Joel Barbujiani Sígolo

Detecção de contaminantes em espécie bioindicadora (Corbicula fluminea) - Rio Ribeira de Iguape - SP

The study assessed heavy metal concentrations in the tissue samples of Corbiculafluminea, by ICP-OES. In the tissues, average levels of 23.99 µg/g of Cu, 144.21 µg/g of Zn, 0.71 µg/g of Cd, 7.10 µg/g of Cr and 2.41 µg/g of Pb were detected ahowing that this last value is high and above the ANVISA reference (2.00 µg/g) for fish and other products. The results suggest that natural processes occuring in the Ribeira de Iguape River are not sufficient for purification so that metals remain in the water and can accumulate in the trophic chain.

Associação de resíduos da metalurgia com sedimentos em suspensão - Rio Ribeira de Iguape

For approximately 40 years, the Ribeira de Iguape River received mining wastes derived from metallurgical slag produced and discharged by Plumbum S/A, a company with an office in Adrianopolis (Parana-Brazil). In order to verify the contribution of these residues to the river contamination, it was necessary to carry out physical and chemical characterizations such as grain size evaluation, chemical analyses, MEV/EDS exams and leaching tests. The residues are magnetic, and have high Zn (average of 118.004,33 mg/kg) and Pb (average of 34.018,00 mg/kg) concentrations wich classifies them in Class I of Solid Residues according to the ABNT-NBR 10.004 norm (1987a) since they exceed by a factor of 34 the allowed Pb concentration (1.000 mg/kg) for deposition of such material. The leaching test, in accordance with the ABNT-NBR 10.005 norm (1987b) showed that this residue resists acid attack. The concentration of extracted Pb was 0.46 mg/kg, well below the recommended value. The sediments in suspension were examined by MEV/EDS and chemical analyses in order to check for the presence of scoria. Rounded fragments typical of metallurgical residues were found in which Pb, Zn, As and Cu are present. This indicates that the metallurgy residues launched into the river by Plumbum are being transported, comminuted and incorporated into the sediments which may increase the disponibility for the biota.

Sediment Geochemistry and Climatic Influences in a River Influenced by Former Mining Activities: the Case of Ribeira de Iguape River, SP-PR, Brazil

The Ribeira de Iguape River (RIR) was historically contaminated by residues from mining activities. These activities ceased in the late 1990’s, but the residues remained deposited along the river banks. This study aimed to evaluate the sediment characteristics of the RIR in different hydro-meteorological conditions and detect eventual changes in the geochemistry. Three sampling surveys were conducted, in which sediments were collected in 6 sites, and then analyzed for sediment textures and metals concentrations. Sediments were predominantly sandy, and samples collected downstream to the mining areas tended to be enriched by metals, especially Pb, Cr, Cu, Ni and Zn. Concentrations of metals in sediments tended to be higher after rainstorm episodes, evidencing the pollution sources are not totally controlled and that the stormwater runoff may carry metals to the RIR.

Biogeochemical processes and the diversity of Nhecolândia lakes, Brazil

The Pantanal of Nhecolândia, the worlds largest and most diversified field of tropical lakes, comprises approximately 10,000 lakes, which cover an area of 24,000 km(2) and vary greatly in salinity, pH, alkalinity, colour, physiography and biological activity. The hyposaline lakes have variable pHs, low alkalinity, macrophytes and low phytoplankton densities. The saline lakes have pHs above 9 or 10, high alkalinity, a high density of phytoplankton and sand beaches. The cause of the diversity of these lakes has been an open question, which we have addressed in our research. Here we propose a hybrid process, both geochemical and biological, as the main cause, including (1) a climate with an important water deficit and poverty in Ca(2+) in both superficial and phreatic waters; and (2) an elevation of pH during cyanobacteria blooms. These two aspects destabilise the general tendency of Earths surface waters towards a neutral pH. This imbalance results in an increase in the pH and dissolution of previously precipitated amorphous silica and quartzose sand. During extreme droughts, amorphous silica precipitates in the inter-granular spaces of the lake bottom sediment, increasing the isolation of the lake from the phreatic level. This paper discusses this biogeochemical problem in the light of physicochemical, chemical, altimetric and phytoplankton data.

Uso do bivalve límnico Anodontites tenebricosus (LEA, 1834) no biomonitoramento de metais do Rio Ribeira de Iguape

USING THE FRESHWATER BIVALVE Anodontites tenebricosus (LEA, 1834) AS A BIOMONITOR OF METALS IN THE RIBEIRA DE IGUAPE RIVER. This study investigated the contamination of the Ribeira de Iguape River – RIR by Cd, Zn, Cr and Pb, using the bivalve Anodontites tenebricosus as a biomonitor. Metal concentrations in tissue samples were measured by HR-ICPMS. Bivalve tissues exhibited mean levels of 1.00 µg/g Cd; 152.89 µg/g Zn; 14.79 µg/g Cr and 4.40 µg/g Pb. Lead concentrations were comparable to those reported for moderately contaminated sites. The results showed that Pb is bioavailable to the bivalves, exhibiting high concentrations and exceeding both natural and reference values for human consumption. The freshwater bivalve Anodontites tenebricosus is a suitable biomonitor of contamination by metals.

Sensoriamento Remoto na Análise do Alinhamento das Lagoas do Pantanal da Nhecolândia, MS

Among the several kinds of pantanais, the Nhecolândia sub-region deserves prominent role for presenting peculiar landscape. Its main feature is the presence of numerous lakes, which are divided into “baias” and “salinas” (fresh and brackish, respectively). The study aimed to quantify and analyze the orientation and aligning intensity of the major axes of these water ponds, in order to contribute for understanding the formation and functioning of this intriguing and yet unknown region. Firstly, we adopted the object-oriented classification method on Landsat 5 satellite image, TM sensor. Then, we used a specific algorithm for identifying the alignment of the ponds. As results, we recognized 17,631 lakes, 17,050 being baias and 577 salinas. These ponds are aligned in two directions - NE and NW -, which would be associated to the directions of the winds prevailing during the origin of the Nhecolândia lakes.

The expression of neotectonics in the Pantanal da Nhecolândia, State of Mato Grosso do Sul - Brazil

Pantanal da Nhecolândia is one of the most well-preserved areas in the State of Mato Grosso do Sul. Located in the southern part of the Taquari River megafan, it is in tectonic contact with the fault escarpments of the Maracaju-Campo Grande plateaus to the east and with the fault escarpments of the Bodoquena plateau to the west, which continue to north. To the south and to the north, the limits are marked respectively by the lineaments of the Negro and Taquari Rivers. Nhecolândia is characterized by the existence of at least 17,631 lagoons, 17,050 (96.70 %) of which are of fresh water (baías) and 577 (3.3 %) of salty water (salinas). Studies based on (Landsat) satellite images and use of free software (QGIS, version 2.8.3) and GIS (Geographic Information Systems) revealed that the major axes of the lagoons are aligned along two directions, NE (62.49 %) and NW (37.51 %), with modes concentrated between N30-40E and N30-40W, suggesting in both cases the role played by tectonic control (neotectonics) in their formation. Evidences of fluvial origin are presented for these groups of lagoons, as well as for their tectonic alignment.

Characterization and Availability of Toxic Metals in Solid Mine Tailing: Ribeira Valley (Brazil)

Acid mine drainage formation and metal mobility is currently a great concern in abandoned mines. Ribeira Valley (Brazil) is an example of bad planning on closing inactive mines, where the waste was disposed directly on the soil near the river, without any protection and leaving the toxic metals capable of leaching. The aim of the present study was to evaluate the mobility and availability of toxic metals from a profile probing collected from a deposit of mining waste. To achieve this goal, simulations were carried out with different environmental conditions (pH very acid and natural). Geological and geotechnical characterization, leaching tests, solubilization and pH variation (3, 5 and 7) were performed. The results showed a predominance of sand fraction and high concentration of Zn and Pb in tailing. The mineralogy contains sulphite, carbonates and high concentration of barite and the pH of samples remained in neutral to alkaline, showing the impossibility of formation of acid drainage. The leaching and solubilization tests showed high concentration of extracted Pb, probably extracted from cerussite (carbonate), showing the mobility of this metal and classifying the waste as hazardous (according to Brazilian norm). Extraction with pH variation test exhibited significant metal release in all pH tested, including neutral one. In conclusion, waste does not generate acid drainage, even though in certain environmental conditions, such as acid or neutral pH, it may release toxic metal. The release of toxic metals can be toxic to biota. The tailing needs to be adequately covered to avoid any contact with animals or people who live near the river.

Peat-assisted phytoremediation of waste foundry sands: plant growth, metal accumulation and fertility aspects.

We investigated the potential of peat additions to improve plant growth and fertility and to reduce plant metal uptake in waste foundry sands (WFS) landfills. The WFS contains 78211 mg kg−1 and 371 mg kg−1 concentrations of Cr and Ni, respectively, and varied metal concentrations. The experiment investigated the growth of Brassica juncea plants on fertilized WFS mixed with peat at concentrations of 0, 2.5, 5, and 10% (w/w). The highest peat treatment allowed substantial plant growth and increased Ni mass in shoots, which was positively correlated to shoot biomass increments. On a concentration basis, peat additions did not increase shoot Ni values, thus suggesting that plants grown on peat-treated WFS may not increase risks to human and ecological receptors. Chromium was below detection levels in shoots for all peat treatments. Peat-treated substrates also promoted increased CEC values and higher water holding capacity, therefore improving the WFS agronomical properties. These results indicate that peat can be used as an amendment to assist in the phytoremediation of WFS landfill areas. However, there was evidence for increased mobilization of Cr and Ni in the substrate solution which can pose a threat to local groundwater.

Dobras atectônicas em crostas ferruginosas de Pirapora do Bom Jesus-SP e Bacia Terciária de São Paulo

This paper discusses the genesis of folds in iron crust developed in Tertiary sediments of the Sao Paulo Basin (Sao Paulo-SP) and sediments in Proterozoic metasediments host rocks of the Sao Roque Group in Southeastern Brazil. Both iron crusts made up basically of iron hydroxides and present textural organization, similar chemical and mineralogical composition, although they are located in different rocks and geologic settings. They are constituted basically by iron hydroxides. Diverse diagram link the evolution of both sedimentary host-rocks and iron crusts composition, to a geochemical origin. These iron crusts were formed by remobilisation and concentration of iron oxides and hydroxides, originated by the descending meteoric water and groundwater level oscillation, related to seasonal climatic variations and uplift relief ascending movements. No correlation was observed between structural data for iron crust fold and tectonic fold or regional deformation patterns in host-rocks. This indicates that tectonic processes of folding where not directly involved in the origin of this folded iron crust. In addition, fractures in the Pirapora outcrop formed by neotectonic reactivation of regional lineaments, were the conduits for water flow, allowing iron oxides and hydroxides are to be precipitated. Oxides and hydroxides are precipitated obliquely to the fractures in the dransdown cone formed by the groundwater level down. The group formed by the deposition of this oxides and hydroxides in the dransdown cone show structures like folds delineates the pattern and feature of folded iron crusts observed in this outcrop.