Modelling the biphasic sorption of simazine,imidacloprid, and boscalid in water/soil systems

The sorption kinetics of simazine (6-chloro-N,N′-diethyl-1,3,5-triazine-2,4-diamine), imidacloprid (1-(6-chloro-3-pyridylmethyl)-N-nitroimidazolidin-2-ylideneamine), and boscalid (2-chloro-N-(4′-chlorobiphenyl-2-yl)nicotinamide), three pesticides of wide use in agriculture, was determined in five different water/soil systems over a time interval from the initial few seconds to about 1 month. In all the experiments, sorption kinetics showed a biphasic pattern characterized by an initial, relatively short phase with a high sorption rate and a later phase with much a lower sorption rate. Initial sorption capacity increased with soil organic carbon content and with sorbate hydrophobicity. We postulate that the first phase of the process involves a fast second-order sorption reaction on superficial sites of soil particles, whereas the second phase depends on diffusion-controlled migration to internal binding sites. A kinetic equation based on this hybrid model accurately fitted all data sets. Less satisfactory results were obtained employing the pseudo-first order, pseudo-second order, Elovich, two site non-equilibrium, or Weber-Morris equation. The superior performance of the hybrid model for describing boscalid sorption probably reflects the high hydrophobic character and consequent low diffusion rates of this compound. The accuracy of modelling was in any case strongly dependent on the time interval considered.     

Experimental Evaluation of Waste Tires Utilization in Cement Kilns

ABSTRACT

The present work outlines the main results of a full-scale study conducted on the utilization of waste tires as auxiliary fuel in cement production. Experimental tests were conducted for determining the influence of shredded tires on combustion conditions, emissions produced, and the characteristics of clinker obtained, for feeding ratios over 35% in terms of total heat input. The addition of tire chips did not lead to any appreciable modification in either the whole process or the quality of clinker produced; gaseous emissions were mostly unaffected, with significant improvements related to the reductions obtained in nitrogen and sulfur oxides concentrations. Experimental findings from tests conducted with tire chips exposed to kiln combustion flue gases compare favorably with the typical burnout times derived from theoretical approaches. These experimental data and calculations to estimate particle trajectories beyond the injection point, through proper theoretical analysis of the kinetic behavior, result in important indications for the shredding operation and for optimum injection modes.     

Biomonitoring aquatic environmental quality in a marine protected area: a biomarker approach

The main aims of the present study, conducted in the framework of the MONIQUA-Egadi Scientific Project, were twofold: first, to make the first step in the development and validation of an ecotoxicological approach for the assessment of marine pollution in coastal environments on the basis of a set of biomarker responses in new sentinel species; and second, to obtain preliminary information on environmental quality in an Italian marine protected area, the Egadi Islands (Sicily). Several cytochrome P450-dependent mixed-function oxidase activities were measured in the following sentinel species: rainbow wrasse Coris julis, gastropod limpet Patella caerulea, and sea urchin Paracentrotus lividus. The results suggest that specimens from the Favignana Harbor may be exposed to P450 inducers, whereas most of the other sites seem to share similar environmental quality. The proposed approach has potential for assessment of environmental quality in marine protected areas.     

Impact of elevated CO(2) and nitrogen fertilization on foliar elemental composition in a short rotation poplar plantation

The experiment was carried out on a short rotation coppice culture of poplars (POP-EUROFACE, Central Italy), growing in a free air carbon dioxide enriched atmosphere (FACE). The specific objective of this work was to study whether elevated CO(2) and fertilization (two CO(2) treatments, elevated CO(2) and control, two N fertilization treatments, fertilized and unfertilized), as well as the interaction between treatments caused an unbalanced nutritional status of leaves in three poplar species (P. x euramericana, P. nigra and P. alba). Finally, we discuss the ecological implications of a possible change in foliar nutrients concentration. CO(2) enrichment reduced foliar nitrogen and increased the concentration of magnesium; whereas nitrogen fertilization had opposite effects on leaf nitrogen and magnesium concentrations. Moreover, the interaction between elevated CO(2) and N fertilization amplified some element unbalances such as the K/N-ratio.     

Assessment of susceptibility of olive cultivars to the Bactrocera oleae (Gmelin, 1790) and Camarosporium dalmaticum (Thüm.) Zachos & Tzav.-Klon. attacks in Calabria (Southern Italy)

Within the framework of research concerning the application of techniques alternative to chemical pesticides for control of parasites, the C.R.A. Experimental Institute for Olive Growing for many years has been performing a large investigation in order to detect sources of genetic resistance in olive germplasm. In the present study we observed the behavior related to the olive fly (Bactrocera oleae) infestation and Camarosporium dalmaticum infection of ten olive cultivars farmed under the same agronomic and climatic conditions in Calabria, Southern Italy. The sampling and the data collecting were carried out in three different ripening times.The drupe amount of oleuropein and cyanidine was detected by laboratory analyses in order to verify a possible correlation between these molecules and the level of infestation/infection of the above-mentioned parasites. The obtained data were submitted to analysis of variance. In relation to the fungal infection the results displayed that cvs Tonda nera dolce showed the lowest susceptibility, while the cv Giarraffa turned out to be the most susceptible. The less susceptible cultivars to the phytophagous were Tonda nera dolce and Bhardi Tirana. Since the less susceptible cultivar to olive fly attacks are the same observed in relation to the susceptibility to olive fruit rot, it is suggested a relation between the olive fly infestation and the fungal infection. It suggests the utility to achieve these results both to transfer directly to the farmers' world and to emphasize ecosystem health and biodiversity conservation.     

Tsunami Survey Expedition: Preliminary Investigation of Maldivian Coral Reefs Two Weeks After the Event

On December 26th 2004, a earthquake west of Sumatra generated a devastating tsunami. Hundreds of thousands of people fell victim. Economic losses were greatest in those countries dependant on tourism. The impact in the Maldives on persons and things was modest. Immediately following the event and notwithstanding the lack of scientific data, the mass media gave catastrophic reports on the state of coral reefs in the area. This paper reports on the first survey on coral reefs in the Maldives after the Tsunami. Ocean walls, passes, inner reefs, and shoals in the North and South Malé atolls, were surveyed two weeks after the event. Significant damage was recorded in the passes in the South Malé atoll. Our observations showed that the damage was more or less extensive depending on latitude and topography. Sri Lanka may have broken the wave’s rush, reducing the extent of the impact on northern atolls. The water’s acceleration inside the passes was so intense as to cause reef collapses. The observed damage represents a minimum fraction of the entire coral reef system. Tourist perception of the area seems unchanged. These data may be used to disseminate correct information about the state of Maldives coral reefs, which would be useful in relaunching local economy.     

A biological method to monitor early effects of the air pollution caused by the industrial exploitation of geothermal energy

The suitability of a set of ecophysiological parameters, to be used as early warning indicator to detect signs of a worsening environment around geothermal power plants, was tested by comparison with the diversity of epiphytic lichens, a well-established indicator of geothermal air pollution. Samples of the lichen Evernia prunastri were transplanted around a geothermal power plant at Larderello (Tuscany, Italy) and at a control site, and integrity of cell membranes, concentration of chlorophyll a, b and carotenoids, chlorophyll integrity and variations in pH of thalli were measured. The results showed that cell membrane damage, expressed by changes in electrical conductivity, could be used to detect early (exposure periods as short as 1 month) deleterious effects of geothermal air pollution.     

Contribution of vehicular traffic and industrial facilities to PM10 concentrations in a suburban area of Caserta (Italy)

PM10 levels have been recorded in the suburban area of Caserta (Italy) from February to October 2012. The daily limit was exceeded in 13 % of the determinations, with no significant difference between weekdays and weekends. Benzo[a]pyrene concentrations were in the range 0.01–0.46 ng/m³, thus, never exceeding the National Standard. The B(a)P-eq was 0.20 ng/m³. PM10 peaks were associated with wind from east–northeast. The same was observed for Ca concentrations, whereas no relation with wind direction was observed for organic pollutants. The results point to a local limestone quarry and cement factory as the likely major source of PM10 pollution in the area investigated.     

Synthesis and Characterization of Lactic Acid Oligomers: Evaluation of Performance as Poly(Lactic Acid) Plasticizers

The use of fully bio-based and biodegradable materials for massive applications, such as food packaging, is an emerging tendency in polymer research. But the formulations proposed in this way should preserve or even increase the functional properties of conventional polymers, such as transparency, homogeneity, mechanical properties and low migration of their components to foodstuff. This is not always trivial, in particular when brittle biopolymers, such as poly(lactic acid) (PLA), are considered. In this work the formulation of innovative materials based on PLA modified with highly compatible plasticizers, i.e. oligomers of lactic acid (OLAs) is proposed. Three different synthesis conditions for OLAs were tested and the resulting additives were further blended with commercial PLA obtaining transparent and ductile materials, able for films manufacturing. These materials were tested in their structural, thermal and tensile properties and the best formulation among the three materials was selected. OLA with molar mass (M_n) around 1,000 Da is proposed as an innovative and fully compatible and biodegradable plasticizer for PLA, able to replace conventional plasticizers (phthalates, adipates or citrates) currently used for films manufacturing in food packaging applications.     

Behavior of TiO2 nanoparticles during incineration of solid paint waste: A lab-scale test

In order to assess the potential impacts posed by products containing engineered nanoparticles, it is essential to generate more data about the release of these particles from products’ life cycle. Although first studies were performed to investigate the release of nanoparticles from use phase, very few data are available on the potential release from recycling or disposal of nano-enhanced products.In this work, we investigated the behavior of TiO₂ nanoparticles from incineration of solid paint waste containing these particles. Solid paint debris with and without TiO₂ nanoparticles were treated in a lab scale incineration plant at 950 °C (combustion temperature) and in oxidizing atmosphere. The obtained ashes were also vitrified with additives and the release of Ti was finally evaluated by leaching test. From our incineration lab-scale experiment, we did not observe a release of TiO₂ nanoparticles into the atmosphere, and Ti was attached to the surface of obtained solid residues (i.e. ashes). The characterization of ashes showed that TiO₂ nanoparticles reacted during the incineration to give calcium titanate. Finally, a very low release of Ti was measured, less 1 mg/kg, during the leaching test of ashes vitrified with glass cullet and feldspathic inert. Our work suggests that TiO₂ nanoparticles added in paints may undergo to physicochemical transformation during the incineration, and that Ti found in ashes may be strongly immobilized in glass matrix. Since this conclusion is based on lab-scale experiment, further research is required to identify which nanoparticles will be emitted to the environment from a real-word-incineration system of household hazardous waste.