Surfactant-modified SiO₂/FeS nanocomposites for remediation of cadmium pollution

To improve the remediation and antioxygenic properties of ferrous sulfide (FeS) nanomaterials toward heavy metals is the focus of current research. This study employed a combination of sodium carboxymethylcellulose (CMC) and sodium dodecyl benzene sulfonate (SDBS) for the modification of FeS nanomaterials supported by porous silicon (SiO₂/FeS) to serves as an efficient amendment for cadmium pollution. The optimized slurry with the mass ratio of CMC/SDBS to be 1:3 showed enhanced dispersion and antioxidant effects on SiO₂/FeS (the mass ratio of surfactant to FeS was 1:1). This formulation exhibited the smallest particle size (D₅₀ = 0.66 µm) and the highest absolute Zeta potential values exceeding 30 mV. Also, the obtained products demonstrated effective remediation of cadmium-contaminated solutions, with Cd(II) primarily forming stable CdS and CdSO₄ products through ion exchange and chemical precipitation. The adsorption capacity of SiO₂/FeS-CMC/SDBS 1:3 for cadmium in air and nitrogen was remained during 30 d, reaching about 158 mg/g. Notably, under low concentration Cd contamination, the adsorption capacity of SiO₂/FeS-CMC/SDBS 1:3 exceeded that of SiO₂/FeS-CMC and SiO₂/FeS-SDBS without acidification risk. In summary, this research highlights the improved remediation and antioxygenic properties achieved through CMC and SDBS co-modification of SiO₂/FeS, providing a new amendment for Cd remediation.