engleski

Influence of Cu/ZSM-5 preparation method on CWPO of phenol

The necessity to remove organic pollutants i.e. phenol from the industrial wastewater streams has forced the development of new technologies that can produce better results in terms of pollutant removal and process efficiency in the combination with the low investment and operating costs. One of the new emerging processes with a potential to fulfill this demands is a catalytic wet peroxide oxidation, commonly known as a CWPO process. The oxidative effect of the hydrogen peroxide is intensified by the addition of the heterogeneous catalyst that can reduce the operating conditions to atmospheric pressure and temperatures bellow 373 K [1]. In this work oxidation of phenol with hydrogen peroxide on Cu/ZSM-5 catalysts was studied. The catalysts samples with different content of catalytic active centers were prepared by two different methods: by ionic exchange from the protonic form of commercial ZSM-5 zeolite, and by direct hydrothermal synthesis. The catalytic tests were carried out in a stainless steel Parr reactor in batch operation mode at the atmospheric pressure and the temperature range from 323 to 353 K. The initial concentration of phenol and hydrogen peroxide was 0.01mol dm-3 and 0.1mol dm-3, respectively. It was found that the activity of catalyst increases with increasing of copper content on zeolite and that the activity of Cu/ZSM-5 prepared by direct hydrothermal synthesis is higher then the activity of catalyst prepared by ion exchange method, which is also confirmed by the Ea. Activation energy in phenol oxidation was from 66.20 to 95.77 kJ mol-1 what depend on catalysts preparation method.

Phenol oxidation ; Hydrogen peroxide ; Zeolites ; Hydrothermal synthesis ; Ion exchange ; Kinetics

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