Experimental study and test of a new biosorbent prepared from bean peels to remove Rhodamine B from industrial wastewaters

Abstract

Bean peels solid wastes are present in abundance, with no evident use and with no cost, hence their application as a new biosorbent to remove Rhodamine B (RhB) from wastewaters effluents from the textile industry. This was motivated by the performance achieved by many natural solid compounds when used as biosorbents, particularly in the removal of organic and inorganic pollutants mainly from industrial, agriculture, and even household wastewaters. The effects of different parameters on the adsorbent capacity, such as the contact time, the adsorbent dose (1–20 g/L), and the initial concentration of RhB (2–1,000 mg/L), initial pH (2–12) were investigated. The results showed that the retention process was rapid and the adsorption equilibrium could be reached after 25 min with an adsorbent dose of 10 g/L. The highest Rhodamine removal efficiency value was 99.16% for a high concentration of 1,000 mg/L. Equilibrium adsorption results followed the Freundlich isotherm, whereas the experimental kinetics data were best fitted to the pseudo-second-order equation. Finally, the obtained results confirm that bean peels had a large capacity of adsorption, making it an effective and economical biosorbent to remove RhB from wastewaters.