ELECTRON-MICROPROBE STUDIES ON SOIL SAMPL ES WITH VARYING HEAVY-METALCONTAMINATION .1. METHODS AND ANALYSIS OF ELEMENTS IN PEDOGENIC OXIDES

EMA point analysis, line scan profiles and microprobe photos were perf ormed on thin sections from 19 soil samples with variing heavy metal c ontent to show the distribution of elements in soil particles on a mic roscopic level. The investigations showed that the detection limits ge nerally have a range of 110-830 mg/kg in anorganic soil matrix respect ively 80-320 mg/kg in organic soil matrix. The element specific heavy metal accumulation capacities on the pedogen oxides compared to the av erage content of the soil samples can be described for Co, Ni, Cu, Zn, Cd and Pb. The maximum trace element accumulations in concretions rel ated to their element total content in the soil samples were by Co 3.1 70 times, Ni 6.635 times, Cu 323 times; Zn 112 times, Cd 2.000 times a nd by Pb 745 times. The accumulation and immobilization of heavy metal s by iron oxides suggests that additions of Fe oxides could be used to reduce heavy metal availability and leaching to the subsoil on highly contaminated soils.