Printed wiring boards for mobile phones: characterization and recycling of copper

The popularization of mobile phones, combined with a technological evolution, means a large number of scrap and obsolete equipment are discarded every year, thereby causing economic losses and environmental pollution. In the present study, the printed wiring boards scrap of mobile phones were characterized in order to recycle some of the device components, using techniques of mechanical processing, hydrometallurgy and electrometallurgy. The use of the techniques of mechanical processing (milling, particle size classification, magnetic and electrostatic separation) was an efficient alternative to obtain a concentrated fraction (mainly iron in the magnetic fraction and copper in the conductive fraction) and another fraction containing polymers and ceramics. At the end of mechanical processing, a concentrated fraction of metals could be obtained with an average concentration of 60% copper. This concentrated fraction in metals was dissolved in aqua regia and sent to electrowinning to recover 92% of the dissolved copper. The obtained cathodes have a copper content above 95%, which demonstrates the technical feasibility of recovery of copper using the techniques of mechanical processing, hydrometallurgy and electrometallurgy.     

Recent changes in flood preparedness of private households and businesses in Germany

Using the focusing event framework, a comprehensive analysis of private households’ and businesses’ preparedness was undertaken in the aftermath of the 2002 and 2006 flood events on the Elbe River in Germany. In August 2002, preparedness of households (n = 235) and businesses (n = 103) was low: 30% of the households and 54% of the businesses took no precautionary measures before the flood event. Many undertaken emergency measures were ineffective, since only 26% of all households knew how to react when the flood warning came, and only 9% of businesses had an emergency plan in place. Due to this extreme flood, double-loop learning occurred in many households and businesses, so that many did implement precautionary measures. The distribution of adopted precautionary measures for households fits well to Preisendörfer’s low-cost hypothesis, but does not apply for businesses. Only 10% of the households (n = 112), but still 29% of the businesses (n = 41) were unprepared before the flood in 2006. Significant improvement in flood preparedness activities is still necessary. Particularly for businesses, regulatory programs and programs encouraging proactive behaviour should be implemented. The focusing event framework proofed to be a useful tool for a differentiated analysis of the responses to and learning due to a disaster also in the commercial and private sector.     

Combination effects of anticholinesterasics in acetylcholinesterase of a fish species: effects of a metallic compound,an organophosphate pesticide,and a pharmaceutical drug

The simultaneous presence of distinct compounds in the aquatic environment can be causative of various toxicological interactions. This scenario challenges ecotoxicologists, since the assessment of toxicological effects caused by the simultaneous presence of multiple substances is by far more complicated. An illustrative example can be given by mentioning the anticholinesterasic compounds: by studying the level of cholinesterase impairment of an exposed organism, it is possible to ascertain the level of exposure to all anticholinesterasics (despite their chemical classes and natures) that the organism was subjected to. In this work, we describe the effects of three chemically different, albeit mechanistically, and toxicologically similar compounds (copper, chlorfenvinphos, and pyridostigmine) on cholinesterases of the fish Gambusia holbrooki. The results showed that the combinatorial effects may be of considerable extent, even for levels of exposure that are close to the ones already reported in the wild, for each isolated compound.     

Effects of environmentally relevant concentrations of metallic compounds on the flatfish Scophthalmus maximus: biomarkers of neurotoxicity,oxidative stress and metabolism

Flatfish species, such as the turbot (Scophthalmus maximus), are common targets for toxic effects, since they are exposed through the food chain (ingestion of contaminated preys) and are in direct contact with the waterborne contaminant and sediments. Furthermore, these fish species live in close proximity to interstitial water that frequently dissolves high amounts of contaminants, including metals. Despite this significant set of characteristics, the present knowledge concerning flatfish contamination and toxicity by metals is still scarce. To attain the objective of assessing the effects of metals on a flatfish species, S. maximus specimens were chronically exposed to lead, copper and zinc, at ecologically relevant concentrations, and biochemical (oxidative stress: catalase and glutathione S-transferases activities, and lipid peroxidation; neurotoxicity: cholinesterase activity) parameters were assessed on selected tissues (gills and liver). Copper had no significant effects on all tested parameters; lead was causative of significant increases in liver GSTs activities and also in lipoperoxidation of gill tissue; exposure to zinc caused a significant increase in catalase activity of gill tissue. None of the tested metals elicited noteworthy effects in terms of neurotoxicity. The obtained results showed that only the metal lead is of some environmental importance, since it was able to cause deleterious modifications of oxidative nature at relevant concentrations.     

Biochemical effects of acetaminophen in aquatic species: edible clams Venerupis decussata and Venerupis philippinarum

Acetaminophen (paracetamol) is one of the most used pharmaceutical drugs, due to its antipyretic and analgesic properties that turn it into a primary choice in varied pathologies and conditions. However, and despite its massive use, acetaminophen is not exempt of adverse effects, especially when administered in over dosage, which are related to the formation of toxic metabolites by oxidative pathways. It is thus possible to observe that toxicity caused by acetaminophen is usually mediated by reactive oxygen species and can result in multiple effects, ranging from protein denaturation to lipid peroxidation and DNA damage. The occurrence of acetaminophen has been reported in the aquatic environment, being important to address the potential exertion of toxic effects on nontarget environmentally exposed organisms. The present study intended to characterize the effects of acute acetaminophen exposure on physiological traits (antioxidant defense, oxidative damage) of two species of bivalves, namely, the edible clams Venerupis decussata and Venerupis philippinarum. Results showed a significant increase in all oxidative stress biomarkers, evidencing the bioactivation of acetaminophen into a deleterious prooxidant, triggering the onset of deleterious effects. Furthermore, strong interspecific differences were observed among responses of the two tested species, which was a major issue due to intrinsic ecological implications when one considers that both species share the same habitat.     

Remediation procedure used for contaminated soil and underground water: A case study from the chemical industry

This is a case study of contamination by a non-aqueous phase liquid (NAPL) that leaked from a chemical plant. The remediation procedure adopted for the initial phase of the plume migration was a plastic diaphragm wall coupled with a series of water extraction wells designed to avoid environmental impact on the surrounding ecosystems. Monitoring has shown that the containment is successful, and additional measures that contribute to accelerating remediation have been adopted. The authors wished to investigate how remediation might be further enhanced. The use of in situ aeration coupled with a system of soil vapor extraction (AS/SVE) has been chosen, since the remediation of sites with characteristics similar to those in this study, if based exclusively on dissolved-phase control, would take several decades to be completed. The transport of contaminant plumes has been simulated by using an analytical model to evaluate the effectiveness of the natural attenuation of the contaminant. The results of the simulation have confirmed the limited effectiveness of the natural attenuation of the contaminant, as well as the effective increase of remediation that would occur if the AS/SVE system is applied. A sensitivity analysis that included several combinations of increments of parameters that correspond to the decay rate of the source and the dissolved plume has simulated what might happen if the AS/SVE system is implemented.     

Vacuum pyrolysis process for remediation of hydrocarbon-contaminated soils

A vacuum pyrolysis process was used for the remediation of hydrocarbon–contaminated soils from “Les Vidangeurs de Montréal” site in Mascouche in the province of Québec, near Montréal. Ten samples were tested on a laboratory scale batch reactor, and one sample was tested on a prototype process development unit. The process is simple, efficient, reliable, and economically competitive with other existing technologies. The vacuum pyrolysis process efficiently treated soils contaminated with a variety of pollution levels and types, irrespective of the soil matrix, providing treated soils meeting the A criterion (noncontaminated, residential level) of the Ministry of Environment Québec (MENVIQ). The pyrolytic oil and the noncondensable pyrolytic gases can be used as makeup fuel in the process, because they have a high calorific value and their combustion should not pose any emission problems. The waterphase effluent must be treated before discharge.     

Distribution in Portugal of some pollutants in the lichen Parmelia sulcata

During the months of July and August 1993 a lichen (Parmelia sulcata Taylor) collection campaign was held in Portugal where samples were obtained from olive tree bark at 228 sites, following a grid of 10 x 10 km along the Atlantic coast and 50 x 50 km in the interior of the country. The samples were analysed by instrumental neutron activation analysis and proton induced X-ray emission techniques. Concentration data patterns for the pollutants As, Cr, Hg, Ni, Pb, S, Sb, Se, and V were obtained for the whole country surface by making use of an extinction rule of 1/r(3), preventing any cut-off distance from being artificially introduced. Some pollution sources were identified: (1) oil-powered plants on the Lisbon-Setúbal axis (V, Ni), (2) coal-power plants in Porto and Sines (S, Se), (3) traffic in the northern area and the Lisbon-Setúbal axis (Pb), (4) a chemical industry south of Porto (Hg, As), and (5) soil influence (Cr, Sb). Arsenic and chromium results largely exceed, in a few areas, the concentrations acceptable to plants, and in a few spots also Hg, Ni, and Pb data.     

A study about remedial measures to reduce 222Rn concentration in an experimental building

Radon gas emanating from underground can spread to adjoining closed areas. It can concentrate and reach levels which represent a risk to people's health. It is well known that radon presence in most areas depends mainly on the area's geological features. Indoor radon concentrations further depend on the type of structure, construction materials and the technology used for the building. Therefore, indoor radon monitoring is of primary importance for deciding whether remedial measures are to be adopted for reducing harmful concentrations. This approach has been tried by measuring radon concentration in an experimental building situated in Milan (Italy). This building situated in a geological area that is considered at low radon risk. The results were obtained after analysing radon concentration in indoor rooms, crawl spaces, soil gas and in the atmosphere outside and by measuring before and after adoption of remedial measures. The study shows that improper building design can give rise to higher indoor radon accumulation even in an area of poor radon exhalation. Furthermore, the results enable quantification of the effectiveness of the remedial measures.