Abstract
The foul odor of rivers is often linked to poor water quality and unhealthy air. In this study, variations in water quality and hydrodynamics near the confluence of the Shakujii and Sumida Rivers in Tokyo, Japan, were monitored, and their effects on sum generation were analyzed. The Shakujii River, facing scum and odor issues, was monitored hourly for on-site scum coverage. Samples of scum, sediment, and water were collected and subjected to odor analysis. The odor characteristics were assessed using an electronic nose odor machine and then correlated with human olfactory sense. Results indicated that salinity, dissolved oxygen (DO), rainfall, sediment, and topography influenced scum formation. Scum coverage was higher when salinity was below 1 psu and DO was below 6 mg/L. Organic acids (14.2%) and hydrogen sulfide (14.4%) were the primary odor components of sediment in the Shakujii River. In the Sumida River sediments, organic acids (4%) and sulfurs (1%) were prominent. The Shakujii River sediment exhibited the highest odor index and showed a 62.43% similarity with scum. These results could support efforts to address scum and odor issues in the area. They could provide new insights into on-site formation based on actual river hydrodynamics and water quality variations.
Graphical abstract