[Catalytic degradation of PCB77 by microwave-induced nano-particle metal oxides in diatomite].
The degradation of PCB77 in diatomite by microwave-induced catalytic oxidation was studied in a sealed vial, including four effects such as microwave (MV) radiating time, addition of different nano-particle metal oxides, concentration and type of acids and dosage of MnO2. The results indicated that PCB77 could be removed significantly by microwave-induced catalytic oxidation. Compared to control reactor (without MV radiation), the removal rate of PCB77 increased by twice after 1 min. In addition, the removal rate of PCB77 under MV radiation was gradually increased with time of radiation and then reached equilibrium after 10 min. The removal rates are about 50% and 20% by addition of H2SO4 and ultrapure water respectively. No significant removal was observed by addition of NaOH and without aqueous media. Moreover, catalytic degradation of PCB77 by microwave-induced nano-particle MnO2 had best removal rate was up to 90% after 1 min, in contrast with addition of nano-particle Fe2O3, CuO and Al2O3. The removal rate raised from 37.0% to 98.5% rapidly with the concentration of H2SO4 ranged from 1 mol/L to 8 mol/L, and H2SO4 mainly played a role of acidification but not oxidation. The addition of 0.01, 0.03 and 0.05 g MnO2 showed the similar result.
State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China. gyhuang@issas.ac.cn
Guan-yi
GY
Huang
Ling
L
Zhao
Yuan-hua
YH
Dong
D002384:Catalysis; D007692:Diatomaceous Earth / Q000737:chemistry*; D017895:Manganese Compounds / Q000737:chemistry; D053768:Metal Nanoparticles / Q000737:chemistry*; D008872:Microwaves; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry; D011078:Polychlorinated Biphenyls / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects; D012989:Soil Pollutants / Q000737:chemistry / Q000302:isolation & purification* / Q000528:radiation effects
D017895:Manganese Compounds; D010087:Oxides; D012989:Soil Pollutants; D007692:Diatomaceous Earth; C033787:diatomite; D011078:Polychlorinated Biphenyls; C016552:manganese dioxide; C028451:3,4,3',4'-tetrachlorobiphenyl