title: Efficient removal of dyes by a novel magnetic Fe3O4/ZnCr-layered double hydroxide adsorbent from heavy metal wastewater.
abstract: A novel magnetic Fe(3)O(4)/ZnCr-layered double hydroxide adsorbent was produced from electroplating wastewater and pickling waste liquor via a two-step microwave hydrothermal method. Adsorption of methyl orange (MO) from water was studied using this material. The effects of three variables have been investigated by a single-factor method. The response surface methodology (RSM) based on Box-Behnken design was successfully applied to the optimization of the preparation conditions. The maximum adsorption capacity of MO was found to be 240.16 mg/g, indicating that this material may be an effective adsorbent. It was shown that 99% of heavy metal ions (Fe(2+), Fe(3+), Cr(3+), and Zn(2+)) can be effectively removed into precipitates and released far less in the adsorption process. In addition, this material with adsorbed dye can be easily separated by a magnetic field and recycled after catalytic regeneration with advanced oxidation technology. Meanwhile, kinetic models, FTIR spectra and X-ray diffraction pattern were applied to the experimental data to examine uptake mechanism. The boundary layer and intra-particle diffusion played important roles in the adsorption mechanisms.
authors.affiliation: School of Environmental and Chemical Engineering, Shanghai University, No. 99 Shangda Road, Shanghai 200444, PR China.
authors.forename: Dan
authors.initials: D
authors.lastname: Chen
authors.forename: Yang
authors.initials: Y
authors.lastname: Li
authors.forename: Jia
authors.initials: J
authors.lastname: Zhang
authors.forename: Wenhui
authors.initials: W
authors.lastname: Li
authors.forename: Jizhi
authors.initials: J
authors.lastname: Zhou
authors.forename: Li
authors.initials: L
authors.lastname: Shao
authors.forename: Guangren
authors.initials: G
authors.lastname: Qian
mesh_terms: D000327:Adsorption; D000465:Algorithms; D000704:Analysis of Variance; D001391:Azo Compounds / Q000737:chemistry; D002857:Chromium / Q000737:chemistry*; D004396:Coloring Agents / Q000302:isolation & purification*; D004595:Electroplating; D052203:Ferrosoferric Oxide / Q000737:chemistry*; D006256:Hazardous Waste / Q000032:analysis*; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry; D007202:Indicators and Reagents; D007700:Kinetics; D019216:Metals, Heavy / Q000302:isolation & purification*; D046529:Microscopy, Electron, Transmission; D008872:Microwaves; D009584:Nitrogen / Q000737:chemistry; D012044:Regression Analysis; D013696:Temperature; D013816:Thermodynamics; D014865:Waste Disposal, Fluid / Q000379:methods*; D062065:Wastewater / Q000032:analysis*; D015032:Zinc / Q000737:chemistry*
chemical_list: D001391:Azo Compounds; D002857:Chromium; D004396:Coloring Agents; D052203:Ferrosoferric Oxide; D006256:Hazardous Waste; D006878:Hydroxides; D007202:Indicators and Reagents; D019216:Metals, Heavy; D009584:Nitrogen; D062065:Wastewater; D015032:Zinc; C100258:methyl orange