Adsorption studies of organic dyes on reduced graphene oxide (rGO) and calcium carbonate
In the present study, we discuss two important adsorbents, reduced graphene oxide (rGO) and Calcium carbonate. These two materials have been identified as effective adsorbents over a wide range of dyes. We have discussed the adsorption of two important anionic dyes, Methyl orange and Congo red by rGO and Calcium carbonate respectively. Adsorption kinetics of Methyl orange on rGO is discussed in detail and it is observed to follow second order kinetics. Temperature and pH effect on the adsorption of this dye has also been discussed. Vaterite phase Calcium carbonate is reported to have a porous surface and is found to adsorb anionic dye efficiently. Adsorption of dye materials from the industrial waste water prevents these toxic materials from getting into natural water resources and hence prevents the water pollution. Adsorption is one of the effective and economical ways to prevent water pollution in the present scenario.
Keywords: hummers method, dyes, adsorption isotherm, calcite phase, vaterite phase, rietveld refinement