Six marine sediment cores from the Gulf of Lions continental slope (700-1700 in water depth) were analyzed for stable lead isotopes and Pb-210 geochronology in order to reconstruct lead atmospheric fallout pattern during the last century. The detrital lead contribution is 25 mu g g(-1) and the mean sediment anthropogenic inventory is 110 +/- 7 mu g cm(-2), a little bit higher than atmospheric deposition estimate. Anthropogenic lead accumulation in sediments peaked in early 1970s (1973 +/- 2) in agreement with lead emissions features. For the period 1986-1997, the sediment signal also reflect the decrease of atmospheric lead described by independent atmospheric fallout investigations. The anthropogenic Pb deposition in the late 1990s was similar to the 1950s deposition, attesting thus of the output of European environmental policies.

National audience

[Departement_IRSTEA]GMA [TR1_IRSTEA]21 - TECHNEAU / EPURE | International audience | Phosphorus removal from wastewater has been of growing interest for some decades to avoid eutrophication in surface water. In subsurface constructed wetlands precipitation and adsorption are the main mechanisms responsible of P uptake. The use of calcareous media is attractive because of p-ca interactions. Two media (calcite and recycled crushed concrete (rcc)) were examined in batch and continuous systems. They show attractive sorption capacities using batch experiments, however experiments carried out in open reactors pointed out some limitation in retention capacities and effluent quality. rcc was sensitive to a strong dissolution leading to a quick phosphorus precipitation but induced high conductivity and ph values in the treated water. Calcite efficiency depended on the material dissolution rate, directly linked to the carbonate equilibrium of the solution. Microscopic observations of the calcite surface show crystal making of phosphorus precipitate. Crystal growth seems to be the main P uptake once materials surfaces are covered. No experimental condition allows to reach an effluent concentration below 2 mgp.l-1.

[Departement_IRSTEA]Ecotechnologies [TR1_IRSTEA]TED [Axe_IRSTEA]TED-EPURE | International audience | Modeling water flow in a VFCW is a prerequisite to model wastewater treatment using process based filtering models. As for soils, when the vertical structure varies in different material types, it has a significant impact on water flow passing through it. The heterogeneous filtering material is composed of a mix of mineral porous material, and organic matter which makes its hydraulic characterization a difficult task. Indeed, the porosity may serve as preferential flow paths through which water can bypass most of the soil porous matrix in a largely unpredictable way. Consequently, non-equilibrium conditions in pressure heads are created between preferential flow paths and the soil matrix pore region. Preferential flows limit the applicability of standard models for water flow that are commonly based on Richards’ equation. Even if it is possible to simulate water content variations within a VFCW, we can not correctly model outflow with the standard van Genuchten-Mualem function. A number of various model approaches have been proposed to overcome this problem. These models mostly try to separately describe flow and transport in preferred flow paths and slow or stagnant pore regions. The objective of this study was to compare the various existing models simulating the preferential flows within the French VFCWs. Moreover, by assuming that several layers hydraulically different compose the VFCW, we tested at which layer(s) it is necessary to apply the non-equilibrium models. A tracer experiment was performed to evaluate the non-equilibrium degree. It was conducted on a 100 p.e. plant in operation since 2004. Monitoring consisted in measuring inlet and outlet flows, infiltration rates and water content at a time interval of 1 minute. We used the HYDRUS-1D software package containing various non-equilibrium flow modeling approaches. The physical non-equilibrium transport models were used to simulate outflow, the tracer breakthrough curve as well as water contents within a French-type VFCW. Physical non-equilibrium models include the dual-porosity model (mobile-immobile water model, with water content mass transfer or head mass transfer), and the dual-permeability model (matrix and fracture pore regions). We also applied a bimodal single-domain approach (Durner model) in order to see if it is actually necessary to use non-equilibrium models to effectively simulate VFCW outflow. Performance of the various non-equilibrium models (accuracy and limitation) was assessed by comparing the simulated and measured tracer fluxes using the mean square relative error (MSRE) of prediction. The comparison between measured and simulated tracer breakthrough curves indicates that the non-equilibrium (dual-porosity or dual-permeability model) approach seem to be the most appropriate for simulating preferential flow paths. In addition, simulations reveal that all layers participate in the preferential flow path process. These preferential flow paths are mainly due to the sludge layer that has been developed on the surface of VFCW since its start-up (swelling/shrinking during the feeding/rest periods) and to the network of roots and rhizomes present in it.

Microplastics (MP) are contaminants able to cause adverse effects on organisms. MPs are capable to interact with other environmental contaminants, including pesticides, altering their toxicity. The objective of the study was to research the sublethal effects (enzymatic activity) of pesticides alone and in combination with MPs. Cholinesterase enzymes are used as biomarkers to determine and evaluate the effects produced in organisms after exposure to pollutants. This study showed the acetylcholinesterase (AChE) enzymatic activity in the tissue of Solea senegalensis exposed to two environmental pollutants, the insecticide chlorpyrifos (CPF) and antibacterial triclosan (TCS) with and without microplastics (MPs). Solea senegalensis was chosen because it is a species in high demand because of its high economic value in southern Europe, as well as the use of this species in ecotoxicology and its increasing use as sentinel species, which justify using it to assess biological effects of pollutants. Toxicity tests were performed in organisms exposed to concentrations of between 5 and 80 mu g/L CPF and 0.1 and 0.4 mg/L TCS for 96 h. In addition, each test incorporated MPs that were added at different concentrations in order to evaluate their role as a possible enhancer of the effects caused by the previous pollutants. In the case of CPF, the head and muscle tissue cholinesterase activity was inhibited from a concentration of 5 mu g/L both without and with MPs, and the AChE enzymatic activity for the treatment with MPs was approximately half the activity for the treatment without MPs in the tissues studied. Besides, TCS inhibited the cholinesterase activity at a concentration of 0.3 mg/L in the muscle of S. senegalensis. In contrast, no significant differences were observed in the TCS + MP treatment compared to the controls. These results showed the importance of studies in assessing the anticholinesterase effects of pesticides combined with microplastics due to the abundance of these contaminants in the marine environment and the role of cholinesterase activity (biomarker) in the neurotransmission of key physiological processes.

Water stored in open-pit lakes can be a water resource when the mine is closed. This study aimed to develop a reliable model to evaluate the water quality, based on the sulphate concentration, in the Reocín Mine area (Spain) by using geostatistical algo rithms. To this end, water samples were taken from the beginning of the flooding period in November 2004 until August 2020. The model showed that the sulphate concentration was highest between February 2009 and February 2012 and decreased as the flooding process progressed. The area with the highest concentration (2000 mg L-1) was the central part of the study area, where the mine is located, while in the northeast and southwest, the values from the beginning of the flooding period were lower, below 500 mg L-1. In the last obtained model, the values decreased considerably to 1300 mg L-1 in the central area and below 250 mg L-1 in the northeast and southwest areas. The modelling conducted to assess the water quality in the area of influence of the mine determined that the flooding process has little influence on the water in the rivers and streams in the area, since the sulphate concentration measured in the adjacent rivers and streams was less than 250 mg L-1, indicating that anomalous concentrations were only found in the open-pit area. It was shown that geostatistical algorithms are useful tools that can be used to model the intensity and extension of water pollutants in space over time.

Noise pollution is a pervasive factor that increasingly threatens natural resources and human health worldwide. In particular, large-scale changes in road networks have driven shifts in the acoustic environment of rural landscapes during the past few decades. Using sampling plots from the Spanish Landscape Monitoring System (SISPARES), 16 km2 each, we modelled the spatio-temporal changes in road traffic noise pollution in Ecoregion 1 of Spain (approximately 66,000 km2). We selected a study period that was characterised by significant changes in the size of the road network and the vehicle fleet (i.e. between 1995 and 2014) and used standard and validated acoustic computation methods for environmental noise modelling (i.e. European Directive, 2002/49/EC) within sampling plots. We then applied a multiple linear regression to expand noise modelling throughout the whole of Ecoregion 1. Our results showed that the noise level increased by 1.7 dB(A) in average per decade in approximately 65% of the territory, decreased by 1.3 dB(A) per decade in about 33%, and remained unchanged in 2%. This suggests that road traffic noise pollution levels may not grow homogeneously in large geographical areas, maybe due to the concentration of large fast traffic flows on modern motorways connecting towns. Our research exemplifies how landscape monitoring systems such as cost-effective approaches may play an important role when assessing spatio-temporal patterns and the impact of anthropogenic noise pollution at large geographical scales, and even more so in a global context of constricted resources and limited availability of historical data on traffic and environmental noise monitoring.

Embargo until February 12, 2022 | Cost-efficient and environmentally friendly treatment of hydraulic fracturing effluents is of great significance for the sustainable development of shale gas exploration. We investigated the synergistic effects of plant-microbial treatment of shale gas fracturing waste fluid. The results showed that illumination wavelength and temperature are direct drivers for microbial treatment effects of CODCr and BOD5, while exhibit little effects on nitrogen compounds, TDS, EC, and SS removals as well as microbial species and composition. Plant-microbial synergism could significantly enhance the removal of pollutants compared with removal efficiency without plant enhancement. Additionally, the relative abundance and structure of microorganisms in the hydraulic fracturing effluents greatly varied with the illumination wavelength and temperature under plant-microbial synergism. 201.24 g water dropwort and 435 mg/L activated sludge with illumination of 450–495 nm (blue) at 25 °C was proved as the best treatment condition for shale gas fracturing waste fluid samples, which showed the highest removal efficiency of pollutants and the lowest algal toxicity in treated hydraulic fracturing effluents. The microbial community composition (36.73% Flavobacteriia, 25.01% Gammaproteobacteria, 18.55% Bacteroidia, 9.3% Alphaproteobacteria, 4.1% Cytophagia, and 2.83% Clostridia) was also significantly different from other treatments. The results provide a potential technical solution for improved treatment of shale gas hydraulic fracturing effluents. | acceptedVersion

peer reviewed

Filterable PM2.5 concentrations and their chemical characterizations were analyzed for 67 boilers and 25 indirect furnaces located in the Metropolitan Area of Costa Rica from February 2014 to November 2015. The PM2.5 samples were characterized by their composition, focusing on trace elements, inorganic ions and organic and elemental carbon. The results of PM2.5 concentrations ranged from 72 to 735 mgm-3, with the highest concentrations found for sources using biomass fuel, particularly Type B boilers, and the lowest values for diesel boilers. Further speciation of fine particulate matter (PM) showed significant levels of vanadium and nickel for boilers that use heavy fuel oil (bunker); 4886 and 1942 μgm-3, respectively. Copper and manganese were the most relevant metals for biomass burning sources, due to plant absorption from the soil. As for ion concentration, sulfate presented the highest concentrations for biomass boilers and furnaces, whereas chloride only presented the highest concentrations for furnaces. To complete the balance, organic and elemental carbon (OC and EC) analyses were made, in which biomass burning sources presented values five times higher than oil fuels. A Spearman's correlation analysis was made for the data set, revealing significant relationships between heavy metals, sulfate, and fine PM with respect to heavy fuel oil. For the biomass sources, the correlations pointed to K, Na, Mn and, in some cases, oxygen. | Se analizaron las concentraciones filtrables de PM2.5 y sus caracterizaciones químicas para 67 calderas y 25 hornos indirectos ubicados en el Área Metropolitana de Costa Rica desde febrero de 2014 hasta noviembre de 2015. Las muestras de PM2.5 se caracterizaron por su composición, centrándose en oligoelementos, iones inorgánicos y carbono orgánico y elemental. Los resultados de las concentraciones de PM2.5 variaron de 72 a 735 mgm-3, con las concentraciones más altas encontradas para fuentes que utilizan combustible de biomasa, particularmente calderas Tipo B, y el valores más bajos para calderas diesel. Una mayor especiación de partículas finas (PM) mostró una significativa niveles de vanadio y níquel para calderas que utilizan fuel oil pesado (bunker); 4886 y 1942 mgm-3, respectivamente. El cobre y el manganeso fueron los metales más relevantes para las fuentes de combustión de biomasa, debido a Absorción de plantas del suelo. En cuanto a la concentración de iones, el sulfato presentó las mayores concentraciones para calderas y hornos de biomasa, mientras que el cloruro solo presentó las concentraciones más altas para los hornos. Para completar el balance, se realizaron análisis de carbono orgánico y elemental (OC y EC), en los cuales las fuentes de combustión de biomasa presentaron valores cinco veces superiores a los combustibles derivados del petróleo. La correlación de Spearman. Se realizó un análisis para el conjunto de datos, revelando relaciones significativas entre metales pesados, sulfato y PM fino con respecto al fuelóleo pesado. Para las fuentes de biomasa, las correlaciones apuntaron a K, Na, Mn y, en algunos casos, oxígeno. | As concentrações filtráveis ​​de PM2,5 e suas caracterizações químicas foram analisadas para 67 caldeiras e 25 fornos indiretos localizados na Região Metropolitana da Costa Rica de fevereiro de 2014 a novembro de 2015. As amostras de PM2,5 foram caracterizadas por sua composição, com foco em oligoelementos, íons inorgânicos e carbono orgânico e elementar. Os resultados para as concentrações de PM2,5 variaram de 72 a 735 mgm-3, com as concentrações mais altas encontradas para fontes que usam combustível de biomassa, particularmente caldeiras Tipo B, e os valores mais baixos para caldeiras a diesel. A maior especiação de partículas finas (PM) mostrou níveis significativos de vanádio e níquel para caldeiras que usam óleo combustível pesado (bunker); 4886 e 1942 mgm-3, respectivamente. O cobre e o manganês foram os metais mais relevantes para as fontes de combustão da biomassa, devido à absorção das plantas do solo. Em relação à concentração de íons, o sulfato apresentou as maiores concentrações para caldeiras e fornos a biomassa, enquanto o cloreto apresentou as maiores concentrações apenas para os fornos. Para completar o balanço, foram realizadas análises de carbono orgânico e elementar (OC e EC), nas quais as fontes de combustão de biomassa apresentaram valores cinco vezes maiores que os combustíveis derivados do petróleo. A correlação de Spearman. Uma análise foi realizada para o conjunto de dados, revelando relações significativas entre metais pesados, sulfato e MP fino em relação ao óleo combustível pesado. Para fontes de biomassa, as correlações apontaram para K, Na, Mn e, em alguns casos, oxigênio. | Universidad Nacional, Costa Rica | Universidad Autónoma Metropolitana, México | Escuela de Ciencias Ambientales