Phosphorus fractionation in sediments of tropical semiarid reservoirs
The reduction of external loads of phosphorus (P) is the main action to control eutrophication in lakes. However, the elimination of these sources is not always sufficient for lakes' recovery, because the P accumulated in the sediment can be released for decades after it has accumulated. Thus,...
| Autores: | , , , |
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| Tipo de recurso: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2018 |
| País: | Brasil |
| Institución: | Universidade Federal do Rio Grande do Norte (UFRN) |
| Repositorio: | Repositório Institucional da UFRN |
| Idioma: | inglés |
| OAI Identifier: | oai:repositorio.ufrn.br:123456789/30882 |
| Acceso en línea: | https://repositorio.ufrn.br/handle/123456789/30882 |
| Access Level: | acceso abierto |
| Palabra clave: | Bioavailable phosphorus Tropical reservoirs Eutrophication Restoration |
| Sumario: | The reduction of external loads of phosphorus (P) is the main action to control eutrophication in lakes. However, the elimination of these sources is not always sufficient for lakes' recovery, because the P accumulated in the sediment can be released for decades after it has accumulated. Thus, to restore a lake, it is also necessary to reduce its internal P loading. For this, it is essential to know the composition of P in the sediment to evaluate the potential P availability. In this study, the forms of P in the sediment of two reservoirs in a semiarid tropical region were investigated. The forms of P were determined by fractionation, sorting out the forms in loosely sorbed P (P-Water), reductantsoluble P (P-BD), metal oxide-bound P (P-NaOH), P bound to organic matter (P-Humic), calcium-bound P (P-HCl) and residual P (P-residual). The sediment was collected in September 2016 and sliced in situ. The total amount of P forms in the sediment varied from 5 mg kg−1 to 349 mg kg−1 in the Gargalheiras Reservoir and from 12 mg kg−1 to 371 mg kg−1 in the Cruzeta Reservoir. Despite some variation in amounts at different depths, the general range of fractions in Gargalheiras and Cruzeta was: P-BD N P-NaOH N P-HCl N P-water N P-Residual N PHumic. In both reservoirs, the predominant form was BD, followed by NaOH and HCl. The first two forms are available and released easily, making them bioavailable for eutrophication processes and thus phytoplankton growth |
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