Chromium removal using resin supported nanoscale zero-valent iron

• Published in: Journal of environmental management 2013-10, Vol.128, p.822-827
• Main Authors: Fu, Fenglian, Ma, Jun, Xie, Liping, Tang, Bing, Han, Weijiang, Lin, Suya
• Format: Article
• Language: English
• Subjects: Animal, plant and microbial ecology; Applied ecology; Applied sciences; Biological and medical sciences; Cation Exchange Resins - chemistry; chemical reduction; Chromium; Chromium - isolation & purification; Chromium removal; Conservation, protection and management of environment and wildlife; Coprecipitation; Cr(VI) wastewater; Diffraction; Efficiency; Exact sciences and technology; Fundamental and applied biological sciences. Psychology; General aspects; Hydrogen-Ion Concentration; ion exchange; Iron; Iron - chemistry; Kinetics; Metal Nanoparticles; Microscopy, Electron, Scanning; Nanoscale zero-valent iron (nZVI); Nanostructure; Pollution; Polymers; Precipitation; Recycling; Reduction (chemical); Resin; Resins; Scanning electron microscopy; Support; Waste Disposal, Fluid - methods; wastewater; Wastewaters; Water Pollutants, Chemical - isolation & purification; Water treatment; Water treatment and pollution; X-Ray Diffraction
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2013.06.044

Resin supported nanoscale zero-valent iron (R-nZVI) was synthesized by the borohydride reduction method. Batch experiments were conducted to evaluate the factors affecting Cr(VI) removal. It was found that nZVI loads, resin dose, pH value and initial concentration of Cr(VI) were all important factors. Scanning electron microscopy showed that the nZVI particles in R-nZVI became sphere after reacting with Cr(VI). This phenomenon was attributed to the co-precipitation of Cr(III) and Fe(III) on the surface of resin. X-ray diffraction pattern confirmed that Fe0 diminished after the reaction. At optimum conditions, the Cr(VI) removal efficiency was 84.4% when the initial concentration of Cr(VI) was 20.0 mg/L. Regeneration of R-nZVI and resin was possible. R-nZVI can also remove Cr(III) efficiently. However, the removal mechanisms of Cr(VI) (anion) and Cr(III) (cation) are different. The former is chemical reduction, while the latter is ion exchange at pH below 6.3 and precipitation at pH above 6.3. This study demonstrates that R-nZVI has the potential to become an effective agent for treating wastewater containing Cr(VI) and Cr(III). [Display omitted] •Resin supported nZVI was synthesized to treat wastewater containing chromium.•R-nZVI can efficiently remove both Cr(VI) and Cr(III).•R-nZVI can be recycled for several times.•R-nZVI is an effective reagent in the remediation of chromium pollution.