| Autor: |
Silva, Lílian Irene Dias da, Pontes, Fernanda Veronesi Marinho, Carneiro, Manuel Castro, Monteiro, Maria Inês Couto, de Almeida, Marcelo Dominguez, Neto, Arnaldo Alcover |
| Předmět: |
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| Zdroj: |
Chemical Speciation & Bioavailability; 2011, Vol. 23 Issue 3, p183-187, 5p |
| Abstrakt: |
Tanned leather shavings from Brazilian tanneries were analysed in order to assess the chromium extractability and bioavailability, and consequently its potential release into other environmental compartments when the shavings are deposited on landfill sites. The conventional SM&T (Standard, Measurement and Testing Programme) sequential extractions scheme was applied. Also, Cr(VI) and Cr(III) concentrations in the oxidizable fraction were determined. The results indicated high total chromium concentrations (1.04, 1.46 and 2.74%) in the samples A, B and C, respectively. A significant quantity of chromium (about 6 - 11% of total chromium) was easily released in slightly acidic conditions (step 1). This fraction is the most labile, and therefore the most dangerous and bioavailable for the surrounding environment. Less chromium (1 - 3% of total chromium) was released in reducing conditions (step 2), whereas about 0.5 - 3% of total chromium was strongly associated to the leather shaving structure (residual fraction - step 4), and therefore, its release under environmental conditions would be unlikely. Most of chromium (about 83 - 92% of the total chromium) was bound to the organic matter, as expected, since it was released in oxidizing condition (step 3). Part of chromium released in this fraction was also converted into Cr(VI), which is more labile and toxic than Cr(III). Considering the chromium concentrations, the sequentially extracted fractions may be ordered as follows: oxidizable > exchangeable > reducible > residual. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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