Study on purification mechanism in soil penetration facility for effluents from urban area and control strategies

In this study, demonstration experiments for removal of pollutants from road surface runoff during storm events were carried out under natural conditions in an outdoor pilot-scale soil penetration facility. In general, soil retains suspended matter and removes dissolved matter by adsorption. However, issues such as reduced purification capacity resulting from clogging and recovery of purification capacity during periods of intermittent supply of the storm water affect the removal efficiency of pollutants. Therefore, this study aimed at clarifying purification mechanisms during storm events and understanding how the structural characteristics of the soil penetration facility affect purification capacity based on long-term continuous measurements. In addition, modeling the purification mechanism under changing characteristics of rainfall in the long-term was undertaken.