Ozonation of Tertiary Treated Wastewater - A Solution for Micro Pollutant Removal?

Abstract

The design criteria for wastewater treatment plants (WWTP) and the sludge retention time, respectively, have a significant impact on micropollutant removal. The upgrade of an Austrian municipal WWTP to nitrogen removal (best available technology, BAT) resulted in increased elimination of most of the analyzed micropollutants. Substances, such as bisphenol-A, 17a-ethinylestradiol and the antibiotics erythromycin and roxithromycin were only removed after the upgrade of the WWTP. Nevertheless, the BAT was not sufficient to completely eliminate these compounds. Thus, a pilot scale ozonation plant was installed for additional treatment of the effluent. The application of 0.6 g O3 g DOC-1 increased the removal of most of the micropollutants, especially for compounds that were not degraded in the previous biological process, as for example carbamazepine and diclofenac. These results indicated that the ozonation of WWTP effluent is a promising technology to further decrease emissions of micropollutants from the treatment process. Additionally to the assessment of the removal potential for micropollutants, the technology was evaluated for the disinfection potential in regard to bacterial standard hygienic parameters and model viruses and the impact on acute and genotoxic activities. Furthermore the endocrine potential was investigated. © Springer Science+Business Media B.V. 2011.