Assessment of Shear Strength Characteristics and Zinc Adsorption Capacities of Zeolite-Amended Soils for Adsorptive Fill Materials

Abstract

In industrial complexes, gas stations and railbeds, soil and groundwater contamination have occurred frequently and at a high concentration. Especially, zinc, which is one of the most common contaminants in the industrial areas, is needed to be controlled properly. A concept of fill layer construction using adsorptive soil materials is introduced in this study to minimize spreading of contamination. The purpose of this study is to evaluate shear strength characteristics and adsorption capacity of candidate materials for adsorptive fill materials. The candidate materials consist of weathered granite soil as a base material and natural zeolite for adsorptive materials. The composition methods were amendment and partial substitution. Amendment was the composition method that zeolite similar to particle size distribution of weathered granite soils was amended to weathered granite soils. Partial substitution was the method that fine parts of weathered granite soils were substituted with fine particles of natural zeolite. Shear stength characteristics and adsorption capacities of zeolite-amended soils and partially substituted materials through compaction test, direct shear test and sorption isotherm equilibrium test. In case of amendment, test results showed that internal friction angle was decreased with increasing zeolite content while adsorption capacity was increased linearly. In case of partial substitution, shear strength parameters and adsorption capacities were higher than those of zeolite-amended soils. That is, partially substituted materials could be developed as adsorptive fill materials with maximizing adsorption capacity of materials and maintaining the shear strength of materials at weathered granite soils level.