Sustainable Removal of Heavy Metal Ions from Mineral Wastewater Using Waste Basalt Fiber

Heavy metal ions in wastewater endanger ecology and human health, requiring cost-effective treatments. This study innovatively converts abandoned basalt fibers (BFs) into high-performance adsorbents (BFSN) via NaOH etching and chelation with nitrilotriacetic acid (NTA)/carboxymethyl starch (CMS), introducing target functional groups. Characterizations (XPS, FTIR, zeta potential) reveal Cu2+/Pb2+ adsorption mechanisms: -COO− chelation, N-containing group ion exchange, and electrostatic adsorption. Kinetics fit a pseudo-first-order model (R2 > 0.98) and isotherms fit the Langmuir model, confirming monolayer chemisorption. BFSN has excellent thermal stability (≤2% mass loss at 800 °C) and post-adsorption integrity (≈0.11% mass loss post-loading). Waste-derived BFSN, cheaper than commercial adsorbents, has strong economic viability. This “waste-to-value” approach offers efficient, sustainable large-scale heavy metal wastewater remediation, advancing waste utilization and ecological restoration in water treatment.