Evaluation of the Biosorption Capacity of Orange and Passion Fruit Peels to Remove Copper, Cadmium and Lead

Objective: To investigate the capacity of orange and passion fruit peels as biosorbents for the metals copper, cadmium and lead in aqueous solutions. Theoretical Framework: Population and industrial growth leads to an increase in the generation of waste and effluents, which can cause negative impacts when not treated. The presence of toxic metals in the environment contributes to air, soil and water pollution, causing environmental problems and problems for living beings. Method: The zero charge point was calculated to define the best pH to be used; the metal removal capacity was evaluated in relation to contact time. The functional groups were identified by infrared spectroscopy, and the materials were observed by scanning microscopy. Results and Discussion: According to the results of the zero charge point, the pH to be used is greater than 5.4 for Pêra orange peel and greater than 4.7 for Azedo passion fruit peel. Orange peel showed 92% for copper removal, 100% for lead and 98% for cadmium; passion fruit peel obtained 90% biosorption for copper, 94% for lead and 93% for cadmium. Using infrared, the -NH, -OH and -CH groups were identified as responsible for biosorption, along with the irregular and porous nature of the materials observed under microscopy. Research Implications: Use a sustainable, fast and low-cost methodology for the decontamination of aqueous solutions that contain residues of the studied metals. Originality/Value: The reuse of waste and low-cost strategies highlight the ease of operation, contributing to sustainable development.