The behaviour of cyanides in soil and ground water

In 1993 the coal-based gas production in Denmark stopped, and in the following years pollution investigations of the many gas production sites started. It was found that many of the sites were polluted with a.o. cyanide, primarily as complex iron cyanide compounds. The question is whether leaching of these compounds to the ground water occurs or whether they are stabilized in the soil. Laboratory experiments of the leaching properties and decomposition of the cyanide compounds in soil and ground water show that the behaviour of cyanide depends very much of local conditions like pH and particle size. (LN) 8 refs