Response surface methodology for optimization of 4-nitrophenol degradation by a heterogeneous Fenton-like reaction on nano-zero-valent iron

Abstract

Heterogeneous Fenton-like reactions on nano-zero-valent iron (NZVI) were investigated for the degradation of 4-nitrophenol (4-NP). A three-factor central composite design coupled with response surface method (RSM) was applied to evaluate and optimize the important variables. A significant quadratic model (p-value < 0.05, r²_(adj) = 0.9625) was derived using analysis of variance, which was adequate to perform the optimization of the process variables. Optimum conditions were determined to be 0.66 g/L NZVI, 300 mM H₂O₂, pH 3.0, reaction time 50 min and 100–300 ppm 4-NP. More than 93% of 4-NP was experimentally degraded under the optimum conditions. The experimental results matched well with the predicted results which validated the RSM models with good correlation (r² = 0.9680).

Keywords:

• Fenton-like reaction
• NZVI
• 4-Nitrophenol
• Response surface method

Acknowledgment

The authors gratefully acknowledge the support of this work by the Shahid Beheshti University of Medical Sciences.