Abstract
Experiments on the elution of heavy metals were carried out for three types of rocks (Tuff, Andesite and Shale) under various experimental conditions on pH, rock size, mixture of rocks.
The experimental results showed that Tuff and Andesite increased the alkalinity of water and eluted Mg and Ca. On the other hand, Shale acidified the water and eluted much more heavy metals. Therefore, Tuff and Andesite were defined as an alkali supply rock and Shale as an acid supply rock. It was also found that the smaller size rock eluted much more heavy metals.
In the case that Shale was mixed with Tuff or Andesite, the elution quantity of heavy metals increased, compared with that for an alkali supply rock (Tuff or Andesite). This suggests that the attention should be paid for the use of an acid supply rock in the civilconstruction works.
