title: Natural decrease of dissolved arsenic in a small stream receiving drainages of abandoned silver mines in Guanajuato, Mexico.
abstract: Arsenic release from the abandoned mines and its fate in a local stream were studied. Physicochemical parameters, metals/metalloids and arsenic species were determined. One of the mine drainages was found as a point source of contamination with 309 μg L(-1) of dissolved arsenic; this concentration declined rapidly to 10.5 μg L(-1) about 2 km downstream. Data analysis confirmed that oxidation of As(III) released from the primary sulfide minerals was favored by the increase of pH and oxidation reduction potential; the results obtained in multivariate approach indicated that self-purification of water was due to association of As(V) with secondary solid phase containing Fe, Mn, Ca.
authors.affiliation: Department of Geomatic and Hydraulic Engineering, University of Guanajuato, L de Retana 5, 36000, Guanajuato, Mexico.
authors.forename: Yann Rene Ramos
authors.initials: YR
authors.lastname: Arroyo
authors.forename: Alma Hortensia Serafín
authors.initials: AH
authors.lastname: Muñoz
authors.forename: Eunice Yanez
authors.initials: EY
authors.lastname: Barrientos
authors.forename: Irais Rodriguez
authors.initials: IR
authors.lastname: Huerta
authors.forename: Kazimierz
authors.initials: K
authors.lastname: Wrobel
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Wrobel
mesh_terms: D001151:Arsenic / Q000032:analysis*; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D008800:Mexico; D008906:Mining; D045483:Rivers / Q000737:chemistry*; D012834:Silver; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D014874:Water Pollutants, Chemical; D012834:Silver; D001151:Arsenic