Preparation of stabilized nano zero-valent iron particles via a rheological phase reaction method and their use in dye decolourization

Abstract

In this study, sodium carboxymethyl cellulose (NaCMC)-stabilized nano zero-valent iron (C-nZVI) was synthesized using a rheological phase reaction method. The orthogonal method was used to evaluate the factors influencing C-nZVI properties and this showed that the reaction time, solid–liquid ratio (w/v), grinding time and NaCMC concentration were all important factors. Characterization with scanning electron microscopy validated the hypothesis that the introduction of CMC led to a decrease in aggregation of iron nanoparticles. X-ray diffraction confirmed the existence of Fe⁰ and the strong antioxidant activity of the iron particles. Batch decolourization experiments exhibited that solution pH, C-nZVI dosage and reaction time have significant effects on dye decolourization. A high decolourization efficiency (94.5%) was obtained within 30 min for 100 mg/L of reactive blue-19 at the optimal pH value of 5 and C-nZVI loading of 6 g/L at room temperature. The decolourization rates followed modified pseudo-first-order kinetic equations with respect to dye concentration. The observed removal rate constant was 0.0447 min⁻¹ for the C-nZVI loading of 6 g/L.

Keywords:

• sodium carboxymethyl cellulose
• reactive blue-19
• decolourization
• kinetics

Acknowledgements

This work was funded by the National Natural Science Foundation of China (No. 41102231), and the Key Project for Science and Technology of Jiangxi Provincial Education Department, China (No. GJJ11025).