Leaching tests monolithic materials

American Society for Testing of Materials, Standard test method for static leaching of monolithic waste forms for disposal of radioactive waste, ASTM C 1220-98, 1998. 

For the purposes of describing leaching tests, the description of the leaching mechanisms hence the description of the types of tests are simplified into those which are relevant to granular materials and those which are suitable for monolithic materials. 

A number of reviews of available leaching tests have been carried out (Environment Canada 1990 Wallis etal. 1992 Ure etal. 1993 Quevauviller etal. 1995 CEN/TC/292/NNI 1994 Science of the Total Environmental Special Issue 1996 van der Sloot etal. 1997). Examples of leaching tests performed throughout the world are shown in Table 9.1. As shown in the table, there are more tests available for granular materials than there are for monolithic materials. 

Marr and coworkers described the preparation of Pd nanoparticles-stabilised aerogels using an ionic liquid route [29]. The material was prepared by inclusion of pre-formed Pd colloids (2 nm) stabilised by imidazolium salts in a silica monolith. The material was only tested in the reaction of iodobenzene with butyl acrylate, showing good activity (TON = 2092). No aggregation of Pd particles was observed by TEM however Pd leaching, probably accounting for the activity, was detected by ICP-AES. 

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