Effect of Lead and Zinc on Hydraulic Conductivity and Swelling Characteristics of Nanoclay-Amended Bentonite

Many geotechnical applications, such as landfill liners or covers, require an in-depth understanding of soil swelling and hydraulic conductivity. Bentonites and their amendments are often used for hydraulic barrier applications due to their distinctive properties. This research investigates the suitability of organically modified nanoclay as a bentonite amendment for hydraulic barrier applications. The performance of the nanoclay-bentonite mixture in the presence of different pollutants, such as heavy metals and organic contaminants, necessitates a thorough investigation. This work examines the effects of two heavy metals, lead and zinc, on the swelling properties and hydraulic conductivity of bentonite amended with nanoclay. Free swell test and oedometer tests were conducted on a number of bentonite and nanoclay-amended bentonite (10:90) samples under different concentrations, i.e. 0 ppm (DI water), 100 ppm, and 1000 ppm of lead and zinc. According to the findings, as heavy metal ion concentration rises, free swelling, swelling pressure, and swelling potential of both bentonite and organoclay-bentonite mixture drops. Even though the hydraulic conductivity rises for both the bentonite and nanoclay-amended bentonite, no samples exceeded the hydraulic conductivity criterion for landfill liners. Moreover, the addition of 10% nanoclay to bentonite minimizes the influence of heavy metals on the swelling and hydraulic properties of bentonite.