Leaching tests for environmental assessment of inorganic substances in wastes, Sweden

The paper contains descriptions of methods and laboratory practices for measuring leachability of inorganic substances from waste materials. The test methods include: availability for leaching where an option includes oxidised conditions, equilibrium controlled leaching in batch and column tests and pH influence. Diffusion controlled leaching and lysimeter tests are briefly described. The test performances are discussed and exemplified by results from leaching tests on slags and ashes. The results and the discussion stresses the importance of knowing the fundamental test principles for the leaching tests, i.e., equilibrium and diffusion controlled leaching, as well as the need to further clarify the boundary between the application of these two concepts. Further, a test scheme is described for leaching of inorganic substances from waste materials under equilibrium-like conditions. The scheme includes: time-dependent leaching, availability for leaching in the long-term perspective and the influence on the leaching process of ambient conditions such as pH and redox.