Adsorption of cationic dye on nanostructured biocarbons: kinetic and thermodynamic study

Abstract Nanostructured bio-adsorbents were prepared by physical or chemical activation of the residue supercritical extraction raspberry seed. Their physicochemical properties determined elemental analysis, low-temperature nitrogen adsorption/desorption, Boehm titration and scanning electron microscopy. The biocarbon obtained as a result precursor showed basic character surface its S BET was 700 m 2 /g. seed with potassium carbonate favored generation acidic functional groups this 1177 nanostructured biocarbons used for removal Rhodamine B from aqueous solutions. process best described Langmuir isotherm maximum capacity monolayer 181.82 mg/g 277.83 physically chemically activated samples, respectively. adsorption energy Dubinin–Radushkevich indicated that observed physisorption, while kinetics pseudo-second-order model. negative values Gibbs free spontaneous process. For sample, highest sorption capacities toward in an environment, sample—in environment. yield desorption decreased media: distilled water > hydrochloric acid acetic acid, which means molecules weakly bound to surface.