Experimental Study on the Strength Characteristics of Lead Contaminated Soil with NZVI Treatment

Abstract

This investigation focuses on the shear strength of lead-contaminated soil before and after its stabilization by nanoscale zero valent iron (NZVI)—one of the magnetic nanoparticles (MNPs) having significant stabilization and remediation properties for heavy metal and organics. Being highly toxic carcinogens, lead ions are considered an extensive heavy metal contaminant in groundwater and soil, hazardous to the nervous system and organs of human beings. NZVI has shown an aptitude for effective stabilization when used to treat soil contaminated with heavy metals. In this study, a series of laboratory tests were conducted on lead-contaminated soil subjected to NZVI treatment in different percentages. Microstructures and elements were analyzed to evaluate degradation and morphological variations before and after the treatment, and vane shear tests were conducted to measure the shear strength of the soil with additives of lead nitrate and NZVI. From a microstructural perspective, the morphology of the treated soil indicates that the particle skeleton became more conjoint with use of NZVI. The experimental data show that addition of lead nitrate has a significant negative influence on shearing. It was found that the shear strength of polluted soil was reduced significantly even as that of a treated specimen increased. The investigation indicated that application of NZVI is a promising approach to reusing contaminated ground from the perspectives of both environmental and geotechnical engineering.