Geochemical mapping of arsenic in surface waters and stream sediments of the Quadrilátero Ferrífero, Brazil

Rem: Revista Escola de Minas

Raphael De Vicq Ferreira Da Costa¹  Mariangela Garcia Praça Leite¹  Fellipe Pinheiro Chagas Mendonça¹  Hermínio Arias Nalini Jr.¹ 

关键词: Geochemical Mapping;    Arsenic;    Surface water;    Stream sediments;    Quadrilátero Ferrífero;    mapeamento geoquímico;    arsênio;    águas superficiais;    sedimentos de corrente;    Quadrilátero Ferrífero;   

DOI  :  10.1590/0370-44672015680077

来源: SciELO

【 摘 要 】

A regional study on the arsenic concentration in surface waters and stream sediments, with a density of one sample every 13 km2, was carried out for the first time in the Quadrilátero Ferrífero (Brazil). The region was divided into 3rd order catchment basins, in which 512 areas were sampled. The arsenic concentration was determined in waters and stream sediments after partial digestion with the aid of ICP-OES. The arsenic values found in surface waters ranged from 57.70 to 414 µg.L-1, while for stream sediments, arsenic concentrations ranged from 0.63 to 1691 mg.kg-1, and from the 512 sampling points, 135 (26%) had arsenic concentrations above the limit of detection, which was 0.63 mg.kg-1. It was also found that 106 3rd order catchment basins had values above the third quartile, (5.09 mg.kg-1). The results show that high concentrations of this element are strongly related to the presence of Nova Lima rocks that contain minerals rich in arsenic. However, the anthropogenic influence in such high concentrations cannot be ruled out, as the region has a history of over 300 years of gold mining.

【 授权许可】

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