Removal of E. coli from stormwater by bioretention system: parameter optimization and mechanism

Four bioretention simulation columns were used to study the removal effects and influencing factors ofEscherichia coli(E. coli) in stormwater. The mechanism ofE. coliremoval in the bioretention system was also analyzed. The results show that the removal effects of the four new composite filters are better than that of the conventional filter. The specific surface area and porosity of the filter may be the key factors affecting the removal effect; the increase of the filter depth is beneficial to the removal ofE. coli; the area is conducive to the removal ofE. coli. Excessive depth of the submerged zone will reduce theE. coliremoval effect; drying will reduce theE. coliremoval effect, but it can be restored by rewetting.