Fig. 2. Breakthrough curves of ferricyanide in goethite-coated sand at three pore-water velocities (a, = 0.104 cm min^-1; b, = 0.215 cm min^-1; c, = 0.305 cm min^-1). Lines result from simulations using batch-derived Langmuir isotherm parameters (Eq. [6], s_max = 1.67 x 10^-3 g g^-1, K_L = 176862 g^-1 cm³) with four different forward rate parameters k_f using CARRY. Arrows indicate the beginning of a flow interruption.