Novel two-step vapor-phase synthesis of UV–Vis light active Fe2O3/WO3 nanocomposites for phenol degradation

Supported Fe₂O₃/WO₃ nanocomposites were fabricated by an original vapor phase approach, involving the chemical vapor deposition (CVD) of Fe₂O₃ on Ti sheets and the subsequent radio frequency (RF)-sputtering of WO₃. Particular attention was dedicated to the control of the W/Fe ratio, in order to tailor the composition of the resulting materials. The target systems were analyzed by the joint use of complementary techniques, that is, X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), energy dispersive X-ray spectroscopy (EDXS), X-ray photoelectron spectroscopy (XPS), secondary ion mass spectrometry (SIMS), and optical absorption spectroscopy. The results showed the uniform decoration of α-Fe₂O₃ (hematite) globular particles by tiny WO₃ aggregates, whose content could be controlled by modulations of the sole sputtering time. The photocatalytic degradation of phenol in the liquid phase was selected as a test reaction for a preliminary investigation of the system behavior in wastewater treatment applications. The system activity under both UV and Vis light illumination may open doors for further material optimization in view of real-world end-uses.

     

Health sector recovery in early post‐conflict environments: experience from southern Sudan

Health sector recovery in post‐conflict settings presents an opportunity for reform: analysis of policy processes can provide useful lessons. 1 The case of southern Sudan is assessed through interviews, a literature review, and by drawing on the experience of former technical advisers to the Ministry of Health. In the immediate post‐conflict phase, the health system in southern Sudan was characterised by fragmentation, low coverage of health services, dismal health outcomes and limited government capacity. Health policy was extensively shaped by the interplay of context, actors and processes: the World Bank and the World Health Organization became the primary drivers of policy change. Lessons learned from the southern Sudan case include the need for: sustained investment in assessment and planning of recovery activities; building of procurement capacity early in the recovery process; support for funding instruments that can disburse resources rapidly; and streamlining the governance structures and procedures adopted by health recovery financing mechanisms and adapting them to the local context.     

Accumulation and metal fluxes in the central Venice Lagoon during the last century

Samples from 18 short sediment cores were analyzed for major and trace metals (Al, Fe, Ca, K, Mg, Mn, Si, Ti, Pb, Zn, Cu, Ni, and Cr), ²¹⁰Pb, ¹³⁷Cs, total organic carbon, grain size, and mineralogical composition to find the record of major environmental changes, either natural or anthropogenic, and to establish their chronologies. Some sediments are characterized by nearly constant composition over time, but others clearly show signs of an increasing marine influence, as an increase of the carbonate contents, after the opening of the Malamocco-Marghera Canal in 1969. These changes sometimes obscure the real pattern of pollutants and tracers, which is revealed by normalization against Al. Zn is the most important contaminant, with concentration factors up to 9.3 times the background level, and the most contaminated sediments are those within a few kilometers from the industrial district of Porto Marghera. ²¹⁰Pb activity-depth profiles were used to calculate apparent accumulation rates that provide a basis for the assessment of metal fluxes. The sediments of several sites show a significant increase in anthropogenic metal contamination starting from the second decade of last century, with maximum inputs from 1930 to 1970. The decrease of heavy metal concentrations observed in surficial sediments of some sampling sites could be related to a recent reduction of pollutant inputs.     

Ozone biomonitoring in Northern Italy

This report presents the results of an ozone monitoring experience performed with tobacco indicator plants (Nicotiana tabacum L. cv. Bel-W3). These bioindicators were exposed to ambient air in 23 sites in Northern Italy from 27 April 1987 to 21 October 1987. Typical ozone-induced leaf necrosis was observed in every site. The percentage increase in injured leaf area was estimated weekly and a Leaf Injury Index (LII) was calculated. The weekly series of LIIs were statistically inspected for spatial and temporal relationships. Sample correlation coefficients were statistically significant for almost every possible pair of sites. The time series properties of ten series of LIIs with no missing data were analyzed using Box-Jenkins models. An autoregressive first order model, or AR(1), was selected to remove the autocorrelation from these series. Linear correlation coefficients between prewhitened (i.e. from which autocorrelation had been removed) pairs of LII series were statistically significant. Hence synchronous variations in leaf necrosis could only be related to the regional diffusion of tropospheric ozone.Work carried out as part of the research programme: ENEL's contribution to the knowledge of important environmental issues, Research line; Effects of atmospheric pollution on the land.     

Correlation between environmental parameters and leaf injury in Nicotiana tabacum L. cv. ‘Bel-W 3’

Tobacco plants (Nicotiana tabacum L. cv. Bel-W3) were exposed to ambient air for 25 weeks during the 1987 growing season next to an air pollution monitoring station in Brera (Milan, Italy). The research objective was to study the influence of selected environmental parameters on leaf damage in this plant, which is widely used as an ozone indicator. A multiple linear correlation model was estimated between leaf damage and available meteorological and air pollution data. Leaf injury was positively correlated with ozone integrated exposure and temperature, but negatively with vapour pressure deficit. A linear correlation model was used to estimate ozone integrated exposure from the leaf injury indexWork carried out as part of the research programme: ENEL's contribution to the knowledge of important environmental issues, research line: Effects of atmospheric pollution on the land.     

SOLIDS DISTRIBUTION IN LAKE CHAPALA,MEXICO1

ABSTRACT: Lake Chapala is the largest natural water body in Mexico and also one of the most important shallow lakes in Latin America. For the past several years it has suffered various environmental problems such as the upstream overuse of water, contamination, and sedimentation. For the past 10 years the lake has had less than 50 percent of its historical water level over the past century. No criteria are reported in the literature that establish a water storage volume that will guarantee water quality conditions necessary for the survival of the lake. After determining the behavior of total solids concentrations in relation to the variations in the lake's depth, we proposed a minimum water column height of 5.0 m, representing a storage volume of about 5,000 Mm³. This volume would result in the recommended water quality standards for total dissolved solids. Calculated distribution maps show that the total solids concentration in the lake has increased since the end of the 1970s. The solids are primarily concentrated in the eastern part of the lake, as a consequence of the high solids discharged from the Lerma River, its main tributary.     

Assessing coastal vulnerability to climate change: comparing segmentation at global and regional scales

Recent concerns about potential climate-change effects on coastal systems require the application of vulnerability assessment tools in order to define suitable adaptation strategies and improve coastal zone management effectiveness. In fact, while various research efforts were devoted to evaluate coastal vulnerability to climate change on a national to global level, fewer applications were carried out so far to develop more comprehensive and site-specific vulnerability assessments suitable to plan possible adaptation measures at the regional scale. In this respect, specific indicators are needed to address climate-change-related issues for coastal zones and to identify vulnerable areas at the regional level. Two sets of coastal vulnerability indicators were selected, one for regional and one for global studies, respectively, concerning the same features of coastal systems, including topography and slope, geomorphological characteristics, presence and distribution of wetlands and vegetation cover, density of coastal population and number of coastal inhabitants. The proposed set of indicators for the regional scale was chosen taking into account the availability of environmental and territorial data for the whole coastal area of the Veneto region and was based on site-specific datasets characterized by a spatial resolution appropriate for a regional analysis. Moreover, a GIS-based segmentation procedure was applied to divide the coastline into linear segments, homogeneous in terms of vulnerability to climate change and sea-level rise at the regional scale. This approach allowed to divide the Veneto shoreline into 140 segments with an average length of about 1 km, while the global scale approach identified four coastal segments with an average length of about 66 km. The performed comparison indicated how the more detailed approach adopted at the regional scale is essential to understand and manage the complexities of the specific study area. In fact, the 25-m DEM employed at the regional scale provided a more accurate differentiation of the coastal area's elevation and thus of coastal susceptibility to the inundation risks, compared to the 1-km DEM used at the global level. Moreover, at the regional level the use of a 1:20,000 geomorphological map allowed to differentiate the unique landform class detected at the global level (e.g., fluvial plain) in a variety of more detailed coastal typologies (e.g., open coast eroding sandy shores backed by bedrock) characterized by a different sensitivity to climate change and sea-level rise. Accordingly, the information provided by regional indicators can support decision-makers in improving the management of coastal resources by considering the potential impacts of climate change and in the definition of appropriate actions to reduce inundation risks, to avoid the potential loss of valuable wetlands and vegetation and to plan the nourishment of sandy beaches subject to erosion processes.     

Growth and bleaching of the coral Oculina patagonica under different environmental conditions in the western Mediterranean Sea

The success that the putative alien species Oculina patagonica is able to survive under different environmental conditions may be benefiting its establishment and spreading along the Mediterranean Basin. Our objectives were to determine the response of this species, in terms of growth and bleaching, under different environmental conditions. Field data on colony growth and bleaching were obtained for a period of 18 months (from June 2010 to December 2011), in the Alicante Harbour (38°20′11″N, 00°29′11″W) and the Marine Protected Area of Tabarca (38°09′59″N, 00°28′56″W). Additionally, data on sedimentation rates, chlorophyll a concentration and organic matter were also collected. Moreover, the role of light over growth and bleaching of the coral was also studied with a field experiment. Our results showed that growth rates were similar among localities (eutrophic and oligotrophic environments), decreasing with increasing perimeter of the colony. Growth rates were at a minimum during cold months (13 °C) and enhanced during warm months until a threshold temperature; thereafter, bleaching was observed (>28 °C), being adverse for coral growth. In addition, light attenuation could act such as local stress, increasing the coral bleaching with the increase in seawater temperature. Our findings confirmed that O. patagonica has a broad tolerance to seawater temperature, irradiance and trophic water conditions, in addition to its ability to thrive through bleaching events, mainly in eutrophic environments, probably related to food availability.