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Port sites represent one of the most impacted coastal areas; this impact is due to intensive anthropogenic pressures. In addition to the port complex itself, associated activities, such as indiscriminate disposal of pollutants, including trace metals, affect the local ecosystem. Macroinvertebrate benthic communities are one of the most effective bioindicators of environmental health because of their importance as a primary food source for many fish, birds, and mammals, as well as their influence on sediment stability and geochemical composition. This article evaluates the benthic macrofauna in the Santos Estuarine System (SES), the location of the Santos Port Complex (SPC), linking trace metal levels to differences in microbenthic community structure and pollutant bioavailability. The distribution of Cd, Ni, and Pb was directly related to organic matter deposits, while Cu and Zn appeared to result from port activities. The SES contained a poor benthic macroinvertebrate community, resulting from the contaminated muddy sediments. A significant negative correlation was found between the macrobenthic diversity and concentrations of Cu in the soluble phase; this implied the pollution-induced degradation of the macrobenthos in SES.

Des analyses par uranium-thorium (U–Th-TIMS), par résonance de spin électronique combinée à l’U–Th (ESR/U–Th) et par luminescence stimulée optiquement (OSL) ont été réalisées sur des échantillons provenant de la formation de Waziers, en France septentrionale. Ces trois méthodes ont été respectivement appliquées sur un échantillon de gyrogonite provenant d’un niveau corrélé à l’unité stratigraphique US5, sur des dents d’herbivore provenant de l’unité US4 sous-jacente ou recueillies en limite des US4 et US5 et sur deux prélèvements sédimentaires de l’US4. Les résultats obtenus permettent de dater la mise en place des unités ayant livré les dents analysées de la transition entre le Tardiglaciaire saalien (SIM, 6) et l’Interglaciaire eemien (SIM 5e), en bon accord avec les données paléoenvironnementales disponibles, issues des études malacologiques et palynologiques. Les dates OSL obtenues sur les deux échantillons de sédiments de l’US4 sont globalement compatibles avec celles obtenues par ESR/U–Th sur des dents issues de cette même unité ou de la limite entre US4 et US5. L’âge obtenu sur la gyrogonite, bien qu’indiquant un âge contemporain du SIM 5, apparaît pour sa part légèrement sous-estimé et doit donc bien être considéré comme un âge minimum. Uranium-series (u-series-tims), electron spin resonance combined with u-series (esr/u-series) and optically stimulated luminescence (osl) analyses were carried out on one gyrogonite sample correlated to stratigraphic unit us5, three herbivore teeth collected from unit us4 and at the limit between US4 and US5, and two sediment samples from unit US4 of the Waziers Formation, northern France, respectively. Results enable a correlation of the dated levels to the transition between the Saalian Late Glacial (MIS 6) and the Eemian Interglacial (MIS 5e) periods, in good agreement with the palaeoenvironmental data available from malacological and palynological studies. In addition, OSL results are overall compatible with the combined ESR/U-series age estimates on teeth recovered from the same unit (US4). In contrast, the U-series dating of the gyrogonite provides a MIS 5 age that appears to be slightly underestimated, and should therefore be considered as a minimum age constraint.

Antarctica's lake sediments are valuable geological archives for paleoenvironmental reconstructions of sea level and ice sheet change. It is essential to proceed with an analysis of cores from several locations in one lake to reconstruct detailed environmental changes. In the geomorphological survey of the 61st Japanese Antarctic Research Expedition, we collected four sediment cores in Lake Nurume, located at Langhovde in Lützow-Holm Bay, East Antarctica. We present preliminary results of non-destructive analysis of these cores, such as X-ray CT scanning, physical properties, and visual core descriptions. The obtained results combined with geomorphological settings and model simulations, will provide insight into the potential of these cores for paleoenvironmental reconstructions in Antarctica.

In this study, the natural radioactivity level and its effects on the environment of Lake Van, which is the largest lake in Turkey, were investigated extensively. Initially, 254 soil samples have been collected from the districts (Tusba, Edremit, Gevas, Tatvan, Ahlat, Adilcevaz, Ercis) located around the coastline of Lake Van in eastern Turkey. A Na(TI) detector was used to detect activity concentrations of radium (Ra-226), thorium (Th-232) and potassium (K-40) in each collected soil sample. The obtained average results were compared with available data from Turkey and international data base. The average activity in soil samples was measured as 28.0 +/- 3.7-43.6 +/- 2.2 Bq/kg for Ra-226, 27.3 +/- 4.1-55.4 +/- 4.8 Bq/kg for Th-232 and 377 +/- 42- 706 +/- 40 Bq/kg for K-40. It was observed that the average concentrations of Ra-226, Th-232, K-40 (43.6 +/- 2.2, 55.4 +/- 4.8, 706 +/- 40 Bq/kg, respectively) for Tatvan district and (37.0 +/- 3.5, 51.4 +/- 4.2, 479 +/- 41 Bq/kg, respectively) for Ahlat district were higher than both national and international average value. In addition, radiological effect parameters originating from terrestrial natural radionuclides for the study area; gamma dose rate (D-out), annual effective dose equivalent (AEDE), and lifetime cancer development probability (LCR) were calculated. The D-out, AEDE, LCR (83.0 +/- 3.9 nGy/h, 0.102 +/- 0.005 mSv/y, 0.36 +/- 0.02 x 10(-3), respectively) parameters in Tatvan district were found to be above the international allowable value., Van Yuzuncu Yl University Foundation [2012-FED-B026], This study has been financially supported by the Van Yuzuncu Yl University Foundation (Project Number: 2012-FED-B026).

Sulfate is present in all freshwater and marine environments and is reduced to toxic and corrosive hydrogen sulfide by anaerobic bacteria. By measuring depth profiles of sulfate in sediments, it is possible to obtain estimates of sulfate reduction rates (SRRs). A whole-cell microscale biosensor for sulfate was constructed by placing a mixture of sulfate-reducing and aerobic bacteria in front of a hydrogen sulfide microsensor. The bacteria were supplied with electron donors from a reservoir behind the bacterial biomass. The aerobic bacteria ensured anaerobic conditions in deeper parts of the 150-mu m-thick bacterial layer, so that the sulfate reducers could be active. A typical tip diameter of a sulfate biosensor is 50 mu m. The calibration curve was close to linear in the 0-2 mM range, with a detection limit of about 10 mu M. The 90% response time varied between 90 and 220 s, slowest response at low concentrations. Oxygen and ferrous iron at environmental concentrations gave no interference, but there was a 6% signal difference between stirred and stagnant liquid medium. The sensitivity of the biosensor could be modulated by applying a charge between sensor interior and an external electrode. The lifetime is usually a few weeks. The biosensor was used to measure sulfate profiles in a freshwater sediment.

Since the 1950s, the widespread application of road salt for winter road maintenance and safety in cold regions has led to increased conductivity levels in many freshwater systems. Salting practices have adversely affected freshwater biota; however, the magnitude of ecological impacts may vary by species and ecosystem. Here, we examine diatom assemblage changes during the past ∼200 years from the sedimentary records of five impacted lakes (measured specific conductance values of 149–350 µS·cm−1) and a reference lake (18 µS·cm−1) located in the Muskoka River Watershed, south-central Ontario, Canada. Diatom compositional changes in the road-salt-impacted sites were consistent with increasing conductivity and increased diatom-inferred (DI)-conductivity was evident during the latter half of the 20th century in the impacted lakes, concurrent with known road-salt application. The strongest predictor of DI-conductivity changes among the six lakes was the kilometre equivalents of roads within the watershed (i.e., kilometres of road × number of lanes). Similar to changes observed in a previous study focusing on cladoceran assemblages, we conclude that even modest applications of road salt can affect diatom assemblages in softwater lakes.

International audience; This paper focuses on the development of a geopolymer (GP) mortar that can be cured under ambient conditions using a combination of flash-calcined dredged sediment (FCS), Metakaolin (MK), granulated blast furnace slag (GBFS), and potassium silicate (K2SiO2) as an alkaline reagent (AR). The goal of this research is to reduce carbon emissions from traditional clinker-based materials by using valorized materials in the formulation of the geopolymer binder. The study investigates the effect of the alkaline reagent-to-binder ratio (AR/Bmm) and precursor composition on the mechanical and durability properties of the GP mortar. The results indicate that the lowest AR/B ratio and formulations with higher GBFS percentages have better performance. Porosity test and microstructural analysis tests such as X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) was conducted to ensure the stability of the GP formulations exposed to a sulfuric acid attack test, while nuclear magnetic resonance (NMR) tests validate the Q4(1Si, 3Al) network and their assigned Si/Al ratio. The leaching examination concludes that the GP design is not classified as hazardous materials. © 2023 Elsevier Ltd

The importance of good water quality to environmental and human health cannot be over-emphasised and physicochemical properties are essential in assessing the quality of water around the world. This study therefore, assessed the physicochemical properties of water and sediments in Ikpoba and Ogba Rivers, Edo State, Nigeria, following standard procedures. The results obtained from the study showed that most of the analysed samples were within the safe limits recommended by the WHO. The values for the physicochemical properties of the water samples from both rivers were also within the permissible limits, except for pH (5.7 - 6.6) and dissolved oxygen (2.73 - 6.32mg/l), when values were compared with WHO recommendations. The results from the study also showed observed trends in the results of the various parameters determined by the seasons. Statistical analysis revealed the absence of significant differences (p < 0.05) between the physicochemical and WHO recommendations for water and sediments from both rivers with very few exceptions. It was then recommended that periodic monitoring and assessment of water and sediments in the study area be carried out.

The aim of this study was the systematization and generalization of data obtained by authors during the last decade and the comparison of these data with those obtained by other authors. Gas chromatography (GC-MS) was used for the determination of PAHs and the positive matrix factorization (PMF) model and principal component analysis (PCA) were used for source apportionment of PAHs. It was found that the total concentration of 16 priority PAHs in surface waters varied from 5 to 200 ng/L, whereas the concentration of 16 PAHs in bottom sediments varied from 50 to 700 ng/g. The 2–3-ring PAHs were dominant in water, whereas the 4–6-ring PAHs were dominant in sediments. That was due to PAHs fractionation in the soil–water system. The source apportionment results showed that the PAHs in both water and sediments mostly originated from the combustion of biomass and fossil fuels. In contrast to sediments, there was a PAH fraction in water that did not originate from a single source. The pollution of freshwater ecosystems manifested itself in the lack of correlation between values of octanol/water partitioning coefficients and sediment/water partitioning coefficients of PAHs.

Concentrations of polycyclic aromatic hydrocarbons (PAH) were studied in 36 sediment samples collected from 29 sites in the central Adriatic Sea. The total concentration of PAH showed high variability, ranging from 42.85 µg kg−1 in open sea sediments to 28,662 µg kg−1 in the sediments of Šibenik Bay. Unsubstituted, parent PAH were dominant PAH compounds in the entire area of Šibenik Bay and most of the stations in the coastal area. In Kaštela Bay, methyl PAH concentrations were higher than the concentrations of unsubstituted PAH, whereas in the sediments along the mid-Adriatic transect, similar concentrations of both PAH fractions were determined. PAH sources were investigated by applying the Positive Matrix Factorization software developed by the U.S. Environmental Protection Agency (USEPA). The results indicate the presence of four sources, two of which can be considered petrogenic and two pyrogenic. The contribution of the sources to the total concentration PAH at each station indicates the dominance of pyrogenic sources in Šibenik Bay and at most stations in the coastal area. In the sediments along the mid-Adriatic transversal, as well as in Kaštela Bay, PAHs originate mainly from petrogenic sources. The obtained results show that PMF can be a suitable tool for control of PAH pollution and thus, for the management of various activities in the Adriatic region. Seasonal differences between the contributions of sources in the Kaštela and Šibenik bays indicate that the contribution of traffic to the total concentration of PAH was higher during the tourist season. The carcinogenic risk of PAH determined by toxicity equivalent (TEQ) calculations showed an increased carcinogenic risk in the whole area of Šibenik Bay, regardless of the number of PAH compounds considered for the calculations. A low PAH-related carcinogenic risk was found for the rest of the study area.

Comprehensive studies of the effects of various physical and chemical variables (including heavy metals), antibiotics, and microorganisms in the environment on antibiotic resistance genes are rare. We collected sediment samples from the Shatian Lake aquaculture area and surrounding lakes and rivers located in Shanghai, China. The spatial distribution of sediment ARGs was assessed by metagenomic analysis that revealed 26 ARG types (510 subtypes), dominated by Multidrug, β-lactam, Aminoglycoside, Glycopeptides, Fluoroquinolone, and Tetracyline. Redundancy discriminant analysis indicated that antibiotics (SAs and MLs) in the aqueous environment and sediment along with water TN and TP were the key variables affecting the abundance distribution of total ARGs. However, the main environmental drivers and key influences differed among the different ARGs. For total ARGs, the environmental subtypes affecting their structural composition and distribution characteristics were mainly antibiotic residues. Procrustes analysis showed a significant correlation between ARGs and microbial communities in the sediment in the survey area. Network analysis revealed that most of the target ARGs were significantly and positively correlated with microorganisms, and a small number of ARGs (e.g., rpoB, mdtC, and efpA) were highly significantly and positively correlated with microorganisms (e.g., Knoellia, Tetrasphaera, and Gemmatirosa). Potential hosts for the major ARGs included Actinobacteria, Proteobacteria, and Gemmatimonadetes. Our study provides new insight and a comprehensive assessment of the distribution and abundance of ARGs and the drivers of ARG occurrence and transmission.

Due to the Arctic amplification effect, the Svalbard archipelago is an important area for studying ongoing environmental changes. However, its marine ecosystem is extremely complex. In this study, we analyze modern assemblages of dinoflagellate cysts (dinocysts) and benthic foraminifera from surface sediment samples around Svalbard. We use multivariate statistical analyses to examine relationships between environmental conditions (summer and winter sea surface temperature and salinity, sea-ice cover, etc.) and both microfossil groups to evaluate their use as proxies for reconstructions of the marine environment in the region. Our results show that the most important factor controlling the environment around Svalbard is the Atlantic Water which mostly impacts the western coast, but its influence reaches as far as the eastern coast of Nordaustlandet. However, on a local scale, such factors as the sea-ice cover, the presence of tidewater glaciers, or even the morphology and hydrology of fjords become increasingly important. We found that two dinocyst species, cysts of Polarella glacialis and Echinidinium karaense, can be considered regional winter drift ice indicators. The relationships between environmental parameters and benthic foraminiferal assemblages are much more difficult to interpret. Although statistical analysis shows a correlation of benthic foraminiferal species with various environmental parameters, this correlation might be somewhat coincidental and caused by other factors not analyzed in this study. Nevertheless, the use of two complementary microfossil groups as (paleo)environmental indicators can provide a more comprehensive picture of the environmental conditions.

Management strategies have historically centred around phosphorus loading control into the Great Lakes to address anthropogenic eutrophication. These strategies have met with some successive reducing the total phosphorus (TP) concentrations since 1980s. In the past 20 years, the frequency, extent, and toxicity of harmful algal blooms (HABs), especially cyanobacterial HABs, have increased particularly in the western Lake Erie basin. Factors associated with recent HABs have been linked to increase in nutrient bioavailability from diffuse sources, internal loading, and a shift in nitrogen (N):P ratios, which potentially favours non-N fixing HABs. To address this issue, federal and provincial governments in Canada have identified a 40% reduction target in TP and soluble reactive phosphorus (SRP) to mitigate nearshore HABs. However, this is a complex issue and there is still limited information on the dynamics of nutrient transport from adjacent tributaries to the western basin of Lake Erie to provide an effective watershed nutrient management plan. Further, rivers and streams are often viewed as a conduit transporting nutrients directly into lakes. This thesis aims to investigate mechanistic changes in nutrient bioavailability, identify causal sources and sinks specifically for P and N, and investigate the interplay between in-stream sediment process and nutrient cycling along a river-lake continuum. To investigate change in P bioavailability, state-of-the-art in situ wet chemical analysers were deployed to measure three fractions of P, including TP, total dissolved phosphorus (TDP) and SRP, in the Sturgeon Creek watershed and nearshore of Lake Erie. After quantifying biofouling effects during six-month deployment in the field, the calibrated high-frequency data suggest considerable spatiotemporal variation in nutrient bioavailability. The results show approximately 40% of P entering the nearshore area is considered as bioavailable. For the first time, ratios of SRP:TP were continuously measured in real-time in the field, presenting a promising tool for in situ P monitoring beyond the shoreline of Lake Erie. Real-time observations were later correlated to sediment investigations. Sediments were identified based on the potential to sequester or release P (source vs sink) along the river-lake continuum. This information was linked to impacts from land uses within the watershed of Sturgeon Creek. Water and riverbed sediments were collected from eight sites along the transect from headwater to the nearshore of Lake Erie. Analyses for nutrient chemistry, stable nitrate isotopes and sediment equilibrium phosphorus concentration (EPC0) were performed. Typically, Sturgeon Creek sees 2- , 9- , and 18-fold higher concentrations of nitrate-nitrogen (NO3-N), TP, and SRP, respectively, compared to other agricultural watersheds in the region. Stable isotope analyses suggest the sources of NO3 are likely influenced by mixing of inorganic nitrate fertiliser and organic/manure fertiliser. Although most of the locations are net phosphorus sinks, limited phosphorus retention capacity is observed in river segments where the concentrations of P has accumulated. The evidence from this study suggests a combination of nutrient influence from both residential areas and horticulture in the region. To identify the bacterial influence in this watershed on nutrient dynamics, Sturgeon Creek riverbed sediments were collected for microbial metabarcoding and metatranscriptomic analyses. The results were paired with the observed nutrient chemistry from the water column along the transect. Water samples were analysed for NO3-N, nitrite-nitrogen (NO2-N) and ammonium-nitrogen (NH4- N). Analyses of the bacterial community structure shows no significant differences in alpha diversity of active taxa. Interestingly, nitrate reducers are abundant across all sites. Post wetland locations reveal a shift in microbial communities towards anaerobic taxa, including sulphatereducing bacteria and methanotrophs. Supporting metranscriptomics analyses indicate an active N metabolism; denitrification is the dominant pathway (32 to 55%), followed by nitrification (5 to 21%) along the transect. Collectively, this investigation provides a clear link between water column chemistry and sediment microbial metabolism. Key genes of N transformation exhibit a strong correlation with the change in concentration of NO3-N, NO2-N and/or ratio of NO2/NO3. This thesis demonstrates that nutrient bioavailability, sources, and sinks can be significantly influenced by land use change along the river-lake continuum and highlights the important role of sediment microbial processes in nutrient cycling and overlying water quality. Through incorporating multiple tools, it is likely to effectively uncouple the complexity of biogeochemical processes along the river-lake continuum that under heavily anthropogenic influence. The approaches established within this work can further contribute to nutrient management design and watershed mitigation and restoration.

This study investigates the contribution of river morphology towards the occurrence of manganese (Mn) in both sediment and surface water (SW), considering the temporal climatic and spatial conditions. The Boac and Mogpog rivers on the island province of Marinduque, Philippines, were examined in this study. These rivers are downstream of the two abandoned open mine pits at San Antonio and Tapian, where mining disasters occurred in 1993 and 1996, respectively. Field sampling programs were conducted in 2019, 2021 and 2022 to measure the Mn concentrations in sediment and SW, and the physicochemical parameters in SW during the same sampling event. Geographic Information System (GIS) tools were employed to characterize the morphology of each river, specifically river slope, river bends, sinuosity, and channel width and length. The Boac and Mogpog rivers were divided into 22 and 15 river segments, respectively, to account for spatial heterogeneity of all parameters. Correlation (r) analysis on the average Mn concentration and river morphology within each segment was performed and indicated that river bends (Boac r = 0.421, Mogpog r = 0.356) and sinuosity (Boac r = 0.403, Mogpog r = 0.352) had the highest correlation with Mn concentrations in sediment. While river slope (Boac r = 0.716, Mogpog r = 0.282) and sinuosity (Boac r = 0.505, Mogpog r = 0.257) were the highest for Mn in SW. This confirmed that the planform of the river affected the accumulation of Mn due to its effect on sediment deposition along the river and its potential to adsorb and/or desorb metals. Furthermore, the pH of SW also directly correlated with sediment Mn (r = 0.293), and inversely correlated with SW Mn (r = −0.465), which was expected as acidic water promotes the release of metals from sediments to SW. The results from this study will aid local government, environmental engineers and managers in their mitigation program through identification of the areas and segments in the river that contain the highest and the least contamination. This is to optimize financial and human resources during river system remediation and monitoring. Data and information extracted from this study are useful in other areas of similar condition.

The study investigated the composition and content of Σ15PAH in the surface and core sediments from Dachan Bay (DCB) in Shenzhen city and discussed the effects of urban development and regional energy structure on the marine environment through the spatial distribution, vertical profile, and sources of Σ15PAH. The results indicated that the concentrations of Σ15PAH in the sediments of DCB ranged between 299 ng/g and 2336 ng/g in the surface sediments and between 65 ng/g and 994 ng/g in the core sediments. The horizontal spatial distribution of PAHs content with decreasing concentrations from the coastal to central areas implied the land-based input of PAHs. The vertical profile of high PAHs concentration in 0 cm–60 cm suggested that the PAHs pollution is attributed to the urban development of Shenzhen since 1950, especially after the 1980s. According to features of the low molecular weight (LMW)/high molecular weight (HMW), PAHs diagnostic ratios and their relationships with total organic carbon (TOC) and oil, the pyrogenic PAHs were mainly from the combustion of petroleum and byproducts in the surface and 0 cm–60 cm sediments but from the combustion of biomass in 60 cm–190 cm sediments, which corresponded with the variation of energy structure in surrounding areas. This study suggested that urban development and regional energy structure have a great impact on PAHs distribution in DCB and further controls of land-based pollutant emissions are still needed.

Heavy metal pollution can adversely impact marine life, such as crabs, which can accumulate it in different organs and potentially transfer and biomagnify along the food chain in aquatic ecosystems. This study aimed to examine the concentrations of heavy metals (Cd, Cu, Pb, and Zn) in sediment, water, and crab tissues (gills, hepatopancreas, and carapace) of the blue swimmer crab Portunus pelagicus in the coastal areas of Kuwait, northwestern Arabian Gulf. Samples were collected from Shuwaikh Port, Shuaiba Port, and Al-Khiran areas. The accumulation of metals in crabs were higher in the carapace > gill > digestive gland, and the highest metal concentration was found in crabs collected from Shuwaikh > Shuaiba > Al-Khiran. The metal concentrations in the sediments were in the order Zn > Cu > Pb > Cd. Zn was the highest metal concentration detected in marine water sampled from the Al-Khiran Area, whereas the lowest metal was Cd sampled in water from the Shuwaikh Area. The results of this study validate the marine crab P. pelagicus as a relevant sentinel and prospective bioindicator for evaluating heavy metal pollution in marine ecosystems.

Soil samples under periwinkle sediments were collected from Choba and Nkpolu markets in Port Harcourt. Analysis was carried out on them using AAS to detect the presence of heavy metals. The results showed that the concentrations of these metals ranged from 0.548-1.024mg/kg for chromium; 0.174-0.263mg/kg for zinc; 0.439-0.643mg/kg for copper; 1.535-1.676mg/kg for iron; 0.323-0.499mg/kg for cadmium; 0.561-0.864mg/kg for manganese; 0.255-0.0468mg/kg for nickel and 0.302-0.535mg/kg for cobalt. Heavy metals are not easily excreted from shells but tend to bio-accumulate over a long period of time, especially during the rainy season. Heavy metal concentration above the permissible limit is harmful to soil, plant growth and causes severe health problems to humans. The use of waste shells in road and house construction is the best approach to reducing the effect of heavy metal pollution by shells. Keywords: Periwinkle Shells, AAS, Heavy Metals, Soil, Sediments, Pollution. Title: DETERMINATION OF HEAVY METALS IN SOILS UNDER PERIWINKLE SHELL DUMPSITES LOCATED IN CHOBA AND NKPOLU MARKETS IN PORT HARCOURT, NIGERIA Author: Oriji, O.G, John, Godson Nnamdi International Journal of Recent Research in Life Sciences (IJRRLS) ISSN 2349-7823 Vol. 10, Issue 2, April 2023 - June 2023 Page No: 10-13 Paper Publications Website: www.paperpublications.org Published Date: 13-April-2023 DOI: https://doi.org/10.5281/zenodo.7825127 Paper Download Link (Source) https://www.paperpublications.org/upload/book/DETERMINATION%20OF%20HEAVY-13042023-3.pdf, International Journal of Recent Research in Life Sciences (IJRRLS), ISSN 2349-7823, Paper Publications, Website: www.paperpublications.org

The ever-growing worldwide demand for fired clay brick has resulted in the shortage of clay in many parts of the world. Therefore, there is a need to look for more sustainable alternative materials for the brick manufacturing. This study has investigated the potential use of the untreated Drava River sediment as a substitute material for clay in the production of fired bricks, with the research being conducted at both laboratory and industrial level. At the laboratory level, brick specimens were prepared by mixing clay with different river sediment proportions (ranging from 10 to 50 wt%) and were fired at 950 °C, with microstructural and various physical–mechanical properties being analyzed. Elevated carbonate content in Drava river sediment results in higher weight loss during firing at temperatures up to 950 °C, comparing to firing pure brick-making clay. Consequently, the addition of sediment increases porosity of fired bricks, which results in lowering of their mechanical properties. Results reveal that the compressive strength of the pure clay sample was 79.5 MPa, while the compressive strength of the sample with the addition of river sediment from 10 wt% to 50 wt% decreased from 73.9 MPa to 26.2 MPa, respectively. Despite the lower compressive strength, the 26.2 MPa is still above the limit value of 10 MPa specified in the standard EN 772–1 [1]. At the industrial level, hollow clay bricks were prepared with 20 wt% of the river sediment and fired in a tunnel kiln. Inclusion of the river sediment also decreased compressive strength from 38 MPa for pure mixture to 26 MPa for 20 wt% of the sediment addition, confirming usability of Drava sediment in brick production. In addition, LCA study has been conducted to evaluate the environmental impacts associated with the industrial production of classic bricks and bricks with the addition of the river sediment. The obtained results have shown that the bricks made with the addition of the Drava River sediment are sustainable and environmentally friendly and meet all the requirements specified in the relevant regulatory standard. Nasl. z nasl. zaslona. Opis vira z dne 11. 4. 2023. Bibliografija. Abstract.

ispartof: JOURNAL OF PLANT NUTRITION AND SOIL SCIENCE vol:186 issue:3 pages:311-320 status: published

This study was carried out to investigate builds up a rule map on various radiological factors in and around the Euphrates River in Iraq. Radon levels, radium content and surface and mass radon exhalation rates for 20 sediment tests gathered from different districts along the Euphrates River, Iraq, (about 500km long) using the can technique, with the CR-39 plastic detector. Radon fixation esteems were viewed as going from 835.0 to 2797.7 Bq.m-3with a normal worth of 1703.5 Bq.m-3. The normal worth of radium content was viewed as 12.5 Bg.kg-1while the most minimal and most elevated determined upsides of radium content (CRa) were 6.1 and 20.5 Bq.kg-1, respectively. The radon exhalation rates (surface ESand mass Em) for the study sediment samples were found to vary from (0.41 to 1.37) Bq.m-2.h-1and from (0.09 to 0.31) Bq.kg-1.h-1with average values of 0.83 Bq.m-2.h-1and 0.19 Bq.kg-1.h-1, respectively. The values of CRafor all sediment samples were lower than the recommended value of 30 Bq.kg-1given by UNSCEAR. Hence, the results show that the study area is safe as far as the health hazard effects are concerned, and the values of radium content in all surveyed sites are lower than the allowable limit.

In order to successfully implement nature-based solutions as (part of) coastal defense, there is a need for insight into their efficiency and their reliability. The wave-attenuation capacity of vegetated coastal ecosystems like seagrasses and salt marshes has been widely studied. However, their stability on the medium to long term (i.e., engineering timescales) needs to be quantified. Key wave attenuating ecosystems like salt marshes have a high internal stability. However, their lateral extent is strongly influenced by the vertical (sediment) stability of adjacent mudflats and / or seagrass meadows. In this thesis the sediment stability thresholds of subtidal and lower intertidal ecosystems (from seagrass meadows up to tidal flats) under strong current and wave attack is quantified. Typically such thresholds are measured via field measurements or laboratory flume experiments. The problem with these approaches is, however, that field measurements lack hydrodynamic control, so thresholds can only be measured indirectly, and laboratory experiments require ecosystem transplantation or the use of mimics. Field flumes have therefore been developed as a way to generate controlled hydrodynamics in situ, and have been used to quantify sediment stability thresholds in seagrass meadows and on tidal flats (chapters 2 and 4). We explored the Seagrass – Sediment – Light (SSL) feedback by measuring sediment resuspension for various seagrass densities and sediment types (chapter 3). We were able to establish a general relation between seagrass density and sediment stability. This relation was then implemented in a simplified wave model which was used to assess the effects of changes in typical waves and storminess. We found that seagrasses are resilient to storms, but can be sensitive to changes in typical wind conditions depending on the topographical setting. Benthos influence the stability of tidal flats. This is a complex interaction, because there are many species which all act differently. The effects of different species can be generalized via their energy consumption. We tested this approach in the field, but we still found a large variability (chapter 4). Therefore, we conducted an experiment where we assessed how different combinations of highly contrasting species change sediment stability (chapter 5). We found that the species with the strongest individual effect overruled the effects of other species. When implementing nature-based solutions for coastal defense, there is a risk of accumulation of pollutants like microplastics. We assessed microplastic trapping within various biogenic habitats (chapter 6). We found that the susceptibility of a biogenic habitat to plastic accumulation was determined by their ability to reduce turbulence near the seabed. Furthermore, smaller particles are much more likely to be sequestered as they can ‘hide’ between larger sediment grains.

In order to successfully implement nature-based solutions as (part of) coastal defense, there is a need for insight into their efficiency and their reliability. The wave-attenuation capacity of vegetated coastal ecosystems like seagrasses and salt marshes has been widely studied. However, their stability on the medium to long term (i.e., engineering timescales) needs to be quantified. Key wave attenuating ecosystems like salt marshes have a high internal stability. However, their lateral extent is strongly influenced by the vertical (sediment) stability of adjacent mudflats and / or seagrass meadows. In this thesis the sediment stability thresholds of subtidal and lower intertidal ecosystems (from seagrass meadows up to tidal flats) under strong current and wave attack is quantified. Typically such thresholds are measured via field measurements or laboratory flume experiments. The problem with these approaches is, however, that field measurements lack hydrodynamic control, so thresholds can only be measured indirectly, and laboratory experiments require ecosystem transplantation or the use of mimics. Field flumes have therefore been developed as a way to generate controlled hydrodynamics in situ, and have been used to quantify sediment stability thresholds in seagrass meadows and on tidal flats (chapters 2 and 4). We explored the Seagrass – Sediment – Light (SSL) feedback by measuring sediment resuspension for various seagrass densities and sediment types (chapter 3). We were able to establish a general relation between seagrass density and sediment stability. This relation was then implemented in a simplified wave model which was used to assess the effects of changes in typical waves and storminess. We found that seagrasses are resilient to storms, but can be sensitive to changes in typical wind conditions depending on the topographical setting. Benthos influence the stability of tidal flats. This is a complex interaction, because there are many species which all act differently. The effects of different species can be generalized via their energy consumption. We tested this approach in the field, but we still found a large variability (chapter 4). Therefore, we conducted an experiment where we assessed how different combinations of highly contrasting species change sediment stability (chapter 5). We found that the species with the strongest individual effect overruled the effects of other species. When implementing nature-based solutions for coastal defense, there is a risk of accumulation of pollutants like microplastics. We assessed microplastic trapping within various biogenic habitats (chapter 6). We found that the susceptibility of a biogenic habitat to plastic accumulation was determined by their ability to reduce turbulence near the seabed. Furthermore, smaller particles are much more likely to be sequestered as they can ‘hide’ between larger sediment grains.

In order to successfully implement nature-based solutions as (part of) coastal defense, there is a need for insight into their efficiency and their reliability. The wave-attenuation capacity of vegetated coastal ecosystems like seagrasses and salt marshes has been widely studied. However, their stability on the medium to long term (i.e., engineering timescales) needs to be quantified. Key wave attenuating ecosystems like salt marshes have a high internal stability. However, their lateral extent is strongly influenced by the vertical (sediment) stability of adjacent mudflats and / or seagrass meadows. In this thesis the sediment stability thresholds of subtidal and lower intertidal ecosystems (from seagrass meadows up to tidal flats) under strong current and wave attack is quantified. Typically such thresholds are measured via field measurements or laboratory flume experiments. The problem with these approaches is, however, that field measurements lack hydrodynamic control, so thresholds can only be measured indirectly, and laboratory experiments require ecosystem transplantation or the use of mimics. Field flumes have therefore been developed as a way to generate controlled hydrodynamics in situ, and have been used to quantify sediment stability thresholds in seagrass meadows and on tidal flats (chapters 2 and 4). We explored the Seagrass – Sediment – Light (SSL) feedback by measuring sediment resuspension for various seagrass densities and sediment types (chapter 3). We were able to establish a general relation between seagrass density and sediment stability. This relation was then implemented in a simplified wave model which was used to assess the effects of changes in typical waves and storminess. We found that seagrasses are resilient to storms, but can be sensitive to changes in typical wind conditions depending on the topographical setting. Benthos influence the stability of tidal flats. This is a complex interaction, because there are many species which all act differently. The effects of different species can be generalized via their energy consumption. We tested this approach in the field, but we still found a large variability (chapter 4). Therefore, we conducted an experiment where we assessed how different combinations of highly contrasting species change sediment stability (chapter 5). We found that the species with the strongest individual effect overruled the effects of other species. When implementing nature-based solutions for coastal defense, there is a risk of accumulation of pollutants like microplastics. We assessed microplastic trapping within various biogenic habitats (chapter 6). We found that the susceptibility of a biogenic habitat to plastic accumulation was determined by their ability to reduce turbulence near the seabed. Furthermore, smaller particles are much more likely to be sequestered as they can ‘hide’ between larger sediment grains.

Namen raziskave je bil ugotoviti mineralno in geokemično sestavo vzorcev sedimenta Koseškega bajerja, ki se nahaja na severozahodnem delu Ljubljanske kotline. Iz sredine jezera smo odvzeli jedro vrtine KS in naredili natančen sedimentološki popis jedra, granulometrijsko analizo vzorcev ter pripravili vzorce za nadaljnje raziskave. Ugotovili smo, da naši vzorci pripadajo trem skupinam: malo peščen meljast pesek, zelo malo meljasta peščena glina in malo meljast glinen pesek. Z rentgensko praškovno difrakcijo (XRD) smo v obravnavanih vzorcih določili kremen, dolomit, albit, sadro, illit in kalcit. V izbranih vzorcih KS-20, KS-40, KS-55 in KS-65 smo našli glinene minerale illit, klorit in kaolinit. Z visoko ločljivostnim masnim spektrometrom z induktivno sklopljeno plazmo (HR-ICP-MS) smo v vzorcih določili detajlno elementno sestavo glavnih oksidov in težkih kovin. V vzorčni vrtini smo našli največjo vsebnost SiO2 (43,31–74,76 %), kateri sledi Al2O3 (12,52–17,25 %), najmanj pa je MnO (0,02–0,07 %). Najvišje vsebnosti težkih kovin, pripadajo elementom Cu (273,6 mg/kg), Zn (266 mg/kg), Pb (106,8 mg/kg) in Cd (2,2 mg/kg), najnižje vsebnosti pa elementom Sb (0,6 mg/kg), As (14,6 mg/kg), Mo (4,7 mg/kg) in Ni 36(mg/kg). Z statističnimi analizami smo dokazali, da se vsebnosti težkih kovin z globino znižujejo, posledično lahko sklepamo, da so v zgornjih cm jedra zvišane vsebnosti težkih kovin antropogenega izvora. Gre predvsem za vpliv kmetijstva, prometa in kurjave. Mineraloško in elementno sestavo vzorcev smo potrdili tudi z uporabo elektronske mikroskopije, in sicer z vrstičnim elektronskim mikroskopom s spektrometrom energijske disperzije (SEM-EDS). Potrdili smo naslednje minerale: kremen, kalcit, sadro in glinene minerale. V omenjenih vzorcih pa smo zaznali minerale, ki lahko veljajo kot potencialni nosilci težkih kovin: cirkon, ilmenit, rutil, pirit in minerali REE. The aim of the study was the mineralogical and geochemical analysis of the sediments of the Koseze Lake, located in the northwestern part of Ljubljana. We took the core from the KS well in the middle of the lake. The core was then taken to the Department of Geology at the Faculty of Natural Sciences, where we conducted a detailed sedimentological inventory of the core and granulometric analysis of the samples. We determined that our samples belonged to three groups: slightly sandy-silty sand, very slightly silty-sandy clay, and slightly silty-clay sand. X-ray powder diffraction (XRD) was used to determine quartz, dolomite, albite, chlorite, kaolinite, gypsum, illite, and calcite in the samples studied. The clay minerals illite, chlorite and kaolinite were found in selected samples KS-20, KS-40, KS-55 and KS-65. Using a high-resolution inductively coupled plasma mass spectrometer (HR-ICP-MS), we determined the detailed elemental composition of the major oxides and heavy metals in the samples. HR-ICPMS Analysis of the oxides revealed the highest SiO2 content (43.31-74.76%), followed by Al2O3 (12.52-17.25%) and the lowest MnO (0.02-0.07%). The highest heavy metal contents show the elements Cu (273,6 mg/kg), Zn (266 mg/kg), Pb (106 mg/kg) and Cd (2,2 mg/kg). The statistical analyses have shown that the heavy metal contents decrease with depth, from which we conclude that the increased heavy metal contents are of anthropogenic origin. This is mainly due to the impact of agriculture, transport and heating. The mineralogical and elemental composition of the samples was also confirmed by electron microscopy using a scanning electron microscope with energy dispersion spectrometer (SEM-EDS). The minerals confirmed with SEM-EDS were quartz, calcite, gypsum and clay minerals. In the samples mentioned above, we also detected minerals that are potential carriers of heavy metals: zircon, ilmenite, rutile, pyrite and REE minerals.

Northwestern Russia remains the only region in Northern Eurasia where no regional chironomid-based inference model for quantitative palaeoclimatic reconstructions has been developed. Using palaeolimnological methods, we investigated the subfossil chironomid remains in surface sediments from a data set of 98 lakes from nine subregions of the European part of Northern Russia. We identified 143 chironomid taxa in the investigated lakes. Multivariate statistical analyses of chironomid and environmental data demonstrated that the mean July air temperature (T July), distance from the tree line, water depth, pH, and altitude explain the most significant variance in chironomid distribution. T July appeared to be the most important environmental variable. We established a chironomid-based inference model for reconstructing T July from subfossil data. The resulting West Russian two-component WA-PLS model includes 96 lakes (two lakes were excluded as outliers), 143 chironomid taxa, r2 = 0.84 (r2 boot = 0.60), RMSEP boot = 1.34 °C, and can be recommended for application in palaeoclimatic studies in the East of Northern Eurasia.

Using the non-invasive aquatic eddy covariance technique, we provide the first oxygen (O2) uptake rates from within coral gardens at the Condor seamount (Azores). To explore some of the key drivers of the benthic O2 demand, we obtained benthic images, quantified local hydrodynamics, and estimated phototrophic biomass and deposition dynamics with a long-term moored sediment trap. The coral gardens were dominated by the octocorals Viminella flagellum and Dentomuricea aff. meteor. Daily rates of O2 uptake within 3 targeted coral garden sites (203 to 206 m depth) ranged from 10.0 ± 0.88 to 18.8 ± 2.0 mmol m-2 d-1 (mean ± SE) and were up to 10 times higher than 2 local sandy reference sites within the seamount summit area. The overall mean O2 uptake rate for the garden (13.4 mmol m-2 d-1) was twice the global mean for sedimentary habitats at comparable depths. Combined with parallel ex situ incubations, the results suggest that the octocorals might contribute just ~5% of the observed O2 uptake rates. Deposition of particulate organic matter (POM) assessed by the sediment trap accounted for less than 10% of the O2 demand of the coral garden, implying a substantial POM supply circumventing the deployed traps. Our results expand the database for carbon turnover rates in cold-water coral habitats by including the first estimates from these largely understudied coral gardens.

Coastal methane (CH4) emissions dominate the global ocean CH4 budget and can offset the "blue carbon" storage capacity of vegetated coastal ecosystems. However, current estimates lack systematic, high-resolution, and long-term data from these intrinsically heterogeneous environments, making coastal budgets sensitive to statistical assumptions and uncertainties. Using continuous CH4 concentrations, delta C-13-CH4 values, and CH4 sea-air fluxes across four seasons in three globally pervasive coastal habitats, we show that the CH4 distribution is spatially patchy over meter-scales and highly variable in time. Areas with mixed vegetation, macroalgae, and their surrounding sediments exhibited a spatiotemporal variability of surface water CH4 concentrations ranging two orders of magnitude (i.e., 6-460 nM CH4) with habitat-specific seasonal and diurnal patterns. We observed (1) delta C-13-CH signatures that revealed habitat-specific CH4 production and consumption pathways, (2) daily peak concentration events that could change >100% within hours across all habitats, and (3) a high thermal sensitivity of the CH4 distribution signified by apparent activation energies of similar to 1 eV that drove seasonal changes. Bootstrapping simulations show that scaling the CH4 distribution from few samples involves large errors, and that similar to 50 concentration samples per day are needed to resolve the scale and drivers of the natural variability and improve the certainty of flux calculations by up to 70%. Finally, we identify northern temperate coastal habitats with mixed vegetation and macroalgae as understudied but seasonally relevant atmospheric CH4 sources (i.e., releasing >= 100 mu mol CH4 m(-2) day(-1) in summer). Due to the large spatial and temporal heterogeneity of coastal environments, high-resolution measurements will improve the reliability of CH4 estimates and confine the habitat-specific contribution to regional and global CH4 budgets.

Lake Magadi, East African Rift Valley, is a hyperalkaline and saline soda lake highly enriched in Na, K, CO, Cl, HCO, and SiOand depleted in Caand Mg, where thick evaporite deposits and siliceous sediments have been forming for 100000 years. The hydrogeochemistry and the evaporite deposits of soda lakes are subjects of growing interest in paleoclimatology, astrobiology, and planetary sciences. In Lake Magadi, different hydrates of sodium carbonate/bicarbonate and other saline minerals precipitate. The precipitation sequence of these minerals is a key for understanding the hydrochemical evolution, the paleoenvironmental conditions of ancient evaporite deposits, and industrial crystallization. However, accurate determination of the precipitation sequence of these minerals was challenging due to the dependency of the different hydrates on temperature, water activity, pH and pCO, which could induce phase transformation and secondary mineral precipitation during sample handling. Here, we report a comprehensive methodology applied for monitoring the evaporitic mineral precipitation and hydrochemical evolution of Lake Magadi. Evaporation and mineral precipitations were monitored by using in situ video microscopy and synchrotron X-ray diffraction of acoustically levitated droplets. The mineral patterns were characterized by ex situ Raman spectroscopy, X-ray diffraction, and scanning electron microscopy. Experiments were coupled with thermodynamic models to understand the evaporation and precipitation-driven hydrochemical evolution of brines. Our results closely reproduced the mineral assemblages, patterns, and textural relations observed in the natural setting. Alkaline earth carbonates and fluorite were predicted to precipitate first followed by siliceous sediments. Among the salts, dendritic and acicular trona precipitate first via fractional crystallization─reminiscent of grasslike trona layers of Lake Magadi. Halite/villiaumite, thermonatrite, and sylvite precipitate sequentially after trona from residual brines depleted in HCO. The precipitation of these minerals between trona crystals resembles the precipitation process observed in the interstitial brines of the trona layers. Thermonatrite precipitation began after trona equilibrated with the residual brines due to the absence of excess COinput. We have shown that evaporation and mineral precipitation are the major drivers for the formation of hyperalkaline, saline, and SiO-rich brines. The discrepancy between predicted and actual sulfate and phosphate ion concentrations implies the biological cycling of these ions. The combination of different in situ and ex situ methods and modeling is key to understanding the mineral phases, precipitation sequences, and textural relations of modern and ancient evaporite deposits. The synergy of these methods could be applicable in industrial crystallization and natural brines to reconstruct the hydrogeochemical and hydroclimatic conditions of soda lakes, evaporite settings, and potentially soda oceans of early Earth and extraterrestrial planets., This work was supported by European Research Council Grant No. 340863, the Spanish Ministerio de Economiá y Competitividad via Project No. CGL2016-78971-P, Junta de Andalucía via Project No. P18-FR-5008, and Spanish Ministerio de Ciencia, Innovacion y Universidades Grant No. BES- 2017-081105

This study focused on the investigation of Actinomycetes strains isolated from sediment sample of Cheliff River estuary in Mostaganem (North-west of Algeria). Identification of the 5 strains of Actinomycetes isolated from sediments by morphological, biochemical methods and by16S rRNA gene sequence analysis revealed that four strains belonged to the genus Streptomyces and one - to the genus Nocardia. No strains of Actinomycetes were isolated from water samples. The optimum growth of all strains was recorded between 28°C and 30°C and at pH 7-9. All strains had halotolerant and mesophile behavior except SSG which grew very well at 45°C and could be considered as thermotolerant bacteria. Antibacterial activity was tested against five pathogenic bacteria as Escherichia coli ATCC 25922, Staphylococcus aureus ATCC 6538, Salmonella typhi ATCC 9289, Bacillus subtilis ATCC 6633 and Pseudomonas aeruginosa ATCC 2785. All isolated strains exhibited an inhibitory activity against at least one human pathogenic bacterium. Streptomyces sp. strain SSG showed antibacterial effect against four pathogenic tested bacteria followed by Streptomyces sp. SSB1, Streptomyces sp. SSM and Nocardia sp. NSR. This study revealed that Cheliff River estuary contains Actinomycete species (Streptomyces and Nocardia) with proved antibacterial activity and could be a new source for isolation of antibiotic producing bacteria against human pathogenic bacteria

Microplastics are contaminants of emerging concern. In particular, research on the ecological effects of microplastics on microorganisms has attracted widespread attention. In this study, the role of characteristics of microplastics and environmental factors on microorganisms in sediments along the Daihai Lakeshore were investigated. Microscopic identification of microplastics revealed that the most common characteristics of microplastics were fiber, black color and particle size

Le 2 octobre 2020, des précipitations diluviennes s'abattent sur l'arrière-pays niçois. Plusieurs vallées sont alors meurtries, dont la vallée de la Vésubie où le bilan humain et socio-économique a été lourd de conséquences. Un retour d'expérience (RETEX) sur les conséquences de la crue torrentielle a été réalisé quelques mois après la catastrophe. Celui-ci a concerné l'évaluation des impacts géomorphologiques de la crue torrentielle et des phénomènes gravitaires, l'évaluation de l'exposition des réseaux stratégiques aux inondations et aux mouvements de terrain. Le RETEX a permis une analyse critique des documents de prévention et de gestion en place au moment de la crue. Il souligne les vulnérabilités de ce territoire de montagne, certaines intrinsèques comme la diversité des aléas naturels et leur intensité, l'enclavement des vallées, l'espace restreint, etc., et d'autres externes comme l'implantation de populations et d'activités en zone à risque et le développement de réseaux stratégiques ou critiques non adaptés au contexte de la montagne. On october 2, 2020, heavy rain fell on the hinterland of Nice. Several valleys were affected, including the Vésubie valley, where severe human and socio-economic damages were reported. A feedback report (RETEX) on the effects of the torrential flood was carried out a few months after the disaster. This concerned the assessment of the geomorphological impacts of the torrential flood and gravity phenomena, the exposure of strategic networks to flooding and ground movements. The feedback report allowed a critical analysis of the prevention and management tools in place at the time of the flood. It underlines the vulnerabilities of this mountain territory, some intrinsic such as the diversity of natural hazards and their intensity, the enclosure of the valleys, the confined space... and others external such as the establishment of populations and activities in risky areas, the implementation of strategic or critical networks which are insufficiently adapted to the mountain context.

Dans le contexte d'aggravation des aléas naturels et des risques associés induits par la croissance urbaine, les sociétés doivent davantage répondre à l'enjeu du développement d'outils de prévention. Comme le souligne la stratégie internationale de réduction des risques naturels, les méthodes participatives, basées sur le partage de l'information et la transmission de connaissances sur les risques, sont plébiscitées. Nous présentons ici une démarche d'acquisition de savoirs sur les dynamiques naturelles et humaines dans un territoire à risque, à des fins de transmission d'une culture pratique du risque. Cette démarche, développée dans le cadre d'une recherche-action et généralisée dans un modèle, a été appliquée à trois territoires à risque glissement de terrain. À partir des similitudes et des contrastes dans la perception du risque par les populations et les acteurs, des pistes d'amélioration de la prévention sont proposées, en même temps que la posture de recherche-action pour traiter les risques majeurs est discutée. In the context of the worsening of the major natural hazards induced by urban growth, societies must respond more to the challenge of developing prevention tools. As underlined by the International Strategy for Disaster Reduction, participatory methods, based on the sharing of information and the transmission of knowledge on risks are acclaimed. We present here an approach to acquiring knowledge on natural and human dynamics in a territory subject to landslide risk for the purpose of transmitting a practical risk culture. This approach, developed through action research, generalized in a model, was applied to three landslide risk areas. Based on the similarities and contrasts in the perception of risk by the populations, ideas for improving prevention are proposed at the same time as the action-research posture to treat major risks is discussed.

Riveraine du Léman, la ville de Thonon-les-Bains, soucieuse de l'évolution morphologique de son littoral, a souhaité une collaboration entre chercheurs et praticiens sur la question de l'érosion des rives du lac. Un suivi sur 10 ans (2010-2020) a montré que le recul littoral, parfois important (jusqu'à 1,50 m), dépend à la fois de processus biophysiques (essentiellement les vagues et la dérive littorale créées par la bise) et de forçages anthropiques (rétention des sédiments par les barrages amont, activité de prélèvements de sédiments à l'embouchure de la Dranse dans le Léman et batillage initié par la navigation). L'impact majeur de cette érosion littorale exacerbée étant d'ordre économique (alimentation artificielle régulière coûteuse) et paysager (grignotage du sentier littoral risquant de déstabiliser le mur de Ripaille, patrimoine bâti de la ville), les propositions d'actions ont été fondées, d'une part, sur la restauration douce du littoral (génie végétal) et la suppression d'aménagements en dur (deux épis) pour faciliter la redistribution des sédiments par la dérive littorale et, d'autre part, sur un repositionnement quant à l'extraction des apports naturels de sédiments. Si un rapport de confiance a été établi entre les chercheurs et la ville, la décision de la préfecture de Haute-Savoie de ne pas reconduire l'autorisation de prélèvement sédimentaire, en se fondant, en partie, sur les conclusions de ces études, a suscité une vive réaction de l'entreprise, rendant le dialogue difficile. Toutefois la dernière étude menée sur le littoral thononais (suivi géomorphologique), en révélant une amélioration de la situation (entre 2014 et 2019, le pourcentage de littoral érodé est passé de 60 à 42 %), valorise la décision prise. Next to the Leman Lake, the city of Thonon-les-Bains monitors the morphological evolution of its shoreline. Therefore, the city has commissioned a series of studies over a 10 year-period. These studies have been carried out thanks to the cooperation of researchers in geography and experts in the private sector. The conclusion of the first study on erosion has shown that the significant decline of the shoreline (up to 1.5 meters) is due to biophysical (mainly waves and the lakeside drift caused by the north wind) and human forcing (retention of sediment by upriver dams, extraction of sediment at the intersection of the Dranse River and the Leman Lake and ship-generated waves). The main impact of this erosion is on the economy (frequent and expensive artificial supply of sand) and the landscape (damaged coastal path which endangers the stability of the Ripaille Wall, a built heritage of the city). Thus, proposals have been based on 1/ the soft restoration of the shoreline (eco-engineering techniques), 2/ the suppression of hard structures (two spurs to facilitate the distribution of sediments by the coastal drift), and 3/ a revision of the extraction of the natural supply of sediments. Confidence has been established between the city and the researchers. However, the decision made by the local government to stop future extractions of sediments has caused a strong reaction from the company. Subsequent dialogues have been difficult. Nevertheless, the latest study made on the lakeshore of Thonon has shown an improvement of the situation: the percentage of eroded lakeshore has decreased from 60 % to 42 % between 2014 and 2019. This result underlines the revelancy of the decision made by the local government, despite the fear of a possible socioeconomic fallout.

L'augmentation des températures dans un contexte de changement climatique devrait être accompagnée par une hausse de l'évaporation et de l'évapotranspiration (ET0). Toutefois des études ont montré une baisse de l'évaporation (ou de l'évapotranspiration) dans certaines régions du monde. Ce contraste entre la baisse de l'évaporation et l'augmentation des températures, qui varie en fonction des zones climatiques, est connu sous le nom de "paradoxe d'évaporation". L'objectif de ce travail est d'en examiner les causes dans la vallée du fleuve Sénégal. Les données climatiques (évaporation, pluie, température, humidité relative, durée d'insolation) observées aux stations de Bakel, Podor, Matam et Saint-Louis, ont été traitées sur la période 1981-2015. La méthodologie comporte : 1/ la détection des ruptures par le test de PETTITT, 2/ l'analyse de la relation entre l'évaporation / évapotranspiration et les variables climatiques par le test de corrélation de PEARSON, 3/ la détection des tendances de l'évaporation / ET0 et des variables climatiques par le test de MANN-KENDALL et la pente de SEN. Les ruptures de l'évaporation et de l'évapotranspiration sont respectivement identifiées dans les années 1990 et 2000. La corrélation de PEARSON montre que l'évaporation et l'ET0 ont pour relation la plus forte, celle avec l'humidité relative. Le test de MANN-KENDALL révèle une baisse significative (p-value ˂ 0,001) de l'évaporation et une évolution nuancée (baisse et hausse) de l'évapotranspiration de référence. Cette baisse de l'évaporation, combinée à une hausse significative de la température, met en évidence l'existence d'un paradoxe d'évaporation dans la vallée du fleuve Sénégal. Ce paradoxe d'évaporation s'explique ici par la hausse significative de l'humidité relative et de la pluviométrie, mais aussi par la baisse significative de la durée d'insolation. The increase in temperatures in a context of climate change should be accompanied by an increase in evaporation or evapotranspiration (ET0). However, studies have shown a decrease in evaporation (or evapotranspiration) in certain regions of the world. This contrast between the decrease in evaporation and the increase in temperature, which varies according to the climatic zones, is known as the "evaporation paradox". The objective of this work is to examine the causes in the climatic context of the Senegal River Valley. The climatic data (evaporation, rain, temperature, relative humidity, insolation) observed at the stations of Bakel, Podor, Matam and Saint-Louis were used over the period 1981-2015. The methodology includes: 1/ the detection of ruptures by the PETTITT test, 2/ the analysis of the relationship between evaporation / evapotranspiration and climatic variables by the PEARSON correlation test, 3/ the detection of trends in Evaporation / ET0 and climate variables by the MANN-KENDALL test and SEN’s slope. The breaks in evaporation and evapotranspiration are respectively identified in the 1990s and 2000s. The PEARSON correlation shows that evaporation and ET0 have their strongest relationship with the relative humidity. MANN-KENDALL's test reveals a significant decrease (p-value ˂ 0.001) in evaporation and a mixed trend (decrease and increase) in reference evapotranspiration. This decrease in evaporation, combined with a significant increase in temperature, highlights the existence of an evaporation paradox in the Senegal river valley. This evaporation paradox is explained here by the significant increase in relative humidity and rainfall, but also by the significant decrease in sunshine hours.

Sediment properties such as water content (WC) and grain size (GS) are essential to characterize the environmental conditions of tidal flats. This article aimed to develop appropriate models to estimate the WC and GS of surface sediments for an intertidal flat on the Red river delta (Vietnam) using Sentinel 2A (S2A) images. The spectral reflectance, WC, and GS of 96 sub-samples from 12 sediment samples collected on December 17, 2017 were measured to clarify their relationships. The WC was highly correlated with the reflectance ratio of two shortwave-infrared bands, R(2190)/R(1610) (R² = 0.93). The median GS (D₅₀) at 0%, 15%, and 20% of WC was significantly correlated with the reflectance ratio of the near-infrared band (842 nm) versus the visible-green band (560 nm) (R² > 0.78). Next, D₅₀ was estimated from a multivariate regression model using this band ratio, the visible-red band (665 nm), and WC. The accuracy of the models was verified by comparisons with WC and D₅₀ from 20 samples collected on March 12th 2019 (RMSE of both WC and D₅₀ < 15%). Then, the WC and sediment type distributions were mapped by applying these models to two S2A scenes. The maps showed high WC (>30%) in very fine sediments (silts), which is consistent with other intertidal flats with similar sediment types. This article was limited to fine sediment samples. Therefore, our next step is to incorporate coarse sediments into the models to provide more universal mapping of WC and sediment types.

Palk Bay is a marine protected area with a sensitive ecosystem like coral reefs, seagrass meadows, and mangroves with rich biodiversity. Observations indicate that these ecosystems are at risk from organic contaminants like petroleum hydrocarbon. In view of this Total Petroleum Hydrocarbons (TPHs) were measured in the surface sediments from the Palk Bay. Sediment samples were extracted in n-hexane and quantified using a fluorescence spectrophotometer. The concentrations of TPH varied from 0.78 ± 0.28 to 2.70 ± 0.84 μg/g (wet wt.) and were relatively higher in southern region than the northern. Higher TPH levels at the Bay are attributed to the anthropogenic activities and hydrodynamic characteristics. Analysis of sediment texture and organic carbon can provide insights into the distribution of TPH. Significant correlation was found between the sediment texture with TPHs and TOC. The average proportions of sediment grain sizes were 88.39 ± 3.92% of sand, 70.54 ± 2.24% of loamy sand, 62.22 ± 3.76% of sandy loam, and 29.58 ± 5.59% silt loam. Silt and clay of sediment have more capacity to hold the TPH because of their particle size. This is in consonance with the observed TOC levels in the range of 0.11 ± 0.05% and 2.78 ± 1.12% (dry weight). TPH concentrations are observed within the permissible limits and the data may serve as baseline information for identifying pristine coastal ecosystems like Palk Bay.

The biodiversity of actinobacteria in the Mediterranean Sea habitat has drawn limited attention compared to that paid to terrestrial habitats. The work presented here focused on the biodiversity of culturable marine actinobacteria from sediments and seawater collected from the Algerian coast, and led to the identification of 114 actinobacterial isolates. The morphological study revealed higher actinobacterial diversity in sediment than in seawater. Fifty strains were selected for 16 S rRNAgene sequencing. The results revealed that the isolates belonged to ten different genera, Streptomyces (n = 17) and Micromonospora (n = 15) being the most dominant. The remaining actinobacterial isolates, identified as belonging to rare genera, included Nocardia (n = 5), Nocardiopsis (n = 3), Saccharothrix (n = 2), Rhodococcus (n = 2), Promicromonospora (n = 2), Nonomuraea (n = 2), Actinomadura (n = 1) and Saccharomonospora (n = 1). Interestingly, through 16 S rRNA sequence-based identification and phylogenetic analysis, two strains of the genus Streptomyces (MAT1 and MAS22) and a strain of the genus Nonomuraea (MAG8) both constituted a novel species. Screening of antibacterial activity of identified isolates against a panel of human pathogenic bacteria demonstrated that 36% of the isolates were active, particularly against Gram-positive bacteria. The ability to grow in the presence of NaCl and seawater revealed that 98% of the strains were halotolerant, with different levels of NaCl acceptance (from 3 to 13%) but no isolates required seawater to grow.

Detailed petrographic and geochemical properties of WPNSA ground mosaic mortar were determined by multi-analytical approaches, and its construction history was revealed by the OSL dating method. The ground mosaics of WPNSA in Laodicea are observed in an area of 20x14 m2, partially deteriorated. The ground mosaic mortar exhibits 5 layers which consist of statumen, rudus (coarse grained mortar with 3-4 cm thickness), nucleus (fine grained mortar with 2-3 cm thickness), bedding mortar (1-2 mm thickness), and tesselatum. Transitions between layers are not obvious. Mortar samples were obtained by mixing weak graded “fine sand” aggregates with the lime binder (aggregate to binder ratio is 1:2 by volume). Aggregates consist of marble, mica schist, quartzite, serpentinite, gabbro, harzburgite, limestone, travertine, ceramic, quartz, calcite, mica minerals, pyroxene fragments. Shrinkage cracks and lime lumps are commonly observed in mortar samples. The WPNSA mortar samples generally show similar features, indicating that there was no change in the raw material as well as on the application technique used during the construction. The archaeological record together with the Optically Stimulated Luminescence (OSL) ages indicate that the ground mosaic in WPNSA was built up between the middle of the 4th century and the beginning of the 5th centuries AD, and then the building was abandoned by the great earthquake at the beginning of the 6th century., Periodico di Mineralogia, Vol. 92 No. 1 (2023)

Sub-Antarctic fjords are among the environments most affected by the recent climate change. In our dynamically changing world, it is essential to monitor changes in these vulnerable settings. Here, we present a baseline study of “living” (rose-bengal-stained) benthic foraminifera from fjords of South Georgia, including fjords with and without tidewater glaciers. Their distribution is analyzed in the light of new fjord water and sediment property data, including grain size and sorting, total organic carbon, total sulfur, and δ13C of bulk organic matter. Four well-defined foraminiferal assemblages are recognized. Miliammina earlandi dominates in the most restricted, near-shore and glacier-proximal habitats, Cassidulinoides aff. parkerianus in mid-fjord areas, and Globocassidulina aff. rossensis and an assemblage dominated by Ammobaculites rostratus, Reophax subfusiformis, and Astrononion echolsi are in the outer parts of the fjords. Miliammina earlandi can tolerate strong glacial influence, including high sedimentation rates in fjord heads and sediment anoxia, as inferred from sediment color and total organic carbon / sulfur ratios. This versatile species thrives both in the food-poor inner reaches of fjords that receive mainly refractory petrogenic organic matter from glacial meltwater and in shallow-water coves, where it benefits from an abundant supply of fresh, terrestrial, and marine organic matter. A smooth-walled variant of C. aff. parkerianus, apparently endemic to South Georgia, is the calcareous rotaliid best adapted to inner-fjord conditions characterized by moderate glacial influence and sedimentation rates and showing no preference for particular sedimentary redox conditions. The outer parts of fjords with clear, well-oxygenated bottom water are inhabited by G. aff. rossensis. Ammobaculites rostratus, R. subfusiformis, and A. echolsi dominate in the deepest-water settings, with water salinities ≥ 33.9 PSU and temperatures 0.2–1.4 ∘C, characteristic of winter water and Upper Circumpolar Deep Water. The inner- and mid-fjord foraminiferal assemblages seem specific to South Georgia, although with continued warming and deglaciation, they may become more widespread in the Southern Ocean.

Road dust (RD), roadside soils (RS) and river surface sediments (sediments) are important materials for evaluating contaminant levels in urban areas. This study aims to investigate the contaminant characteristics, pollution levels and ecological risks of RD, RS and sediments of potentially toxic elements (PTEs), including Cr, Ni, Cu, Zn, As, Cd, Hg and Pb, in the central urban area of Zhengzhou. Results reveal that RD shows a higher concentration of PTEs when compared to the other two environments. The spatial distribution characteristics suggest that PTEs in RD, RS and sediments may come from different sources. The geo-accumulation index (Igeo) was used to describe that the RD was moderately to extremely contaminated with Cd and Hg, while both RS and sediments were significantly enriched with Cd and Hg. For RD, RS and sediments, the potential ecological risk (RI) demonstrates a high potential ecological risk from Cd and Hg. Overall, PTEs in Zhengzhou road dust present a moderate risk.

Anthropic activities are responsible for the increase in environmental contamination, especially in aquatic systems, demanding studies to assess and monitor contamination levels in different water bodies. We have done a chemical characterization of eleven sediments in order to evaluate the level of contamination by domestic sewage from the Capibaribe River, between the cities of Santa Cruz do Capibaribe and Toritama in the state of Pernambuco, Brazil. The classical analyses were performed, as well as the determination of sterol biomarkers using liquid chromatography coupled to tandem mass spectrometry. Sterol ratios corroborated the presence of fecal-derived organic matter, mainly in the sediments collected in regions of higher population occupation. The multivariate statistical analysis clearly showed the regions from the most contaminated to the least contaminated, indicating the severe contamination by domestic sewage in the region. To the best of our knowledge, this is the first study to assess anthropic contamination of the Capibaribe River by using sterol biomarkers and classical analyses in an integrative data interpretation. This can be helpful when making decisions about preventive and corrective actions for human health concerns.

Leaching behaviour is an important evidence of soil quality. The assessment of leaching of heavy metals from the contaminated soil is vital for environmental applications. However, leaching may differ in soil stabilised by various ratios of binders. In this study we measured leaching behaviour of soil contaminated by As, Cd, Co, Cr, Cu, Hg, Ni, Pb, V, Zn, methyl Hg, aliphatic compounds of hydrocarbons, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and dissolved organic carbon (DOC). To evaluate leaching of these substances we tested the effects of changed amount of binder (120 kg and 150 kg) and binder ratios (70/30 %, 50/50 % and 30/70 %) added to soil samples. Soil was dredged from several stations in Ostrand area, SCA Sundsvall Ortvikens Pappersbruk. The results demonstrated a systematically decreasing leaching with the increased slag. The contribution of this research include: (i) devising systematic approach to extract information on leaching from stabilised soil collected from the coastal area of Bothnian Bay, (ii) developing a workflow for stabilising soils by various combination of Portland cement Basement CEM II/A-V (SS EN 197-1) and ground granulated blast furnace slag (GGBFS), Bremen type (SS EN 15167-1), (iii) determining water ratio and density for the untreated and stabilised soil and performing comparative analysis, (iv) evaluating chemical content of pollutants and toxic elements in the aggregated soil samples. Treatment of the contaminated soil by binders improved its parameters by the increased strength and decreased leaching of heavy metals and toxic elements.

The accumulation of microplastics (MPs) in the sediments of a stormwater treatment pond was studied to gain knowledge on how these facilities protect the natural environment against this emerging pollutant. Thirteen sediment samples were analyzed for MPs down to 10 μm, mapping the pattern of accumulation in the pond. The average abundance in terms of MP-number and mass was 11.8 μg kg−1and 44,383 item kg−1, respectively. They were rather unevenly distributed, with concentrations varying up to two orders of magnitude within the pond, showing that a trustworthy quantification of MPs retained by such units must rely on many and well-distributed subsamples. Buoyant MPs made up 95.4 % of the MP-mass and 83.5 % of the MP-number and in most of the sampled locations, polypropylene dominated the polymer fingerprint, followed by polyethylene. No spatial pattern in the distribution of MPs in the pond was identified. Instead, the MP content correlated to the organic matter and silt content, indicating that the processes leading to deposition could be similar. A computational fluid dynamics model was set up and used to simulate the transport mechanisms governing the conveyance of MPs in the pond from water to sediments. The results showed that the combination of advection and dispersion were likely the driving mechanism for buoyant (and non-buoyant) MPs to get in contact with the sediment bed and spread over the pond. Once in contact with the sediments, the MPs would have some probability of being permanently incorporated and hereby preventing them from entering the downstream aquatic environment.

Concentrations of polycyclic aromatic hydrocarbons (PAH) were studied in 36 sediment samples collected from 29 sites in the central Adriatic Sea. The total concentration of PAH showed high variability, ranging from 42.85 µg kg−1 in open sea sediments to 28, 662 µg kg−1 in the sediments of Šibenik Bay. Unsubstituted, parent PAH were dominant PAH compounds in the entire area of Šibenik Bay and most of the stations in the coastal area. In Kaštela Bay, methyl PAH concentrations were higher than the concentrations of unsubstituted PAH, whereas in the sediments along the mid-Adriatic transect, similar concentrations of both PAH fractions were determined. PAH sources were investigated by applying the Positive Matrix Factorization software developed by the U.S. Environmental Protection Agency (USEPA). The results indicate the presence of four sources, two of which can be considered petrogenic and two pyrogenic. The contribution of the sources to the total concentration PAH at each station indicates the dominance of pyrogenic sources in Šibenik Bay and at most stations in the coastal area. In the sediments along the mid-Adriatic transversal, as well as in Kaštela Bay, PAHs originate mainly from petrogenic sources. The obtained results show that PMF can be a suitable tool for control of PAH pollution and thus, for the management of various activities in the Adriatic region. Seasonal differences between the contributions of sources in the Kaštela and Šibenik bays indicate that the contribution of traffic to the total concentration of PAH was higher during the tourist season. The carcinogenic risk of PAH determined by toxicity equivalent (TEQ) calculations showed an increased carcinogenic risk in the whole area of Šibenik Bay, regardless of the number of PAH compounds considered for the calculations. A low PAH-related carcinogenic risk was found for the rest of the study area.

В настоящей статье поставлена задача - отразить современный научный уровень в области геологического изучения и литолого-фациальных особенностей в горюче-сланцевом бассейне Кызылкума. Выполнено литолого-фациальное моделирование территории Кызылкума в период накопления в бассейне седиментации исходного субстрата горючих сланцев. Характеризуются литолого-геохимические особенности, вещественный состав и металлоносность горючих сланцев, которые могут явится стратегическим сырьем для получения многих ценных товаров народного потребления., In the article under consideration, the task is to reflect the modern scientific level in the field of geological study and lithological-facies features of the oil-shale basin of Kyzylkum. Lithological and facisubstrate of oil shale in the sedimentation basin. The lithological and geochemical features, the mes modeling of the territory of Kyzylkum was performed during the accumulation of the initial material composition and metallicity of oil shales, which can be a strategic raw material for obtaining many valuable consumer goods, are characterized., Нефтяная провинция, Выпуск 1 (33) 2023, Pages 72-80

Sediment formation in drinking water distribution systems can lead to brown water at customer taps. Previous studies have shown that sediment formation is closely linked with (micro)biological processes in the distribution system, however the mechanism is not fully understood. Most available studies on discoloration or sediment formation mechanism are based on modeling, pilot-scale experiments, or low frequency data collected during pipe flushing. In this study, long-term sediment development in a large-scale drinking water distribution system was studied at one location over 11 years and at several locations along a known water trajectory during one year. Particulate material was collected at several locations using built-in and mobile filters that were connected to transport and distribution pipes in a semi-continuous manner. The volume of the collected material varied seasonally and the highest volumes were collected in the summer season. The material followed similar variations as temperature, invertebrates biomass and concentration of Aeromonas. The results showed that particulate matter of the sediment at downstream distribution locations was not released by the treatment works but instead forms along the distribution network, with increasing particle/floc size, biomass and Fe and Mn content. The large crustacean, Asellus, contributed to material production through feces excretion and formation of detritus by degradation of exoskeletons of dead animals. Detailed chemical characterization of the collected material showed the presence of proteins, calcium carbonate and iron precipitates. A similar sediment composition in a reference distribution system where customer complaints about brown water are experienced less frequently suggests that the sediment formation mechanism is the same but that water quality of the treatment effluent impacts the extent of material formation and growth of invertebrates. Overall, the results indicate that sediment formation in the distribution system is the result of complex combinations of (micro)biological and bio-chemical processes, including aggregation of particles with organic and inorganic matter, microbial growth on particles and biofilm, biomineralization, and growth of invertebrates. The determining factors to limit sediment formation, however, could not be identified. Further research is required to focus on the impact of treatment on shaping the distribution system ecosystem.

International audience

High-mountain lakes and rivers are usually oligotrophic and strongly influenced by atmospheric transport processes. Thus, wet deposition of reactive N species (Nr), mainly in the form of nitrate (NO), is a major source of N input in these high-mountain ecosystems. Bacterial denitrifiers are thought to be largely responsible for reduction of NO to nitrous oxide (NO) and molecular dinitrogen (N) as main biological pathway of N removal in these ecosystems. Nitrifiers, through the oxidation of ammonium to NO, can also be a source of NO and NO. However, there is uncertainty regarding the abiotic and biotic factors controlling Nr elimination from aquatic ecosystems at different altitudes and seasons. We examined the efficiency of Nr removal as NO and N (total removal) or N only (clean removal) in a model lake and its downwater river ecosystem (Sierra Nevada, Spain) representative of Mediterranean high-mountain freshwater ecosystems along an altitudinal gradient during the warm period of the year. Denitrification activity and the abundance of nitrifiers and denitrifiers in sediments were measured at thaw, mid ice-free and late ice-free periods. We found the efficiency of total and clean removal of Nr increased from the downwater river to the high-mountain lake. Regardless of the location, the efficiency of total removal of Nr decreased over the ice-free period whereas that of clean removal of Nr peaked at mid ice-free period. The efficiency of total removal of Nr was mainly controlled by the abundance of archaeal nitrifiers and bacterial denitrifiers. Abiotic (ammonium and NO concentration) and biotic (mainly nosZI-type denitrifiers) factors drove changes in the efficiency of clean removal of Nr. Our results suggest that abiotic and biotic factors can control the efficiencies of Nr removal in Mediterranean high-mountain lakes and their downwater rivers, and that these efficiencies increase with altitude and vary over the ice-free period., We thank two anonymous reviewers and Editor (Dr. Sergi Sabater) whose criticism greatly improved the manuscript. This study was funded by FEDER/Junta de Andalucía-Consejería de Economía y Conocimiento/Proyecto (A-RNM-237-UGR18), and partially by PID2020-118872RB-I00 (MICIN/AEI/10.13039/501100011033) projects. This research is also part of the project “Thematic Center on Mountain Ecosystem & Remote sensing, Deep learning-AI e-Services University of Granada-Sierra Nevada” (LifeWatch-2019-10-UGR-01), which has been co-funded by the Ministry of Science and Innovation through the FEDER funds from the Spanish Pluriregional Operational Program 2014-2020 (POPE), LifeWatch-ERIC action line.

Mesocosms allow the simulation of environmentally relevant conditions and can be used to establish more realistic scenarios of organism exposure to nanoparticles. An indoor mesocosm experiment simulating an aquatic stream ecosystem was conducted to assess the toxicokinetics and bioaccumulation of silver sulfide nanoparticles (Ag2S NPs) and AgNO3 in the freshwater invertebrates Girardia tigrina, Physa acuta and Chironomus riparius, and determine if previous single-species tests can predict bioaccumulation in the mesocosm. Water was daily spiked at 10 μg Ag L−1. Ag concentrations in water and sediment reached values of 13.4 μg Ag L−1 and 0.30 μg Ag g−1 in the Ag2S NP exposure, and 12.8 μg Ag L−1 and 0.20 μg Ag g−1 in the AgNO3. Silver was bioaccumulated by the species from both treatments, but with approximately 1.5, 3 and 11 times higher body Ag concentrations in AgNO3 compared to Ag2S NP exposures in snails, chironomids and planarians, respectively. In the Ag2S NP exposures, the observed uptake was probably of the particulate form. This demonstrates that this more environmentally relevant Ag nanoform may be bioavailable for uptake by benthic organisms. Interspecies interactions likely occurred, namely predation (planarians fed on chironomids and snails), which somehow influenced Ag uptake/bioaccumulation, possibly by altering organisms´ foraging behaviour. Higher Ag uptake rate constants were determined for AgNO3 (0.64, 80.4 and 1.12 Lwater g−1organism day−1) than for Ag2S NPs (0.05, 2.65 and 0.32 Lwater g−1organism day−1) for planarians, snails and chironomids, respectively. Biomagnification under environmentally realistic exposure seemed to be low, although it was likely to occur in the food chain P. acuta to G. tigrina exposed to AgNO3. Single-species tests generally could not reliably predict Ag bioaccumulation in the more complex mesocosm scenario. This study provides methodologies/data to better understand exposure, toxicokinetics and bioaccumulation of Ag in complex systems, reinforcing the need to use mesocosm studies to improve the risk assessment of environmental contaminants, specifically NPs, in aquatic environments.

We reconstruct the Holocene shore displacement of the Vastervik-Gamlebyviken area on the southeast coast of Sweden, characterised by a maritime cultural landscape and archaeological significance since the Mesolithic. Sediment cores were retrieved from four lake basins that have been raised above sea level due to the postglacial land uplift and eustatic sea level changes after the melting of the Fennoscandian Ice Sheet. The cores were radiocarbon dated and analysed for loss on ignition and diatoms. The isolation thresholds of the basins were determined using LiDAR data. The results provide evidence for the initiation of the first Littorina Sea transgression in this area at 8.5 thousand calibrated years before present (cal. ka BP). A relative sea level rise by similar to 7 m a.s.l. is recorded between 8.0 and 7.5 cal. ka BP with a highstand at similar to 22 m a.s.l. between 7.5 and 6.2 cal. ka BP. These phases coincide with the second and third Littorina Sea transgressions, respectively, in the Blekinge area, southern Sweden and are consistent with the final deglaciation of North America. After 6.2 cal. ka BP, the relative sea level dropped below 22 m a.s.l., and remained at similar to 20 m a.s.l. until 4.6 cal. ka BP coinciding with the fourth Littorina Sea transgression in Blekinge. From 4.6 to 4.2 cal. ka BP, the shore displacement shows a regression rate of 10 mm a(-1) followed by a slowdown with a mean value of 4.6 mm a(-1) until 1.6 cal. ka BP, when the relative sea level dropped below 3.3 m a.s.l. The Middle to Late Holocene highstand and other periods of minor sea level transgressions and/or higher salinity between 6.2 and 1.7 cal. ka BP are attributed to a combination of warmer climate and higher inflow of saline waters in the southern Baltic Sea due to stronger westerlies, caused by variations in the North Atlantic atmospheric patterns.