EJMP&EP





Degradation of phenol by photocatalytic oxidation

A. A. Ismail*, I. A. Ibrahim and R.M. Mohamed

Central Metallurgical R&D Institute, CMRDI, P.O.Box 87 Helwan, Cairo, Egypt


Received 27 November 2002; accepted 15 June 2003




ABSTRACT

Phenol is a major environment contaminated from various industries such as coke, pesticides, insecticides, fungicides and dyes due to high toxicity on the skin, eyes and mucous membrane in humans. Industrial wastewater containing phenols are conventional treated by FeSO4 and H2O2 to oxidize phenol to CO2 and H2O. FeSO4 is converted to Fe2(SO4)3 and H2O2 is decomposed and then the reactants could not be recycled. In addition the ferric sulfate is dumped and water is not reused. A new process was developed based on treatment with V2O5 - SiO2 photocatalyst or ozone in presence of UV light. The process is advantageous as the photocatalysts could be recycled and water could be reused. The process was successfully applied for treatment of wastewater produced from coke plant. The percent degradation of the phenol is increased from 47.31 to 72 % using V2O5 - SiO2 xerogel loading from 0.333 to 1.333 wt. % in presence of UV light. The rate constant was increased from 0.0025 to 0.0036 min-1 using different V2O5 - SiO2 xerogel loading and the reaction kinetics were found to be first order. On the other hand, the optimum conditions of photocatalytic degradation of phenol using ozone were obtained as the following: 1.6 wt. % ozone concentration and 0.85 m3/h airflow. The phenol removal efficiency using these conditions was 99% and the reaction was found to obey first order reaction.


Keywords: Photocatalytic; Degradation; Phenol; V2O5; Ozone



* Corresponding author
   E-mail : adelali11@yahoo.com