Merits of polyoxotungstates as environmental remediation catalysts: a novel wet oxidation technology for refractory industrial pollutants.
The catalytic effect of silicadodecatungstate (SiW12O40(4-)) on the oxidation of nitrobenzene in subcritical water (T = 100-300 degrees C; P = 0.1-8.6MPa, pH = 2.6) was examined. In the absence of SiW12O40(4-) catalyst nitrobenzene oxidation slowed down significantly after a brief period of rapid degradation and an average of 40% nitrobenzene removal. The catalytic effect of SiW12O40(4-) becomes particularly pronounced after a temperature dependent induction period. Catalyzed wet air oxidation continued until the degradation of the parent compound was complete provided that experimental conditions were harsh enough (T > 200 degrees C). Product distribution analysis suggested that the oxidation paths for catalyzed and uncatalyzed wet air oxidation of nitrobenzene are similar, but the analysis was not definitive.
Alaton
I Arslan
IA
Department of Environmental Engineering, Istanbul Technical University, Maslak, Istanbul, Turkey. arslanid@itu.edu.tr
Ferry
J L
JL
D002384:Catalysis; D007220:Industrial Waste; D009578:Nitrobenzenes / Q000737:chemistry / Q000302:isolation & purification*; D010084:Oxidation-Reduction; D011108:Polymers; D017973:Tungsten Compounds / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
D007220:Industrial Waste; D009578:Nitrobenzenes; D011108:Polymers; D017973:Tungsten Compounds; C036077:nitrobenzene