Combination of Photocatalytic and Biological Process for Treatment of Wastewater

The combined phenol treatment approaches were carried out in two separate sequences (photo-biodegradation and bio-photodegradation). TiO2/ZnO/N was used in photodegradation part and mixed consortia in biodegradation part. In the sequence where the photocatalytic was employed as a pretreatment, nearly 70% of initial 50 ppm of phenol were removed within 6 h reaction, whereas a total phenol degradation of 81% was achieved in another sequence. The combined treatment enhanced overall phenol removal compared to single treatment alone. The characterization of catalyst powder synthesis by X-ray diffraction (XRD) confirmed the phase composition of TiO2/ZnO/N composites while Field Electron Scanning Electron Microscopy (FESEM) indicates intimate association of catalyst within surface methodologies.