This study was conducted to evaluate the odor reduction efficacy of the dip injection wet scrubber (DIWS) using tap water as washing fluid. The NH3 and H 2 S removal efficiency of 7 day batch operated DIWS was evaluated twice over a total of 14 days of experiment. The NH 3 removal efficiency ranged from 26 to 37%. The H 2 S removal efficiency was between 22 and 30%. The pH of the washing fluid maintained below 8 and theNH 4+ concentration tended to keep constant around 350 ppm after 5 days of washing-fluid replacement. Therefore, the 5-day washing fluid replacement interval is more preferable than the 7-day interval. The NH 4+ concentration and the electrical conductivity (EC) showed a high correlation. The EC measurement can be used as an alternative to conventional NH 4+ concentration measurement method for real time monitoring of washing fluid condition.