Removal of Phenol from Sewage Effluent Using Activated Sludge Coupled with Photo-oxidation Process

摘要

Treatment of hazardous phenolic substances that are discharged to environment has a significant interest since decades. Biological treatment using freely suspended sludge is the most economical treatment method, but, is considered inactive for treatment of phenolic substances due to the complexity in their chemical structure. The degradation of phenol was experimentally investigated using separate and coupled biological and photo-catalytic processes. The degradation was carried out at different concentrations of phenol from 10 to 100 ppm. The results showed no degradation of phenol using biological treatment, and as expected, the bacterial colony growth was reduced by 50 percent due to lack of nutrient. The results of photo-catalytic process using titanium dioxide (TiO2) indicated the removal of 80 percent of phenol especially for concentration below 40 ppm. Bacterial colony growth during photo-oxidation test was dramatically reduced and no colony growth was found after 90 minutes after commencing time of experiment. On this basis, the results of using the combined advanced oxidation process with biological treatment, suggested that the photo-catalytic process would be considered as a post-treatment to the biological process.