Estimation of the Reduction of Human Exposure to Wastewater-Derived Contaminants by Upgrading Wastewater Treatment

This study aims to quantify the reduction of human exposure to two wastewater derived contaminants (triclosan and carbamazepine) achieved by installation of ozonation after biological wastewater treatment. Concentrations at drinking water abstraction points in two different watersheds were estimated before and after installation of ozonation using a Monte Carlo simulation to account for variability in the removal efficiency in WWTPs, instream attenuation and other factors. For the Yodo River in Japan, ozonation would result in a greater decrease in exposure than in the Trinity River in Texas because natural attenuation reduces the concentrations of the compounds as they are transported downstream in the Trinity River. In both cases, ozonation minimizes human exposure and protects aquatic organisms in the receiving waters.