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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Influência da adição de nitrato de cálcio e de PhoslockTM no abatimento dos fluxos de nutrientes e metais na interface sedimento-coluna de água em um sistema lacustre eutrofizado

Oliveira, Aline Fernandes de 16 February 2012 (has links)
Made available in DSpace on 2016-06-02T20:36:39Z (GMT). No. of bitstreams: 1 4391.pdf: 8625111 bytes, checksum: e00e22df63d1e8465e8dac05269fccb1 (MD5) Previous issue date: 2012-02-16 / Financiadora de Estudos e Projetos / This research project evaluated the changes in the fluxes of nutrients and metals at the sediment-water interface as a result of sediment treatment by the additions of PhoslockTM and calcium nitrate solution. The experiments were executed in situ using mesocosms that were assembled in the Ibirité Reservoir (MG). The calcium nitrate addition experiments showed nutrients flux abatement for Porthophosphate, ammoniacal-N and nitrate-N that were ≥ 90% whilst for the metals Fe and Mn the percentages reached 48 and 69%, respectively, as a result of sediment oxidation promoted by the intensification of denitrification rates. For the PhoslockTM addition the percentages of reduction in the fluxes across sediment-water interface was over 90% for P-orthophosphate and ammoniacal-N, 78% for nitrate-N and for the metals, Fe and Mn, 47 and 50%, respectively, as a result of the increased adsorption capacity of sediments due an excess of adsorbent material left on sediment surface. / Este projeto avaliou a capacidade de abatimento dos fluxos de metais e nutrientes na interface sedimento-coluna de água da represa de Ibirité (MG), comparando-se duas diferentes tecnologias de remediação de sistemas lacustres, a adição de PhoslockTM e de nitrato de cálcio. Os experimentos foram realizados in situ, com montagem de mesocosmos na citada represa. Os resultados referentes ao tratamento com injeção de nitrato de cálcio mostraram, em função da oxidação dos sedimentos promovida por esta tecnologia, um abatimento dos fluxos de nutrientes (P-ortofosfato, N-amoniacal, N-nitrato) iguais ou superiores a 90%, enquanto que para os metais Fe e Mn, as porcentagens de abatimento de fluxo alcançaram 48 e 69%, respectivamente. Para o tratamento dos sedimentos com a adição de PhoslockTM, devido ao aumento da capacidade de adsorção dos sedimentos promovida pelo excesso de material adsorvente depositado na superfície dos mesmos, as porcentagens de redução dos fluxos sedimento-água foram superiores a 90% para o P-ortofosfato e N-amoniacal, 78% para o N-nitrato, e para os metais (Fe e Mn), 47 e 50%, respectivamente.

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