Wang, et al (2024) Characterization and adsorption properties of rectorite/sludge-derived 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 composites for Pb(II) removal. Adsorption Science & Technology. DOI: 10.1177/02636174241287698

Recent research has introduced an innovative composite material, rectorite/sludge-derived biochar (REC/SDBC), designed to remove lead (Pb(II)) from contaminated water effectively. This composite combines the natural adsorption properties of biochar and rectorite clay, both chosen for their capacity to capture heavy metals from water.

Produced from sewage sludge, biochar is a carbon-rich material known for its high surface area and functional groups that aid in adsorption. Rectorite, a clay mineral with good ion-exchange properties, further enhances the composite’s adsorption potential. Researchers achieved an optimal REC:SDBC ratio of 3:1, yielding a maximum lead adsorption capacity of 26.89 mg per gram. This is higher than using either rectorite or biochar individually. The study also showed that Pb(II) adsorption on REC/SDBC is most effective at a pHpH is a measure of how acidic or alkaline a substance is. A pH of 7 is neutral, while lower pH values indicate acidity and higher values indicate alkalinity. Biochars are normally alkaline and can influence soil pH, often increasing it, which can be beneficial More of 5.0 and reaches equilibrium within 120 minutes.

Kinetic analysis revealed that the adsorption process follows a pseudo-second-order model, indicating that chemisorption—chemical bonding involving ion exchange and surface interactions—dominates the reaction. The mesoporous structure and stability of REC/SDBC composites contribute to their durability and effectiveness as adsorbents in water treatment.

Overall, REC/SDBC composites offer a sustainable and efficient approach for mitigating lead contamination in wastewater, supporting cleaner water systems through affordable, scalable technology.