Arsenic speciation and trace element analysis of the volcanic río Agrio and the geothermal waters of Copahue, Argentina

Farnfield, HR; Marcilla, AL; Ward, NI

HERO ID

1255507

Reference Type

Journal Article

Year

2012

Language

English

PMID

22819888

HERO ID 1255507
In Press No
Year 2012
Title Arsenic speciation and trace element analysis of the volcanic río Agrio and the geothermal waters of Copahue, Argentina
Authors Farnfield, HR; Marcilla, AL; Ward, NI
Journal Science of the Total Environment
Volume 433
Page Numbers 371-378
Abstract Surface water originating from the Copahue volcano crater-lake was analysed for total arsenic and four arsenic species: arsenite (iAs(III)), arsenate (iAs(V)), monomethylarsonic acid (MA(V)) and dimethylarsinic acid (DMA(V)) and other trace elements (Fe, Mn, V, Cr, Ni, Zn). A novel in-field technique for the preconcentration and separation of four arsenic species was, for the first time, used for the analysis of geothermal and volcanic waters. Total arsenic levels along the río Agrio ranged from <0.2-3783μg/l As(T). The highest arsenic levels were recorded in the el Vertedero spring (3783μg/l As(T)) on the flank of the Copahue volcano, which feeds the acidic río Agrio. Arsenite (H(3)AsO(3)) predominated along the upper río Agrio (78.9-81.2% iAs(III)) but the species distribution changed at lago Caviahue and arsenate (H(2)AsO(4)(-)) became the main species (51.4-61.4% iAs(V)) up until Salto del Agrio. The change in arsenic species is potentially a result of an increase in redox potential and the formation of iron-based precipitates. Arsenic speciation showed a statistically significant correlation with redox potential (r=0.9697, P=0.01). Both total arsenic and arsenic speciation displayed a statistically significant correlation with vanadium levels along the river (r=0.9961, P=0.01 and r=0.8488, P=0.05, respectively). This study highlights that chemical speciation analysis of volcanic waters is important in providing ideas on potential chemical toxicity. Furthermore there is a need for further work evaluating how arsenic (and other trace elements), released in volcanic and geothermal streams/vents, impacts on both biota and humans (via exposure in thermal pools or consuming commercial drinking water).
Doi 10.1016/j.scitotenv.2012.05.098
Pmid 22819888
Wosid WOS:000308787500040
Is Certified Translation No
Dupe Override No
Comments |WOS:000308787500040
Is Public Yes
Language Text English
Keyword Arsenic; Arsenic speciation; Volcanic/geothermal water; Argentina; Copahue; ICP-MS
Is Qa No