This work presents a geochemical study conducted on the abandoned Tinoca Copper mine (southeast Portugal) to evaluate the potential hazard in surrounding areas particularly the effect on the Abrilongo River Dam which receivesthe acid waters from the mine watershed. The characterization of the area was performed over a period of 3 y and involved the study of waters, sediments and mine wastes. A sequential extraction methodology was conducted on the sediments and mine wastes and five elements were selected (Cu, Fe, Zn, Cd and Pb). The statistical and spatial analysis allowed the inference of the affinities between the chemical elements and specific mineralogical phases and to characterize chemical behaviour such as mobility and bioavailability. The results show that the distance to the source (mine-waste deposit), the point of zero charge, and the dynamics of the system are factors that control the behaviour of the elementss tudied. The acid drainage is characterized by an average pH of 2.5 and concentrationsof copper 20 timesgreater than the legal limit for irrigation waters.

Calcium carbonate forms three polymorphic minerals that are found in a variety of environments at the Earth’s surface. Other compounds in the aqueous system can inhibit or enhance the probability of one phase or another, favour growth of specific crystal faces, and change the rate of recrystallization. Control of crystal systems requires understanding of the relationships between the foreign agent and the CaCO3 mineral surface. This work, which examines the transformation of vaterite to calcite, is part of a larger project that aims to define some of the parameters that control calcite recrystallization and grain coarsening.

Metals have been central to the development of human civilization from the Bronze Age to the present although historically, mining and smelting have been the cause of local environmental pollution with the potential to harm human health. Despite problems from artisanal mining in some developing countries, modern mining for Western standards now uses the best available mining technology combined with environmental monitoring, mitigation and remediation measures to control emissions to the environment. The relocation and removal of large quantities of mineral and waste could also release chemicals into the environment including surface water, ground water and soil during the mining lifecycle. There are only few published methods available for prioritizing hazardous chemicals. These fail to recognize differences between organic and inorganic chemicals make it necessary to develop separate screening and prioritization procedures for those two different classes of chemicals. In this study, we focus on the development of screening and prioritization procedure in risk assessment for inorganic chemicals with particular reference to those used, generated and released in mining operations.

Unlike planktonic systems, reaction rates in biofilms are often limited by mass transport, which controls the rate of supply of contaminants into the biofilm matrix. To help understand this phenomenon, we investigated the potential of magnetic resonance imaging (MRI) to spatially quantify copper transport and fate in biofilms. For this initial study we utilized an artificial biofilm composed of a 50:50 mix of bacteria and agar. MRI successfully mapped Cu2+ uptake into the artificial biofilm by mapping T2 relaxation rates. A calibration protocol was used to convert T2 values into actual copper concentrations. Immobilization rates in the artificial biofilm were slow compared to the rapid equilibration of planktonic systems. Even after 36 h, the copper front had migrated only 3 mm into the artificial biofilm and at this distance from the copper source, concentrations were very low. This slow equilibration is a result of (1) the time it takes copper to diffuse over such distances and (2) the adsorption of copper onto cell surfaces, which further impedes copper diffusion. The success of this trial run indicates MRI could be used to quantitatively map heavy metal transport and immobilization in natural biofilms.

The steroid hormones and their cellular receptors responsible for the sexual development and activity ofh umans and other vertebrates evolved in the late Precambrian—Cambrian and have remained unchanged since that time. Growth factors, which are small molecular weight proteins responsible for growth, sexual maturation and also for the cell cycle whereby cells replicate themselves evolved at around the same time. The molecular structures of hormones and growth factors in different vertebrates are essentially the same, so that a chemical capable of causing harmful effects in one species is likely to cause ill effects in other, even taxonomically distinct, species. The particular effects can vary because individual hormones and growth factors are associated with different functions in different species.

The S. Domingos abandoned mine is a major source of pollutant-metals contamination. Slags from the 19th-20th century contain the most hazardous material. However, the release of pollutant metals depends on the metal-retention capability of weathering products. This work shows that Zn is not effectively retained by these weathering products while As and Pb are partially stored in sulphates. Copper, on the other hand, has a different behaviour and is the most leachable of the elements studied.

Earthworms are an essential part of the soil fauna in many global soils, represent a significant proportion of the soil biomass and are regarded as a useful indicator of soil health and quality (Edwards, 2004). They are also often the subject of inoculation programmes during the restoration of degraded lands (Butt, 1999) and the inoculation of earthworms to metal-contaminated soils has been suggested(Dickinson, 2000) largely due to the role earthworms are known to play in soil formation at such sites (Frouz et al., 2007).

Nano-technology has a lot to contribute toward efforts for a sustainable environment. In addition to the promise of sensors, monitoring devices and functional particles, there is new, fundamental information to begaine d by applying nm-scale measuring techniques to natural materials. Improved understanding of the interaction of fluids with natural solids can lead us to new solutions for some of society’s problems, especially in the realm of clean water and safe treatment of waste. Ultra-high resolution lets us define the molecular-scale processes responsible for uptake of contaminants such as transition metals (e.g. Ni and Cr), radioactive species (e.g. Np) and organic compounds (e.g. glyphosate, a pesticide), while they adsorb on minerals such as calcite and Fe oxides and in some cases, are immobilized by solid-solution formation. With molecular-level resolution, we can see changes that with our traditional methods would only be visible after years or geological time.

Two sites with five wells in the Danube-Tisza interfluvial were studied in order to help understand the genesis of the high-As content of shallow ground water. Separation of As species was carried out in the field as it proved to be the best method by which to preserve the As species. Different geochemical environments could be separated by the speciation studies which correlate with the concentrations of oxyanion-forming elementss uch asV, Se, Mo, U and W.

Natural Mn oxides are an important component of biogeochemical cycles in many environmental settings. Mn oxides are strong oxidizing agents, facilitating the breakdown of organic contaminants and enhancing humification of soil organic matter. Interactions with metals and radionuclides, including surface adsorption, sequestration and oxidation can lead to incorporation of metals into insoluble mineral phases and a consequent reduction in bioavailability of toxic contaminants. Because of these properties, addition of Mn oxides may prove an effective treatment method for land contaminated by a range of organic and inorganic contaminants.

In recent years it has become apparent that the novel properties of nanomaterials may predispose them to a hitherto unknown potential for toxicity. A number of recent toxicological studies of nanomaterials exist, but these appear to be fragmented and often contradictory. Such discrepancies may be, at least in part, due to poor description of the nanomaterial or incomplete characterization, including failure to recognise impurities, surface modifications or other important physicochemical aspects of the nanomaterial. Herew em ake a casef or the importance of good quality, well-characterized nanomaterials for future toxicological studies, combined with reliable synthesis protocols, and we present our efforts to generate such materials. The model system for which we present results is TiO2 nanoparticles, currently used in a variety of commercial products.

Fly ash from secondary Pb metallurgy was submitted to the pH-static leaching procedure according to the PrEN 14997 European leaching standard. The 48 h pH-static leaching experiments were performed on (1) fresh untreated fly ash and (2) previously washed fly ash with a cumulative wash step of 60 l kg-1. Greater release ofmetallic contaminants (Pb, Cd, Zn) was observed in the acidic pH range for both ashes. Washing significantly reduced the release of Cd and Zn, but greater concentrations of Pb were observed in leachates from washed fly ash due to the more important leaching of anglesite (PbSO4). The PHREEQC-2 speciation-solubility calculations showed that anglesite, phosgenite (PbCl2·PbCO3) and laurionite (Pb(OH)Cl) are the most important solubility-controlling phases for Pb, which is the most important contaminant.

We have applied atomistic simulation techniques to model the continuous CdCO3-CaCO3 solid solution and to investigate the thermodynamic properties. All inequivalent substitutional configurations were considered for the single unit cell and the (2x1x1) supercell for the full range of Cd concentrations, as well as doping between 0and 16.7 mol.% Cd for the (2x2x1) supercell. Our calculations show that segregation of Cd2+ and Ca2+ is energetically favourable when compared with any other cation distribution. No cation ordering is expected at high temperature and the system behaves as an ideal solid solution above 200 K, due to the configurational entropy. The lattice parameters change with the Cd concentration, where they are predicted to follow a linear relationship, due only to cation substitution but not cation ordering.

Geochemical anomalies can be used in mineral resource exploration. We demonstrate a technique for mapping anomalies. The Gangdese mineral district in Tibet, west China was chosen as a study area for identifying geochemical anomalies and predicting Cu mineral resources using sediment geochemical data. The results show that the anomalies are associated both with known deposits in the middle of the study area, but also with E—W and N——E oriented faults in the north of area. These areas should be explored for undiscovered Cu mineral deposits.