ABSTRACT
In this work the leaching of molybdenum from pulverized coal ash addressed to illustrate the similarities between a number of leach testprocedures. It highlights the usefulness of the different methods in obtaining information to assess the release and fate potentially hazardous components from waste materials in the soil system. For this purpose, column leaching tests, batch extraction procedures, lysimeter measurements, diffusion measurements, measurements of the interaction at the waste/soil interface and migration measurements at low percolation rates have been carried out. The combined information from these methods leads to a more detailed insight into the factors relevant to the impact assessment of undesirable components from combustion residues. The sequence of diffusion, interface interaction and migration measurements using radiotracers yields valuable information about the behaviour of the stable elements, which is difficult to gain from conventional techniques. The simplicity of the procedure and the versatility in studying the influence of variations in relevant parameters (e.g. pH, complexing capacity, redox) offers a great potential in tackling the complex phenomena occuring in waste/soil systems.
