Coupling of photocatalysis and biological treatment for phenol degradation: Application of factorial design methodology

In this study,the first part was focused on the photodegradation of phenol. the second part concerned a comparison between photocatalytic,biological,and biophotocatalytic treatments. a full factorial experimental design methodology was used to evaluate the effects of phenol concentration,tio2 concentration and ph on phenol photodegradation. the mathematical model employed for 23 factorial design with interaction verifies the good correlation between the observed and the predicted response values with r2 and r2adj of 99.77% and 98.97% respectively. furthermore the model provides the excellent relationship between the independent variables (factors) and the response. under the optimal conditions values obtained by the factorial experimental design methodology (phenol concentration 20 mg/l,tio2 concentration 2 g/l and ph 9),the predicted percentage of degradation was 64.09%. the combined photocatalytic-biological treatment significantly reduced the degradation time of phenol. thus,a complete phenol biodegradation of 100 mg/l occurs in 15 hours when using a photocatalytic as a pre-treatment,whereas the biodegradation alone required 47 hours. © 2017,university of mohammed premier oujda morocco.