Freundlich isotherm best described the uptake of RhB onto RH (R2 value of 0.9969), this suggest that adsorption was not onto a uniform site rather a multilayer adsorption
occurred in RhB-RH system. However, monolayer adsorption also played a very important role in the dye uptake onto RH (R2 for Langmuir is 0.9876).
The maximum monolayer adsorption capacity for the uptake of RhB onto RH was obtained to be
666.67 mg/g, larger percentage of the adsorbed RhB molecules was recorded within the rapid adsorption (Section 3.3,Fig. 5).
The Adsorption energy (E) obtained from Dubinin–Radushkevich (D-R) isotherm was 6.11 kJ/mol suggesting that the uptake of RhB onto RH was by physisorption.
Obtained maximum monolayer adsorption capacity (qmax) for the uptake of RhB onto RH has been compared with qmax for other adsorbents available in the literatures (Table 5).
RH apparently exhibits higher performance than other adsorbents earlier reported.