Removal of Refractory Contaminants Wastewater Using Biological Treatment Followed by Photocatalytic

Eman Emam, S.-U Geissen, A Vogelpohl
Biological treatment is considered environment-friendly and relatively cheap, but the complete removal of different contaminants is questionable. Photocatalytic process is widely used for the removal of refractory non-biodegradable compounds from industrial and municipal wastewater. Photocatalytic process has been investigated to purification of the refractory contaminants real commercial The activities of three wastewater after two steps of an aerobic biological treatment. 100 and
more » ... gussa P25, Hombikat UV) photocatalysts (2 oxide (TiO types of titanium di an aerated investigated using was concentration-2 TiO PC 50) were studied. In addition, photoreactor which was modified for batch experiments. After biological treatment the total organic carbon (TOC) degraded from 28 to 11 mg/L. The remaining of the hydrocarbon content was found 4.6 mg/L. Additionally, the biochemical oxygen demand (BOD 5) to chemical oxygen demand (COD) ratio less than 0.02, the biological treatment was assumed to be complete. The results of photocatalytic treatment showed that, the TOC in the wastewater is able to remove with different photocatalysts, but at different reaction rates. Degussa P25 was more active than UV-100 and PC 50 photocatalysts with TOC degradation reached 83%. The degradation rate of TOC was increased with increasing P25 photocatalyst concentration up to 5 g/L. The degradation rate of the TOC in the wastewater was found to be pseudo first order and the maximum rate was achieved with P25. Reduction of 88 % of hydrocarbon content was achieved by P25.