A Green Alternative to Hydrogen SulfideMetal Separation from Devarda's Alloy Using Garlic (Allicin-Rich) Aqueous Extract

Abstract:

This study explores a sustainable and eco-friendly alternative to hydrogen sulfide for metal separation from Devarda’s alloy using an allicin-rich aqueous extract of garlic. Conventional methods for metal precipitation often rely on hydrogen sulfide gas, which is highly toxic, corrosive, and poses significant environmental and safety concerns. In contrast, garlic contains allicin and other sulfur-containing compounds capable of interacting with metal ions through complexation and precipitation mechanisms. In this work, an aqueous garlic extract was employed as a natural sulfur donor to facilitate the separation of metals from Devarda’s alloy under mild conditions. The biogenic sulfur compounds effectively induced selective precipitation of metal ions, demonstrating comparable efficiency to traditional sulfide-based methods. This approach eliminates the need for hazardous reagents, reduces operational risks, and aligns with green chemistry principles by utilising renewable and biodegradable materials. Furthermore, the method offers a cost-effective and accessible alternative suitable for laboratory and potential industrial applications. The findings highlight the potential of plant-derived sulfur compounds as viable substitutes for conventional toxic reagents in metallurgical and wastewater treatment processes. Overall, the use of garlic extract represents a promising step toward safer, sustainable, and environmentally responsible metal separation technologies.