Mamey Apple Peel for Cr³⁺ Removal from Contaminated Waters

The aim of this study was to evaluate the capacity of an adsorbent based on mamey apple (Mammea americana L.) peel for Cr³⁺ removal. Aqueous mediums based on distilled water and different initial concentrations of Cr³⁺, with a dose of 10 g of adsorbent per liter, were used. The residual concentrations of Cr³⁺ were determined by atomic absorption spectrophotometry, obtaining optimum values of pH of 2.9, the adsorbent particle size of 300 µm, and stirring rate of 300 rpm, for Cr³⁺ removal. Kinetic studies indicate a chemical adsorption process, with the best adjustment to pseudo-second-order models (R² ≥ 0.9973), a contact time of 120 min to reach the adsorbent-Cr³⁺ equilibrium, and a good fit to the Freundlich model (R² = 0.9291), with an adsorption intensity n of 1.5876. So, our results suggest that Cr³⁺ ions can be efficiently removed by using mamey apple peel-adsorbent.