title: Rapid decolorization of azo dye methyl orange in aqueous solution by nanoscale zerovalent iron particles.
abstract: Azo dyes are recalcitrant and refractory pollutants that constitute a significant burden on the environment. The report here is focused on the decolorization treatment of water soluble azo dye methyl orange (MO) by chemically synthesized nanoscale zerovalent iron (NZVI) particles. Experimental variables such as initial dye concentration, iron dosage, solution pH and temperature were studied systematically. Batch experiments suggest that the decolorization efficiency was enhanced with the increase of NZVI dosage and reaction temperature, but decreased with increasing initial dye concentration and initial solution pH. Further studies indicated that existence of inorganic salt (Na(2)SO(4)) could inhibit the decolorization of MO. Kinetic analyses based on the experimental data elucidated that the decolorization process followed a first order exponential decay kinetics model. The activation energy was determined to be 35.9 kJ/mol.
authors.affiliation: School of Chemical and Environmental Sciences, Henan Key Laboratory for Environmental Pollution Control, Henan Normal University, Xinxiang, Henan 453007, PR China. fanjing@henannu.edu.cn
authors.forename: Jing
authors.initials: J
authors.lastname: Fan
authors.forename: Yanhui
authors.initials: Y
authors.lastname: Guo
authors.forename: Jianji
authors.initials: J
authors.lastname: Wang
authors.forename: Maohong
authors.initials: M
authors.lastname: Fan
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D003116:Color; D004396:Coloring Agents; D006863:Hydrogen-Ion Concentration; D007220:Industrial Waste / Q000517:prevention & control*; D007501:Iron / Q000737:chemistry*; D053758:Nanoparticles / Q000737:chemistry; D012996:Solutions; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000737:chemistry; D018508:Water Purification / Q000379:methods*
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D007220:Industrial Waste; D012996:Solutions; D014874:Water Pollutants, Chemical; C100258:methyl orange; D007501:Iron