Search results for " Sediments"
showing 10 items of 217 documents
Ecotoxicity assessment of natural attenuation effects at a historical dumping site in the western Baltic Sea.
2005
During the late 1950s and early 1960s of the past century, industrial waste material highly enriched in various contaminants (heavy metals, PAHs) was dumped in the inner Mecklenburg Bay, western Baltic Sea. Large-scale shifts in the spatial distribution of heavy metals in surface sediments were mapped by geochemical monitoring in the mid-1980s and 12 years later in 1997. A further study in 2001 was designed to investigate the small-scale spatial distribution of contaminants inside, on top of, and around the historical dumping ground and to examine possible effects to benthic organisms (Arctica islandica, microbiological toxicity tests). The site is located within an area characterized by a …
Ashes from Sewage Sludge and Bottom Sediments as a Source of Bioavailable Phosphorus
2018
Phosphorus is an element necessary for the growth of plants. As phosphate rock gets depleted, it becomes an increasingly scarce resource. Therefore, it seems necessary to implement simple methods of cheap and effective phosphorus recovery from waste. The ashes of municipal sewage sludge and bottom sediments constitute particularly valuable sources of phosphorus. However, these materials usually carry significant amounts of pollutants, including heavy metals. Optimization of ash phosphorus sequential extraction methods from a thermal conversion of sewage sludge and bottom sediments allows to select an effective and simple technology of phosphorus recovery, while maintaining low heavy metal p…
Use of biological and sedimentation models for designing Peñíscola WWTP.
2004
This paper presents Peñíscola wastewater treatment plant design. Peñíscola is a tourist city in Castellón (Spain), whose population changes significantly between summer and the rest of the year. The design of the biological and settling treatment units has been confirmed by computer model simulations and provided for biological organic matter, nitrogen and phosphorus removal. Two different treatment schemes have been proposed in order to optimize the plant performance during both seasonal operations. During low-load season, the plant will be operated under extended aeration conditions, so further sludge stabilization will not be needed. During high-load season, the plant will be operated un…
Vertical distribution of AhR-activating compounds in sediments contaminated by modernized pulp and paper industry
2013
Increased ethoxyresorufin-O-deethylase (EROD) activity is a sensitive biomarker of exposure to the chemicals which activate the aryl hydrocarbon receptor (AhR) and induce the cytochrome P450 system, such as many polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). Pulp bleaching was one of the main sources of PCDDs and PCDFs until elemental chlorine free (ECF) and total chlorine free bleaching processes since 1990s have remarkably decreased but not completely eliminate discharges of these chemicals. In addition, historically contaminated sediments may act as a source of these persistent contaminants. In this study, the contam…
Halorhabdus rudnickae sp. nov., a halophilic archaeon isolated from a salt mine borehole in Poland
2016
Two halophilic archaea, designated strains WSM-64 and WSM-66, were isolated from a sample taken from a borehole in the currently unexploited Barycz mining area belonging to the >Wieliczka> Salt Mine Company, in Poland. Strains are red pigmented and form non-motile cocci that stain Gram-negative. Strains WSM-64 and WSM-66 showed optimum growth at 40 °C, in 20% NaCl and at pH 6.5-7.5. The strains were facultative anaerobes. The major polar lipids of the two strains were phosphatidylglycerol (PG2), phosphatidylglycerol phosphate methyl ester (PGP-Me) and sulfated diglycosyl diether (S-DGD). Menaquinone MK-8 was the major respiratory quinone. The DNA G+C content of strain WSM-64 was 61.2 mol% b…
Coastal Evolution in a Mediterranean Microtidal Zone: Mid to Late Holocene Natural Dynamics and Human Management of the Castellò Lagoon, NE Spain
2016
We present a palaeoenvironmental study of the Castelló lagoon (NE Spain), an important archive for understanding long-term interactions between dynamic littoral ecosystems and human management. Combining geochemistry, mineralogy, ostracods, diatoms, pollen, non-pollen palynomorphs, charcoal and archaeo-historical datasets we reconstruct: 1) the transition of the lagoon from a marine to a marginal environment between ~3150 cal BC to the 17th century AD; 2) fluctuations in salinity; and 3) natural and anthropogenic forces contributing to these changes. From the Late Neolithic to the Medieval period the lagoon ecosystem was driven by changing marine influence and the land was mainly exploited …
The response of cultured meiofaunal and benthic foraminiferal communities to lead exposure: Results from mesocosm experiments
2018
Lead (Pb) has been regarded as a very toxic element that poses a serious threat to biota. A mesocosm experiment is performed to assess the influence of Pb on meiofaunal (metazoans within 45-500 µm) and benthic foraminiferal (protozoans) communities. To this end, sediments bearing such communities are incubated in mesocosms, exposed to different levels of Pb in seawater, and monitored for up to eight weeks. Concentrations of Pb below 1 ppm in water do not promote a significant increase of this metal in sediments. Relatively high concentrations of Pb seem to affect meiofaunal and benthic foraminiferal communities by reducing their richness or diversity, and the abundance of the most sensitive…
Sorption of polycyclic aromatic hydrocarbons (PAHs) to carbonaceous materials in a river floodplain soil
2007
We report on sorption isotherm of phenanthrene (Phe) for river floodplain soil associated with carbonaceous materials, with particular attention being devoted to the natural loading of Phe. Our sorption experiments with original soil samples, size, and density sub-fractions showed that the light fraction had the highest sorption capacity comparable to low rank coals. In addition, the light fraction contributed most for the sorption of Phe in total soil samples. K(oc) values for all fractions were in the same range, thus indicating that coal and coal-derived particles in all samples are responsible for the enhanced sorption for Phe. Sorption was strongly nonlinear and the combined partitioni…
Recent benthic foraminiferal assemblages and their relationship to environmental variables on the shoreface and inner shelf off Valencia (Western Med…
2014
The environmental variables that determine the distributions of benthic foraminiferal assemblages on the shoreface and inner shelf of the north of Valencia province (Western Mediterranean) are identified. The possible influence of variables such as water depth, distance from shore, hydrodynamics, substrate type, carbonate content, organic matter content and human activity is evaluated. Multivariate cluster-Q-type analysis and redundancy analysis (RDA) are used to identify the environmental variables that have the greatest influence on the assemblage distribution. The spatial distribution of the assemblages is closely associated with water depth and substrate. The diversity and abundance of …
Distribution of REEs in box-core sediments offshore an industrial area in SE Sicily, Ionian Sea: Evidence of anomalous sedimentary inputs
2009
The distribution of rare earth elements and yttrium (REEs+Y) has been investigated in box-core sediments recovered from four stations in the Sicilian coastal zone seawards of Augusta, one of the most industrialized and contaminated areas in the Mediterranean region. Shale-like REE patterns and low Y/Ho ratios (close to the chondritic ratio) suggest a dominant terrigenous (geogenic) source for REE. Slight enrichment of LREE over the HREE is interpreted as due to preferential adsorptive transfer of LREE from seawater to sediment particles. Samples from offshore cores exhibit slightly positive Gd and negative Ce anomalies. It is here hypothesized that main drivers of anthropogenic Gd flux towa…