LS Bodenschutz und Rekultivierung
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- FG Geopedologie und Landschaftsentwicklung (23) (remove)
BTU
Phytoremediation of sites contaminated with iron cyanides can be performed using poplar and willow trees. Poplar and willow trees were grown in potting substrate spiked with ferrocyanide concentrations of up to 2,000 mg kg-1 for 4 and 8 weeks respectively. Soil solution and leaf tissue of different age were sampled for total cyanide analysis every week. Chlorophyll content in the leaves was determined to quantify cyanide toxicity. Results showed that cyanide in the soil solution of spiked soils differed between treatments and on weekly basis and ranged from 0.5 to 1,200 mg l-1. The maximum cyanide content in willow and poplar leaves was 518 mg kg-1 fresh weight (FW) and 148 mg kg-1 FW respectively. Cyanide accumulated in the leaves increased linearly with increasing cyanide concentration in the soil solution. On the long term, significantly more cyanide was accumulated in old leaf tissue than in young tissue. Chlorophyll content in poplar decreased linearly with increasing cyanide in the soil solution and in leaf tissue, and over time. The inhibitory concentration (IC50) value for poplars after 4 weeks of exposure was 173 mg l-1 and for willow after 8 weeks of exposure—768 mg l-1. Results show that willows tolerate much more cyanide and over a longer period than poplars, making them very appropriate for remediating sites highly contaminated with iron cyanides.
Our study deals with agricultural recultivation of open cast brown coal mining areas in Lusatia, Eastern Germany. In this region the largest brown coal (lignite) mining area of Germany is located. Lignite mining activities lead to major disturbances of the landscape. Recultivation efforts attempt to regenerate mining areas for agricultural land use options. The geological “parent” material is of saaleian origin, has a sandy texture and was excavated from several meters depths before mining and is now used for recultivating the excavated area. Consequently, it is free of recent soil organic carbon. The substrate itself is unstructured. The partly wet or dry substrate is subjected to strong mechanical stresses during the excavation, deposition, refilling and levelling processes throughout the year. This practice leads to more or less compacted soils/substrates which may result in small yields of agricultural crops. In this context we investigate the effect of different organic soil additives in combination with different recultivation crop rotations on the development of soil structure for improved agricultural land use. Our experimental site has been heaped up and levelled off in 2006 and 2007. On each of the 24 experimental sub areas undisturbed soil samples have been taken to characterise the substrates according to their mechanical and hydraulic parameters and to determine the scattering of these parameters on a site that is assumed to be recultivated as homogenously as possible. First results of our ongoing experimental study indicate that the soil physical properties such as texture, bulk density, precompression stress, air permeability and saturated hydraulic conductivity are not identical on each of the 24 subplots. The soil physical properties behave differently in relation to each other. E.g. we found a negative correlation between bulk density (∼1.35–∼1.90 g/cm3) and precompression stress (∼30–70 kPa) and no decisive interrelation between bulk density and air permeability or saturated hydraulic conductivity.
Landwirtschaftliche Versuchsfläche Tagebau Jänschwalde - Versuchsdesign und Flächenherstellung
(2013)
Analysis of 288 percussion drillings from depths of up to seven meters and a 120 m long excavated section provide new and detailed information on the Late Quaternary to Late Holocene floodplain evolution from the most important Central European iron-mining region of the 15th century. The generalized sequence of the Vils River floodplain is built of five units representing facies of different genesis (rock/saprolite, gravel, sand, loam, peat) that are identified by physical, chemical, and mineralogical parameters (grain size, clast shape, and content, TOC, bulk mineralogy). Along the 87 km length of the valley, different units/facies are found at the Upper Vils River (UVR 1-5) and at the Lower Vils River (LVR 1-4b). In both river sections, fine-grained material (flood loam) forms the major part (up to 4 m) of the alluvial sequence. 29 age determinations (24 14C, 4 IRSL, 1 tree-ring analysis) show increasing accumulation of flood loam in the last millennium. The data correlate with the beginning of mining at the Vils River and hence suggest a causal connection with mining activities in the catchment—both on the slopes and in the floodplain—with intense deposition of flood loams.