Application of zero-valent iron nanoparticles for the removal of aqueous zinc ions under various experimental conditions

• Published in: PloS one Vol. 9; no. 1; p. e85686
• Main Authors: Liang, Wen, Dai, Chaomeng, Zhou, Xuefei, Zhang, Yalei
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 09.01.2014; Public Library of Science (PLoS)
• Subjects: Adsorption; Atmospheric corrosion; Cadmium; Cadmium - chemistry; Continuous flow; Dissolved oxygen; Efficiency; Engineering; Ethanol; Experiments; Hydrogen-Ion Concentration; Ions; Iron; Iron - chemistry; Laboratories; Materials Science; Metals; Nanoparticles; Nanoparticles - chemistry; Nanoparticles - ultrastructure; Oxidation-Reduction; Oxygen; Oxygen - chemistry; pH effects; Photoelectron Spectroscopy; Precipitation (Meteorology); Rheology; Selectivity; Sodium; Solutions; Spectrum analysis; Studies; Water Pollutants, Chemical - isolation & purification; X-Ray Diffraction; Zinc; Zinc - isolation & purification; Zinc compounds; China
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0085686

Application of zero-valent iron nanoparticles (nZVI) for Zn²⁺ removal and its mechanism were discussed. It demonstrated that the uptake of Zn²⁺ by nZVI was efficient. With the solids concentration of 1 g/L nZVI, more than 85% of Zn²⁺ could be removed within 2 h. The pH value and dissolved oxygen (DO) were the important factors of Zn²⁺ removal by nZVI. The DO enhanced the removal efficiency of Zn²⁺. Under the oxygen-contained condition, oxygen corrosion gave the nZVI surface a shell of iron (oxy)hydroxide, which could show high adsorption affinity. The removal efficiency of Zn²⁺ increased with the increasing of the pH. Acidic condition reduced the removal efficiency of Zn²⁺ by nZVI because the existing H⁺ inhibited the formation of iron (oxy)hydroxide. Adsorption and co-precipitation were the most likely mechanism of Zn²⁺ removal by nZVI. The FeOOH-shell could enhance the adsorption efficiency of nZVI. The removal efficiency and selectivity of nZVI particles for Zn²⁺ were higher than Cd²⁺. Furthermore, a continuous flow reactor for engineering application of nZVI was designed and exhibited high removal efficiency for Zn²⁺.