Development of a new automated clean-up system for the simultaneous analysis of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs) and 'dioxin-like' polychlorinated biphenyls (dl-PCB) in flue gas emissions by GPC-SPE

A comprehensive clean-up method for quantitative analysis of polychlorinated biphenyls (PCBs) and polychlorinated dibenzo-p-dioxins and dibenzo-furans (PCDD/Fs) in one single extract of environmental samples was developed. Since the chemical nature and toxicity of planar PCBs are similar to those of PCDD/Fs, dioxin-like PCBs and PCDD/Fs are often surveyed together in their exposure assessments. The development of a method for the simultaneous analysis of PCBs and PCDD/Fs in environmental samples is invaluable. The automated clean-up system evaluated in this work consists of three additional steps after traditional extraction: the chromatography on gel permeation (GPC), the concentration of the solvent through the use of an in-line evaporation module and the further purification and separation of PCDDs/Fs and dl-PCBs on an alumina cartridge in the 'SPE module'. In this work, three fly ash samples from an interlaboratory study with different PCDD/F and PCB levels were Soxhlet-extracted and then cleaned up using an automated system. PCDD/Fs and PCBs were determined using isotope dilution and high resolution gas chromatography/high resolution mass spectrometry. The determined values of 17 PCDD/Fs were consistent with the certified values and the relative standard deviations (RSDs) of the determined values were less than 20%. The recoveries of (13)C labeled PCDD/Fs and planar PCBs, and their RSDs were within the ranges specified in EPA1613 and 1668a methods, respectively. An accurate and reliable method was successfully developed and can be used in the simultaneous analysis of PCDD/Fs and planar PCBs in environmental samples.     

Seasonal and pluri-annual variability of sediment accumulation and organic matter fluxes in the Northwestern Adriatic shelf and its relationship with the frontal system

Twenty eight short sediment cores, collected along six transects in two areas influenced by the frontal system formed by the Po River, were analysed for Th and Cs in order to improve our knowledge on short time scale sediment deposition, accumulation and mixing. Sedimentological and mineralogical parameters were also analysed._ The decreasing Cs activities and C/N values in surface sediments indicate a decreasing input of terrestrial material during the study period. Furthermore, low excess thorium activities and inventories at some sites, together with low sedimentary organic matter concentrations in the southern area, suggest that the productivity in summer 1997 was lower than in 1996. Temporal and spatial shifts of the front exert a strong influence on short time scale deposition of particulate matter in the northern area, while the front position is more stable in the southern area, influencing both seasonal and interannual deposition._ The comparison between apparent seasonal and pluri-annual accumulation rates suggests, for the northern area, a sedimentation pattern characterized by temporal deposition of material on to the sea floor, with periodical resuspension. The net apparent accumulation is 0.1-0.4 r g r cm r yr. The same occurs for the southern area, where values are higher, probably due to the longer persistence of the frontal system in the same area over the years. Here, both seasonal and pluri-annual deposition showed the same pattern, but seasonal values were two to three times higher with a net apparent accumulation rate of 0.3-0.8 r g r cm r yr. Organic carbon and nitrogen concentrations are generally less than 1.3 and 0.2% d.w., with lower values in the southern area. By contrast, mass fluxes showed higher values in the southern area, while the rate of removal over a pluri-annual time scale is generally high.     

Landscape-scale spatial distribution of the Lanner Falcon (Falco biarmicus feldeggii) breeding population in Italy

Falco biarmicus feldeggii is one of the most threatened taxa in Europe. Its global population is estimated at a few hundred pairs unequally scattered in a vast and fragmented area stretching from Sicily to the Caspian Sea. Most recent counts showed that Italy hosts a large part (>25%) of the whole population. Consequently, Italian authorities promoted a national action plan. In this framework, we carried out the first national survey for the Lanner Falcon in Italy (2003-2004). Our study area covered the whole breeding range, i.e., Sicily and the Italian peninsula (n = 2909 cells 10 x 10 km). When possible, we considered also additional information from previous regional investigations (1993-2001). First, we estimated size and distribution of each breeding subpopulation. Then, we tried to identify, at landscape level, the main environmental features linked to the spatial distribution of the nesting sites. We found the Lanner Falcon in 184 cells (6.4% of the total grid map), but we estimated no more than 140-172 pairs (70-80 of which are in Sicily) in the same breeding season. Higher levels of isolation characterize the continental breeding cells whereas in Sicily cells are much more clustered. Altitude is the main factor influencing cell aggregations in Italy; nevertheless, other environmental variables, such as climate, precipitation, and vegetation may be important. Our results show that the conservation measures adopted in Italy are somewhat inadequate given the low number of breeding pairs included in protected areas (23%-28%). Many small and scattered special areas of conservation (SAC) devoted to conserve priority habitats fit the irregular spatial aggregations of Lanner Falcon sites better than several large special protection areas (SPA).     

Concentration of Cd, Cu, Pb, Zn, Al, and Fe in soils of Manresa, NE Spain

The aims of this study were to determine the contents of cadmium (Cd), copper (Cu), lead (Pb), zinc (Zn), aluminium (Al), and iron (Fe) (aqua regia-extractable) in 27 soil plots (54 samples) from Manresa, NE Spain, and to establish relationships between heavy metals and some soil properties. The main soil types were surveyed and the median concentrations (mg kg(-1)) obtained were Cd 0.28, Cu 20.3, Pb 18.6, Zn 67.4, Al 22,572, and Fe 21,551. Element concentrations for these soils were lower than the published values for the Valencia region (Spain) and Torrelles and Sant Climent municipal districts (Catalonia, Spain). In terms of soil properties, the results of this study suggest that, in Manresa soils, both trace element adsorption and retention are influenced by several properties such as clay minerals, carbonates, organic matter, and pH. All element contents were positively correlated with clay content. Pb and Zn were negatively correlated with pH and CaCO(3).     

Simultaneous determination of volatile and semivolatile organic compounds in soil

A microscale solvent extraction (MSE) method was developed for the simultaneous determination of volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) in soil. Tests of precision, recovery, and comparability to other Environmental Protection Agency (EPA) methods have been completed, and the MSE method compares well to Soxhlet and sonication extraction. Based on these validation data, EPA has assigned number 3570 to this method. Method 3570 has several advantages, including reduced use of solvent and soil sample, generating much less laboratory waste. Laboratory space and labor requirements are reduced as compared to many other sample preparation methods. Consequently, Method 3570 can provide comparable chemical data at less cost or environmental impact.     

An environmental analysis for comparing waste management options and strategies

The debate on different waste management practices has become an issue of utmost importance as human activities have overloaded the assimilative capacity of the biosphere. Recent Italian law on solid waste management recommends an increase in material recycling and energy recovery, and only foresees landfill disposal for inert materials and residues from recovery and recycling. A correct waste management policy should be based on the principles of sustainable development, according to which our refuse is not simply regarded as something to eliminate but rather as a potential resource. This requires the creation of an integrated waste management plan that makes full use of all available technologies. In this context, eMergy analysis is applied to evaluate three different forms of waste treatment and construct an approach capable of assessing the whole strategy of waste management. The evaluation included how much investment is needed for each type of waste management and how much "utility" is extracted from wastes, through the use of two indicators: Environmental yield ratio (EYR) and Net eMergy. Our results show that landfill is the worst system in terms of eMergy costs and eMergy benefits. Composting is the most efficient system in recovering eMergy (highest EYR) from municipal solid waste (MSW) while incineration is capable of saving the greatest quantity of eMergy per gram of MSW (highest net eMergy). This analysis has made it possible to assess the sustainability and the efficiency of individual options but could also be used to assess a greater environmental strategy for waste management, considering a system that might include landfills, incineration, composting, etc.     

Electrochemical oxidation of benzene on boron-doped diamond electrodes

This work presents an electrochemical investigation of the benzene oxidation process in aqueous solution on boron-doped diamond (BDD) electrodes. Additionally, in order to determine the main products generated during the oxidation process, electrolysis and high performance liquid chromatography experiments were carried out. The complete degradation of this compound was performed aiming to a further application in waste water treatment. The cyclic voltammetry studies indicate that benzene is irreversibly oxidized in acid medium (H₂SO₄ 0.5 M) on the BDD electrode surface at 2.0 V versus Ag/AgCl in a diffusion controlled process. During the cycling, other products are generated, and a pair of peaks was observed that can be associated with the oxi-reduction of anyone of the following species: hydroquinone, benzoquinone, resorcinol or catechol. The electrolysis experiments were carried out at 2.4 and 2.5 V on the BDD electrode surface in a solution containing 1 × 10⁻² M of benzene (below the saturation concentration in aqueous solution), for 3 and 5 h, respectively. The main products measured were: hydroquinone, resorcinol, p-benzoquinone, catechol and phenol. The complete electrochemical benzene degradation was performed in the electrolysis experiments using a rotating BDD disc electrode (2.5 V for 5 h) and the main products detected were all measured at concentrations lower than 10⁻⁵ M in this condition. The boron-doped diamond electrode had proved to be a valuable tool for the electrochemical degradation of the benzene, a very stable chemical compound.     

Chemical analyses of spring waters and factor analysis to monitor the functioning of a karstic system. The role of precipitations regimen and anthropic pressures

An approach is presented to study the functioning of a karstic massif and assess the adverse effects of the anthropogenic pressure by monitoring some water chemical and physical parameters of its main springs. The approach has been applied to the Sette Comuni Plateau (Veneto Region, Italy) hosting a well developed karstic system, whose aquifer presents high vulnerability and undergoes a relevant anthropogenic pressure. The Oliero springs, amongst the largest karstic springs in Europe, are the main water output of the plateau. Electrical conductivity, pH, dissolved O(2), hardness, alkalinity, chemical oxygen demand, total suspended solids, ionic species (NH(4)(+), NO(3)(-), NO(2)(-), PO(4)(3-), SO(4)(2-), Cl(-), F(-)), elements (Cr(III), Cr(VI), Mn, Fe, Ni, Cu, Zn, As, Cd, Hg, Pb), and some chlorinated solvents were monitored for one year. This study presents the application of a factor analysis on the water parameters enabling the identification of the dominant chemical and biological processes and pollution sources affecting the karstic system. Results show four factors which are interpreted as karstification, photosynthesis, storm flow pollution and anions. Finally, by associating metals, chemical oxygen demand and total suspended solids with the amount of rainfall in the 48 h before samplings, further detailed information to the fast response of the aquifer to precipitation events was detected and interpreted according to the factor analysis results. The proposed approach, by providing information on the functioning of the aquifer, may help the management of the karstic plateau and is easily adaptable to similar environments.     

Soils and sediments of the Thua Thien-Hue Province (central Vietnam): recognizing trace element sources and the likely influence of natural events

Trace element concentrations have been measured in soil and sediment samples taken from the Thua Thien Hue (TT-H) Province and the Tam Giang-Cau Hai (TG-CH) Lagoon in 2002 and 2004. Results show that the lagoon is only slightly contaminated by elements such as Ag, Cd, Cr, Cu, Ni, Pb and Zn, whereas As, probably naturally enriched in this Asian region, reaches values above the lowest internationally accepted sediment quality guidelines. Concentrations in soils are ascribable to natural sources and distributions in the TG-CH Lagoon are mainly influenced by river inputs, with Ag and Cd undergoing estuarine desorption processes. However, concentration-depth profiles of most trace elements in sediments show a recent increasing trend that might be linked to the economic development of the area. The comparison of porosity and (210)Pb depth profiles (confirmed also by Cd and As) from repeated samplings of the same core locations in the TG-CH Lagoon seems to account for a loss of 5-10 cm of surficial sediment that took place during the time interval between the two samplings. It is hypothesized that extreme meteorological events (e.g. a major typhoon that hit the area in November 2003) could be responsible for such sediment displacement.