Nobutoshi Tanaka* and Toshihiko Matsuto**

*Professor, Department of Environmental and Sanitary Engineering, Faculty of Engineering, Hokkaido University
**Associate Professor, Department of Environmental and Sanitary Engineering, Faculty of Engineering, Hokkaido University

+ Correspondence should be addressed to Nobutoshi Tanaka:
Hokkaido University
(North 13, West 8, Kita-ku, Sapporo, 060 Japan)

Abstract

Observed data of NaCl transport experiments with unsaturated and steady water flow in medium sand, incinerator ash and artificial refuse layer were simulated by a dispersion model, or two-component model. Parameters of each model were obtained as functions of flow rate. The two-component model can simulate observed data in the ash and refuse layer. The dispersion model can also simulate observed data at a very low flow rate. According to this result and theoretical consideration, it is suggested that the two-component model should be a model for high flow rate for convenience. Secondly, solute wash-out experiments by step-like or random pulse-like precipitations were done. The characteristics of solute wash-out in solid waste layers were also discussed. These observed curves were simulated by the dispersion model, or two-component model with the above obtained parameters. Consequently, the simulation almost succeeded for the sand layer and were less successful for the ash layer and refuse layer.

Key words: sanitary landfill layer, unsaturated water flow, solute transport, dispersion model, two-component model