Tian, et al (2024) Mineralization and stabilization of toxic Pb²⁺ ions using CMC loaded S/P co-doped 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 composite. Separation and Purification Technology. https://doi.org/10.1016/j.seppur.2024.129161

Biochar composites offer a promising method for addressing the challenge of heavy metal pollution, specifically lead (Pb2+) contamination. This study focused on developing a high-capacity adsorbent made from carboxymethyl cellulose-loaded sulfur-phosphorus co-doped biochar (CMC@SP2BC) to stabilize and mineralize lead ions. The biochar was produced by pyrolyzing soybean straw under oxygen-limited conditions. Experimental results demonstrated that the CMC@SP2BC composite could remove up to 829.3 mg of Pb2+ per gram, under optimal conditions. Lead removal was primarily achieved through chemical precipitation, with additional mechanisms such as ion exchange, complexation, and physical adsorption contributing to the process.

The lead immobilized by the biochar was converted into stable mineral forms like PbSO4 and Pb3(PO4)2, as confirmed through structural analysis and modeling simulations. The research also highlighted the effectiveness of CMC@SP2BC in treating real groundwater samples, where it reduced lead concentrations to meet both Class I and Class II water standards.

This work represents a significant step toward the environmentally sustainable treatment of lead contamination. By incorporating sulfur and phosphorus into the biochar structure, this approach improves the efficiency of heavy metal stabilization, reducing the risks associated with lead bioavailability and promoting long-term ecological safety. This biochar composite method could offer an effective and scalable solution for lead remediation in various contaminated environments.