Complementary assessment of As, Cu and Zn environmental availability in a stabilised contaminated soil using large-bore column leaching, automatic microcolumn extraction and DGT analysis.

Soil pollution with trace elements is a concerning issue worldwide. Monitoring of soil pollution and remediation protocols need still from valid complementary analytical approaches able to detect changes in speciation and lability of metals in soils (e.g.

Synergic use of chemical and ecotoxicological tools for evaluating multi-contaminated soils amended with iron oxides-rich materials.

Abandoned waste piles from ancient mining activities are potential hot spots for the pollution of the surrounding areas. A pot experiment was carried out to check the potential toxicity of the dumping material present in one of these scenarios, and several amendments were tested to attenuate the spread of the contamination events. The waste material had an acid pH and a large total concentration of As and Cu.

Assessing the ecotoxicological effects of long-term contaminated mine soils on plants and earthworms: relevance of soil (total and available) and body concentrations.

The interactions and relevance of the soil (total and available) concentrations, accumulation, and acute toxicity of several essential and non-essential trace elements were investigated to determine their importance in environmental soil assessment. Three plant species (T. aestivum, R.

Amendment application in a multi-contaminated mine soil: effects on soil enzymatic activities and ecotoxicological characteristics.

Several amendments were tested on soils obtained from an arsenopyrite mine, further planted with Arrhenatherum elatius and Festuca curvifolia, in order to assess their ability to improve soil's ecotoxicological characteristics. The properties used to assess the effects were: soil enzymatic activities (dehydrogenase, β-glucosidase, acid phosphatase, urease, protease and cellulase), terrestrial bioassays (Eisenia fetida mortality and avoidance behaviour), and aquatic bioassays using a soil leachate (Daphnia magna immobilisation and Vibrio fischeri bioluminescence inhibition). The treatment with FeSO4 1 % w/w was able to reduce extractable As in soil, but increased the extractable Cu, Mn and Zn concentrations, as a consequence of the decrease in soil pH, in relation to the unamended soil, from 5.

Risk assessment of an abandoned pyrite mine in Spain based on direct toxicity assays.

This research reports the risk assessment of an abandoned pyrite mine using direct toxicity assays of soil and groundwater samples taken at the site. The toxicity of As and heavy metals from mining soils to soil and aquatic organisms was studied using the Multispecies Soil System (MS-3) in soil columns. Ecotoxicological assessment was performed with soil samples diluted with a control soil at concentrations of 12.

Could an abandoned mercury mine area be cropped?

The Almadén area (Spain) is known for its high natural mercury background as well as for the anthropogenic impact due to mining activities. After the end of these activities, appropriate alternative use of the soil has to be found, and agricultural activities stand out as an environmentally-friendly and potentially profitable alternative, giving to the soil a sustainable use without risks for human or animal health according to current legislation. Experiments performed at different scales (involving hydroponics, growth in pots and lysimeters) allow recommendations to be made regarding the adequacy of cultivation of different crops for animal or human consumption before they are sown in the field.

Phytostabilisation with Mediterranean shrubs and liming improved soil quality in a pot experiment with a pyrite mine soil.

Phytoremediation can be a suitable option to manage derelict mine soils. A pot experiment was carried out under semi-controlled conditions with a mine-impacted soil. A further contamination event was mimicked by applying 5% of pyritic sludge.

Natural attenuation of residual heavy metal contamination in soils affected by the Aznalcóllar mine spill, SW Spain.

Non-amended soils affected by pyritic sludge residues were monitored for 7 years to assess the long-term natural attenuation ability of these soils. The decrease in both the total concentration of elements (particularly As) and (NH(4))(2)SO(4)-extractable fractions of Mn, and Zn, below the maximum permissible levels indicate a successful natural ability to attenuate soil pollution. Soil acidification by pyrite oxidation and rainfall-enhanced leaching were the largest contributors to the reduction of metals of high (Mn, Cu, Zn and Cd) and low (Fe, Al, and As) availability.

Using Mediterranean shrubs for the phytoremediation of a soil impacted by pyritic wastes in Southern Spain: a field experiment.

Re-vegetation is the main aim of ecological restoration projects, and in Mediterranean environments native plants are desirable to achieve successful restoration. In 1998, the burst of a tailings dam flooded the Guadiamar river valley downstream from Aznalcóllar (Southern Spain) with sludges that contained elevated concentrations of metals and metalloids, polluting soils and waters. A phytoremediation experiment to assess the potential use of native shrub species for the restoration of soils affected by the spillage was performed from 2005 to 2007, with soils divided into two groups: pH < 5 and pH > 5.

Screening risk assessment tools for assessing the environmental impact in an abandoned pyritic mine in Spain.

This paper describes a new methodology for assessing site-specific environmental impact of contaminants. The proposed method integrates traditional risk assessment approaches with real and variable environmental characteristics at a local scale. Environmental impact on selected receptors was classified for each environmental compartment into 5 categories derived from the whole (chronic and acute) risk assessment using 8 risk levels.

Efficiency of white lupin in the removal of mercury from contaminated soils: soil and hydroponic experiments.

This study examined the ability of the white lupin to remove mercury (Hg) from a hydroponic system (Hg concentrations 0, 1.25, 2.5, 5 and 10 micromol/L) and from soil in pots and lysimeters (total Hg concentration (19.

Feasibility of arsenic phytostabilisation using Mediterranean shrubs: impact of root mineralisation on As availability in soils.

An incubation experiment was carried out to evaluate the rate of arsenic release from roots to soil during root mineralisation, in order to determine the viability of phytostabilisation of metal-polluted soil. Arsenic (As)-loaded roots were mixed with the soil, monitoring arsenic, phosphorus, copper and zinc solubility and pH. Arsenic dynamics in soil during root mineralisation depend on various factors such as mineralisation rate, pH and soil chemistry.

Evolution of arsenate toxicity in nodulated white lupine in a long-term culture.

White lupine is an As-resistant legume that is of interest for phytoremediation of As-contaminated soils. To achieve successful phytoremediation, monitoring of the nutritional status of the selected plant species during the entire culture cycle is required to maintain a plant cover with high biomass production. A long-term pot experiment was carried out with nodulated lupine grown on perlite with 10 and 100 microM As concentrations.

Heavy metals distribution in soils surrounding an abandoned mine in NW Madrid (Spain) and their transference to wild flora.

The present work concerns the distribution and mobility of heavy metals (Fe, Mn, Cu, Zn and Cd) in the surrounding soils of a mine site and their transfer to wild flora. Thus, soils and plants were sampled from a mining valley in NW Madrid (Spain), and total and extractable heavy metals were analysed. Soils affected by mining activities presented total Cd, Cu and Zn concentrations above toxic thresholds.

Comparison of arsenic resistance in Mediterranean woody shrubs used in restoration activities.

Myrtus communis, Arbutus unedo and Retama sphaerocarpa are Mediterranean shrubs widely used in revegetation of semiarid degraded soils. The aim of this work is to study the resistance of these plants to arsenic under controlled conditions, in order to evaluate their potential use in revegetation and/or phytoremediation of As-polluted soils. R.

Chelate-assisted phytoextraction of heavy metals in a soil contaminated with a pyritic sludge.

The occurrence of many polluted areas as that affected by the accident of the Aznalcóllar pyrite mine has promoted phytoremediation as a technology able to reduce the risk of heavy metal contamination at low cost. White lupin plant has been considered a good candidate for phytoremediation. We studied the capacity of several complexing agents to improve the ability of white lupin for heavy metal phytoremediation in soils with multi-elemental pollution from acid pyritic sludge.