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https://hdl.handle.net/1822/7536
Título: | Phosphorus fractionation in volcanic lake sediments (Azores – Portugal) |
Autor(es): | Ribeiro, Daniel Martins, Gilberto Nogueira, R. Cruz, J. Virgílio Brito, A. G. |
Palavras-chave: | Eutrophication Phosphorus extraction Sediment Volcanic lakes |
Data: | Jan-2008 |
Editora: | Elsevier Ltd. |
Revista: | Chemosphere |
Citação: | "Chemosphere". ISSN 0045-6535. 70:7 (Jan. 2008) 1256-1263. |
Resumo(s): | The phosphorus distribution in volcanic sediments of three lakes that are under different anthropogenic pressures in São Miguel island (Azores – Portugal) was evaluated using a sequential extraction scheme. The P-fractionation scheme employs sequential extractions of sediment with NH4Cl, bicarbonate-dithionite (BD), NaOH (at room temperature), HCl and NaOH (at 85 °C) to obtain five P-fractions. The P-fractionation shows that in lakes with higher trophic status (Lake Furnas and Lake Sete Cidades), the NaOH extracted P is the dominant fraction, that contribute with more than 50% to total sedimentary phosphorus. The rank order of P-fractionation for these two lakes was NaOH > NaOH (85 °C) > HCl > BD > NH4Cl for Furnas lake and NaOH > HCl > NaOH (85 °C) > NH4Cl > BD for Sete Cidades lake. On the other hand, the trend of P contribution in the oligotrophic lake Fogo shows that the most inert P pools have the higher concentrations, with more than 50% of the P contribution from the last extraction step with NaOH at 85 °C. For this lake, the rank order of P-fractionation was NH4Cl > BD > NaOH > HCl > NaOH (85 °C). The Phosphorus Maximum Solubilization Potential (P-MSP) was also calculated and the results show that for the more bio-available P-fractions (first and second extraction step), the P-MSP values for Furnas and Sete Cidades lakes are sensibly higher than the results obtained in Fogo lake, an indication of the non-point diffuse load discharged in the first ones. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/7536 |
DOI: | 10.1016/j.chemosphere.2007.07.064 |
ISSN: | 0045-6535 |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CEB - Publicações em Revistas/Séries Internacionais / Publications in International Journals/Series |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
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Ribeiro_Chemosphere[2].pdf | 551,71 kB | Adobe PDF | Ver/Abrir |