4. Conclusion
RH was found to be effective in the uptake of RhB. Optimum adsorption was obtained at pH 3, RhB percentage removal rose up to 88.88% for adsorbent dosage of 2 g/L.
Freundlich isotherm best describe the adsorption of RhB onto RH suggesting that adsorption was onto a non-uniform site.
However initial rapid adsorption was onto a uniform site thus maximum monolayer adsorption capacity was obtained to be 666.67 mg/g.
Adsorption energy (E), ΔH° and desorption studies suggests that the uptake of RhB onto RH was physical in nature.
Elovich, Fraction power, Bangham and intraparticle diffusion models suggests that more than one mechanism was involved in the uptake of RhB onto RH.