An evaluation of direct seeding for reforestation of degraded lands in central São Paulo state, Brazil

As part of a larger study evaluating several silvicultural techniques for restoring tropical moist forests on abandoned agricultural lands in southeastern Brazil, direct seeding with five early-successional Atlantic forest species was tested at three degraded sites, characterized by different soil types and land-use histories, within the Environmental Protection Area at Botucatu, SP. The species used in this study were Chorisia speciosa, Croton floribundus, Enterolobium contorstisiliquum, Mimosa scabrella, and Schizolobium parahyba. Scarified seeds of each of these species were sown in prepared seed spots in replicated, 0.25 ha mixed-species plots at an initial espacement of 1 m x 1 m at each site. of the five species planted, only two, Enterolobium and Schizolobium, showed good seed germination, seedling survival, and early growth rates, averaging 4.1-4.6 cm stem diameter and 1.5-1.7 m height growth during the first 2 years after sowing. These two species constituted 88-100% of the total stand density, which ranged from 1050 to 1790 stems ha(-1) at 2 years. Despite the poor performance of the other species tested, we observed that the natural regeneration of native forest species originating from remnant forests in the general vicinity of our study sites was significantly greater within the direct-seeded plots than in unplanted control plots that were protected from fire and other disturbances. Published by Elsevier B.V. B.V.

Abundance and composition of Rotifera in an abandoned meander lake (Lago Amapá) in Rio Branco, Acre, Brazil

A comunidade de rotíferos do Lago Amapá (meandro abandonado da planície de inundação do Rio Acre) foi investigada sazonalmente. As amostragens foram realizadas semanalmente em três estações de coletas, em dois períodos: estação seca entre 08/V/1997 e 31/X/1997 e estação chuvosa, entre 02/I/1998 e 24/II/1998. A densidade e composição de rotíferos (48 táxons de rotíferos) foram determinadas. A diversidade e abundância foram caracterizadas por serem maiores, respectivamente, nas águas altas e águas baixas. Anova e teste F foram usados, visando observar diferenças sazonais nas variáveis ambientais e rotíferos. Transparência e pH foram estatisticamente altamente significativos (p < 0,01). As análises de correlações de Pearson revelaram que a condutividade elétrica foi negativamente correlacionada com a densidade de rotíferos (r = -0,8824; p < 0,05), na fase de águas baixas, bem como, profundidade, na fase de águas altas (r = -0,7513; p < 0,05). Mudanças sazonais, causadas pelas flutuações do nível da água, e baixa diversificação dos nichos influenciaram a composição e abundância do grupo estudado.

Removal of radionuclides from acid mine waters by retention on adsorbing materials

This study proposes a method for decontamination of acid drainage water from a uranium mine, as an alternative process to lime treatment. The research embodied the recovery of uranium with an ion-exchange resin, treatment of effluent resin with lime, or with inorganic adsorbents and biosorbents. The uranium decontamination level using the resin process was 94% and allowed the recovery of this element as a commercial product. Among the inorganic adsorbents studied, phosphogypsum was effective for Ra-226, Ra-228, and Pb-210 removal. Among the biosorbents, Sargassum sp.was superior in relation to its specific capacity to accumulate and remove Ra-226.

Optimum design of microirrigation systems in sloping lands

When an area to be irrigated has a high slope gradient in the manifold line direction, an option is to use a tapered pipeline to economize on pipe costs and to keep pressure head variations within desired limits. The objective of this paper is to develop a linear optimization model to design a microirrigation system with tapered, downhill manifold lines, minimizing the equivalent annual cost of the hydraulic network and the annual pumping cost, and maximizing the emission uniformity previously established to the subunit. The input data are irrigation system layout, cost of all hydraulic network components, and electricity price. The output data are equivalent annual cost, pipeline diameter in each line of the system, pressure head in each node, and total operating pressure head. To illustrate its capability, the model is applied in a citrus orchard in Sao, Paulo State, Brazil, considering slopes of 3, 6, and 9%. The model proved to be efficient in the design of the irrigation system in terms of the emission uniformity desired.

Molecular characterization of Acidithiobacillus ferrooxidans and A-thiooxidans strains isolated from mine wastes in Brazil

Nineteen strains of Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, including 12 strains isolated from coal, copper, gold and uranium mines in Brazil, strains isolated from similar sources in other countries and the type strains of the two species were characterized together with the type strain of A. caldus by using a combination of molecular systematic methods, namely ribotyping, BOX- and ERIC-PCR and DNA-DNA hybridization assays. Data derived from the molecular fingerprinting analyses showed that the tested strains encompassed a high degree of genetic variability. Two of the Brazilian A. ferrooxidans organisms (strains SSP and PCE) isolated from acid coal mine waste and uranium mine effluent, respectively, and A. thiooxidans strain DAMS, isolated from uranium mine effluent, were the most genetically divergent organisms. The DNA-DNA hybridization data did not support the allocation of Acidithiobacillus strain SSP to the A. ferrooxidans genomic species, as it shared only just over 40% DNA relatedness with the type strain of the species. Acidithiobacillus strain SSP was not clearly related to A. ferrooxidans in the 16S rDNA tree.

Design of microirrigation systems in sloping lands using linear programming

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Geochemical Study of the Itabirite Iron Ores of the Alegria Mine - Quadrilátero Ferrífero, Minas Gerais, Brazil

The iron ores of Alegria mine are composed of itabirites enclosing minor bodies of high-grade ores. The itabirites are classified according to mineralogical composition in five types: martite-rich, goethite-rich, specularite-rich, magnetite-rich and anphibolite-rich ores. The hematites are martite-rich, magnetite-rich, specularite-rich and more rarely, amphibolite-rich. Other classification criteria of the ores are based on the physical properties and the degree of compaction. As such, the itabirites and hematites can be classified as hard, friable and soft types. The mineralogical/textural evolution of the ores is linked to the pressure and temperature conditions that accompanied the tectonic processes in anphibolite facies and the different degrees of subsequent surficial weathering processes. Petrographic and microstructural studies indicate that the magnetite and amphibole bearing itabirites represent the parent rocks that created the other itabirites and that the specularite itabirites and the hard martite types are related to silica dissolution and redeposition in zones of high and low strain. Most of itabirites ores correspond to chert oxide facies banded iron formation, except the goethite and amphibole bearing itabirite that resemble a silicate or oxide-silicate facies with minor carbonate impurities. The great mass and pods of soft martite itabirites are probably shaley oxide facies BIFs with little volcanic contribution. Trace element contents of the Alegria's itabirites show strong dissimilarities with BIFs associated with volcanism (Algoma type), but closely ressemble to the Lake Superior type, with high content in Cr, Co and low V, Ni, Cu and Zn. Although the absolute contents of REE present in the Alegria's itabirites are, in general very low, the pattern when normalised by NASC is similar to the great majority of the Archean and Paleoproterozoic BIFs elsewhere in the world, and characterised by positive Eu anomaly.

Transforming open mining pits into fish farms: Moving towards sustainability

The legacy of mining activities has typically been land 'returned to wildlife', or, at some sites, degraded to such an extent that it is unsuitable for any alternate use. Progress towards sustainability is made when value is added in terms of the ecological, social and economic well-being of the community. In keeping with the principles of sustainable development, the innovative use of flooded open pits and tailings impoundments as commercial, recreational or ornamental fish farms should be considered in some locations, as it could make a significant contribution to the social equity, economic vitality and environmental integrity of mining communities. This article highlights the growing significance of aquaculture and explores the benefits and barriers to transforming flooded pits and impoundments into aquaculture operations. Among other benefits, aquaculture may provide a much-needed source of revenue, employment and, in some cases, food to communities impacted by mine closure. Further, aquaculture in a controlled closed environment may be more acceptable to critics of fish farming who are concerned about fish escapes and viral transmissions to wild populations. Despite the potential benefits, aquaculture in flooded pits and impoundments is not without its complications - it requires a site-specific design approach that must consider issues ranging from metals uptake by fish, to the long-term viability of the aquatic system as fish habitat, to the overall contribution of aquaculture to sustainability. © 2004 United Nations. Published by Blackwell Publishing.

Leaching of Ni and Cu from mine wastes (tailings and slags) using acid solutions and A. ferrooxidans

The objective of this work is to evaluate the acidic and biological leaching of tailings containing Ni/Cu from a flotation and smelting plant. Acidithiobacillus ferrooxidans, strain LR, was used for bioleaching at pH 1.8 and chemical controls were run parallel to that. The acidic leaching was done within 48 hours at pH 0.5 and 1.0. In the slag inoculated flasks the redox potential was high (600 mV), thus indicating oxidative bacterial activity, however, the obtained results after 15 days showed only around 13% Ni and 8% Cu extractions, which were not different to those of the controls. For the flotation tailings bioleaching extractions were approximately 45% for Ni and 16% for Cu while differing figures were obtained for the chemical controls. These were 30% and 12% respectively. Here we could observe that the presence of bacterial activity led to a higher solubility of Ni. Acid leaching of slag showed higher nickel and copper extractions: 56% and 24% respectively at pH 0.5 and 21% and 11% at pH 1.0. However, the acid consumption was 320 and 150 Kg/ton of slag, respectively, both much higher than in bacterial assays. These results indicated that Ni and Cu solubilization from the slag is acid dependent no matter the redox potential or ferric iron concentration of the leaching solution. For flotation tailings, acid treatment showed extractions of 23% for Ni and 16% for copper at pH 0.5 and 22% and 28%, respectively at pH 1.0. The acid consumption was also higher: 220 and 120 Kg/ton, at pH 0.5 and 1.0, respectively. Based on own findings we could observe that acid leaching is found to be more effective for slag, though the acid consumption is much higher, while for the flotation tailings, bacterial leaching seems to be the best alternative. © (2009) Trans Tech Publications.

Impactos sociais da mineração do folhelho pirobetuminoso sobre a comunidade rural Dois Irmãos, desapropriada para fins de utilidade pública

The aim of this paper is to present the effects of social impacts of Petrobras/Six mining of oil shales over the rural community Dois Irmãos, located at Sao Mateus do Sul city, Paraná state. For making mining areas, PETROBRAS/SIX needs to expropriate areas of its interest. In 2010, for the implementation of the mine Dois Irmão, the last one, 90 families were evicted and they directly suffered the impacts of mining. Of these, 62 families were interviewed in order to investigate the main effects suffered with the expropriation. These results showed that the community had difficulties in upgrading its way of life in new places, experiencing how different types of problems were triggered from the loss of the lands.

Could contaminant induced mutations lead to a genetic diversity overestimation?

Contaminant driven genetic erosion reported through the inspection of selectable traits can be underestimated using neutral markers. This divergence was previously reported in the aquatic system of an abandoned pyrite mine. The most sensitive genotypes of the microcrustacean cladoceran Daphnia longispina were found to be lacking in the impacted reservoir near the entrance of the metal rich acid mine drainage (AMD). Since that divergence could be, at least partially, accounted for by mutagenicity and genotoxicity of the AMD, the present study aimed at providing such a characterization. The Allium cepa chromosomal aberration assay, using root meristematic cells, was carried out, by exposing seeds to 100, 10, 1, and 0.1 % of the local AMD. Chromosomal aberrations, cell division phases and cell death were quantified after the AMD exposure and after 24 and 48 h recovery periods. The AMD revealed to be mutagenic and genotoxic, even after diluting it to 1 and 0.1 %. Dilutions within this range were previously found to be below the lethality threshold and to elicit sublethal effects on reproduction of locally collected D. longispina clonal lineages Significant mutagenic effects (micronuclei and chromosomal breaks) were also found at 0.1 % AMD, supporting that exposure may induce permanent genetic alterations. Recovery tests showed that AMD genotoxic effects persisted after the exposure. © 2013 Springer Science+Business Media New York.

Determination of in situ speciation of manganese in treated acid mine drainage water by using multiple diffusive gradients in thin films devices

Acid mine drainage (AMD) is a serious environmental problem that creates acidic solution with high Mn concentrations. The speciation of residual Mn from AMD after an active treatment involving the addition of a neutralizing agent can reliably evaluate the treatment efficiency and provide knowledge of the Mn species being inputted into the environment. The aim of this study was to evaluate the in situ lability and speciation of Mn using the diffusive gradients in thin films (DGT) technique with treated drainage water from a uranium mine (TAMD). DGT devices with different binding phases (Chelex-100 and P81 and DE81membranes) were used to perform the in situ speciation of Mn. A comparison of the results from deploying DGT in the laboratory and in situ shows that the speciation of Mn in TAMD should be performed in situ. Linear deployment curves (from in situ experiments) indicate that the DGT device containing the Chelex-100 binding phase can be used to evaluate Mn lability in TAMD. The labile Mn fraction (from in situ measurements) obtained using the device containing the Chelex-100 resin ranged from 63 to 81% of the total Mn concentration and, when compared to the speciation obtained using the CHEAQS software, indicated that this device was capable of uptaking the free Mn2+ and a portion of the MnSO4(aq). The values obtained using the DGT technique were compared to those from on site solid phase extraction, and a good agreement was found between the results. The amount of negative Mn species sampled by DE81 device was insignificant (<1.5%) for all of the sites. Sites containing a relatively small amount of Ca (<40mgL-1) and measured using devices containing the P81 membrane agreed with the concentration predicted by the CHEAQS software for positive Mn species (Mn2+ and Mn(OH)+). Nevertheless, the speciation obtained using the CHEAQS software indicated that the concentrations of positive Mn species were underestimated for sites with relatively high Ca concentrations (>150mgL-1), which take place due to the saturation of binding sites in the P81 membrane. © 2013 Elsevier B.V.

Condições dos solos em áreas de pousio dos cultivos praticados por índios Guarani, em Ubatuba (SP)

Pós-graduação em Agronomia (Energia na Agricultura) - FCA

DESIGN OF MICROIRRIGATION SYSTEMS IN SLOPING LANDS USING LINEAR PROGRAMMING

Quando a área a ser irrigada apresenta um elevado gradiente de declive na direção das linhas de derivação, uma opção de dimensionamento é o uso de tubulações com vários diâmetros para economizar no custo e também para manter a variação de pressão dentro dos limites desejados. O objetivo deste trabalho foi desenvolver um modelo de programação linear para dimensionar sistemas de irrigação por microaspersão com linhas de derivação com mais de um diâmetro e operando em declive, visando a minimização do custo anualizado da rede hidráulica e do custo anual com energia elétrica, além de assegurar que a máxima variação de carga hidráulica na linha será respeitada. Os dados de entrada são: configuração da rede hidráulica do sistema de irrigação, custo de todos os componentes da rede hidráulica e custo da energia. Os dados de saída são: custo anual total, diâmetro da tubulação em cada linha do sistema, carga hidráulica em cada ponto de derivação e altura manométrica total. Para ilustrar a potencialidade do modelo desenvolvido, ele foi aplicado em um pomar de citros no Estado de São Paulo, Brasil. O modelo demonstrou ser eficiente no dimensionamento do sistema de irrigação quanto à obtenção da uniformidade de emissão desejada. O custo anual com bombeamento deve ser considerado no dimensionamento de sistemas de irrigação por microaspersão porque ele gera menores valores de custo anual total quando comparado com a mesma alternativa que não considera aquele custo.

Representantes da megafauna pleistocênica do sítio fossilífero de Pau Ferrado (Jaupaci, Goiás)

Pós-graduação em Geociências e Meio Ambiente - IGCE