(?) The intraparticle diffusion model depends on Morris – Weber equation 40 as written:
Q_(t )=K_i t^0.5+C (4)
Where Ki is the intraparticle diffusion constant (mg/g min0.5) and the intercept (C). Plotting Qt vs. t1/2 give straight line did not pass through the origin with Ki=0.74, 0.85 and 0.57 mg/g min0.5, (R2 = 0.53, 0.59, 0.73) as shown in fig.1b. The intercept values (film thickness) were 1.01, 0.71 and 1.03 for the sorption of Br.G, To.B and Tr.B. the boundary layer effect is high for Tr.B as a great value of C. The deviation exist in linear consists of two level (Moawed et el., 2014),