Process Parameter Optimization for Cr (VI) Reduction Using Zero-Valent Iron Nanoparticles Via Response Surface Methodology

The present study explores the removal of Cr (VI) from contaminated water using green-synthesized zero-valent iron nanoparticles derived from Aegle marmelos leaf extract. Batch adsorption experiments were conducted to investigate the effect of key variables—solution pH, zero-valent iron nanoparticles dose, contact time, and initial Cr (VI) concentration—on removal efficiency. The analysis revealed that pH, nanoparticle dosage, and contact time significantly influenced Cr (VI) removal, with optimal removal efficiency (∼97.6%) observed at pH 2.3, nanoparticle dosage of 2.63 g/L, and 30 min of contact time. Regression analysis and ANOVA confirmed the statistical significance and robustness of the model (R2 = 0.9987). The study demonstrates that zero-valent iron nanoparticles are a highly effective, eco-friendly adsorbent for Cr (VI) removal, offering potential for industrial wastewater treatment applications.