The optimisation of operating parameters of dye removal: application of designs of experiments

ABSTRACT

There have been observed numerous adverse environmental effects on Reactive Red 2 (RR2) such as carcinogenesis, mutagenesis and chromosomal damage; therefore, in this study, zero-valent iron nanoparticles were synthesised and studied for removal of RR2 from aqueous solution. Response Surface Methodology (RSM) based on Central Composite Design (CCD) was used to optimise the test conditions of the removal of RR2. The effects of dye concentration (5–25 mg L⁻¹), ultrasound time (30–150 s), NZVI amount (0.05–0.45 g) and pH (2–14) were examined in a dye removal and each variable was coded at five levels. The optimal values of dye concentration, ultrasound time, NZVI amount and pH were estimated at 20 mg L⁻¹, 100 s, 0.35 g and 2, respectively. The results showed that the process had the highest ability to remove the RR2 and dye decomposition efficiency was increased by increasing the amount of NZVI and the ultrasound time. It has an inverse relationship with an increase in pH and dye concentration.

KEYWORDS:

• Dye removal
• zero-valent iron nanoparticles
• response surface methodology
• reactive red 2

Acknowledgments

The authors are grateful to University of Payame Noor, for kind support.

Disclosure statement

No potential conflict of interest was reported by the authors.