Decolorization mechanisms of an anionic dye by using zero-valent iron nanoparticles: application of response surface modeling for the optimization process

作者：Simsek Utku Bulut; Turabik Meral^*

来源：Desalination and Water Treatment, 2017, 81: 303-314.

DOI：10.5004/dwt.2017.21102

• Acid Red 42
• Decolorization
• Degradation
• Optimization
• Response surface methodology
• Zero-valent iron nanoparticle

In this study, decolorization of Acid Red 42 (AR 42) by zero-valent iron nanoparticles (nZVI) was investigated in a batch system. Surface composition of nZVI was characterized by scanning electron microscopy, electron dispersive X-ray spectrometer and X-ray diffractogram methods. Three main decolorization mechanism steps that surface reactions including sorption and chemical reaction controlled decolorization of the azo dye were proposed as (i) the cleavage of the azo bonds by reduction of anionic dye, (ii) adsorption of anionic dye on the iron oxides and (iii) decolorization of the azo chromophores by hydrogen peroxide formed in the presence of dissolved oxygen. The response surface methodology was applied in designing the dye removal experiments for evaluating the interactive effects of independent variables and determining the optimum condition. Four independent variables such as nZVI concentration, initial dye concentration, temperature and pH were coded with low and high level and dye removal (%) was obtained as response. The results showed that while the increase in the nZVI concentration and temperature showed positive effects, the increase in pH and initial dye concentration showed negative effect on dye removal efficiency. The interactive effects of whole variables were also investigated.

• 出版日期2017-6