An improved UV/Fe3+ process by combination with electrocatalysis for p-nitrophenol degradation.
p-nitrophenol (PNP) was investigated as a model pollutant under the improved UV/Fe3+ process by combination with electrocatalysis. In the individual UV/Fe3+ process, PNP degradation rate was dependent on Fe(III) concentration and decreased during degradation due to the depletion of ferric ion and thus it was very difficult to reach the quick mineralization of organics. These drawbacks could be significantly overcome in the modified UV/Fe3+ process, and synergetic effects for PNP and COD removal were observed at two investigated Fe(III) concentrations. The enhancements on the degree of conversion for PNP and COD in presence of 0.5 mM Fe(III) were 184% and 242%, respectively, and PNP of initial concentration of 1.0 mM could be completely removed within 1 h. Thus such a process would be very attractive to the rapid mineralization of the biorefractory compounds for wastewater treatment. The possible reasons for the synergetic effects were the electrochemical regeneration of ferric ion and the role of the oxygen that formed on the anode. Based on degradation intermediates identification and synergetic effect probe, a general reaction pathway for PNP degradation in the improved process was proposed.
Zhou
Minghua
M
Institute of Environmental Engineering, Zhejiang University, Hangzhou 310027, China. skynumen@yahoo.com
Lei
Lecheng
L
D002384:Catalysis; D004566:Electrodes; D005290:Ferric Compounds / Q000737:chemistry*; D015394:Molecular Structure; D009596:Nitrophenols / Q000032:analysis* / Q000528:radiation effects; D010084:Oxidation-Reduction; D014466:Ultraviolet Rays; D014874:Water Pollutants, Chemical / Q000032:analysis* / Q000528:radiation effects; D018508:Water Purification / Q000295:instrumentation / Q000379:methods*
D005290:Ferric Compounds; D009596:Nitrophenols; D014874:Water Pollutants, Chemical; C000499:ferric oxide; C024836:4-nitrophenol