“…at t=0, C w-f =C 0,w and u=u 0 (25) Where C w-f is water concentration in feed phase, C 0,w is its initial value and u 0 is the initial velocity of the feed flow. The boundary conditions for mass conservation equations in the feed phase are as follows: at z=L, Outflow condition (26) at z=0, C w-f =C 0,w (Inlet boundary) (27) at r=R 3 ,…”