Synergistic effect of magnetic magnetite and greigite nanoparticles dispersed pinewood biochar for aqueous lead(II) and cadmium(II) adsorption
Year: 2025
Type: article
Abstract: Heavy metals such as lead and cadmium cause adverse effects on all living organisms. Their remediation is complex in the aqueous phase. Biochar is a low-cost, environmentally friendly adsorbent material that exhibited a limited ability to adsorb Pb 2+ and Cd 2+ . Iron-based magnetite and greigite nanoparticles have proven high adsorption capacity due to high amounts of oxygen and sulfur-contained functional groups per unit volume. In this study, a mixture of greigite and magnetite nanoparticles was simultaneously synthesized on pinewood biochar (BC), aiding co-precipitation from a Fe 2+ /Fe 3+ and S 2- salts mixture (Fe 3 O 4 -Fe 3 S 4 /BC), that offers a cost-effective, sustainable, and efficient material for Pb 2+ and Cd 2+ removal. BC, Fe 3 O 4 -Fe 3 S 4 /BC, and Pb 2+ and Cd 2+ adsorbed Fe 3 O 4 -Fe 3 S 4 /BC materials were characterized to differentiate surface morphologies , elemental compositions , and surface chemical states. The Fe 3 O 4 -Fe 3 S 4 /BC composite exhibited an average nanoparticle diameter of ∼20 nm. Fe 3 O 4 -Fe 3 S 4 /BC showed Langmuir adsorption capacities of 138.9 and 49.5 mg g -1 for Pb 2+ and Cd 2+ at pH 5 (25 °C). Pb 2+ and Cd 2+ followed pseudo-second-order kinetics, and the equilibriums were achieved after ∼2 h and ∼30 min, respectively, for 125 and 1250 μmol L -1 concentrations, respectively, where the fast adsorption rates make Fe 3 O 4 -Fe 3 S 4 /BC hybrid system a practical option for real-time treatment. Further, adsorption performances were influenced by ionic strength , dose optimization, and the presence of competing ions, suggesting the potential for fine-tuning adsorbent conditions in practical applications. This study enhanced the understanding of adsorption characteristics for a treatment facility that can effectively remediate lead and cadmium-contaminated wastewater. While there have been studies on using biochar and nanoparticles separately for Pb 2+ and Cd 2+ adsorption, this research bridges the gap by demonstrating the synergistic effect for Pb 2+ and Cd 2+ adsorption from hybrid magnetite-greigite nanoparticles .
Source: Cleaner Water
Institution: Prairie View A&M University
Language: English
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $1,230
OpenAlex ID: W4407114443