Water quality improvement by advanced treatment processes of GAC filtration and ozonation over an eight-year period

Water quality improvement by the advanced GAC (granular activated carbon) treatment processes of filtration and ozonation was evaluated using one sample plant in this study. For the evaluation, the percentage removal performances of selected target contaminants were compared using a statistical technique. This evaluation showed that GAC filtration and ozonation were generally effective in improving the water quality with respect to alkylbenzene sulfonate (ABS), KMnO₄ consumption and turbidity. Ozonation was effective in ABS removal, while GAC filtration was not. GAC filtration was mainly responsible for reduction of KMnO₄ consumption, while the ozonation effect was minimal. Both GAC filtration and ozonation contributed to turbidity reduction. The study reports that pre-determination of a specific goal for a target contaminant is important for effective evaluation of advanced water treatment. Applying the same design conditions that have proved effective in pilot-scale experiments to an actual plant was also important for successful advanced treatment.