Impact of Heavy Metals on Geotechnical and Microstructural Properties of Soils

Soils contaminated with heavy metals present significant challenges for geotechnical engineers. Despite numerous dispersed studies lacking sufficient focus on the impact of heavy metals on geotechnical properties of soils. There remains a need for a comprehensive review to advance future research in this area. When soil is contaminated by the accumulation of waste, heavy metal pollutants, and leachate infiltration, its mechanical behavior and environmental geotechnical properties are altered. The effects of heavy metal contaminants on each soil's properties vary, exhibiting both similarities and differences. This review aims to critique and analyze previous studies on the effects of such pollution on various soil types. It focuses on studies conducted between ۲۰۱۴ and ۲۰۲۴; examining the effects of major heavy metals such as lead, zinc, nickel, cadmium, etc., on key geotechnical properties of soils such as clay, bentonite, marl, clayey sand. The findings indicate that geotechnical properties such as permeability, Atterberg limits, shear strength, compaction characteristics, and consolidation properties are highly dependent on the type of soil, the type of contaminant, the concentration of the contaminant, and the duration of contamination. Fine-grained clay soils are more affected by heavy metal pollutants, while these pollutants have a negligible impact on sand. Additionally, research shows that heavy metal pollutants like lead and arsenic significantly alter the microstructural properties of clay soils, including particle aggregation, increased density, and porosity. According to the results of previous studies, zinc nitrate has a lesser effect on shear strength parameters compared to lead nitrate, and lead has a more significant impact on consolidation and compaction properties compared to zinc.

کلیدواژه ها:

heavy metals ، Geotechnical Properties ، Soil types ، soil structure