堆積性泥岩からの強酸性水の生成に関する実験的検討

概要

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Strong acid water generation from mudstone exposed to the atmosphere through excavation and dredging was observed in sedimentary layers corresponding to the period from the Neogene to the Pleistocene. This phenomenon has been recently related to environmental problems associated with large-scale construction.This paper describes the phenomenon on the acid leachate from mudstone using a batch test and an experimental landfill test. Generation of acid water is estimated as the leaching of sulfate from pyrite contained in mudstone due to oxidation reactions in the presence of oxygen and water. Rut, it is shown that leaching of sulfate is depressed under coexistence with chlorine. In this test, pH decreased to 2.8 and SO42- concentration increased to 2,300mg·l-1. Oxidation reactions and acid-water migration in the field were examined using an experimental landfill 2.5m in height composed of mudstone dredged from the sea bed and cap soil. From observations of oxygen concentration in pore, we determined that the zone affected by oxidation is limited to about 0.5 to 0.6m penetration under the cap soil with 0.5m of depth due to consumption and diffusion of oxygen in pores.
社団法人　日本水環境学会の論文
1997-06-10