Adsorption of methylene blue in potato peel using batch and fixed-bed column systems

Abstract

The search for an efficient and low cost adsorbent for the treatment of wastewaters containing dyes motivated this work. The efficiency of the adsorbent from agro-waste, potato peel (Solanum tuberosum L.), was tested using the cationic dye methylene blue as adsorbate. Adsorption studies were conducted in batch and fixed-bed column systems. The parameters evaluated in batch system were: point of zero charge (PZC), kinetics and adsorption isotherm, applying the theoretical models of Langmuir and Freundlich. With fixed-bed column it was possible to obtain saturation and reuse curves of the adsorbent and recovery of the dye. The Langmuir isotherm model was the best fit to the experimental data, with a maximum amount adsorbed (qmax) of 48.7 mg g-1. The maximum adsorption capacity of the column was 35.83 mg g-1. It was also verified the possibility of recovery the dye using HCl solution and reusing the adsorbent after this process.