Comparison of O_3-BAC and GAC for Removing Micropollutants from Drinking Water

摘要

Studied was the comparison of ozone-biological activated carbon (O_3-BAC) and granular activated carbon (GAC) processes for advanced drinking water treatment. The effects by O_3-BAC and GAC were evaluated based on the removal of the indexes including COD_(Mn), UV_(254), TOC, BDOC, (NH_4)~+-N, NO_3~--N and NO_2~--N. The results showed that the treatment effect by O_3-BAC was better than that by GAC alone. When ozone dose was at its optimal level 2.0mg/L, the removal efficiencies of COD_(Mn), UV_(254) and TOC by O_3-BAC were 15.1%, 17.4% and 16.2% respectively higher than that by GAC alone. Furthermore, BDOC removal by O_3-BAC process was four times as much as that by GAC process. The (NH_4)~+-N and NO_2～-N of O_3-BAC effluent were both lower than that of GAC alone. Ozone increased the lower molecule weight organic compounds capable of being easily adsorbed by activated carbon and improved the biodegradability of the organic matters in the water so as to strengthen the biological treatment capability for organic pollutants by the subsequent treatment units.