Shin-ichi Sakai*, Satoshi Mizutani* and Hiroshi Takatsuki*

* Kyoto University, Environment Preservation Center

+ Correspondence should be addressed Shin-ichi Sakai:
(Yoshida-honmachi, Sakyo, Kyoto 606-01 Japan)

Abstract

An overview on waste leaching tests is provided, describing the recent findings by IAWG (International Ash Working Group). Information about the official leaching test procedure used in each country is presented first. Next, the conception of "release" is introduced. This means the leaching quantity per weight of waste, and the pH-dependent test, which treats the leaching data based on the final pH of leachate. Moreover, the Availability Test, which gives the leachable quantity under the worst conditions is introduced. Based on real rainfall and the mass of the waste at the final landfill, low L/S leaching tests are also described. Finally, considering the ANC (Acid Neutralization Capacity) of the waste, the two-stage batch test is proposed. The first step is to look at short-term leaching behavior where L/S is low and the leachant is distilled water. The second step is to look at long-term leaching behavior. In this step, L/S is high and the leachant is an acidic solution (for the low ANC waste) and a basic solution (for the high ANC waste).

Key words: leaching test, release, availability test, pH-dependent test, acid neutralizing capacity