The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
This chapter presents carbon isotope data of soil organic matter (SOM), collected in natural forest ecosystems in different sites from Brazil. The studied areas are located in Londrina (Southern part of the country), Piracicaba (Southeast), Salitre (Central) and Altamira (Northern). This study is part of the research program on tropical and sub-tropical soils in Brazil, of which the main objective...
Differences in 137Cs soil-to-plant transfer for two types of soils under tropical climatic conditions are discussed with reference to pedology and geochemical partitioning. Using acid oxisol soils with low exchangeable K contents, transfer factor (Tf) values ranged from 0.18 to 0.41 for black beans. Basic oxisol with normal exchangeable K contents presented lower Tf values: 0.06 to 0.11. These values...
The quality of groundwater, as well as surface waters, is of primary concern in waste and tailings disposal technology. However, due to natural processes at the disposal site, dissolution and mobilization of toxic compounds may occur. In this case, the sorption phenomena in soils play a key role, which determines the transport of toxic compounds to receiving waters, and consequently their fate. This...
Two basic aspects recently accepted in the understanding of water composition and soil evolution are dissolution/precipitation kinetics and how open are natural systems are to the passage of fluid. In the light of these two aspects a new generation of geochemical models of coupled chemical reactions and solute transport has been developed. An equilibrium condition is not assumed a priori in these...
Spatial distribution, biomass, production and phenological data were obtained for two natural populations of the cat-tail Typha dominguensis in Lagoa de Maricá, a shallow sub-tropical lagoon. The area covered by T. dominguensis was estimated by satellite imagery and aerial photography. The values obtained by the two methods are concordant and close to 13 % of total wetland area. For both sites, plant...
This chapter describes possibilities of using instrumental multi-element methods to answer various ecological questions. Emphasis is placed on the ecosystem-related approach and thus on comparison of various ecosystems and their compartments. The basis for this is a project by the International Union of Biological Sciences (IUBS) aimed at establishing “element concentration catalogues in ecosystems”...
This chapter reports a thorough study of the geochemistry of some metals in the sediments of the Patos lagoon, one of the biggest coastal lagoons in the world (and the biggest in Brazil). After a screening study of the sediments, which considered the granulometry, organic carbon, organic nitrogen and sulphur contents, Pb, Cu, Zn and Cr concentrations of more than 100 samples collected all over the...
The Camaquã Copper Mines were closed in 1996 after more than one century of active exploitation. The mines are located in the basin of João Dias creek in the upper course of the Camaquã River, Rio Grande do Sul State, Southern Brazil. The mine-generated effluents enriched in heavy metals were released into the João Dias creek. Both anthropogenic and natural inputs of heavy metals were mixed and added...
Geochemical partitioning of Zn, Cu, Fe and Mn was determined in the coastal marine sediments of Mar de Plata (Argentina), to assess the degree of contamination and the metal chemistry. The sequential extractions were tested to be included in monitoring programmes of the coastal environments. Five sediment samples were collected in the coastal area near to the city of Mar del Plata and analysed for...
Different areas from the Todos os Santos Bay were monitored and the fate of heavy metals in these environments was determined. From 1982 to 1992, a significant worsening in the availability of heavy metals in the different sites of the Bay was observed. However, it must be emphasised that the comparison between the present results and those obtained from other works rests on a gap of at least three...
The retention of terrigenous metals in coastal regions plays an important role in the oceanic global mass balance of these elements. In Sepetiba Bay (Rio de Janeiro), efficient Cd and Zn removal from the water column was observed due to processes influenced by sediment resuspension and deposition. These mechanisms involve adsorption onto particle surfaces, which is independent of matrix composition...
The geochemical behaviour of mercury in sediments of the São João de Meriti system (Guanabara bay watershed, Rio de Janeiro, Brazil) was studied. Total concentrations of mercury were compared to sediment contents of clay-silt, organic/inorganic carbon, total hydrolyzable amino acids (THAA) and specific amino acids, total sulphur and iron. A sequential extraction was also used to clear up some questions...
Since 1985 the annual gold production in Colombia has been fluctuating between 30 and 35 tons (1–1.4 million ounces troy). Exploitation plants can be found in vein and placer gold deposits. During 1992 a preliminary study was undertaken, resulting in a diagnosis of problems in small scale mining in 6 gold areas (vein type) of Colombia. In order to evaluate the general impact caused to the environment...
Gold has been exploited in the Poconé regions, in Mato Grosso state in Brazil, during the past 13 years using garimpo methods. In this study, background levels of metals were determined by analysing sediments and soils unaffected by mining activities, located upstream of the anthropogenic inputs. The study done in Poconé focuses on Hg, Cu, Pb, Zn, Fe and Mn. In addition, the study aims to evaluate...
The Carson River system of west-central Nevada was subjected to a massive influx of mercury-enriched tailings derived from mining and milling of the Comstock Lode near the end of the 1800s. Detailed investigations have shown that these contaminated tailings were deposited along the Carson River Valley during a period of channel and floodplain aggradation. Following cessation of mining, incision re-exposed...
Groundwater quality and aquifer hydrogeochemistry were investigated in a suburban area of the city of Niteroi where domestic water supply is mainly from this source. Samples of water from deep wells, shallow wells and springs were analysed for parameters indicative of aquifer geology and hydrology: conductivity, alkalinity, HCO3−, Cl−, Na, Fe, silica, Ca, Mg, K and Mn, and those indicative...
This chapter presents a characterization of atmospheric aerosols collected in different places in the Amazon Basin. Both the biogenic aerosol emission from the forest and the particulate material which is emitted to the atmosphere due to the large scale man-made burns during the dry season were studied. The samples were collected during a three year period at three different locations in the Amazon...
Even when an estuary is at steady state, it shows the typical features of a sink for contaminants, although input from rivers into the estuary may result in equal output from the estuary to the sea, thus in such estuaries accumulation of material is practically insignificant. The essential properties which determine the processes and transfer of contaminants to particulate matter are the chemical...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.