Application of different alkaline materials as polluted soil amendments: A comparative assessment of their impact on trace element mobility and microbial functions.

Treatment with chemical amendments is among the best techniques to remediate soils highly polluted with trace elements. The use of waste-derived products has several advantages in this regard, mainly in terms of reducing process costs and conserving natural resources. In this study, the performance of the synthetic zeolite NaP1 derived from coal combustion fly ash (SZ) and the by-product generated from the processing of aluminum salt slags (BP) was evaluated with this aim in comparison to calcite (CC).

Arsenic distribution in a pasture area impacted by past mining activities.

Former mine exploitations entail a serious threat to surrounding ecosystems as after closure of mining activities their unmanaged wastes can be a continuous source of toxic trace elements. Quite often these mine sites are found within agricultural farming areas, involving serious hazards as regards product (feed/food) quality. In this work a grazing land impacted by the abandoned mine exploitation of an arsenical deposit was studied so as to evaluate the fate of arsenic (As) and other trace elements and the potential risks involved.

Trace element levels in an area impacted by old mining operations and their relationship with beehive products.

The environmental status of an area impacted by Roman mining activities was assessed in order to establish the current risks posed by such old mine emplacements. For this purpose, soil samples were collected throughout the mining area and analysed for their total, mobile and mobilizable trace element (As, Cd, Mo, Sb and Zn) contents. Additionally, beehive products (honey and pollen) were also sampled and evaluated for their use as environmental indicators of the area.

A comparative study on the influence of different organic amendments on trace element mobility and microbial functionality of a polluted mine soil.

A mine soil heavily polluted with zinc and cadmium was employed to evaluate the capacity of organic amendments of different origin to simultaneously reduce soil trace element mobility and enhance soil microbial functionality. With this aim, four organic products, namely olive processing solid waste (OPSW), municipal solid waste compost (MSWC), leonardite and peat, were applied individually at different doses (0, 1, 2 and 5%) to mine soil under controlled laboratory conditions. Extraction studies and analysis of soil microbiological parameters (basal soil respiration and dehydrogenase, β-glucosidase, urease, arylsulfatase and acid and alkaline phosphatase activities) were performed to assess the effect of such amendments on soil restoration.

Arsenic distribution in soils and rye plants of a cropland located in an abandoned mining area.

A mining impacted cropland was studied in order to assess its As pollution level and the derived environmental and health risks. Profile soil samples (0-50 cm) and rye plant samples were collected at different distances (0-150 m) from the near mine dump and analyzed for their As content and distribution. These cropland soils were sandy, acidic and poor in organic matter and Fe/Al oxides.