Arsenic (III) removal from groundwater using orange residues: Efficiency and adsorption models under high-andean conditions

Pariguana-Castillo Y.Y.; Quispe-Ccallo N.G.; Vigo-Rivera J.E. · Tecnologia y Ciencias del Agua (2026) · DOI: 10.24850/j-tyca-2026-01-07

Resumen

The present study evaluated the adsorption isotherms of arsenic (III) with the biomass from orange waste (seeds, pulp, and peel) under high-altitude conditions. It begins with the extraction of the biomass from the orange waste and the determination of the As concentration in a groundwater sample from the southern area of Juliaca city, Peru. For the adsorption tests, the jar test apparatus was used (200 rpm for 2 hours), with an experimental statistical design of 3A x 4B; factor A (orange waste: A1 = peel, A2 = seed, and A3 = pulp) and factor B (waste mass: B1 = 2 g, B2 = 3 g, B3 = 4 g, and B4 = 5 g), at a pH of 5 in 500 ml beakers. The As (III) concentration was determined using the silver diethyldithiocarbamate method. Additionally, the biomass characterization was performed by X-ray fluorescence spectroscopy for the chemical composition analysis. The characterization results of the bioadsorbents showed higher amounts of calcium and calcium oxide. The best adsorption biomasses were obtained with 5 g of biomass for the seed (98.10 %) and pulp (97.89 %), and peel, which showed the best result with 4 g (97.59 %). The obtained data were modeled according to the Langmuir, Freundlich, and Temkin isotherm equations. The experimental data showed the best fit with the Langmuir model for all three biomasses in the adsorption process of As(III).

Instituciones: Universidad Peruana Unión