Azusa Ito
Observation and evaluation of removal characteristic of the debris including CSO with a full-scale swirl
Shuji Himeno
Increased awareness of various environmental issues has brought people”Ēs attention to the influences caused by combined sewer overflows (CSOs) into the public water bodies. Therefore, countermeasures against CSOs are now considered very important.The complaints about CSOs are mostly those related to their dirtiness and foul odor.The vortex separators are considered very useful instrument since it can remove debris contained in CSOs and can be installed in small spaces.
In this study we installed a full-scale vortex separator in a wastewater treatment plant to examine its removal efficiency which had not been clearly determined so far.
First, we observed the way how the artificial debris was sucked into the swirl.
And we studied the correlation between the appropriate quantity of outflow and overflow for this experimental vortex separator.
Next we evaluated the removal efficiency of the separator using actual CSOs. The removal efficiency of pollution load was 50 to 57 percent and the concentration efficiency of debris was 176 to 195 percent. However, no strong correlation was found between the inflow debris volume and the removal efficiency. From this finding, we can conclude that the removal efficiency of the vortex separator is greatly influenced by the density and the size of debris.
So, we added many different sizes and densities of plastic articles into the inflow and observed the change in the removal efficiency. It was clarified that vortex separator could remove toilet paper which persistently remains in water, solid material with sedimentation characteristics and floatable solids.
Please use "previous botton" to return the previous page