Showing posts with label Iron. Show all posts
Showing posts with label Iron. Show all posts

Tuesday, 11 October 2016

Copper, Chromium, Nickel, Lead and Zinc levels and pollution degree in firing rage soils

Land Degrad. Develop. 27: 1721–1730 (2016)


Small-arms firing ranges are an important source of metal contaminants in the ecosystems located near these facilities, owing to the constant fall and alteration of the ammunition remnants on the soil, particularly in nearby berms. The objectives of this study were to analyse the pollution of chromium (Cr), copper (Cu), nickel (Ni), lead (Pb) and zinc (Zn) in rifle/pistol shooting range soils, to estimate their availability and to evaluate the influence of the ammunition used. The concentrations of Pb, Zn, Cu, Cr and Ni range from 55 to 6·309, 34 to 264, 19 to 98, 40 to 79 and 11 to 33 mg kg 1, respectively. The moderate acidity and organic matter content favour the availability of Pb, followed by Cu > Zn > Ni > Cr. The values of different contamination indexes (Igeo, pollution index and integrated pollution index) suggest that Pb soil contamination is moderate to heavy, especially in the berm area and moderate for Cu and Zn. Lead ammunition is the main source of pollution, but another one was identified owing to the concentrations of Fe, Cr and Ni detected. Further studies are needed to verify their long-term potential adverse effects.

Friday, 30 September 2016

Poorly-crystalline components in aggregates from soils under different land use and parent material

Catena 144 (2016) 141–150


Fe and Al compounds of low degree of crystallinity are important components for the development and conser- vation of soil structure in many soils. In this work, the influence of parent material and land use on the abundance of poorly-crystalline forms of Fe and Al was studied in six macroaggregate fractions from 28 soils. The soils select- ed are developed on two geological materials with very different composition: granites or amphibolites, and under two land uses: shrubland or agricultural. Poorly crystalline Fe and Al were extracted with oxalic acid–am- monium oxalate (inorganic and organic forms), and with pyrophosphate (organic forms). Soils developed on am- phibolite were richer in organic matter and poorly-crystalline Fe and Al compounds than soils developed on granite. Agricultural soils were impoverished in organic carbon and organic-complexed Al with respect to shrub- land soils, and enriched in inorganic poorly crystalline forms of Fe. The differences related to land use were more evident in the amphibolite soils. Aggregate stability, assessed by water-dispersible clay quantification, decreased in agricultural soils with respect to shrubland soils, in particular for those developed on amphibolite. This reduc- tion of aggregate stability in agricultural soils is likely due to a combination of several processes: loss of organic matter, higher pH, and an overall loss of poorly-crystalline Fe and Al compounds, in particular Al-organic matter complexes.