Development of novel and ecological keratin/cellulose-based composites for absorption of oils and organic solvents

Environmental Science and Pollution Research - Keratin/cellulose cryogels were successfully fabricated using chicken feathers (CF) and cardboard (C) from environmental waste for the first time, to...     

Multi-elemental compound-specific isotope analysis of pesticides for source identification and monitoring of degradation in soil: a review

Environmental Chemistry Letters - The transfer of pesticides from agricultural soils to food and drinking water is a major health issue. There are actually few robust methods to identify,...     

A multi-step bioassay to assess the effect of the deltamethrin on the parasitic wasp Aphidius ervi

Insecticides are widely used for crop protection. Effectiveness of pesticides and beneficial arthropods in an Integrated Pest Management (IPM) program requires a full understanding of how specific pesticides alter natural enemy effectiveness. This may require evaluation of chemicals at different life stages of the insect considered, on different physiological and behavioural components, and also on population dynamic components such as recolonization capacities after a pesticide treatment. Aphidius ervi Haliday (Hymenoptera: Braconidae) is an aphid parasitoid commonly used for the biological control of aphid populations. In this work, our aim was to assess the effects of deltamethrin (pyrethroid) treatments on this parasitoid using a multi-step bioassay. We evaluated its effects on parasitoid emergence, adult survival and longevity, and host searching. Two exposure methods were used, topical and spray, to evaluate impact of the deltamethrin field rate (6.25ga.i./ha) and also to compare the methods of exposure. A four-armed olfactometer was used to investigate effect of deltamethrin on host searching behaviour. When applied at the rate of field exposure, deltamethrin reduced the adult longevity but not the rate of emergence from mummies. Effects varied between the two exposure methods. Two indices were defined: the "population survival index" to measure capacity of parasitoids to recolonize a treated field and the "reproductive potential" to estimate the reduction in reproduction as a function of longevity decrease. These indices predicted effects of deltamethrin on A. ervi in terms of mortality and reduction of recolonization capacities. However, adults that survived residual exposure to deltamethrin retained their ability to orient to host odours. The implications of results in IPM and interest of the methodology used are both discussed.     

A national reconnaissance for selected organic micropollutants in sediments on French territory

To collect a large data set regarding the occurrence of organic substances in sediment, this study presents the examination of 20 micropollutants, as a national survey. The list of target compounds contains two alkylphenols, three polycyclic aromatic hydrocarbons (PAHs) not commonly included in monitoring programmes, six pesticides or metabolites, five pharmaceutical compounds, two hormones, one UV filter and bisphenol A. The selective and sensitive analytical methods, based on quick, easy, cheap, effective, rugged, and safe (QuEChERS) sample preparation followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) or gas chromatography-time-of-flight mass spectrometry (GC-ToF-MS), allow the quantification at limits comprised between 0.5 and 23 ng/g, depending on the compound. The paper summarizes the analytical results from 154 sampling points. Of the 20 target compounds, 9 were determined at least once, and the sediments contained a maximum of 7 substances. The most frequently detected were PAHs (frequency, 77 %; max., 1,400 ng/g). The pharmaceutical compounds, hormones and pesticides were rarely detected in the samples; the most frequently detected was carbamazepine (frequency, 6 %; max., 31 ng/g). In some cases, the levels of PAHs and bisphenol A exceed the predicted no-effect concentration (PNEC) values.     

Development of a reference artificial sediment for chemical testing adapted to the MELA sediment contact assay

Most persistent organic pollutants, due to their hydrophobic properties, accumulate in aquatic sediments and represent a high risk for sediment quality. To assess the toxicity of hydrophobic pollutants, a novel approach was recently proposed as an alternative to replace, refine and reduce animal experimentation: the medaka embryo–larval sediment contact assay (MELAc). This assay is performed with Japanese medaka embryos incubated on a natural sediment spiked with the compound being tested. With the aim of improving this assay, our study developed a reference exposure protocol with an artificial sediment specifically designed to limit natural sediment composition uncertainties and preparation variability. The optimum composition of the new artificial sediment was tested using a model polycyclic aromatic hydrocarbon (PAH), fluoranthene. The sediment was then validated with two other model PAHs, benz[a]anthracene and benzo[a]pyrene. Various developmental end points were recorded, including survival, embryonic heartbeat, hatching delay, hatching success, larval biometry and abnormalities. The final artificial sediment composition was set at 2.5 % dry weight (dw) Sphagnum peat, 5 % dw kaolin clay and 92.5 % dw silica of 0.2- to 0.5-mm grain size. In contrast with natural sediments, the chemical components of this artificial matrix are fully defined and readily identifiable. It is totally safe for fish embryos and presents relatively high sorption capacities for hydrophobic compounds. Studies with other hydrophobic and metallic contaminants and mixtures should be performed to further validate this artificial sediment.     

Corbicula fluminea gene expression modulated by CeO2 nanomaterials and salinity

Environmental Science and Pollution Research - Cerium dioxide nanomaterials (CeO2 NMs) are used in different fields and incorporated in daily products. Several studies highlighted their effects on...     

Thermodynamic and kinetic study of phenol degradation by a non-catalytic wet air oxidation process

This work is dedicated to an accurate evaluation of thermodynamic and kinetics aspects of phenol degradation using wet air oxidation process. Phenol is a well known polluting molecule and therefore it is important having data of its behaviour during this process. A view cell is used for the experimental study, with an internal volume of 150 mL, able to reach pressures up to 30 MPa and temperatures up to 350 °C. Concerning the thermodynamic phase equilibria, experimental and modelling results are obtained for different binary systems (water/nitrogen, water/air) and ternary system (water/nitrogen/phenol). The best model is the Predictive Soave Redlich Kwong one. This information is necessary to predict the composition of the gas phase during the process. It is also important for an implementation in a process simulation. The second part is dedicated to kinetics evaluation of the degradation of phenol. Different compounds have been detected using GC coupled with a MS. A kinetic scheme is deduced, taking into account the evolution of phenol, hydroquinones, catechol, resorcinol and acetic acid. The kinetic parameters are calculated for this scheme. These data are important to evaluate the evolution of the concentration of the different polluting molecules during the process. A simplified kinetic scheme, which can be easily implemented in a process simulation, is also determined for the direct degradation of phenol into H₂O and CO₂. The Arrhenius law data obtained for the phenol disappearance are the following: k = 1.8 × 10⁶ ± 3.9 × 10⁵ M⁻¹ s⁻¹ (pre-exponential factor) and E_a = 77 ± 8 kJ mol⁻¹ (activation energy).     

A critical review of effect modeling for ecological risk assessment of plant protection products

Environmental Science and Pollution Research - A wide diversity of plant protection products (PPP) is used for crop protection leading to the contamination of soil, water, and air, which can have...