Kinetics and isotherms of adsorption of arsenic (III) in aqueous solution using activated carbon with nanoporous structure obtained from organic sewage sludge

Cayo-Dominguez R.; Montalvo-Achic-Huamán C.; Pampa-Quispe N.B. · Tecnologia y Ciencias del Agua (2023) · DOI: 10.24850/j-tyca-14-06-01

Resumen

The objective of this investigation was to study the process of absorption of As (III) ions through activated carbon nanopores derived from organic sewage sludge. The adsorption tests were carried out by placing 16 g/l of activated carbon in contact with solutions of 0.247, 0.406, 0.564, 0.683 and 0.801 mg/l of As (III) in 1L beakers at a time of 24 hours. All the tests were submitted to an agitation speed of 720 RPM, a temperature of 28 °C ± 0.5 °C and the natural pH of the samples. The results of carbon characterization show that this absorbent presented a nanoporous structure with the presence of functional groups (hydroxyl and carboxyl). As for the As (III) adsorption tests, it was determined that activated carbon managed to reduce the metal concentration to 0.004 mg/l, a value that is below those established by the World Health Organization (WHO) for water consumption. Finally, it was concluded that activated carbon showed a 98.4 % efficiency in the absorption of As (III) ions and the experimental data presented a bigger adjustment to the pseudo-second-order model and to Freundlich isotherm, which indicates that the process of absorption of As (III) ions is done in strongly heterogeneous centers through a physical-chemical interaction between the metal and the absorbent.

Instituciones: Universidad Nacional de Juliaca; Universidad Peruana Unión