title: [Degradation effect and mechanism of 2,4-DNT by reduction-ZPF catalytic oxidation].
abstract: ZPF(zeoliteartificial pillared by alpha-FeOOH) which prepared in the laboratory and characterized by FTIR and XRD was used as catalyst, and was tested for its activity in catalytic H2O2, of 2,4-DNT, which is persistent and difficult to be degraded in groundwater. The degradation of 2,4-DNT was examined at different pHs in the reduction, catalytic oxidation and combination technology of reduction-catalytic oxidation reaction systems. Moreover, the removal effect of 2,4-DNT was compared by these three approaches and the catalytic oxidation mechanism was analyzed. The results demonstrated that the removal effect of 2,4-DNT reduced to 2,4-DAT was up to 96.6% in 120 min at pH = 5, which was 1.2, 2.0 times of the rate at pH 7, pH 9 respectively. The catalytic effect was various at different pHs and more significant when the pH close to the zero point of charge of alpha-FeOOH. The order of removal effect of 2,4-DNT at different pHs was pH = 7 > pH = 9 > pH = 5. Compared to single reduction or catalytic oxidation, the removal effect of combination technology was 57.4%, which was evidently improved on the base of 2,4-DNT reduced to 2,4-DAT. The degradation of 2,4-DNT in the presence of ZPF/H2O2 follows a first-order kinetic model and the k(obs) was 0.002 7 min(-1). Due to the concentration of dissolved Fe ion was far less than 0.07 mmol/L, the mechanism was heterogeneous Fenton reaction acting on the surface of the catalyst. Therefore the combination technology was superior to the single treatment of reduction or catalytic oxidation.
authors.affiliation: College of Environmental and Safety Engineering, Changzhou University, Changzhou 213164, China. zh_5101@163.com
authors.forename: Jin-Bao
authors.initials: JB
authors.lastname: Zhang
authors.forename: Bei-Dou
authors.initials: BD
authors.lastname: Xi
authors.forename: Yong-Hai
authors.initials: YH
authors.lastname: Jiang
authors.forename: Ding-Long
authors.initials: DL
authors.lastname: Li
authors.forename: Fei
authors.initials: F
authors.lastname: Deng
authors.forename: Zhi-Fei
authors.initials: ZF
authors.lastname: Ma
authors.forename: Yan-Fei
authors.initials: YF
authors.lastname: Wang
mesh_terms: D002273:Carcinogens / Q000737:chemistry / Q000302:isolation & purification; D002384:Catalysis; D004136:Dinitrobenzenes / Q000737:chemistry / Q000302:isolation & purification*; D060587:Groundwater / Q000032:analysis; D006861:Hydrogen Peroxide / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D007501:Iron / Q000737:chemistry*; D010084:Oxidation-Reduction; D014874:Water Pollutants, Chemical / Q000737:chemistry / Q000302:isolation & purification*; D017641:Zeolites / Q000737:chemistry*
chemical_list: D002273:Carcinogens; D004136:Dinitrobenzenes; C045076:Fenton's reagent; D014874:Water Pollutants, Chemical; D017641:Zeolites; C016403:2,4-dinitrotoluene; D006861:Hydrogen Peroxide; D007501:Iron