Sources of sedimentary organic matter and assessment of heavy-metal levels in estuarine sediments after Fundão dam breach

2021 ◽  
pp. 107507
Author(s):  
J.P. Felizardo ◽  
M.C. Muniz ◽  
M. Vezzone ◽  
R.P. Cardoso ◽  
J. Wasserman ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Sedimentary Organic Matter ◽  
Estuarine Sediments ◽  
Dam Breach ◽  
Metal Levels

Background heavy metal levels in estuarine sediments and organisms in Galicia (northwest Spain) as determined by modal analysis

1995 ◽  
Vol 172 (2-3) ◽  
pp. 175-188 ◽  
Author(s):  
Emilio Carral ◽  
Xoán Puente ◽  
Rubén Villares ◽  
Alejo Carballeira
Keyword(s):  
Heavy Metal ◽  
Modal Analysis ◽  
Estuarine Sediments ◽  
Metal Levels

Molecular characteristics of sedimentary organic matter in controlling mercury (Hg) and elemental mercury (Hg0) distribution in tropical estuarine sediments

2019 ◽  
Vol 668 ◽  
pp. 592-601 ◽  
Author(s):  
Prasad P. Padalkar ◽  
Parthasarathi Chakraborty ◽  
Kartheek Chennuri ◽  
Saranya Jayachandran ◽  
Lamjahao Sitlhou ◽  
...  
Keyword(s):  
Organic Matter ◽  
Elemental Mercury ◽  
Sedimentary Organic Matter ◽  
Estuarine Sediments ◽  
Molecular Characteristics ◽  
Tropical Estuarine

scholarly journals Fractionation of heavy metals in yellow latosol cultivated with vegetables

2018 ◽  
Vol 39 (5) ◽  
pp. 1921
Author(s):  
Laércio Santos Silva ◽  
Izabel Cristina de Luna Galindo ◽  
Vinícius Augusto Filla ◽  
Romário Pimenta Gomes ◽  
Milton César Costa Campos ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Organic Matter ◽  
Heavy Metal Contamination ◽  
Soil Samples ◽  
Chemical Fractionation ◽  
Human Consumption ◽  
Native Forest ◽  
Metal Levels ◽  
Toxic Potential

Sequential extraction or chemical fractionation of heavy metals allows inferences to be made about their origin, occurrence, bioavailability, toxic potential and environmental contamination. Thus, the present study aimed to assess the distribution of Cu, Mn, Ni, Pb and Zn among the different soil fractions and landscape compartments of a yellow latosol cultivated with vegetables. Soil samples were collected from five areas cultivated with tomato (Lycopersicon esculentum, Mill.), lettuce (Lactuca sativa), chili pepper (Capsicum annuum L.) and chard (Beta vulgaris L.) in different slope positions (upper, middle, lower), and four reference areas (native forest), at a depth of 0.00 - 0.20 m. Heavy metal levels were also assessed in water used to irrigate the crops and for human consumption by collecting 200 ml of water samples from reservoirs. The soil samples were sequentially fractionated to quantify the concentrations of adsorbed Cu, Mn, Ni, Pb and Zn in the exchangeable (EF), organic matter (OF), amorphous and crystalline iron oxide fractions (AFeOx and CFeOx). Landscape position only interfered significantly in heavy metal adsorption in the soil for Cu and Ni associated with CFeOx and Zn bound to the EF in the farming areas. The highest Cu, Ni, Pb and Zn levels were found in the fractions with less stable chemical bonds (bound to organic matter), in addition to a strong affinity between Cu, Zn and Mn and the oxide fractions (AFeOx + CFeOx). The low affinity of Pb and Ni for the AFeOx and CFeOx fractions indicates greater contamination potential for the water reservoirs. In the short term, organic matter is the main source of remediation for heavy metal contamination in soil, making it important to adopt conservation practices aimed at reducing OM losses.

Influence of watershed lithology on heavy metal levels in estuarine sediments and organisms in Galicia (North-West Spain)

1995 ◽  
Vol 30 (9) ◽  
pp. 604-608 ◽  
Author(s):  
E. Carral ◽  
R. villares ◽  
X. Puente ◽  
A. Carballeira
Keyword(s):  
Heavy Metal ◽  
Estuarine Sediments ◽  
North West ◽  
Metal Levels

HEAVY METAL SPECIATION IN BOTTOM SEDIMENTS OF THE VYSHNEVOLOTSKY RESERVOIR

2018 ◽  
pp. 46-54
Author(s):  
O. A. Lipatnikova
Keyword(s):  
Heavy Metal ◽  
Organic Matter ◽  
Bottom Sediments ◽  
Metal Speciation ◽  
Organic Matter Content ◽  
Water Reservoir ◽  
Matter Content ◽  
Heavy Metal Speciation ◽  
Mobile Forms ◽  
Manganese Hydroxides

The study of heavy metal speciation in bottom sediments of the Vyshnevolotsky water reservoir is presented in this paper. Sequential selective procedure was used to determine the heavy metal speciation in bottom sediments and thermodynamic calculation — to determine ones in interstitial water. It has been shown that Mn are mainly presented in exchangeable and carbonate forms; for Fe, Zn, Pb и Co the forms are related to iron and manganese hydroxides is played an important role; and Cu and Ni are mainly associated with organic matter. In interstitial waters the main forms of heavy metal speciation are free ions for Zn, Ni, Co and Cd, carbonate complexes for Pb, fulvate complexes for Cu. Effects of particle size and organic matter content in sediments on distribution of mobile and potentially mobile forms of toxic elements have been revealed.

Chemical and Biological Changes in Nelson Lake, Ontario Following Experimental Elevation of Lake pH

1977 ◽  
Vol 12 (1) ◽  
pp. 213-232 ◽  
Author(s):  
N.D. Yan ◽  
W.A. Scheider ◽  
P.J. Dillon
Keyword(s):  
Heavy Metal ◽  
Lake Ontario ◽  
Background Concentrations ◽  
Precambrian Shield ◽  
Metal Levels ◽  
Zooplankton Communities ◽  
Shield Lakes

Abstract Intensive studies of Nelson Lake, a Sudbury area lake of intermediate pH ~5.7), were begun in 1975. The chemistry of the lake was typical of that of most PreCambrian Shield lakes except that low alkalinities and high sulphate concentrations were observed along with elevated heavy metal levels. After raising the pH of Nelson Lake to 6.4 by addition of Ca(OH)2 and CaCO3, the metals were reduced to background concentrations. Phytoplankton and Zooplankton communities, which at pH of 5.7 were typical of PreCambrian lakes, were not affected by the experimental elevation of lake pH.

Oxidative Stress and Heavy Metal Levels of Pholiota limonella Mushroom Collected from Different Regions

2018 ◽  
Vol 12 (2) ◽  
pp. 169-172 ◽  
Author(s):  
Mustafa Sevindik ◽  
Hasan Akgul ◽  
Celal Bal ◽  
Deniz Altuntas ◽  
Ali Imran Korkmaz ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heavy Metal ◽  
Metal Levels

scholarly journals Benthic fluxes of dissolved organic nitrogen in the lower St. Lawrence estuary and implications for selective organic matter degradation

2013 ◽  
Vol 10 (11) ◽  
pp. 7609-7622 ◽  
Author(s):  
M. Alkhatib ◽  
P. A. del Giorgio ◽  
Y. Gelinas ◽  
M. F. Lehmann
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Nitrogen ◽  
Organic Nitrogen ◽  
Bottom Water ◽  
Estuarine Sediments ◽  
Internal Source ◽  
Lawrence Estuary ◽  
Element Partitioning ◽  
Sediment Porewaters ◽  
St Lawrence Estuary

Abstract. The distribution of dissolved organic nitrogen (DON) and carbon (DOC) in sediment porewaters was determined at nine locations along the St. Lawrence estuary and in the gulf of St. Lawrence. In a previous manuscript (Alkhatib et al., 2012a), we have shown that this study area is characterized by gradients in the sedimentary particulate organic matter (POM) reactivity, bottom water oxygen concentrations, and benthic respiration rates. Based on the porewater profiles, we estimated the benthic diffusive fluxes of DON and DOC in the same area. Our results show that DON fluxed out of the sediments at significant rates (110 to 430 μmol m−2 d−1). DON fluxes were positively correlated with sedimentary POM reactivity and varied inversely with sediment oxygen exposure time (OET), suggesting direct links between POM quality, aerobic remineralization and the release of DON to the water column. DON fluxes were on the order of 30 to 64% of the total benthic inorganic fixed N loss due to denitrification, and often exceeded the diffusive nitrate fluxes into the sediments. Hence they represented a large fraction of the total benthic N exchange, a result that is particularly important in light of the fact that DON fluxes are usually not accounted for in estuarine and coastal zone nutrient budgets. In contrast to DON, DOC fluxes out of the sediments did not show any significant spatial variation along the Laurentian Channel (LC) between the estuary and the gulf (2100 ± 100 μmol m−2 d−1). The molar C / N ratio of dissolved organic matter (DOM) in porewater and the overlying bottom water varied significantly along the transect, with lowest C / N in the lower estuary (5–6) and highest C / N (> 10) in the gulf. Large differences between the C / N ratios of porewater DOM and POM are mainly attributed to a combination of selective POM hydrolysis and elemental fractionation during subsequent DOM mineralization, but selective adsorption of DOM to mineral phases could not be excluded as a potential C / N fractionating process. The extent of this C- versus N- element partitioning seems to be linked to POM reactivity and redox conditions in the sediment porewaters. Our results thus highlight the variable effects selective organic matter (OM) preservation can have on bulk sedimentary C / N ratios, decoupling the primary source C / N signatures from those in sedimentary paleoenvironmental archives. Our study further underscores that the role of estuarine sediments as efficient sinks of bioavailable nitrogen is strongly influenced by the release of DON during early diagenetic reactions, and that DON fluxes from continental margin sediments represent an important internal source of N to the ocean.

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