Banana Peel Applied to the Solid Phase Extraction of Copper and Lead from River Water: Preconcentration of Metal Ions with a Fruit Waste

This article reports on an investigation into the ability of minced banana peel to extract lead and copper ions from water and the parameters involved in this process. The kinetics of copper and lead uptake reached equilibrium in 10 min and the extraction of metals ions was favorable above pH 3. The medium was characterized by FTIR, which showed absorption bands of carboxylic and amine groups at 1730 and 889 cm(1), respectively. The adsorption isotherm fitted by Langmuir's model showed maximum adsorption capacities of 0.33 and 0.20 mmol g(-1) (or 20.97 and 41.44 mg g(-1)) for Cu(II) and Pb(II), respectively. Minced banana peel was applied in the preconcentration system and showed approximately 20-fold enrichment factor and the column was I reused for 11 cycles without loss in the percentage of recovery. The proposed method was applied in the determination of Cu(II) and Pb(II) in a sample of raw river water and was validated by comparison with a standard reference material.