Chen, et al (2024) Effective removal of Pb (II) from wastewater by zinc-iron bimetallic oxide-modified walnut shell biocharBiochar is a carbon-rich material created from biomass decomposition in low-oxygen conditions. It has important applications in environmental remediation, soil improvement, agriculture, carbon sequestration, energy storage, and sustainable materials, promoting efficiency and reducing waste in various contexts while addressing climate change challenges. More: A combined experimental and DFT calculation approach. Journal of Environmental Management. https://doi.org/10.1016/j.jenvman.2024.122757

A recent study published in the Journal of Environmental Management explores the effectiveness of walnut shell biochar (WBC) modified with zinc-iron bimetallic oxide (ZF@WBC) for removing lead (Pb(II)) from wastewater. Researchers used a combination of experimental analysis and density functional theory (DFT) calculations to investigate how well this modified biochar adsorbs lead.

The ZF@WBC, produced by impregnating walnut shell biochar with zinc and iron oxides at 600°C, displayed significantly improved adsorption properties. With a surface area of 375.97 m²/g, ZF@WBC’s capacity to adsorb Pb(II) was measured at 104.26 mg/g, over 2.5 times more than unmodified biochar. The study confirmed that chemisorption, primarily via surface complexation, ion exchange, and electrostatic attraction, is the dominant mechanism for lead removal.

Notably, ZF@WBC maintained over 70% lead removal efficiency even in the presence of interfering ions, making it a promising solution for practical wastewater treatment. This research highlights the potential of using agricultural waste, such as walnut shells, for creating environmentally friendly and effective biochar-based adsorbents to address heavy metal contamination in water systems.

This study contributes to the broader goal of sustainable wastewater management by leveraging biochar’s capacity to absorb pollutants while repurposing biomassBiomass is a complex biological organic or non-organic solid product derived from living or recently living organism and available naturally. Various types of wastes such as animal manure, waste paper, sludge and many industrial wastes are also treated as biomass because like natural biomass these More waste.