A carbonaceous adsorbent prepared from biomass waste like wood apple outer shell (Limonia acidissima) by ZnCl2 treatment was investigated for its efficiency in removing Rhodamine B (RDB). Influence of agitation time, adsorbent dose, dye concentration, pH and temperature were explored. Two theoretical adsorption isotherms namely Langmuir and Freundlich were used to describe the experimental results. The Langmuir adsorption capacity (Qo) was found to be 46.7 mg/g and the equilibrium parameter (RL) values indicate favourable adsorption. The experimental data were well fitted with Langmuir isotherm model and pseudo second order kinetic model. Desorption studies showed that ion exchange mechanism might be involved in the adsorption process.