Browsing by Author "Costa, J. P. da"
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- Green synthesis of covellite nanocrystals using biologically generated sulfide: potential for bioremediation systemsPublication . Costa, J. P. da; Girão, Ana Violeta; Lourenço, J. P.; Monteiro, O. C.; Trindade, Tito; Costa, Maria ClaraThis work describes the synthesis of CuS powders in high yield and via an environmentally friendly and straightforward process, under ambient conditions (temperature and pressure), by adding to aqueous copper (II) a nutrient solution containing biologically generated sulfide from sulfate-reducing bacteria (SRB). The powders obtained were composed of CuS (covellite) nanoparticles (NPs) exhibiting a spheroid morphology (<5 nm). The relevance of this method to obtain CuS supported solid substrates has been demonstrated by performing the synthesis in the presence of TiO2 and SiO2 submicron particles. We further extended the work carried out, which substantiates the potential of using biogenic sulfide for the production of covellite nanocrystals and composites, using the effluent of a bioremediation column. Hence, such process results in the synthesis of added value products obtained from metal rich effluents, such as metallurgical and industrial ones, or Acid Mine Drainage (AMD), when associated with bioremediation processes.
- Integrated synthesis of nanosized semiconductors in a bioremediation system for the treatment of AMD using biologically produced sulfidePublication . Costa, J. P. da; Girão, Ana Violeta; Lourenço, J. P.; Monteiro, O. C.; Trindade, Tito; Costa, Maria ClaraThe use of sulfate-reducing bacteria in bioremediation process for the treatment of afluents with high-content of sulfate and metal generates an excess of sulfide.
- Synthesis of nanocrystalline ZnS using biologically generated sulfidePublication . Costa, J. P. da; Girão, Ana Violeta; Lourenço, J. P.; Monteiro, O. C.; Trindade, Tito; Costa, Maria ClaraThis work describes the synthesis of ZnS powders in high yield and via a straightforward process, under ambient conditions (temperature and pressure), by adding to aqueous zinc (II) a nutrient solution containing biologically generated sulfide from sulfate-reducing bacteria (SRB). The powders obtained as above were composed mainly of ZnS (sphalerite) nanoparticles (NP's) exhibiting a spheroidal morphology (20–30 nm). The NP's morphological properties and crystalline phase were not markedly altered by the SRB growth media composition neither by the presence of bacterial cells. The relevance of this method to obtain ZnS supported solid substrates has been demonstrated by performing the synthesis in the presence of TiO2 and SiO2 submicron particles.