Sequential photo-Fenton and sono-photo-Fenton degradation studies of Reactive Black 5 (RB5)

Sequential treatment studies have been done using photo-Fenton and sono-photo-Fenton, and compared with individual processes to analyze possible favorable effects of combined systems for the degradation of Reactive Black 5 (RB5). The coupled system enhances the degradation as compared to the ultrasound or UV-light irradiation processes along with the reduction in treatment time. Batch runs were carried out to investigate the process operational conditions: pH, H2O2 dosage, Fe2+ dosage, and RB5 concentration; to obtain the results at best possible operating conditions render advanced oxidation processe (AOP) competitive with other processes; and to ensure the rapid and complete transformation of the toxic organic compounds to benign chemicals. Degradation observed was 69% under Fenton and 93% under photo-Fenton with experimentally optimized conditions i.e. pH 4, Fe2+ concentration 0.050gL(-1) and H2O2 0.150gL(-1) after 20min. Sono-photo-Fenton treatment enhances the degradation up to 98% with experimentally optimized parameters within 12min of reaction.