Characterization of the Ceara Costal Zone Organic Matter Inputs

International audienceMangroves are extremely sensitive to the global climate change and urbanization impacts. To understand the effect of the urbanization on the organic matter of the coastal zone of Ceará State in north eastern Brazil, a seasonal filed campaigns were carried on in two most environmentally significant river/mangrove systems in the region; the Cocó river, in the metropolitan region of the huge city of Fortaleza, and the Pacoti River, an environmental protection area, without urban influence, on the east coast of the state. A spatial study was also done along the Jaguaribe river, which is the largest river in the state also connected to the largest mangrove area. Organic matter characterization by dissolved organic carbon, spectrofluorescence and fluorescence quenching and metal complexation capacity shows clearly that under urban pressure, the produced organic matter in mangrove area is different, meaning that carbon budget and pollutant fate have to be revised to take in account this difference

Accumulation of heavy metals in sediments of the Parnaíba river delta

This study was carried out to assess the impacts of heavy metals coming into the Parnaíba River Delta in the Brazilian Northeastern region. The sediment concentrations of different heavy metals, such as Pb, Ni, Cr, Cd, Zn, Cu, Fe, Al and Mn, were measured by flame spectrometry. The sediments were collected from 19 sites distributed along 5 estuarine channels. The average concentrations found for Cu and Zn are compatible with the TEL (Threshold Effect Level). However, Cd concentrations were above the PEL (Probable Effect Level) values, while Ni and Cr showed intermediate mean concentrations. There are no established concentration limits for Mn, Al and Fe. These are the first metal biogeochemistry findings in the area and will contribute to the decision-making of environmental authorities, aiming to control the emissions of metallic pollutants in this important area of the Brazilian coast.Centro de Investigaciones Geológica

Accumulation of heavy metals in sediments of the Parnaíba river delta

This study was carried out to assess the impacts of heavy metals coming into the Parnaíba River Delta in the Brazilian Northeastern region. The sediment concentrations of different heavy metals, such as Pb, Ni, Cr, Cd, Zn, Cu, Fe, Al and Mn, were measured by flame spectrometry. The sediments were collected from 19 sites distributed along 5 estuarine channels. The average concentrations found for Cu and Zn are compatible with the TEL (Threshold Effect Level). However, Cd concentrations were above the PEL (Probable Effect Level) values, while Ni and Cr showed intermediate mean concentrations. There are no established concentration limits for Mn, Al and Fe. These are the first metal biogeochemistry findings in the area and will contribute to the decision-making of environmental authorities, aiming to control the emissions of metallic pollutants in this important area of the Brazilian coast.Centro de Investigaciones Geológica

Accumulation of heavy metals in sediments of the Parnaíba river delta

This study was carried out to assess the impacts of heavy metals coming into the Parnaíba River Delta in the Brazilian Northeastern region. The sediment concentrations of different heavy metals, such as Pb, Ni, Cr, Cd, Zn, Cu, Fe, Al and Mn, were measured by flame spectrometry. The sediments were collected from 19 sites distributed along 5 estuarine channels. The average concentrations found for Cu and Zn are compatible with the TEL (Threshold Effect Level). However, Cd concentrations were above the PEL (Probable Effect Level) values, while Ni and Cr showed intermediate mean concentrations. There are no established concentration limits for Mn, Al and Fe. These are the first metal biogeochemistry findings in the area and will contribute to the decision-making of environmental authorities, aiming to control the emissions of metallic pollutants in this important area of the Brazilian coast.Centro de Investigaciones Geológica

Spectroscopic analysis of sediments from a tropical estuary in the Brazilian Northeast

The purpose of this work is to characterize the geochemical composition of sediments of the Parnaíba River delta, in terms of trace metal concentrations, using spectroscopic techniques. A profile sampling campaign was carried out in April 2017. The granulometric analysis of the surface sediments showed that the silt + clay fraction added up to 14.31% of the total. The mean concentrations of heavy metals in the profiles were 1.78 mg.kg-1 for Cd; 10.57 mg.kg-1 for Cr; 11.85 mg.kg-1 for Cu; 24.42 mg.kg-1 for Ni; 47.90 mg.kg-1 for Zn; 152.45 mg.kg-1 for Pb; 1887.28 mg.kg-1 for Mn; 1.12% for Al and 3.49% for Fe. Scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) applied to the sediments from the coast of Ceará showed the morphological diversity of sediment grains. The infrared spectra presented similar functional groups at all tested points, demonstrating that the clay minerals in the different samples probably have the same origin.Centro de Investigaciones Geológica

Spectroscopic analysis of sediments from a tropical estuary in the Brazilian Northeast

The purpose of this work is to characterize the geochemical composition of sediments of the Parnaíba River delta, in terms of trace metal concentrations, using spectroscopic techniques. A profile sampling campaign was carried out in April 2017. The granulometric analysis of the surface sediments showed that the silt + clay fraction added up to 14.31% of the total. The mean concentrations of heavy metals in the profiles were 1.78 mg.kg-1 for Cd; 10.57 mg.kg-1 for Cr; 11.85 mg.kg-1 for Cu; 24.42 mg.kg-1 for Ni; 47.90 mg.kg-1 for Zn; 152.45 mg.kg-1 for Pb; 1887.28 mg.kg-1 for Mn; 1.12% for Al and 3.49% for Fe. Scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) applied to the sediments from the coast of Ceará showed the morphological diversity of sediment grains. The infrared spectra presented similar functional groups at all tested points, demonstrating that the clay minerals in the different samples probably have the same origin.Centro de Investigaciones Geológica

Spectroscopic analysis of sediments from a tropical estuary in the Brazilian Northeast

The purpose of this work is to characterize the geochemical composition of sediments of the Parnaíba River delta, in terms of trace metal concentrations, using spectroscopic techniques. A profile sampling campaign was carried out in April 2017. The granulometric analysis of the surface sediments showed that the silt + clay fraction added up to 14.31% of the total. The mean concentrations of heavy metals in the profiles were 1.78 mg.kg-1 for Cd; 10.57 mg.kg-1 for Cr; 11.85 mg.kg-1 for Cu; 24.42 mg.kg-1 for Ni; 47.90 mg.kg-1 for Zn; 152.45 mg.kg-1 for Pb; 1887.28 mg.kg-1 for Mn; 1.12% for Al and 3.49% for Fe. Scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) applied to the sediments from the coast of Ceará showed the morphological diversity of sediment grains. The infrared spectra presented similar functional groups at all tested points, demonstrating that the clay minerals in the different samples probably have the same origin.Centro de Investigaciones Geológica

Produção científica da área da Química no desenvolvimento da oceanografia no Brasil

This paper analyses the scientific contribution of chemists and of the Brazilian Chemical Society (SBQ) and its publications to the development of Oceanography in Brazil, as well as major drivers of this participation. A total of 528 articles were analyzed. Most articles (72%) originated in research groups not associated with graduate programs in oceanography. Nearly 50% dealt with the contamination of the marine environment, followed by chemical process studies (32%) and analytical methods development (15%). SBQ journals contributed with 78 articles (14.7% of the total), and rank 1st (QN) and 2nd (JBCS) among scientific journals publishing the analyzed articles

Non-conservative behavior of organic matter and its interaction with metals in an equatorial estuary, Brazil

International audienceDroughts are becoming more intense and frequent in the Brazilian semiarid because of El Niño and global climate changes.The Jaguaribe River estuary is a semiarid ecosystem that experiences a reduction in freshwater discharges due to droughts andriver damming. The decrease in freshwater fluxes has increased metal availability through the water residence time increasein the Jaguaribe River estuary. Then, this study aimed to evaluate the dissolved organic matter quality and its interaction withmetals in the Jaguaribe River estuary after a severe drought period. It was performed through carbon analyses, fluorescencespectroscopy, ultrafiltration technique, and determinations of metals by ICP-MS. Optical analysis showed that the dissolvedorganic carbon (DOC) was preponderantly composed of terrestrial-derived humic compounds, while the low ratio betweenthe particulate organic carbon (POC) and chlorophyll-a indicated that POC was predominantly phytoplankton-derived.DOC and POC presented non-conservative removal during the estuarine mixing. DOM and dissolved elements were mostlydistributed within the LMW fraction and presented a low percentage in the colloidal fraction. Li, Rb, Sr, Mo, and U showedconservative behavior, while Cu, Fe, Cr, and V had non-conservative behavior with a significant positive correlation withDOM, suggesting DOM as a relevant driver of metal availability at the Jaguaribe River estuary even during the rainy season