Arsenic-contamination source of groundwater from the Salí basin, Argentina

Arsenic and associated trace-elements in groundwater from the Chaco-Pampean plain, Argentina: Results from 100years of research

“…Desorption reactions are likely to be enhanced by mutual competition between oxyanion species for available adsorption sites on the oxides present (Manning and Goldberg, 1996;. Moreover, the intense evaporation process in shallow aquifers close to the ground surface contributes to the increase of As and TDS (Nicolli et al, 2007(Nicolli et al, , 2010(Nicolli et al, , 2012. Cation-exchange processes also contribute to the increase of Na, K and trace-element concentrations.…”

“…The volcanic glass separated from loess shows a typical ryolitic composition (see also Tables 4 and 5 for trace-element contents: Nicolli et al, 2004Nicolli et al, , 2010. Contents of loess Fe-, Al-and Mn-oxihydroxides Nicolli et al, 2000Nicolli et al, , 2001aNicolli et al, , 2001bNicolli et al, , 2004Nicolli et al, , 2005aNicolli et al, , 2005bNicolli et al, , 2007Nicolli et al, , 2010 Galindo et al,1999;Blanco et al, 2001Blanco et al, , 2006Paoloni et al, 2002Paoloni et al, , 2005Fiorentino et al, 2007;González et al, 2009 Plain Table 1 (continued) sediments from the southern Buenos Aires Province ranges from 6.4 mg/kg (Tertiary loess, Pampa Formation) to 22 mg/kg (Holocene loess-derived alluvial sediments), being slightly higher than the average content in the earth's crust (Blanco et al, 2006). Partition of As in the different loess particle size fractions is a critical factor related to As source, to its geo-availability in the sedimentary sequences, and to its transference to groundwaters (Morrás et al, 2000;Blanco et al, 2006;2011).…”