Photocatalytic decontamination of pharmaceutical effluent in a double tube reactor by ZnO catalyst. Physico chemical characterization and optimization. 

Abstract

This work focused on the study of the elimination of a non-steroidal anti-inflammatory drug (diclofenac) using heterogeneous photo catalysis as a treatment.The study investigated the effect of parameters (catalyst concentration, initial diclofenac concentration, ratio r r = . and volume flow) on the photocatalytic degradation of diclofenac. The analyses performed are pH, electrical conductivity, turbidity, surface tension, chemical oxygen demand, nitrite and diclofenac concentration.The study showed that: The heterogeneous photo catalytic degradation is influenced by :The concentration of the ZnO catalyst; The concentration of 1.5 g/L gives a better degradation in diclofenac with a percentage of elimination of 52%; The initial concentration of diclofenac; The concentration of 100 mg/L of diclofenac gives a better degradation with a percentage of elimination of 52%; The ratio r = ; The three ratios (1; 5; and 10%) give a total degradation after one hour of treatment; The volume flow rate of 25 mL/s gives a total degradation after one hour of treatment. Optimal conditions for heterogeneous photo-catalysis are : [ZnO] = 1.5 g/L, [diclofenac] = 100 mg/L, Volume flow rate = 25 mL/s For a volume flow rate of 20 mL/s, optimal conditions are met by adding H2O2.