[Fly ash-catalyzed oxidation of p-nitro phenol with H2O2].
Fly ash was investigated as a catalyst in the oxidation of p-nitro phenol (PNP) with H2O2 at ambient temperature and pressure. The physical and chemical properties of fly ash were analyzed. The effects of fly ash composition, pretreatment methods and other parameters (such as dosage, pH, reaction time and oxidant concentration) on PNP removal rate were studied. It was found that fly ash with larger specific surface area and higher carbon content demonstrated higher catalytic activity. Heat treatment (350 degrees C) on fly ash could effectively improve the PNP removal rate. With an initial H2O2 concentration of 200 mg/L, 60 g/L heat-treated fly ash could remove 62.38% PNP at 25 degrees C, pH = 2. Specific surface area, carbon and metal oxide contents of fly ash play an important role in the catalysis process. The adsorption control experiment showed that adsorption was the main effect (65.97%) in the catalysis process. The activity of the catalyst gradually increased during its reuse. The PNP removal rate could reach 82.47% and 98.72% in the second and third rounds of reuse, respectively. The removal rate remained at about 99% in the rest 9 rounds of reuse. And the catalytic properties decreased after 12 times uses.
Key Laboratory of Industrial Ecology and Environmental Engineering, Ministry of Education, Dalian University of Technology, Dalian 116023, China. za158@163.com
Ai-Li
AL
Zhang
Fang-Fang
FF
Deng
Ji-Ti
JT
Zhou
Ruo-Fei
RF
Jin
Li-Li
LL
Liang
Guo-Liang
GL
Zhang
D002244:Carbon; D002384:Catalysis; D003031:Coal; D060729:Coal Ash; D006861:Hydrogen Peroxide / Q000737:chemistry*; D007220:Industrial Waste; D009596:Nitrophenols / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D052638:Particulate Matter; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
D003031:Coal; D060729:Coal Ash; D007220:Industrial Waste; D009596:Nitrophenols; D052638:Particulate Matter; D014874:Water Pollutants, Chemical; D002244:Carbon; D006861:Hydrogen Peroxide