Effects of Aeration Treatment in Distributing Reservoir of Water Purification Plant on Trihalomethane Reduction

Abstract

 The Takihata water purification plant started in August 2003. Trihalomethane concentration in drinking water has been the major issue since the start of the plant operation. Therefore, demonstration experiments were conducted in order to investigate the reduction of the trihalomethane concentration by aeration in a distributing reservoir of the plant. The experimental results showed that the trihalomethane concentration decreased exponentially with increased amount of aeration. Meanwhile, the aeration can not remove organic substances in clear water and so the trihalomethane concentration increases again in a water distribution network. This means that it is important to manage the concentration at the end of the network. Therefore, an estimating equation for the concentration in the network was developped using monitoring data. Model analysis using the estimating equation suggested that the aeration in the distributing reservoir enabled a water supply of good quality in the Takihata waterworks system.