GPS-X Technical Reference

Other Models 318
Equation 11.17
where:
E =concentration based removal efficiency (%)
E u
= ultimate settleable solids fraction (at high influent TSS)
C TSS = parameter that controls the exponential shape of the removal efficiency
vs. Influent TSS relationship
TSS inf
SOR
K
= influent total suspended solids concentration (mg/L)
= surface overflow rate (m/h)
= surface overflow rate a 0.5 E u
In this model E u, C TSS, and K are parameters that must be calibrated using measured data.
Once calibrated, the model can be used to predict the removal efficiency achieved in a
high-rate solids separation process, in terms of total suspended solids (TSS), given the
influent TSS and the surface overflow rate (SOR).
The default settleability model parameters provided in GPS-X are based on data taken
from studies conducted by the University of Windsor on a pilot-scale RTB operated at the
Lou Romano Water Reclamation Plant (LRWRP) in Windsor, Ontario, Canada
(Li et al., 2004) that used high doses of cationic polymer as the sole coagulant. A
3-dimensional scatter plot of the pilot plant settleability data is given in Figure 11-12.
Tests that did not use polymer were removed from the data set. The circles represent data
points and the lines or stems show where the points lie in the plane.
At a constant influent TSS, the removal efficiency was observed to decrease with
increasing surface overflow rate. At a constant surface overflow rate, the removal
efficiency increased exponentially with increasing influent TSS and leveled off at TSS
values above approximately 500 mg/L.
GPS-X Technical Reference