Figure 4
From: Hydrodynamics of an Electrochemical Membrane Bioreactor

Block diagram of the (a) TIS, (b) AD and (c) Martin models: Q is the volume flow rate; for the Martin model, f represents volume flow rate fraction of each strand and the dead volume (Vd) = total volume (Vt) - 1st strand region (V1) - 2nd strand region (V2) - … - sth strand region (Vs).