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1.
The horizons of four natural soils were treated with Cu2+ in an acid medium to study the retention capacity of Cu. The possible mineralogical changes arising because of the treatment were also studied. The soil properties and characteristics with the greatest influence on the metal retention and its distribution among the different soil fractions were determined. Crystalline phases of each horizon were determined by X-ray diffraction (XDR). The morphology, structural distribution and particle chemical composition of soil samples were investigated using field emission scanning electron microscopy. Cu distribution in the different geochemical phases of the soil was studied using a sequential extraction. The treatment led to an increase in the amorphous phases and the formation of new crystalline phases, such as rouaite (Cu2(NO3)(OH)3) and nitratine (NaNO3). Cu was also found superficially sorbed on amorphous hydroxy compounds of Fe that interact with albite, muscovite and gibbsite, and also on spherical and curved particles of aluminium clays. The largest amount of Cu retained was in an exchangeable form, and the smallest amount associated with the crystalline Fe oxides and residual fraction. In the surface horizons, the predominant Cu retention process is complexation in organomineral associations, while in the subsurface horizons it is adsorption.  相似文献   
2.
Biomarkers are internationally recognized as useful tools in marine coastal biomonitoring, in particular, as early-warning signals at the level of individual organisms to assess biological effects of pollutants and other stressors. In the present study, Mytilus galloprovincialis has been employed as a sentinel organism to assess biological pollution effects in the Mar Piccolo of Taranto (Southern Italy), a coastal lagoon divided into two small inlets, connected to the open sea through one natural and one artificial narrow openings. Mussels were collected in June 2013 at three sites located within each of the two inlets of the Mar Piccolo. Biological effects were investigated through a suite of biomarkers suitable to reflect effects and/or exposure to contaminants at biochemical and cellular levels. Biochemical biomarkers included glutathione-S-transferase (GST) and acetylcholinesterase (AChE) enzyme activities; as histochemical biomarkers, lysosomal membrane stability, lipofuscin and neutral lipid accumulation, and lysosomal structural changes were considered. As a whole, results highlighted differences among the three study sites, particularly for GST, AChE, and lipofuscins, which are consistent with the variations of the chemical pollutants in sediments. The applied biomarkers showed that a stress syndrome likely to be ascribed to environmental pollutants is occurring in mussels living in the Mar Piccolo of Taranto, in particular, the ones inhabiting the first inlet.  相似文献   
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The co-digestion of a variable amount of fruit and vegetable waste in a waste mixed sludge digester was investigated using a pilot scale apparatus. The organic loading rate (OLR) was increased from 1.46 kg VS/m3 day to 2.8 kg VS/m3 day. The hydraulic retention time was reduced from 14 days to about 10 days. Specific bio-methane production increased from about 90 NL/kg VS to the maximum value of about 430 NL/kg VS when OLR was increased from 1.46 kg VS/m3 day to 2.1 kg VS/m3 day. A higher OLR caused an excessive reduction in the hydraulic retention time, enhancing microorganism wash out. Process stability evaluated by the total volatile fatty acids concentration (mg/l) to the alkalinity buffer capacity (eq. mg/l CaCO3) ratio (i.e. FOS/TAC) criterion was <0.1 indicating high stability for OLR <2.46 kg VS/m3 day. For higher OLR, FOS/TAC increased rapidly. Residual phytotoxicty of the digestate evaluated by the germination index (GI) (%) was quite constant for OLR < 2.46 kg VS/m3 day, which is lower than the 60% limit, indicating an acceptable toxicity level for crops. For OLR > 2.46 kg VS/m3 day, GI decreased rapidly. This corresponding trend between FOS/TAC and GI was further investigated by the definition of the GI ratio (GIR) parameter. Comparison between GIR and FOS/TAC suggests that GI could be a suitable criterion for evaluating process stability.  相似文献   
5.
Abstract

About half of the world's population now lives in urban areas because of the opportunity for a better quality of life. Many of these urban centers are expanding rapidly, leading to the growth of megacities, which are often defined as metropolitan areas with populations exceeding 10 million inhabitants. These concentrations of people and activity are exerting increasing stress on the natural environment, with impacts at urban, regional and global levels. In recent decades, air pollution has become one of the most important problems of megacities. Initially, the main air pollutants of concern were sulfur compounds, which were generated mostly by burning coal. Today, photochemical smog—induced primarily from traffic, but also from industrial activities, power generation, and solvents—has become the main source of concern for air quality, while sulfur is still a major problem in many cities of the developing world. Air pollution has serious impacts on public health, causes urban and regional haze, and has the potential to contribute significantly to global climate change. Yet, with appropriate planning megacities can efficiently address their air quality problems through measures such as application of new emission control technologies and development of mass transit systems.

This review is focused on nine urban centers, chosen as case studies to assess air quality from distinct perspectives: from cities in the industrialized nations to cities in the developing world. This review considers not only megacities, but also urban centers with somewhat smaller populations, for while each city—its problems, resources, and outlook—is unique, the need for a holistic approach to complex environmental problems is the same. There is no single strategy to reduce air pollution in megacities; a mix of policy measures will be needed to improve air quality. Experience shows that strong political will coupled with public dialogue is essential to effectively implement the regulations required to address air quality.  相似文献   
6.
A survey, based on the use of vascular plants to describe the distribution of selected elements (21 in total) was performed in 11 sites in the area of Castelfiorentino (Tuscany, Central Italy) differing for land use, from urban to industrial and rural areas. Lettuce plants grown under standardized conditions were positively used as biodeposimeters of airborne trace elements. Washing was found to be highly significant in reducing concentrations of many elements in the samples, suggesting a general surface contamination of leaves. The typical crustal element Al showed good correlations with Co, Fe, Li and V; on the contrary, Zn and Cd were intercorrelated and showed no connection with crustal indicators. Lead was still a relevant environmental presence, as the experiments were carried out before the ban of leaded gasoline. Source apportionment by factor analysis put in evidence a major contribution of crustal materials, followed by man-related activities; a minor role was ascertained for marine aerosol. A comparison was made between analytical data of lettuce plants grown in our experimental sites and a bulk of commercial lettuce purchased at a local supermarket. It should be stressed how Cu concentrations of commercial material were significantly higher than those found in our plants; this is likely caused by phytosanitary treatments.  相似文献   
7.
The Festival described in this article won the Golden Ball Award for education of the Italian Academy of Lincei. Dr Maria Luisa Cohen, the author, was honoured with the Tree of Learning Award for 1988, by the Commission on Education and Training of the IUCN, for her services to environmental education and her promotion and participation in the Festival.  相似文献   
8.
The paper reports a methodology adopted to face problems related to quality assurance in soil sampling. The SOILSAMP project, funded by the Environmental Protection Agency of Italy (APAT), is aimed at (i) establishing protocols for soil sampling in different environments; (ii) assessing uncertainties associated with different soil sampling methods in order to select the "fit-for-purpose" method; (iii) qualifying, in term of trace elements spatial variability, a reference site for national and international inter-comparison exercises. Preliminary results and considerations are illustrated.  相似文献   
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10.
Neonatal hemochromatosis (NH) is a rare disorder but the most common cause of acute liver failure in neonates. NH is characterized by severe hepatic injury and iron overload and is associated with high perinatal mortality and morbidity rates. NH is often preceded by oligohydramnios and intrauterine growth restriction, suggesting an important impact of NH during fetal life. Stillbirth and prematurity are not uncommon. During the last decade, major discoveries on the etiology of NH have radically changed the management and outcome of this disease. NH is now regarded as an alloimmune disease and is, as such, often referred to as gestational alloimmune liver disease. Antenatal treatment with intravenous immunoglobulins starting at 14 weeks' gestation has been shown to prevent the development of NH in subsequent pregnancies. Postnatal treatment, previously based on the use of anti-oxidants and chelation therapy, has now successfully been replaced by exchange transfusions and intravenous immunoglobulins substitution. This review summarizes the latest discoveries on the etiology of NH and the new recommendations concerning its management and prevention. © 2013 John Wiley & Sons, Ltd.  相似文献   
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