Ascending rate as defined by the Degrémont (1989) relationship.

This relationship is a straight line allowing to determine the value of the cohesion

Figure 5a: This figure represents the result of the method maintaining the sludge height constant in the graduated cylinder at different ascending rate (Vasc=VGD). One sees that the straight slopes for AS processed () and untreated sludge () are almost identical. K()=2.50 ± 0.15 m/h ; r=0.99 / K()=2.62 ± 0.13 m/h ; r=0.99. coefficient K by linear regression (NU=no units).