Aluminium is one of the main soil components. Usually it is a part of non-toxic aluminosilicates but in low pH values its mobility is higher and - especially in monomeric form is toxic for plants. Selenium is an essential element necessary for animals and humans. Its compounds have anticancer and anti mutagenic character. However, its high uptake from environment, e.g. with food or water could lead to various diseases including embryonic deformity, decreased hatchling survival and death to aquatic organisms. Soil contamination with aluminium leads to disturbances in plant growth as a result of low calcium and magnesium uptake. High concentrations of selenium lead to its accumulation in plant tissues what is the beginning of selenium fate in food chain. In this work a cultivated layer of soils located near five industry plants in the town of Opole (southern Poland) were investigated. Aluminium and selenium content in soils is an effect of two factors: its natural occurrence in rocks (natural content) and human activity - especially chemicals from agriculture, industrial and transport pollutants. Aluminium was determined in the range of 3440 to 14804 mg/kg d.w. Obtained results of selenium concentration covered the range from 27.1 to 958.1 μg/kg d.w. These results are slightly higher than concentrations noted in natural or non-polluted soils, but still low. These amounts of selenium could have more positive than negative effects. Aluminium and selenium concentrations were discussed concurrently with base soils parameters, such as pH, EC and granulometric fractions composition.
The problem of the migration of metal ions in the environment remains a current problem in light of the quality of obtained crops. The necessity of more and more frequent use of alternative sources of biogens in the form of waste substances, poses a threat of loading significant amounts of metals into the soil – including heavy metals harmful to human health and life. The article discusses a significant problem, namely the comparison of the results of the environmental impact of waste, obtained on the basis of legally authorized leaching tests (three-stage leaching test according to PN-EN 12457:2006), with results obtained from sequential chemical extraction (performed in 4-step chemical extraction developed and recommended in European Union countries by Communities Bureau of References – BCR). The study covered an investigation of industry fly ash from the combustion of lignite, in which Cu, Zn, Cd, Ni, Pb, Cr, Na, K, Li concentrations and loads were calculated. A mobility of analyzed elements was established on this basis. From heavy metals, the highest values in fraction I were noted for nickel and copper and zinc as well as nickel were noted for fraction IV . Peaking values of electrolytic conductivity in eluates was created by high concentrations of macroelements (Na and K). These tests confirm that the leaching tests used for their application in the natural environment indicate such concentrations at the highest levels that can be obtained at the first or second stage of sequential chemical extraction, and thus their proper full environmental impact is not known.