Partição do cadmio entre o sedimento e a agua intersticial

AUTOR(ES)
DATA DE PUBLICAÇÃO

1991

RESUMO

Cadmium partitioning in the interstitial water of some sediments was evaluated using two different analytical techniques: anodic stripping voltametry (ASV) and atomic absorption spectrophotometry (AAS). Four samples of different sediments were investigated in this work. Two samples from Paranoá Lake (DF), containning 14.6% and 16.8% of organic matter; a third sample showing 2.0% of organic matter was collected in Tietê River (SP). A fourth sample from a mangrove area collected in Ilha do Mel (PR), presented 8.0% of organic matter. The concentration of cadmium measured in the interstitial water of sediments, spiked with different concentrations of metal varied according to the analytical technique used. The results obtained using AAS were always higher or equal to that obtained using ASV. A correlation of 0.999 (n=4) between the concentration of sulphide calculated, based upon the cadmium titration of sediment suspensions, and the acid volatile sulphide (AVS) concentration in the sediment was obtained. The sulphide was extracted using HCl 1.5 M and quantified by potentiometric titrations monitored with an ion-selective electrode (ISE). It was verified that the partition of cadmium is dependent on the sediment oxidation state. The extent of cadmium adsorpion in sediment suspensions submitted to oxidation for 14 days, was up to 3 orders of magnitude lower than the ones compared to the adsorption using sediment "in natura".

ASSUNTO(S)

sedimentos (geologia) cadmio

ACESSO AO ARTIGO

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