The adsorption of methylene blue by DAB was investigated
for the initial dye concentration range 1-5 mg/L at adsorbent dose
of 1 g L1
. The concentrations of dye and the dose of adsorbent
were chosen based on earlier studies with similar system (Tsai
et al., 2011). The initial pH of the dye solution was adjusted to
7.0 by using dilute HCl solution. The flasks were stirred at
400 rpm (rotations per minute) using a magnetic stirrer. The temperature
of dye solution during adsorption studies was maintained
at 25 C. The samples were withdrawn at regular intervals up to 1 h
and were filtered using mixed cellulose ester (MCE) membrane of
pore size 0.45 lm. The dye concentration in the filtered solution
was measured using a UV/Visible spectrophotometer (Model:
UV/1800A, Shimadzu corporation, Kyoto, Japan) at a wavelength
of 663.8 nm (maximum absorbance was observed at this wavelength).
The amount of adsorption at time t, qt (mg g1
) was determined
by,
q