Investigating the feasibility and the optimal location of pulsed ultrasound in surface water treatment schemes

The deterioration of surface water quality due to extreme weather events and increasing human activities has exacerbated the common problems in drinking water production such as filtration fouling and DPBs formation. This in turn has urged for exploring alternative methods for the traditional treatment methods that are able to improve the removal of contaminants with minimal impact on environment and human health. In this study, the application of pulsed and continuous ultrasound for improving the quality of natural water with fresh natural organic matter (NOM) mainly driven from vegetation has been evaluated. The evaluation was performed using cost-effective and quick measurements such as specific UV–vis absorbance, CODMn, alkalinity and conductivity. The changes in the characteristics of NOM induced by ultrasound were used to develop a framework for evaluating ultrasound performance in improving conventional surface water treatment processes and to identify the best fit of ultrasound within the treatment scheme. Results of this study showed that pulsed ultrasound was as effective as or in some cases better than continuous ultrasound in improving water quality. According to the adapted assessment criteria supported by an extensive literature survey, the most effective location of ultrasound treatment within surface water treatment scheme was found to be prior to coagulation/flocculation.