Table 3 Sorption kinetics models for MB uptake by AC(H).

From: Statistical modeling of mutagenic azo dye adsorption on bagasse activated carbon

Kinetic model

Linear form

Nonlinear form

Parameters

Refs.

Pseudo-first order (PFO)

\(\ln \left( {q_{e} - q_{t} } \right) = \ln q_{e} - k_{1} t\)

\(q_{t} = q_{e} \left( {1 - exp - {\text{K}}_{1} t} \right)\)

qt (mg/g): removed amount of MB at time t

qe (mg/g): equilibrium sorption uptake

k1 (g/mg min): rate constant of the first-order adsorption

Lagergren and Svenska37

Pseudo-second order (PSO)

\(\frac{t}{{q_{t} }}\, = \,\frac{1}{{k_{2} \,q_{e}^{2} }} + \,\frac{t}{{q_{e} }}\)

\(q_{t} = \frac{{k_{2} t\left( {q_{e} } \right)^{2} }}{{1 + k_{2} q_{e} t}}\)

qt (mg/g): removed amount of MB at time t

qe (mg/g): equilibrium sorption uptake

k2 (g/mg min): rate constant of the second-order adsorption

Ho and McKay38

Intra-particle diffusion (IPD)

\(q_{t} \, = \,k_{p} \,t^{1/2} \, + \,C\)

qt (mg/g): removed amount of MB at time t

Kp (mg/g min0.5): intra-particle diffusion rate constant

C (mg/g): intercept of the line which reflects the thickness of the boundary layer

kp = slope

C = intercept

Weber and Morris80