Utilize este identificador para referenciar este registo: http://hdl.handle.net/10400.8/604
Título: Phytoremediation of cadmium at different salinities by Scirpus maritimus from the Óbidos Lagoon (Portugal)
Autor: Santos, Márcia
Palavras-chave: Bioremediation
Accumulator plant
Heavy metal
Halophyte plant
Absorption atomic spectrometry
Salt marsh
Data de Defesa: 27-Dez-2011
Resumo: A greenhouse experiment was performed, to verify if phytoremediation of cadmium can be done by using the macrophyte Scirpus maritimus from the Obidos Lagoon (Portugal), plus if water salinity can influence its phytoremediation effectiveness. Two concentrations of cadmium were tested (50 and 100 ƒÊg l-1) to evaluate the plant capability to accumulate cadmium, plus possible toxicity effects of this pollutant. The contamination levels were tested at different water salinity conditions (values equal to 0.0, 5.0, 10.0 and 20.0), in which the plants are usually submerged in, at their natural environment. S. maritimus mortality was mostly determined by the water salinity and not for the cadmium contamination, in which more plants died at higher water salinities. The surge of new shoots, plant length and biomass increments were not proved to be affected by either of those factors, however, plant length and reduction and biomass loss can be induced by increasing water salinities. There was a biofilm development in all trial vessels, independently of the type of treatment involved. These suspended microorganisms and senescent organic matter presented more cadmium, according to initial water level of cadmium. The amount of water dissolved cadmium was positively related to the initial contamination levels of the experiment, but it increased also at higher water salinities. This may have resulted from tissue degradation and disruption from dead plants, possibly potentiated as well by symbiotic organisms and those from the biofilm, some of which may have promoted tissue decomposition and bioavailability of dissolved cadmium. The plants presented more cadmium in the rhizomes, followed by the stems, and less in the leaves. More cadmium accumulated in the plant fs rhizomes, according to higher water contamination levels and lower water salinities. According to the results, salinity could influence the transport of cadmium in the plant, between roots and leaves. However, the phytoremediation of the Obidos Lagoon by S. maritimus, or other similar systems, may be not be possible, due to the salt stress of the plants, the salt interference with the cadmium accumulation, and the normal functions of a plant. But the optimization of phytoremediation processes by S. maritimus could turn possible the use of this plant in freshwater ecosystems.
Descrição: Dissertação de Mestrado em Biotecnologia dos Recursos Marinhos apresentada à ESTM - Escola Superior de Turismo e Tecnologia do Mar do Instituto Politécnico de Leiria
URI: http://hdl.handle.net/10400.8/604
Aparece nas colecções:Mestrado em Biotecnologia dos Recursos Marinhos

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