Effects of dredging operations on sediment quality: contaminant mobilization in dredged sediments from the Port of Santos, SP, Brazil

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

EVALUATION of HEAVY METAL AVAILABILITY IN CONTAMINATED SEDIMENTS FROM THE ILHA SOLTEIRA HYDROELECTRIC DAM on THE PARANA RIVER AT ILHA SOLTEIRA, SP, BRAZIL

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

Phosphate distribution in the sediments along a cascade of reservoirs - (Paranapanema River, SE, Brazil)

Total phosphorus concentrations in the sediment of a cascade of 8 reservoirs located in the Paranapanema River (SE, Brazil) were analysed during two consecutive seasonal periods (2000 and 200 1). The reservoirs of Jurumirim, Chavantes, Salto Grande, Canoas 11, Canoas 1, Capivara, Taquarucu and Rosana were built during the last five decades with the purpose of hydroelectric generation. The sampling points were distributed along a 700 km of river stretch in 19 stations distributed in the river-reservoirs zones and main tributaries as well as in 5 stations representing the adjacent wetlands. The nutrient concentration was determined in samples from surface layers of sediment. Temporal and spatial changes were observed for both years. Three different areas could be identified along the river, considering not only Tot-P variations but also others physical and chemical characteristics such as organic matter concentration, nitrogen concentration of sediment and 02, pH, conductivity and Eh measured in the bottom layer of the water column. Higher values of Tot-P were found in the middle and lower region of the Paranapanema basin (maximum value of 1.96 mg g(-1) in Tibagi River in October/2001). Agricultural practices and cattle raising are the main external sources of nutrient in these regions. Superficial or sub-superficial watershed drainage and tributaries entrances are important nutrient contributors, leading to an increasing accumulation of nutrient in the sediment. This process seems to be especially important in the middle region of the Paranapanema Valley, were the values of Tot-P were higher comparing to the other areas.

Speciation of butyltin derivatives in surface sediments of three southern Brazilian harbors

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Distribution profile and availability of Cr, Ni, Cu, Cd and Pb in different sediments from anhumas surface water collection reservoir, Araraquara-São Paulo State, Brazil

In this work the influence of the anhtropogenic activities in the uptake of metals at a reservoir for public water supply in Araraquara City, São Paulo State, Brazil was studied. For this, the distribution of Cr, Ni, Cu, Cd and Pb in sediments collected from Anhumas reservoir, at seven sampling points and at three depths for each point was investigated. The pseudo-total and available metals contained in the different sediment samples were assessed using an ICP-AES technique. Among the five metals studied, cadmium possesses the largest relative potential availability, with percentages of 20 to 98% for the three different sediment types. In addition, the following decreasing availability order was characterized: Cd > Cu > Pb > Ni > Cr.

Determination of butyltin compounds in surface sediments from the São Paulo State coast (Brazil) by gas chromatography-pulsed flame photometric detection

Occurrence and the effects of butyltin compounds (BTs) have been studied for some years, mainly in countries of the Northern Hemisphere. Due to widespread use of tributyltin compounds (TBTs) and considering their deleterious effects, it is necessary to conduct studies on its occurrence, especially in the marine environment because of its excessive use in coatings of ship hulls to prevent fouling. Moreover, it was important to extend the evaluation to areas where there is no current information about their occurrence. The present work reports the occurrence of BTs in marine sediments of São Paulo state, Brazil. Commercial and leisure harbor sampling sites were selected because these areas are potentially exposed to BTs from antifouling paints used on ship hulls. Analytical conditions for organotin analysis in marine sediments were optimized for GC with pulsed flame photometric detection. Detection limits ranged from 8.4 to 66.3 ng g(-1) using a 610-nm filter, and the linearity range was 20-500 ng g(-1). Concentration levels of BTs were highest in Santos harbor (360 ng g(-1) TBT in average) and Guaruja marina (670 ng g(-1) TBT in average), which seems to be related to intensive boat traffic. Lower levels of BTs were observed in Cananeia, where only fishing boats are present (50 ng g(-1) TBT in average). (C) 2002 Elsevier B.V. B.V. All rights reserved.

Fecal Sterols in Estuarine Sediments as Markers of Sewage Contamination in the Cubatao Area, São Paulo, Brazil

Sterol biomarkers serve as an alternative method for detecting sewage pollution. Sterols were extracted from samples of surface sediment collected in Cubato (the Vila dos Pescadores and Vila Esperan double dagger a communities) and quantified using GC-MS after Soxhlet extraction, cleanup, and derivatization. Fecal contamination was evaluated based on the concentration of coprostanol and the ratio of the selected sterols. The most abundant sterol was cholestanol, followed by coprostanol. The concentrations of coprostanol in surface sediments ranged from a minimum of 4.21 mu g g(-1) dry sediment (Vila dos Pescadores station) to a maximum of 8.32 mu g g(-1) dry sediment (Vila Esperan double dagger a station). A coprostanol concentration of about 10 mu g g(-1) was found, indicating areas of high sewage contamination. Coprostanol levels at sewage stations were higher than in other Brazilian coastal areas, which may be attributed to the fraction of the population without sanitation services.

Lipid biomarkers in surface sediments from an unusual coastal upwelling area from the SW Atlantic Ocean

The coastal upwelling off Cabo Frio (SE Brazilian coast, SEBC) represents an exception to the world`s oceans since the majority of the upwelling areas are located in eastern boundary current systems. Cabo Frio represents an interesting area for investigation due to its tight physical-biological interaction and the importance of the region as a major fishery area in the SEBC. We analyzed a suite of lipid biomarkers to apportion the main sources of organic matter in surface sediments of the continental shelf off Cabo Frio, comparing the area to non-upwelling regions off the SEBC (shelf break off Cabo Frio and continental shelf off Ubatuba). During spring and summer (the upwelling period), diatoms are probably the major sources of polyunsaturated fatty acids (PUFAs) and C-28 sterols in surface sediments from Cabo Frio continental shelf. Sediments sampled in winter showed, in contrast, lower relative abundance of PUFAs and higher stanol/stenol ratio values. In deeper regions off Cabo Frio, elevated concentrations of alkenones, 24-methylcholest-5,22E-dien-3 beta-ol and 24-ethylcholest-5-en-3 beta-ol during the spring may be produced by prymnesiophytes or cryptophytes and cyanobacteria, respectively. In Ubatuba, the C-27 and C-28 sterols are likely derived from omnivorous salps and nanoflagellates. At non-upwelling areas, despite the increase in biomarker concentrations during spring and summer, lower concentrations of PUFAs, phytol and algal sterols than in shelf areas off Cabo Frio suggest the importance of the upwelling system to the rapid transfer of organic carbon to surface sediments. Our results suggest that spatial and temporal variability in organic matter production and deposition merits consideration for constraining the carbon budgets in the coastal region off Cabo Frio. (C) 2008 Elsevier Ltd. All rights reserved.

Distribution of sewage input in marine sediments around a maritime Antarctic research station indicated by molecular geochemical indicators

Sediments from Admiralty Bay, Antarctica were collected during the austral summers of 2002/2003 and 2003/2004 in order to assess the distribution and concentration of sewage indicators originating from Comandante Ferraz Brazilian Antarctic Station. Fecal sterols (coprostanol + epicoprostanol) and linear alkylbenzenes (LABs) ranged from <0.01 to 0.95 mu g g(-1) and <1.0 to 23 ng g(-1) dry weight, respectively. In general, the higher concentrations were found only locally in the vicinity of Ferraz station at Martel Inlet. Baseline values for fecal sterols and coprostanone were calculated as 0.19 and 0.40 mu g g(-1), respectively. According to fecal sterols concentrations, sewage contribution to Martel Inlet has increased more than twice since 1997, as result of the increase in the number of researchers at the station especially during the last decade. A low correlation was found between total LABs and fecal steroids, which could be attributed to the contribution of the natural sources of steroids. (C) 2010 Elsevier B.V. All rights reserved.

Speciation of butyltin derivatives in surface sediments of three southern Brazilian harbors

For the first time, organotin compounds were determined in surface sediment samples collected from Sao Francisco do Sul, Itajai-Navegantes and Imbituba Harbors, located in Santa Catarina State, Brazil. Butyltins (BTs) were determined by gas chromatography with a pulsed flame photometric detector (GC-PFPD) after being modified using the Grignard derivatization method. The concentrations of BTs derivatives ranged from n.d. to 1136.6 ng (Sn) g(-1) of dry weight (dw) sediment for tributyltin (TOT), n.d. to 394.4 ng (Sn)g(-1) dw for dibutyltin (DOT) and n.d. to 312.2 ng (Sn)g(-1) dw for monobutyltin (MBT). The highest concentration of total BTs was found at the Itajai-Acu River dockyard, indicating intense inputs of antifouling paints to the environment. The relative difference in the BTs levels is a particular characteristic of sediments from harbors and may be related to the shipyards and the boat traffic which still use TBT-based antifouling paints.

LEAD DISTRIBUTION AND ISOTOPE SIGNATURE IN BOTTOM SEDIMENTS OF GUAMA RIVER AND GUAJARA BAY (BELEM - PARA)

LEAD DISTRIBUTION AND ISOTOPE SIGNATURE IN BOTTOM SEDIMENTS OF GUAMA RIVER AND GUAJARA BAY (BELEM - PARA). Lead analyses in bottom sediments from the hydrographic system of Belem (Para) indicated low contents of this metal for the sediments from the Guama river, with no significant anthropogenic contribution. A concentration of 18.1 +/- 1.5 mg kg(-1) and Pb-206/Pb-207 isotopic signature of 1.196 +/- 0.002 are assigned for Pb from natural sources. On the other hand, the significant increase of Pb contents in the sediments from the Guajara bay, together with the decrease of Pb-206/Pb-207 ratios (1.172 < Pb-206/Pb-207 < 1.188) point to an anthropogenic lead contribution, originated by the industrial and urban activities of the city of Belem.

A 2400-year record of trace metal loading in lake sediments of Lagoa Vermelha, southeastern Brazil

Sediments of the Lagoa Vermelha (Red Lake), situated in the Ribeira Valley, southeastern Brazil, are made of a homogeneous, organic-rich, black clay with no visible sedimentary structures. The inorganic geochemical record (Al, As, Ba, Br, Co,Cs, Cr, Fe, Mn, Ni, Rb, Sc, Sb, V, Zn, Hg and Pb) of the lake sediments was analyzed in a core spanning 2430 years. The largest temporal changes in trace metal contents occurred approximately within the last 180 years. Recent sediments were found to be enriched in Pb, Zn, Hg, Ni, Mn, Br and Sb (more than 2-fold increase with respect to the "natural background level"). The enhanced accumulation of Br, Sb, and Mn was attributed to biogeochemical processes and diagenesis. On the other hand, the anomalous concentrations of Pb, Zn, Hg and Ni were attributed to pollution. As Lagoa Vermelha is located in a relatively pristine area, far removed from direct contamination sources, the increased metal contents of surface sediments most likely resulted from atmospheric fallout. Stable Pb isotopes provided additional evidence for anthropogenic contamination. The shift of Pb-206/Pb-207 ratios toward decreasing values in the increasingly younger sediments is consistent with an increasing contribution of airborne anthropogenic lead. In the uppermost sediments (0-10 cm), the lowest values of the Pb-206/Pb-207 ratios may reflect the influence of the less radiogenic Pb from the Ribeira Valley District ores (Pb-206/Pb-207 between 1.04 and 1.10), emitted during the last 50 years. (C) 2011 Elsevier Ltd. All rights reserved.

Prismatic magnetite magnetosomes from cultivated Magnetovibrio blakemorei strain MV-1: a magnetic fingerprint in marine sediments?

The magnetic properties (first-order reversal curves, ferromagnetic resonance and decomposition of saturation remanent magnetization acquisition) of Magnetovibrio blakemorei, a cultivated marine magnetotactic bacterium, differ from those of other magnetotactic species from sediments deposited in lakes and marine habitats previously studied. This finding suggests that magnetite produced by some magnetotactic bacteria retains magnetic properties in relation to the crystallographic structure of the magnetic phase produced and thus might represent a magnetic fingerprint for a specific magnetotactic bacterium. The use of this fingerprint is a non-destructive, new technology that might allow for the identification and presence of specific species or types of magnetotactic bacteria in certain environments such as sediments.

Heavy metal distribution in recent sediments along the Tiete River basin (Sao Pauro, Brazil)

The distribution of heavy metals in recent sediments deposited along the Tiete River, a highly polluted river in southeast region of Brazil was studied. Around the metropolitan area of Silo Paulo city (25 million people), the pollution is related to municipal wastes and industrial effluents with reinforced downstream by agricultural activities. The observed increase of heavy metal concentrations is particularly important for Zn in the upper basin and Cu, Co and Cr at mouth. Geo-accumulation index calculation, related to the regional background, showed that the sediments along the basin are seriously polluted by heavy metals of anthropogenic origin, mainly Cu, Co, Cr and Zn. Calculated index suggests medium to very strongly pollution.