Green Solutions for Heavy Metal Woes: Alkali Activated Slag and Biochar Composites as Efficient Pb2+ Sorbents

A study explores alkali activated slag and biochar composites as effective sorbents for Pb2+ removal from water. The synergistic matrix exhibits a high sorption capacity, with ion exchange and chemisorption mechanisms dominating. Precipitation of lead compounds is confirmed through XRD and FTIR analysis, promising efficient and eco-friendly solutions for heavy metal removal.

February 23, 2024

1–2 minutes

Vaičiukynienė, Alaburdaitė, Nizevičienė & Tamošaitis (2024) Sorption properties of Pb²⁺ions from water by alkali activated slag/biochar composites. 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 Conversion and Biorefinery. https://doi.org/10.1007/s13399-024-05434-3

In a recent investigation, researchers explored the potential of combining alkali activated slag and 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 to create a novel sorbent for removing Pb2+ from water. The successful removal of Pb2+ was achieved by crafting a matrix from biochar and alkali activated slag. The sorption capabilities were found to be closely tied to the mineral composition and microstructure of the sorbents.

The study revealed that sample S2, composed of alkali activated slag and 15.4 wt% biochar, exhibited an impressive maximum sorption capacity of 395.0 mg/g for Pb2+ at an initial concentration of 1000 mg/L. Ion exchange and chemisorption were identified as dominant mechanisms in the Pb2+ sorption process, with the possibility of precipitation due to complex formation during adsorption.

Analyzing the results further, XRD and FTIR confirmed the formation of new chemical compounds, including lead carbon hydrogen oxide and susannite. The incorporation of lead cations into the structure of calcium silicate hydrate (CSH) was verified by FTIR analysis. The EDX elemental composition of the sorbent materials indicated successful sorption of Pb2+ through an ion exchange process.

This study highlights the efficiency of three composite sorbents in removing Pb2+ cations from aqueous solutions. By converting low-cost composites of alkali activated slag and biochar into effective sorbents, this research contributes to both waste management and environmental protection efforts. These green solutions provide promise for addressing heavy metal pollution, offering a sustainable path towards a cleaner and healthier environment.