Application Of Biological Indicators For Estimation Of Remediation Of Soil Degraded By Sulphur Industry

Abstract

Abstract The study was conducted on an experiment established in the area of the former Sulphur Mine “Jeziorko.” The remediation was applied to a soil-less formation with particle size distribution of weakly loamy sand, strongly acidified and with bad sorptive properties (Corg. - 2.0 g kg−1; pHKCl - 4.3; T - 7.0 cmol(+) kg−1). In the particular treatments of the experiment the following were applied to the soil-less formation: flotation lime and NPK; lime and sewage sludge; sewage sludge; mineral wool (5 cm 50 cm−1), lime and NPK; mineral wool (5 cm 50 cm−1), lime and sewage sludge; mineral wool (500 m3 ha−1), lime and NPK; mineral wool (500 m3 ha−1), lime and sewage sludge. Plots prepared in that manner were then sown with a mix of grasses. The control was the soil with no amendments. The analyses of the soil material comprised assays of the numbers of particular groups of bacteria and fungi, and of their biochemical and enzymatic activities. The study revealed that all the wastes applied for the remediation caused an increase in the numbers of the bacterial groups studied (copiotrophic, oligotrophic, cellulolytic, lipolytic), as well as in the respiration activity and rate of mineralisation of cellulose. That effect was the most pronounced in the case of sewage sludge. In treatments in which sewage sludge was applied, an increase was also observed in the numbers of the studied fungi (fungi on Martin medium, cellulolytic fungi, lipolytic fungi) and in lipase activity. Whereas, the application of the remaining wastes resulted in a slight decrease in the numbers of the fungal groups under analysis. Comparing the mean annual values of the analysed biological, physical, chemical and physicochemical properties it was found that the biological properties were as sensitive, and in the case of certain tests (numbers of cellulolytic and lipolytic bacteria, rate of cellulose mineralisation) even more sensitive indicators of positive changes taking place in the remediated soil.