillo-Chavez et al, 2000;Armienta et al, 2001) to verify if certain geochemical reactions of As release and immobilization are geochemical feasible .…”

Arsenic mobilization in shallow aquifers of Datong Basin: Hydrochemical and mineralogical evidences

“…The main sources of arsenic in arsenic-contaminated aquifers worldwide are naturally occurring arsenic, either from clay/organic-rich aquitards containing arsenic-rich minerals (e.g., arsenopyrite, arsenian pyrite, and enargite) or from aquifers containing iron and manganese oxides (Korte, 1991;Schreiber et al, 2000;Smedley and Kinniburgh, 2002;Stollenwerk, 2003).…”