Impact of mining activities on soils in a semi-arid environment: Sierra Almagrera district, SE Spain

Field and laboratory-column studies were undertaken in order to investigate soil contamination derived from past mining activity in the Sierra Almagrera (SA) district in southeast Spain. The tailings, soil and sediment samples that were collected showed high concentrations of Ag, As, Ba, Cu, Pb, Sb and Zn when analyzed. The mean concentrations of these elements in the tailings were 29.8, 285.4, 54000, 57.7, 2687.5, 179.0 and 2269.0 ppm, respectively. In the soil samples these decreased to 14.3, 96.9, 24700, 37.5, 1859.1, 168.5 and 815.7 ppm, respectively. Geochemical analyses demonstrated high levels of As, Pb and Zn which were above the intervention values set forth in the Andalusian Regulations for Contaminated Soils for As (>50 ppm), Pb (>500 ppm) and Zn (>2000 ppm). Column experiments and mineralogical studies suggest that the dissolution of sulfates and other secondary phases, accumulated in soils and waste-sites during the dry season, acts to control the mobility of metals. The elution curves obtained from column experiments showed a mobilization of Ba, Cu, Pb and Zn, while a low mobility was seen for Ag, As and Sb.     

Life cycle energy and CO2 emissions analysis of food packaging: an insight into the methodology from an Italian perspective

Packaging is strictly connected to environmental issues as it is a product characterised by high material consumption rate; it is often transported over long distances and has a short life. Providing environmental analysis is, therefore, urgent to identify energy and resources efficient solutions. The paper, taking advantage of a real case study, presents a life cycle-based comparative analysis among three different food packaging systems. The paper compares the life cycle of tin steel, polypropylene and glass-based packaging of an Italian preserves producer. The analysis leads to the conclusion that, for the baseline scenario, polypropylene packaging represents the greenest solution, whereas glass packaging is the worst choice. The paper presents a scenario analysis varying both the method used for accounting for recycling as well as the recycling rates of the packaging materials. Changes in overall results with parameters analysis changing are calculated and highlighted throughout the paper. The impact of a reuse policy of the glass-based solution is also analysed; a model for disposable glass packaging is proposed and the obtained results are compared with the single use polypropylene and tin steel-based packaging. In order to analyse the impact of different End of Life scenarios on the present case study, collecting as well as recycling rates of some European countries have been used. The results revealed a significant fluctuation both in energy consumption and in CO₂ emission as the nation changes. Summing up, a methodology for packaging environmental impact analysis is applied to a real case study, some crucial aspects of the methodology have been analysed in depth in order to give a contribution in packaging environmental impact analysis.     

Quantifying the relative irreplaceability of important bird and biodiversity areas

World governments have committed to increase the global protected areas coverage by 2020, but the effectiveness of this commitment for protecting biodiversity depends on where new protected areas are located. Threshold‐ and complementarity‐based approaches have been independently used to identify important sites for biodiversity. We brought together these approaches by performing a complementarity‐based analysis of irreplaceability in important bird and biodiversity areas (IBAs), which are sites identified using a threshold‐based approach. We determined whether irreplaceability values are higher inside than outside IBAs and whether any observed difference depends on known characteristics of the IBAs. We focused on 3 regions with comprehensive IBA inventories and bird distribution atlases: Australia, southern Africa, and Europe. Irreplaceability values were significantly higher inside than outside IBAs, although differences were much smaller in Europe than elsewhere. Higher irreplaceability values in IBAs were associated with the presence and number of restricted‐range species; number of criteria under which the site was identified; and mean geographic range size of the species for which the site was identified (trigger species). In addition, IBAs were characterized by higher irreplaceability values when using proportional species representation targets, rather than fixed targets. There were broadly comparable results when measuring irreplaceability for trigger species and when considering all bird species, which indicates a good surrogacy effect of the former. Recently, the International Union for Conservation of Nature has convened a consultation to consolidate global standards for the identification of key biodiversity areas (KBAs), building from existing approaches such as IBAs. Our results informed this consultation, and in particular a proposed irreplaceability criterion that will allow the new KBA standard to draw on the strengths of both threshold‐ and complementarity‐based approaches.     

An environmental pressure index proposal for urban development planning based on the analytic network process

This paper introduces a new approach to prioritize urban planning projects according to their environmental pressure in an efficient and reliable way. It is based on the combination of three procedures: (i) the use of environmental pressure indicators, (ii) the aggregation of the indicators in an Environmental Pressure Index by means of the Analytic Network Process method (ANP) and (iii) the interpretation of the information obtained from the experts during the decision-making process.The method has been applied to a proposal for urban development of La Carlota airport in Caracas (Venezuela). There are three options which are currently under evaluation. They include a Health Club, a Residential Area and a Theme Park. After a selection process the experts chose the following environmental pressure indicators as ANP criteria for the project life cycle: used land area, population density, energy consumption, water consumption and waste generation. By using goal-oriented questionnaires designed by the authors, the experts determined the importance of the criteria, the relationships among criteria, and the relationships between the criteria and the urban development alternatives.The resulting data showed that water consumption is the most important environmental pressure factor, and the Theme Park project is by far the urban development alternative which exerts the least environmental pressure on the area. The participating experts coincided in appreciating the technique proposed in this paper is useful and, for ranking ordering these alternatives, an improvement from traditional techniques such as environmental impact studies, life-cycle analysis, etc.     

New Fe-immobilized natural bentonite plate used as photo-Fenton catalyst for organic pollutant degradation

Novel photo-Fenton catalysts were prepared by immobilizing iron species on commercial bentonite plates via two methods: (1) ion exchange reaction (Fe³⁺ vs. Na⁺) by aqueous suspension powder-clay/FeCl₃ followed by plate preparation, and (2) forced hydrolysis of Fe(NO₃)₃ onto a prefabricated clay plate. The last method led to a more photo-active Fe-oxide/bentonite plate. This material allowed, at a non-adjusted initial pH of 5.5 and in the presence of H₂O₂, the total degradation of resorcinol and 55% mineralization in 80 and 100 min of irradiation, respectively. The reached degradation percentages were correlated to the presence of dissolved iron, demonstrating that in these processes, the homogeneous photo-Fenton reactions were mainly responsible for the resorcinol elimination.Likewise, in slurry system, where clay has normally an increased surface area, there was no increase in activity because of a reduced leached iron probably due to the diminished light penetration in the suspension. Despite the lower surface area, in comparison to that of the slurry, the clay plates have the advantage, as heterogeneous photo-catalysts, that separation of the reaction media after treatment is not needed, and thus, a potential use for batch and continuous reaction systems is proposed.     

Arsenic release from pyrite ash waste over an active hydrogeological system and its effects on water quality

Environmental Science and Pollution Research - Arsenic is a potentially toxic element of concern for environmental compartments, and it is a frequent pollutant in many abandoned industrial sites....     

Potential application of 2-(6-ethylamino-3-ethylimino-2,7-dimethyl-3H-xanthen-9-yl) benzoic acid phenyl thiourea for mercury determination

Heavy metal contamination of the environment is a public health problem and research to develop new tools for monitoring the environmental impact of these elements is necessary. This study describes the preparation of a rhodamine-based probe 1 and its potential applications for detecting mercuric ion [Hg(II)] in samples from a nutrition media containing Salvinia auriculata. It was observed that an excess of probe 1 led to quenching in the fluorescence/absorption response, which was evidenced by a decrease in the signal when the stoichiometry differed from 1:1. Consequently, this probe is not suitable for quantitative analysis of Hg(II). Also, probe 1 reacts with methylmercury (MeHg) with different stoichiometry than that observed for Hg(II). These results indicate the potential application of probe 1 for qualitative detection of Hg(II) and MeHg in environmental samples.     

Effect of gas composition in Chemical-Looping Combustion with copper-based oxygen carriers: Fate of sulphur

Chemical-Looping Combustion (CLC) is an emerging technology for CO₂ capture because separation of this gas from the other flue gas components is inherent to the process and thus no energy is expended for the separation. Natural or refinery gas can be used as gaseous fuels and they may contain different amounts of sulphur compounds, such as H₂S and COS. This paper presents the combustion results obtained with a Cu-based oxygen carrier using mixtures of CH₄ and H₂S as fuel. The influence of H₂S concentration on the gas product distribution and combustion efficiency, sulphur splitting between the fuel reactor (FR) and the air reactor (AR), oxygen carrier deactivation and material agglomeration was investigated in a continuous CLC plant (500 W_th). The oxygen carrier to fuel ratio, ?, was the main operating parameter affecting the CLC system. Complete fuel combustion were reached at 1073 K working at ? values ≥1.5. The presence of H₂S did not produce a decrease in the combustion efficiency even when working with a fuel containing 1300 vppm H₂S. At these conditions, the great majority of the sulphur fed into the system was released in the gas outlet of the FR as SO₂, affecting to the quality of the CO₂ produced. Formation of copper sulphide, Cu₂S, and the subsequent reactivity loss was only detected working at low values of ? ≤ 1.5, although this fact did not produce any agglomeration problem in the fluidized beds. In addition, the oxygen carrier was fully regenerated in a H₂S-free environment. It can be concluded that Cu-based oxygen carriers are adequate materials to be used in a CLC process using fuels containing H₂S although quality of the CO₂ produced is affected.