When 1/qe was plotted against 1/Ce according to Eq. (3),
the Langmuir model fitted the experimental data very well
with high correlation coefficients (R2O0.98). The values of
the Langmuir constants Q and b were calculated from the intercepts
and slopes of different straight lines, respectively, at
different temperatures. The calculated results are reported in
Table 1. It was found that Q values decreased with increasing
temperature. Similar observations were reported for the adsorption
of lac dye on silk [17].