TEMPORAL VARIATION OF SALINITY, DO, SSC AND FUNDAMENTAL PROPERTY OF ODOR IN THE CONFLUENCE OF SHAKUJII AND SUMIDA RIVERS

抄録

 Water quality deterioration, together with odor and scum generation have been apparent in urban river estuaries, especially in Tokyo, Japan. In this study, the temporal variation of salinity, dissolved oxygen (DO), suspended sediment concentration (SSC) and scum were investigated in the confluence of Shakujii and Sumida Rivers. The sediment and water samples were collected for odor analysis using the Fragrance and Flavor Analyzer. Salinity intrusion in Sumida River was prominent 1 or 2 days after neap tide which consequently flows into Shakujii River. Hence, salinity intrusion in Shakujii River was affected by hypoxic water flow from downstream of Sumida River, while salinity remained at the deepest point near the confluence. Scum generation was less when DO exceeds 5 mg/l. Hydrogen sulfide and organic acid type compounds were detected for the odor components of scum. The sediment in Shakujii River has the highest odor index among all stations and shows 62.43% similarity with scum.