Biogenic Material With Iron Nanoparticles for As(V) Removal

Abstract

In this work, the chemical conditioning of the pineapple peel and its subsequent pyrolysis process to obtain a carbonaceous matrix fitted with iron nanoparticles are presented. The material was characterized by different analytical techniques, and the sorption capacity of As(V) in aqueous phase was evaluated. The pineapple peel (PP) was analyzed by neutron activation analysis (NAA), showing the presence of elements such as Al, Br, Ce, Co, Cr, Cs, Eu, Hf, K, Mg, Mn, Na, Rb, Sb, Sc, and Zn. These elements are involved in the sorption process of As(V), forming active sites on the surface. By means of the chemical conditioning of the pineapple peel and after a pyrolysis process of 650 °C, an amorphous carbonaceous material (C-180) was obtained with spherical nanoparticles distributed homogeneously on the surface with an average diameter of 39 nm, specific area of 167 m2/g with 7 ± 1 sites/nm2, and isoelectric point of pHi = 11. The maximum percent removal was 77.39% with a maximum retention capacity of 5.73 mg of As/g and an initial concentration of 30 mg/L. The isotherm in relation with the concentration was adjusted to the Freundlich model, indicating that the sorption is carried out through a multilayer chemisorption process, in specific active sites and in a heterogeneous medium.