Removal of chromium, copper, and nickel from an electroplating effluent using a flocculent brewer's yeast strain of Saccharomyces cerevisiae

The release of heavy metals in aquatic systems due to the discharge of industrial wastewaters is a matter of environmental concern. Heat-inactivated cells of a flocculent strain of Saccharomyces cerevisiae were used in the bioremediation, in a batch mode, of a real electroplating effluent containing Cu, Ni, and Cr. In this approach, no previous reduction of Cr(VI) to Cr(III) was required. Cr(VI) was selectively removed (98%) by yeast biomass at pH 2.3. At this pH, Cr(VI) is mainly in the form of HCrO4− and yeast surface is surrounded by H+ ions, which enhance the Cr(VI) interaction with biomass binding sites by electrostatic forces. Subsequently, pH of the effluent was raised up to 6.0; this pH maximizes the efficiency of cations removal since at this pH the main binding groups of yeast cells are totally or partially deprotonated. The passage of effluent through a series of sequential batches, at pH 6.0, allowed, after the third batch, the removal of Cu(II), Ni (II), Cr total, and Cr(VI) in the effluent to values below the legal limit of discharge. The strategy proposed in the present work can be used in plants for the treatment of heavy metals rich industrial effluents containing simultaneously Cr(VI) and Cr(III).The authors thank to the "Fundacao para a Ciencia e a Tecnologia" (FCT) from Portuguese Government for the financial support of this work with FEDER founds, by the Project POCTI/CTA/47875/2002. Manuela D. Machado is also gratefully acknowledged for a grant scholarship financed under the same project and another grant from FCT (SFRH/BD/31755/2006)

Report on Influence of conflict, gender, and class relations on availability of water in the household

This review essay lays out the conceptual and historical groundwork for the primary research that the WATERSPOUTT social science team will carry out through the project period over four research sites in Ethiopia, Malawi, South Africa and Uganda. We have described it as a report synthesising secondary data on conflict, gender, and class relations in the four case study areas. However, it is emphatically not intended as an exhaustive description of the specificities of the four research sites – the sections that follow will traverse quite unevenly across these regions. The essay will instead offer an overarching reading of how these research sites are situated within wider structures and relationships of power. It will engage the recurrent themes and key debates that have dominated the relevant literatures in the fields of social theory and historical and social studies in order to build a broad foundation of understanding for the empirical research that is to come

Report on Influence of conflict, gender, and class relations on availability of water in the household

This review essay lays out the conceptual and historical groundwork for the primary research that the WATERSPOUTT social science team will carry out through the project period over four research sites in Ethiopia, Malawi, South Africa and Uganda. We have described it as a report synthesising secondary data on conflict, gender, and class relations in the four case study areas. However, it is emphatically not intended as an exhaustive description of the specificities of the four research sites – the sections that follow will traverse quite unevenly across these regions. The essay will instead offer an overarching reading of how these research sites are situated within wider structures and relationships of power. It will engage the recurrent themes and key debates that have dominated the relevant literatures in the fields of social theory and historical and social studies in order to build a broad foundation of understanding for the empirical research that is to come

Report on Influence of conflict, gender, and class relations on availability of water in the household

This review essay lays out the conceptual and historical groundwork for the primary research that the WATERSPOUTT social science team will carry out through the project period over four research sites in Ethiopia, Malawi, South Africa and Uganda. We have described it as a report synthesising secondary data on conflict, gender, and class relations in the four case study areas. However, it is emphatically not intended as an exhaustive description of the specificities of the four research sites – the sections that follow will traverse quite unevenly across these regions. The essay will instead offer an overarching reading of how these research sites are situated within wider structures and relationships of power. It will engage the recurrent themes and key debates that have dominated the relevant literatures in the fields of social theory and historical and social studies in order to build a broad foundation of understanding for the empirical research that is to come