259 research outputs found

    Evaluation of the influence of surfactants in the bioaccumulation kinetics of sulfamethoxazole and oxazepam in benthic invertebrates

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    The potential ecotoxicological effects of mixtures of contaminants in the aquatic environment are generating a global concern. Benthic invertebrates, such as the crustacean Gammarus fossarum, are key in the functioning of aquatic ecosystems, and are frequently used as sentinel species of water quality status. The aim of this work was to study the effects of a mixture of the most frequently detected surfactants in the bioconcentration kinetics of two pharmaceuticals in G. fossarum, evaluating their potential enhancing or suppressing effects. Laboratory exposure experiments for both pharmaceuticals and surfactants (concentration ratio 1:25) were set up for two individual compounds, the anxiolytic oxazepam and the antibiotic sulfamethoxazole. Gammarid samples were processed using microQuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) extraction. Pharmaceuticals concentration in the organisms was followed-up by means of nanoliquid chromatography coupled to tandem mass spectrometry (nanoLC-MS/MS). Results indicated a similar mode of action of the surfactants in the bioconcentration kinetics of both drugs, decreasing the accumulation rate in the organism. Oxazepam showed a higher accumulation potential than sulfamethoxazole in all cases. Depuration experiments for oxazepam also demonstrated the high depurative capacity of gammarids, eliminating > 50% of the concentration of oxazepam in < 6 h.Postprint (author's final draft

    Design of Hybrid PAH Nanoadsorbents by Surface Functionalization of ZrO2 Nanoparticles with Phosphonic Acids

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    This study focuses on the preparation of innovative nanocomposite materials based on surface modification of commercial nano-ZrO2 optimized from Bronsted acid-base surface reactions. This surface modification was carried out by direct grafting of suitable phosphonic acids bearing a vinylic or phenylic substituent in aqueous solution. Different loading quantities of the anchoring organophosphorus compounds were applied for each materials synthesis. The resulting nanohybrids were thoroughly characterized by infrared spectroscopy (DRIFT), solid-state nuclear magnetic resonance (NMR), nitrogen adsorption-desorption (BET), thermogravimetric analysis (TG), and X-ray photoelectron spectroscopy (XPS), demonstrating the reliability and efficient tunability of the surface functionalization based on the starting Zr/P ratio. Our nanocomposite materials exhibited a high specific surface area as well as complex porosity networks with well-defined meso-pore. The as-prepared materials were investigated for the adsorption of a mixture of 16 polycyclic aromatic hydrocarbons (PAHs) at 200 ng center dot mL(-1) in an aqueous solution. Adsorption kinetics experiments of each individual material were carried out on the prepared PAHs standard solution for a contact time of up to 6 h. Pretreatments of the adsorption test samples were performed by solid-phase extraction (SPE), and the resulting samples were analyzed using an ultrasensitive GC-orbitrap-MS system. The pseudo-first-order and the pseudo-second-order models were used to determine the kinetic data. The adsorption kinetics were best described and fitted by the pseudo-second-order kinetic model. The correlation between the nature of the substituent (vinylic or phenylic) and the parameters characterizing the adsorption process were found. In addition, an increase of PAHs adsorption rates with phosphonic acid loading was observed

    Removal of emerging micropollutants from wastewater discharges by powdered and micro-grain activated carbon - Progress of the CarboPlus® project

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    International audienceThe implementation of a tertiary treatment in conventional wastewater treatment plants is more and more considered by managers to reduce the emerging contaminant discharges into the aquatic environment. In this context, a collaboration between the public sanitation service of Paris conurbation and the Water Environment and Urban Systems laboratory has been initiated since 2013 to study at large scale a pilot (CarboPlus® - SAUR/STEREAU) based on a high concentration fluidized bed activated carbon reactor (>100 kg/m3) with continuous fresh activated carbon injection. The objectives of this project are to i) characterize the efficiency of the process for emerging pollutants for powdered (PAC) and micro-grain (µGAC) activated carbons, ii) characterize the parameters influencing the sorption mechanism (organic matter, operating parameters, activated carbon structure and properties, etc.) and iii) identify the eventual improvements of the conventional quality parameters.In addition to the 14 campaigns already performed in 2013 in PAC configuration, 14 campaigns have been planed in 2014 (8 already performed) to study the fate of 131 micropollutants, including 61 pharmaceuticals and hormones and 70 other emerging pollutants, in addition to conventional wastewater parameters. This presentation aims at displaying the pilot efficiency in µGAC configuration and comparing it to the PAC configuration. The use of µGAC instead of PAC has several operational and economical advantages, but this new type of carbon was never tested with wastewater. Based on the first 8 campaigns, the results tend to indicate that the pilot is as efficient with µGAC than with PAC. In particular, ketoprofen, paracetamol, ibuprofen, ofloxacin, ciprofloxacin, trimethoprim, roxithromycin, atenolol, propranolol, carbamazepine, oxazepam, lorazepam and estrone have removals higher than 80% in average. In addition, first results on the other emerging micropollutants show high or very high removals for pesticides (60-95%), bisphenol A (60-90%), alkylphenols (60-95%), PFOS (75-95%) and X-ray contrast agents (50-70%). Moreover, the high solid retention time (60-90 days) of the µGAC leads to a biological activity within the reactor, as displayed by NO2- (65-99%) and NH4+ (20-70%) removals. However, the results are still partial at this stage of the project, another µGAC dose is currently tested on the pilot and complementary lab-scale tests are still performed to better understand the sorption mechanism

    Mussel as a Tool to Define Continental Watershed Quality

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    Bivalves appear as relevant sentinel species in aquatic ecotoxicology and water quality assessment. This is particularly true in marine ecosystems. In fact, several biomonitoring frameworks in the world used mollusks since several decades on the base of contaminant accumulation (Mussel Watch, ROCCH) and/or biological responses called biomarker (OSPAR) measurements. In freshwater systems, zebra and quagga mussels could represent alternative sentinels, which could be seen as the counterparts of mussel marine species. This chapter presents original studies and projects underlying the interest of these freshwater mussels for water quality monitoring based on contaminant accumulation and biomarker development measurements. These sentinel species could be used as a tool for chemical/biological monitoring of biota under the European water framework directive and for the development of effect-based monitoring tools

    Inter-laboratory mass spectrometry dataset based on passive sampling of drinking water for non-target analysis

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    Non-target analysis (NTA) employing high-resolution mass spectrometry is a commonly applied approach for the detection of novel chemicals of emerging concern in complex environmental samples. NTA typically results in large and information-rich datasets that require computer aided (ideally automated) strategies for their processing and interpretation. Such strategies do however raise the challenge of reproducibility between and within different processing workflows. An effective strategy to mitigate such problems is the implementation of inter-laboratory studies (ILS) with the aim to evaluate different workflows and agree on harmonized/standardized quality control procedures. Here we present the data generated during such an ILS. This study was organized through the Norman Network and included 21 participants from 11 countries. A set of samples based on the passive sampling of drinking water pre and post treatment was shipped to all the participating laboratories for analysis, using one pre-defined method and one locally (i.e. in-house) developed method. The data generated represents a valuable resource (i.e. benchmark) for future developments of algorithms and workflows for NTA experiments
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