Extraction of a copper contaminated soil material by an amino acid containing residue hydrolysate .1. Time course of copper elution and characterization of reactive binding forms

A copper contaminated (Cu content: 244 mg kg(-1)) soil material sampled from an area formerly cultivated with hops (Humulus lupulus), was extracted within sixteen days in a column test facility (soil packing per column: 4.1 kg dry weight) by the percolation of an amino acid containing blood meal hydrolysate. The objectives of the study were to record the time course of copper elution, to determine the resulting degree of copper removal and to examine the specific extractability of the various copper binding forms. Until the maximum concentration in the column effluent was reached, the time course of the Cu release went parallel to the throughput of the amino acids. As a consequence, the velocity of the copper mobilization and transport seems to be ruled by the hydrodynamic flux of the percolate mainly. In total 62% of the soil bound copper were removed by the hydrolysate. Above-average amounts were extracted from the binding forms 2-4 defined according to Zeien and Brummer (1989). As a result, the copper forms, which are mostly responsible for potential. ecotoxicological effects, could be widely diminished.