Combined phytoremediation of metal-working fluids with maize plants inoculated with different microorganisms and toxicity assessment of the phytoremediated waste

The aim of this study was to validate the effectiveness of a phytoremediation procedure for metal-working fluids (MWFs) with maize plants growing in hydroponic culture in which the roots grow on esparto fibre and further improve bioremediation potential of the system with root beneficial bacteria, seeking a synergistic effect of the plant–microorganism combination. Chemical oxygen demand (COD), pH, total and type of hydrocarbons measured after phytoremediation indicated that the process with maize plants was successful, as demonstrated by the significant decrease in the parameters measured. This effect was mainly due to the plant although inoculated microorganisms had a relevant effect on the type of remaining hydrocarbons. The success of the phytoremediation process was further confirmed by two toxicity tests, one of them based on chlorophyll fluorescence measurements on maize plants and another one based on cyanobacteria, using a bioluminescent toxicity bioassay; both tests demonstrated that the phytoremediated waste was significantly less toxic than the initial non-phytoremediated MWFs.     

Efficiency of energy recovery from waste incineration,in the light of the new Waste Framework Directive

This paper deals with a key issue related to municipal waste incineration, which is the efficiency of energy recovery. A strong driver for improving the energy performances of waste-to-energy plants is the recent Waste Framework Directive (Directive 2008/98/EC of the European Parliament and of the Council of 19 November 2008 on waste and repealing certain Directives), which allows high efficiency installations to benefit from a status of “recovery” rather than “disposal”. The change in designation means a step up in the waste hierarchy, where the lowest level of priority is now restricted to landfilling and low efficiency wastes incineration. The so-called “R1 formula” reported in the Directive, which counts for both production of power and heat, is critically analyzed and correlated to the more scientific-based approach of exergy efficiency. The results obtained for waste-to-energy plants currently operating in Europe reveal some significant differences in their performance, mainly related to the average size and to the availability of a heat market (district heating).     

Proximity to wood industries and respiratory symptoms in children: a sensitivity analysis

Increased prevalence of respiratory and irritation symptoms was found in children who live near a large wood industrial park. Proximity to the wood industries was used as indicator of exposure. This study describes a sensitivity analysis for the results of the survey. All the children (3-14 years) living in the area were surveyed through a parental questionnaire (n = 3854) and their addresses were geocoded. The distances from each child's home and school to the closest industry were combined, weighted and used as an indicator of exposure. A sensitivity analysis was performed to check 1) the robustness of the results to the choice of weights used for defining the exposure indicator, 2) the effect of outliers on risk estimates and 3) the sensitivity on the functional form used for modeling the dose-response function. The choice of the weights did not influence the association between proximity to the industries and respiratory symptoms. Excluding the subjects who lived far away from the industries showed that in a radius of 5 km from the industries the study did not had enough power to estimate a gradient in the dose-response function. Besides, results were sensitive to the choice of the functional form used for modeling the minimum distance. The sensitivity analyses confirmed the overall increasing trend of respiratory symptoms with proximity to the industries and pointed out that all the assumptions made for defining a proxy of exposure need to be carefully checked.     

Wind-induced noise alters signaler and receiver behavior in vibrational communication

Noise that masks communication signals can affect the evolution of signal form and decisions about when and where to communicate. For the many invertebrates that communicate using plant-borne vibrations, wind is considered to be the major source of environmental noise. However, the influence of wind-induced vibrations on signaling behavior has not been experimentally tested. We tested the hypothesis that wind-induced noise influences signaling behavior in a plant-feeding insect (the treehopper, Enchenopa binotata ‘Ptelea’) in which mating is preceded by a vibrational duet between females and mate-searching males. We first characterized the diel signaling patterns of males in the field to identify the wind conditions under which signaling typically takes place. We then experimentally tested two predictions of the hypothesis: (1) that males use gap detection to initiate signaling during relatively wind-free periods; and (2) that females respond less to signals given in the presence of wind-induced vibrations. Both predictions were met, indicating that wind-induced noise is an important influence on the behavior of insects that use plant-borne vibrations.     

Detection of Listeria monocytogenes in ready-to-eat food by Step One real-time polymerase chain reaction

The aim of this study was to follow contamination of ready-to-eat food with Listeria monocytogenes by using the Step One real time polymerase chain reaction (PCR). We used the PrepSEQ Rapid Spin Sample Preparation Kit for isolation of DNA and MicroSEQ® Listeria monocytogenes Detection Kit for the real-time PCR performance. In 30 samples of ready-to-eat milk and meat products without incubation we detected strains of Listeria monocytogenes in five samples (swabs). Internal positive control (IPC) was positive in all samples. Our results indicated that the real-time PCR assay developed in this study could sensitively detect Listeria monocytogenes in ready-to-eat food without incubation.     

Preliminary study on persistence in soil and residues in maize of imidacloprid

The aim of this work was to study the distribution of imidacloprid in soil and its translocation to roots and aerial parts of maize plant. The main objective was to assess imidacloprid residues in field environment, in order to provide data on honeybees exposure level to such an active substance. Imidacloprid has been detected and quantified by Triple Quadrupole HPLC-MS-MS. Pesticide persistence in the soil and its residues in pollen and in maize plants have been evaluated during the growing of maize plants developed from seeds dressed with Gaucho 350 FS (imidacloprid: 1.0 mg/seed). The sowing has been performed by means of a pneumatic precision drill. Samples have been collected at 30, 45, 60, 80, 130 days after the sowing, as pollen samples have been collected at the tasseling. Imidacloprid presence in aerial part of maize plant declined to 2-3 μg/kg 80 days after the sowing, while concentration in kernel at harvest was <1 μg/kg. Maize pollen represents an important part of protein supply of beehives, and it is of critical importance to bee foraging. The values detected (imidacloprid residues <1 μg/kg) showed that maize pollen source should not be relevant for acute toxicity impact on honey bees.     

The impact of heterogeneity on the distribution of CO2: Numerical simulation of CO2 storage at Ketzin

Numerical modelling of multiphase flow is an essential tool to ensure the viability of long-term and safe CO₂ storage in geological formations. Uncertainties arising from the heterogeneity of the formation and lack of knowledge of formation properties need to be assessed in order to create a model that can reproduce the data available from monitoring. In this study, we investigated the impact of unknown spatial variability in the petrophysical properties within a sandy channel facies of a fluviatile storage formation using stochastic methods in a Monte Carlo approach. The stochastic method has been applied to the Ketzin test site (CO₂SINK), and demonstrates that the deterministic homogeneous model satisfactorily predicts the first CO₂ arrival time at the Ketzin site. The equivalent permeability was adjusted to the injection pressure and is in good agreement with the hydraulic test. It has been shown that with increasing small-scale heterogeneity, the sharpness of the CO₂ front decreases and a greater volume of the reservoir is affected, which is also seen in an increased amount of dissolved CO₂. Increased anisotropy creates fingering effects, which result in higher probabilities for earlier arrival times. Generally, injectivity decreases with increasing heterogeneity.     

Understanding the processes in a historically relevant thermal and mineral spring water by using mixing and inverse geochemical models

Environmental Geochemistry and Health - The thermal mineral water of Peñón de los Baños spa (Mexico City) has been used for over 500&nbsp;years starting in pre-Hispanic times and...     

Ozone sensitivity of currant tomato (Lycopersicon pimpinellifolium), a potential bioindicator species

The wild tomato species Lycopersicon pimpinellifolium (currant tomato) was exposed to different O3 concentration, both in controlled environment fumigation facilities and in open-top chambers, to assess its sensitivity and to verify its potential as a bioindicator plant. Plants appeared particularly sensitive to O3 at an early stage of growth, responding with typical chlorotic spots within 24 h after exposure to a single pulse of 50 ppb for 3 h, and differentiating peculiar symptoms, such as reddish necrotic stipples, bronzing and extensive necrosis, depending on O3 concentration. Histo-cytochemical investigations with 3,3'-diaminobenzidine, to localize H2O2, and Evans blue, to detect dead cells, suggested that currant tomato sensitivity to O3 could be due to a deficiency in the anti-oxidant pools. The combination of these stainings proved to be useful, either to predict visible symptoms, early before their appearance, and to validate leaf ozone injury.