Effect of Upflow Biological Aerated Filter as a Alternative of Rapid Sand Filter in Advanced Water Treatment System

Given the deteriorated water quality in rivers that are used as sources of drinking water, the performance of existing filtration processes must be improved. In particular, the inefficiency of rapid sand filters prior to the post-ozonation process of the advanced water treatment system (AWTS) in reducing organic matter has resulted in the introduction of more effective processes. Downflow biofilm aerated filters (BAFs) are an alternative to rapid sand filters in drinking water treatment plants and were introduced to investigate their characteristics for removing particulate and organic matter in river water used as a drinking water source. In this study, zeocarbon was employed as the filter media in the BAF, which was packed to a thickness of 3 m. The filtration velocity ranged from 90 to 100 m/d, and Nakdong river water was used as the raw water. The results indicated that the removal efficiencies of UV₂₅₄, dissolved organic carbon (DOC), trehalomethan formation potential (THMFP), KMnO₄ consumption, DOC, and color ranged from 80% to 85%. In addition, the removal efficiency of NH4⁺_-N ranged from 70% to 85%. Moreover, column-shaped filter media achieved 10%-20% higher efficiency than ball-shaped media. The results indicate that the BAF process is a suitable alternative to rapid sand filters.