Modeling of Combined Sewerage Overflow Induced Escherichia Coli and Adenovirus Transport in Tokyo Bay
Modeling of Combined Sewerage Overflow Induced Escherichia Coli and Adenovirus Transport in Tokyo Bay
Previously Published Material: only a part of the presentation been previously reported to the website of University of Tokyo, Japan, from where the study was carried out as a master thesis in 2009. That was in an initial stage. Later on the research was upgraded and enriched.
Abstract ID#: 32998
English Abstract:
Fecal coliform and some other bacteria have been used worldwide to indicate coastal water quality for a long time. Some numerical modeling has been done currently to investigate the fate and transport of fecal bacteria in coastal water. However, no such efforts have been made for viruses. In this study, a virus (adenovirus) was included as an indicator along with fecal bacteria, Escherichia coli. A three-dimensional hydrodynamic model coupled with a pathogen model was used to understand the processes affecting pathogen transport in Odaiba area of Tokyo Bay after a sewerage overflow event. Field observation was also conducted to verify the model. The model results show the typical two to three-day wet weather effect of stormwater discharges where as observed data shows that the effects remain longer in surface water. Storm induced discharge from pumping stations and tidal influence was identified as the dominant factor. Modeling result also shows that high pathogen levels are not necessarily tied with amount of rainfall. Even in small precipitations (<5mm), pathogen concentration can increase significantly. Though higher viral plume observed right after every storm events like that of bacteria, the viral concentration was not always consistent with bacteria. Therefore, the traditional bacterial indicators are not adequate to reflect the presence of pathogenic viruses, in managing coastal water.