Productivity and Biomass of the
Seagrasses of the Gulf of Mannar
Biosphere Reserve

Abstract :

A carbonaceous adsorbent prepared from an indigenous waste by acid treatment was tested for its efficiency in removing Rhodamine B (RDB). The parameters studied include agitation time, initial dye concentration, carbon dose, pH and temperature. The adsorption followed first order reaction equation and the rate is mainly controlled by intra-particle diffusion. Freundlich and Langmuir isotherm models were applied to the equilibrium data. The adsorption capacity (Qm) obtained from the Langmuir isotherm plots were 84.842, 88.574, 92.425 and 96.284 mg/g respectively at an initial pH of 7.0 at 30, 40, 50 and 600 C. The temperature variation study showed that the Rhodamine B adsorption is endothermic and spontaneous with increased randomness at the solid solution interface. Significant effect on adsorption was observed on varying the pH of the Rhodamine B solutions. Almost 83% removal of Rhodamine B was observed at 600 C. The Langmuir and Freundlich isotherms obtained, positive êH0 value, pH dependent results and desorption of dye in mineral acid suggest that the adsorption of Rhodamine B on FBC involves physisorption mechanism.