University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Stefan Fleck
(2012):
Trace element uptake by plants from soils affected by a red mud spill in Ajka, Hungary.
Master / Diploma Thesis - Institut für Bodenforschung (IBF),
BOKU-Universität für Bodenkultur,
pp 34.
UB BOKU
obvsg
- Abstract:
- On October 4, 2010 a dam of one of the red mud reservoirs of the Ajkai Timfolgyar alumina plant in Ajka (Hungary) broke covering roughly 800 ha of land in a 5–10 cm thick layer of red mud characterised by high salinity, high alkalinity and concentrations of several trace elements above ambient values. The Hungarian government remediated the polluted land by removing the top soil layer containing the bulk of the red mud. This thesis examines how trace element bioavailability and soil fertility have been affected by the months-long red mud cover. Pure red mud and two affected soils from the area were characterised using aqua regia digestion, ammonium nitrate- and water extracts, and a sequential extraction procedure optimised for Arsenic fractions in soil. Plant toxicity and trace metal availability was tested in pot experiments with Lupinus albus, Zea mays, Plantago lanceolata, and Brassica napus. Soil extracts revealed no disconcerting trace element concentrations in cleared and red mud spiked soils. No statistically significant impact of red mud on plant growth was measured for L. albus and Z. mays, but an unexpected and complete die-back of B. napus and P. lanceolata occurred two weeks after planting. Increasing red mud content in soils increased plant uptake of Cd, Mn, U, Ca, K, Mg, Na, P, Mn and Mo. No trace element concentrations above trigger values for animal fodder were measured in plant shoots; however, trigger values for Arsenic were exceeded in roots of L. albus. Our data suggests that removal of the red mud layer alone proved to be a sufficient remediation measure for the affected land. The main concerns for the cleared soils were elevated pH and salinity (especially Sulfate) which are issues related to soil fertility rather than to human health.
- Beurteilende(r): Wenzel Walter