João Graciano Mendonça Filho

Polycyclic aromatic hydrocarbons (PAHs) in burning and non-burning coal waste piles

The coal waste material that results from Douro Coalfield exploitation was analyzed by gas chromatography with mass spectrometry (GC-MS) for the identification and quantification of the 16 polycyclic aromatic hydrocarbons (PAHs), defined as priority pollutants. It is expected that the organic fraction of the coal waste material contains PAHs from petrogenic origin, and also from pyrolytic origin in burning coal waste piles. The results demonstrate some similarity in the studied samples, being phenanthrene the most abundant PAH followed by fluoranthene and pyrene. A petrogenic contribution of PAHs in unburned samples and a mixture of PAHs from petrogenic and pyrolytic sources in the burning/burnt samples were identified. The lowest values of the sum of the 16 priority PAHs found in burning/burnt samples and the depletion LMW PAHs and greater abundance of HMW PAHs from the unburned coal waste material relatively to the burning/burnt material demonstrate the thermal transformation attributed to the burning process. The potential environmental impact associated with the coal waste piles are related with the release of petrogenic and pyrolytic PAHs in particulate and gaseous forms to soils, sediments, groundwater, surface water, and biodiversity.

Organic Facies: Palynofacies and Organic Geochemistry Approaches

The concept of organic facies, as well as the definitions and means of the different facies became a very important tool to palaeoenvironmental characterization, basin analysis and fossil fuel exploration. The application of this concept is the best way to integrate microscopy and geochemical techniques to study kerogen contained in sedimentary rocks. Thus, palynofacies analysis and bulk geochemical methods (organic facies) are used to characterize the sedimentary organic matter (kerogen and bitumen). Palynofacies analysis involves the integrated study of all aspects of the kerogen assemblage: identification of the individual particulate components, assessment of their absolute and relative proportions and preservation states. The correlation between palynofacies and geochemical data provides the organic facies models that point out the depositional environmental conditions and hydrocarbon source rock potential.

Early diagenesis and clay mineral adsorption as driving factors of metal pollution in sediments: the case of Aveiro Lagoon (Portugal)

This work aims to define the factors driving the accumulation of metals in the sediment of the lagoon of Aveiro (Portugal). The role of initial diagenetic processes in controlling trace metal retention in surface sediment is traced by mineralogy, magnetic susceptibility and geochemical analyses. Although several studies have focused on the metal distribution in this polihaline and anthropized coastal lagoon, most of them have been solely focused on the total metal concentrations. This study instead represents the first attempt to evaluate in a vast area of the Aveiro Lagoon the role of biogeochemical processes in metal availability and distribution in three extracted phases: exchangeable cations adsorbed by clay and elements co-precipitated with carbonates (S1), organic matter (S2) and amorphous Mn hydroxides (S3). According to the sediment guideline values, the sediment is polluted by, for instance, As and Hg in the inner area of the Murtosa Channel, Pb in the Espinheiro Channel, Aveiro City canals and Aveiro Harbour, and Zn in the northern area of the Ovar Channel. These sites are located near the source areas of pollutants and have the highest total available concentrations in each extracted phase. The total available concentrations of all toxic metals are however associated, firstly, with the production of amorphous Mn hydroxides in most of the areas and, secondly, with adsorption by organic compounds. The interplay of the different processes implies that not all of the sites near pollution sources have polluted surface sediment. The accumulation of metals depends on not only the pollution source but also the changing in the redox state of the sediments that may cause alterations in the sediment retention or releasing of redox-sensitive metals. Results of this work suggest that the biogeochemical processes may play a significant role in the increase of the pollutants in the sediment of the Aveiro Lagoon.

Geomicrobiology of cores from Suruí Mangrove - Guanabara Bay - Brazil

The aim of this work was to quantify the biopolymers associated to esterase enzymes and identify bacterial respiratory activity in four cores collected in Suruí Mangrove, Guanabara Bay - RJ. Biopolymer concentration was 1000 times lower than previously reported in the literature, indicating the need for creating and establishing eutrophication indicative rates and records compatible with tropical coastal systems. The biochemical representative relationships in the cores were equivalent to those from studies on coastal marine environments made in the Northern Hemisphere. The esterase enzymes in the sediment proved efficient in the mineralization of biopolymers, even with preferentially anaerobic metabolic physiology. Despite the lack of incipient geomicrobiological studies, the results highlighted the possible application of microbiology to a better understanding of geological processes.

Biochemical Composition and Foraminiferal Content of Sediments for Determining Bottom Sector Environments in Guanabara Bay (Rio de Janeiro, Brazil)

ABSTRACT Clemente, I.M.M.M.; da Silva, F.S.; Laut, L.L.M.; Frontalini, F.; da Costa, V.L.; da Conceição Rodrigues, M.A.; Pereira, E.; Bergamaschi, S.; Filho, J.G.M., and Martins, M.V.A., 2015. Biochemical composition and foraminiferal content of sediments for determining bottom sector environments in Guanabara Bay (Rio de Janeiro, Brazil). Three cities in Brazil—Rio de Janeiro, Niterói, and São Gonçalo—with an estimated total population of 11 million people, are located in the surroundings of Guanabara Bay (RJ-Brazil), making it a highly contaminated coastal system. Because of its importance, Guanabara Bay has been one of the most studied coastal environments in Brazil. Despite that, this study represents the first investigation, to our knowledge, to couple benthic foraminifera with the quantity and quality of organic matter in the area. The spatial distribution of water salinity and the surface sediment reduction potential, grain size, total organic carbon, sulfur, bacterial organic carbon, biopolymers such as carbohydrates, proteins, lipids, bacterial enzyme esterase, and total foraminiferal assemblages were studied at 30 stations in Guanabara Bay. Based on these data, six bottom environments—industrial, marginal urban, marginal urban/industrial mixing, eutrophic, transitional, and outer— were identified and described.

Polycyclic aromatic hydrocarbons in sediments from Rodrigo de Freitas Lagoon in the urban area of Rio de Janeiro, Brasil

Regular (non-alkylated) polycyclic aromatic hydrocarbons (PAHs) and their alkylated homologues were determined in sediments from Rodrigo de Freitas Lagoon using gas chromatography with mass selective detector (GC-MSD). Concentrations varying from 405 to 11734 ng·g−1 were found for total PAHs (regular and alkylated homologues). The study showed a pyrogenic and petrogenic contribution, probably due to the incomplete burning of fossil fuels as a result of the intense traffic of boats and motor vehicles added to the anthropogenic activity of several gas stations present in the region of Rodrigo de Freitas Lagoon. According to the National Oceanic and Atmospheric Administration (NOAA) Sediment Quality Guide, PAHs concentration should not exceed 4000 ng·g−1 (Long et al., 1995) The obtained data present values above the NOAA limit for some sampling points indicating chronic contamination of those sites probably due to anthropogenic activities related to petroleum and its derivatives.

Cyanobacterial Diversity in Microbial Mats from the Hypersaline Lagoon System of Araruama, Brazil: An In-depth Polyphasic Study

Microbial mats are complex, micro-scale ecosystems that can be found in a wide range of environments. In the top layer of photosynthetic mats from hypersaline environments, a large diversity of cyanobacteria typically predominates. With the aim of strengthening the knowledge on the cyanobacterial diversity present in the coastal lagoon system of Araruama (state of Rio de Janeiro, Brazil), we have characterized three mat samples by means of a polyphasic approach. We have used morphological and molecular data obtained by culture-dependent and -independent methods. Moreover, we have compared different classification methodologies and discussed the outcomes, challenges, and pitfalls of these methods. Overall, we show that Araruamas lagoons harbor a high cyanobacterial diversity. Thirty-six unique morphospecies could be differentiated, which increases by more than 15% the number of morphospecies and genera already reported for the entire Araruama system. Morphology-based data were compared with the 16S rRNA gene phylogeny derived from isolate sequences and environmental sequences obtained by PCR-DGGE and pyrosequencing. Most of the 48 phylotypes could be associated with the observed morphospecies at the order level. More than one third of the sequences demonstrated to be closely affiliated (best BLAST hit results of ≥99%) with cyanobacteria from ecologically similar habitats. Some sequences had no close relatives in the public databases, including one from an isolate, being placed as “loner” sequences within different orders. This hints at hidden cyanobacterial diversity in the mats of the Araruama system, while reinforcing the relevance of using complementary approaches to study cyanobacterial diversity.

Lipid biomarkers profile—presence of coprostanol: recent sediments from Rodrigo de Freitas Lagoon—Rio de Janeiro, Brazil

Coprostanol (contribution characteristic from anthropogenic pollution) and other lipid biomarkers (sterols, fatty alcohols and fatty acids) were identified and quantified in recent sediment extracts from Rodrigo de Freitas Lagoon, a touristy spot of Rio de Janeiro—Brazil, using gas chromatography with mass selective detector (GC-MSD). The determination of lipid biomarkers profile indicates an autochthonous biogenic contribution due to the presence of phytoplankton, zooplankton, bacteria and dinoflagellates. The allochthonous biogenic contribution was confirmed by detection of biomarkers from higher plants in the sediments due to the influence of the Atlantic Forest inserted in the studied region. The concentration of the studied compounds varied from 5.53 to 216.47 μ g.g− 1 for sterols, 0.47 to 5.35 μ g.g− 1 for fatty alcohols, 20.15 to 66.22 μ g.g− 1 for fatty acids and 0.08 to 3.98 μ g.g− 1 for coprostanol. The presence of coprostanol was attributed to illegal untreated sewage discharge in the pluvial collector which ends up in the Lagoon.

Advances in the Stratigraphy and Geochemistry of the Organic-Rich Lower Jurassic Series of the Lusitanian Basin (Portugal)

Here we present the main results of a study of the high-resolution stratigraphy of the Lower Jurassic organic-rich marine series in the Lusitanian Basin, Portugal. In this basin, the Lower Jurassic consists mainly of an alternating marl–limestone succession (upper Sinemurian–Toarcian), with some intervals enriched in organic matter (upper Sinemurian and Pliensbachian). These Lower Jurassic carbonate units correspond to the Coimbra, Agua de Madeiros, Vale das Fontes, Lemede, and S. Giao/Cabo Carvoeiro formations. In the last few years, these units have been the subject of a multidisciplinary and integrated stratigraphic analysis, based on the study of a range of biotic and abiotic parameters. In our study, high-resolution analysis of these units in the main reference sections of the basin have allowed seven main themes to be developed, involving sedimentological and sequential analysis, ammonite biostratigraphy, macroinvertebrate palaeontology and palaeoecology, ostracod analysis, chemostratigraphy, organic and petrographic geochemistry, and gamma-ray analysis. Besides the novel results obtained in each scientific domain, the integration of all the collected data has improved our knowledge of not only the stratigraphy and sedimentary knowledge of the Lower Jurassic carbonates but also the hydrocarbon generation potential of the different Sinemurian and Pliensbachian units.

Matéria orgânica particulada e atividade bacteriana nos sedimentos superficiais da Baía de Guanabara, no Rio de Janeiro, Brasil

The aim of this work was to analyze bacterial esterases enzymes associated with the organic particulate, which gets to the superficial sediments of the Guanabara Bay, in Rio de Janeiro, Brazil. Thirty samples of superficial sediment were collected, in which grain size, total organic carbon, sulfur, activity of the esterases enzymes, and particulate components of organic matter under microscopy were analyzed. The results had shown that the textural class was between 62.65 to 85.63% for silt, 7.51 to 12.87% for clays, and 4.46 to 29.59% for sand. The average total organic carbon (TOC) and sulphur (S) were 3.78 and 0.77%, respectively. The highest esterases value was found in station 18 (4.69 μg fluorescein/h/g) and the lowest in 24 (1.25 μg fluorescein/h/g). The average of activities was of 3.20 μg fluorescein/h/g. The palynofacies analysis showed a predominance of the amorphous (82.4%), palynomorphe (9.2%), and phytoclast (8.4%) organic matters. The amorphous organic matter is predominant in all samples and the esterases enzymes activities are associated with the silt-clay. The palynomorphes are associated with sand. Cuticles, sporomorphes, and Botryococcus are directly related to to fluvial fluxes of rivers. The combined results of the analyses on organic geochemistry (elementary analysis) and microscopical techniques (transmitted and fluorescence light) disclose organic facies, with predominance of amorphous organic matter. The intense fluorescence coloring, together with raised value of total organic carbon (>;6%) indicate high rate of preservation and low content of free oxygen in the environment. These results correspond to an organic facies, like marine shale, which is a characteristic of a deposited facies under persistent anoxic water column with anaerobic microbial activity.