In recent years, dye wastewater caused serious effects on environmental ecology and human health. Thus, in the present study, hydroxylamine (HA) was used to improve the Fe 3 O 4 /H 2 O 2 process for removing the typical dye pollutant (tartrazine). Only 2.8% tartrazine could be removed in Fe 3 O 4 /H 2 O 2 system within 60 min at the reaction of 1 g/L Fe 3 O 4 , 1 mM H 2 O 2 , and pH 4 while 97.5% tartrazine could be removed within 20 min after adding 1 mM HA into the Fe 3 O 4 /H 2 O 2 system. Compared with Fe 3 O 4 /H 2 O 2 system, the removal rate for removing tartrazine in Fe 3 O 4 -HA/H 2 O 2 system could enhance more than 100 times. Electron paramagnetic resonance tests (EPR), radical quenching experiments and quantitative determination demonstrated that • OH was the major reactive species for removing tartrazine in Fe 3 O 4 -HA/H 2 O 2 system and • OH produced concentration in Fe 3 O 4 -HA/H 2 O 2 system was also much higher than that in Fe 3 O 4 /H 2 O 2 system. The key factors affecting tartrazine removal in Fe 3 O 4 -HA/H 2 O 2 system were also conducted. The optimal HA dosage, Fe 3 O 4 dosage, and H 2 O 2 dosage was 1 mM, 1 g/L and 1 mM. The optimal initial pH in Fe 3 O 4 -HA/H 2 O 2 system was 3, but compared with Fe 3 O 4 /H 2 O 2 system, the tatrazine removal efficiency could significantly improve under any initial pH condition. Fe 3 O 4 -HA/H 2 O 2 process had strong adaptability to inorganic ions and good applicability to different pollutants. Fe 3 O 4 -HA/H 2 O 2 process also exhibited good recycle ability for tartrazine removal. Overall, Fe 3 O 4 -HA/H 2 O 2 process is an effective and good practical applicability approach for dye wastewater treatment.
Shengtao Jiang,Jianzhong Zhu,Ying Ding,Shuli Bai,Yujiang Guan,Jia Wang
The characteristics and influencing factors for dinitrotoluene degradation by nano-Fe3O4-H2O2 were studied, and the nano-scale Fe3O4 catalyst was prepared by the coprecipitation method, with dinitrotoluene wastewater as the degradation object. The results showed that the catalytic reaction system within the pH value range of 1 to 9 could effectively degrade dinitrotoluene, and the optimal pH value was 3; with the increase of catalyst dosage, the degradation efficiency and the catalytic reaction rate of dinitrotoluene grew as well. The optimal catalyst dosage was 1.0 g/L when the H2O2 dosage was within the range of 0 to 0.8 mL/L; the degradation efficiency and reaction rate grew with the increase of H2O2 dosage. With further increase of H2O2 dosage, degradation efficiency and reaction rate decreased; under the best conditions with the H2O2 dosage of 0.8 mL/L, the catalyst concentration of 1 g/L and the pH value of 3 at room temperature (25 °C), the degradation rate of the 100-mg/L dinitrotoluene in 120 min reached 97.6%. Through the use of the probe compounds n-butyl alcohol and benzoquinone, it was proved that the oxidation activity species in the nano-Fe3O4-H2O2 catalytic system were mainly hydroxyl radical (•OH) and superoxide radicals (HO2 •), based on which, the reaction mechanism was hypothesized.
危险品化学品经营许可证（带存储）