The time required for removal of Br.G, To.B and Tr.B by [email protected] was tested by shaking dye solutions at different time (3-60 min). Fig.1AS showed that the acceptance time need for complete removal of Br.G, To.B and Tr.B were 60, 60 and 15 min, respectively. Speed for percentage removal of dyes increase with time until got saturation for active sites.
The diffusion rates of Br.G, To.B and Tr.B onto [email protected] were estimated using Weber-Morris (4), Bangham (5) and Reichenberg (6) equations.
Q_(t )= K_i ?t (4)
log?log??C?/(C?-Q_(t ) m)? = log??(K? m)/(2.303 V) +? log?t ? (5)
?t=-0.4977-ln??(1-F)? (6)
Where ki (mg/g min1/2) is the intraparticle diffusion rate coefficient, the ?t value is a mathematical function of F = Qt/Qe. Di is the effective diffusion coefficient, and ? and k? are constants. Qe (mg/g) and Qt (mg/g) are the sorption capacity at equilibrium and after time t (min).