The use of biotechnology to explore low-grade ore deposits and mining tailings is one of the most promising alternatives to reduce environmental impacts and costs of copper extraction. However, such technology still depends on improvements to be fully applied in Brazil under industrial scale. In this way, the bioleaching, by Acidithiobacillus ferrooxidans, in columns and stirred reactors were evaluated regarding to copper extraction of a mineral sulfide and a weathered ore from the Brazilian Amazon region. Samples (granulometry of 2.0/4.75 mm) were characterized by X-ray diffraction (XRD), energy dispersive X-ray fluorescence (EDXRF) spectrometry and scanning electrons microscopy (SEM). The pH and Oxidation-reduction potential (Eh) were daily monitored and leachate samples were collected for copper extraction determination by EDXRF. After 47 days, the columns bioleaching efficiency was 1% (1298 mg Cu·L−1) and 0.95% (985 mg Cu·L−1) for 2.00/4.75 mm sulfide ore, respectively, whereas the stirred reactors bioleaching resulted in 4% (348 mg Cu·L−1) for the mineral sulfide and 47% (295.5 mg Cu·L−1) for the weathered ore.
During the last couple of years it has been possible to witness the progressive commodification of Lisbon. The adoption of neoliberal strategies of urban development -oriented towards competitiveness and aimed at putting Lisbon at the forefront of the international metropolitan group -has contributed to the reshaping of its landscape. The organization of flagship events, privatization of public spaces and development of local policies oriented towards the promotion of creative industries, and the increasing relevance that various forms of tourism have assumed, illustrate well the path that has been followed. However, expressions of urban citizenship against this destructive trajectory have emerged, showing that the urban development of Lisbon is a contentious process and has to face multiple strategies of resistance. In this paper we look at three expressions of citizenship in Mouraria, a neighbourhood located in the historical centre of Lisbon, in which the tensions and contradictions between neoliberal urbanism and urban citizenship take place.
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