Chapter 4: Activated Sludge Modelling - IqTMA-UVa

S and X in CSTR (no decay)Monod model: µ = µ m S/(K s +S)Under steady state: µ = D, therefore D = µ m S/(K s +S)Solving this equation S = DK s /(µ m – D)S mass balance: VdS/dt = 0 = QS 0 – QS + r su V r su V = - Q(S 0 -S)Since r su V= (-r g /Y)V = - µVX/Y = -DVX/Y = -QX/Y (since D = Q/V) Q(S 0 – S) = QX/Y = DX = Y(S 0 – S)(This could have be obtained directly from the expression of the trueyield)9