Preparation of alumina-supported Fe-Al-La composite for fluoride removal from an aqueous matrix

• Published in: Environmental science and pollution research international 2023-03, Vol.30 (14), p.42416-42426
• Main Authors: Gasparotto, Juliana M., Pinto, Diana, de Paula, Natalie, Maraschin, Manoel, Franco, Dison S. P., Carissimi, Elvis, Foletto, Edson L., Jahn, Sergio L., Silva, Luis F. O., Dotto, Guilherme L.
• Format: Article
• Language: English
• Subjects: Adsorbents; Adsorption; Adsorptivity; Aluminum oxide; Aluminum Oxide - chemistry; Aquatic Pollution; Aqueous environments; Atmospheric Protection/Air Quality Control/Air Pollution; Drinking water; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Fluorides; Fluorides - chemistry; Groundwater; Humans; Hydrogen-Ion Concentration; Iron; Kinetics; Legislation; Research Article; Spectroscopy, Fourier Transform Infrared; Surface chemistry; Surface water; Waste Water Technology; Water; Water consumption; Water Management; Water Pollutants, Chemical - chemistry; Water Pollution Control; Water Purification; Water resources
• ISSN: 1614-7499; 0944-1344; 1614-7499
• DOI: 10.1007/s11356-023-25231-1

Using groundwater for human consumption is an alternative for places with no nearby surface water resources. Fluoride is commonly found in groundwater, and the consumption of this water for a prolonged time in concentrations that exceed established limits by WHO and Brazilian legislation on water potability (1.5 mg L −1 ) can cause harmful problems to human health. For this reason, fluoride removal is an important step before water consumption. In this work, activated alumina was impregnated with Fe-Al-La composite and employed for the first time as an adsorbent for fluoride removal from an aqueous environment. XRD, SEM/EDS, FT-IR, and point of zero charge were used to characterize the prepared adsorbent. The adsorptive performance of adsorbent material was investigated by employing a 2 3 -central composite design (CCD), and the obtained experimental conditions were pH = 6.5 and adsorbent dosage = 3.0 g L −1 . A maximum adsorption capacity of 8.17 mg g −1 at 298 K and pH = 6.5 was achieved by Langmuir isotherm to describe the adsorption. The kinetic model that better described experimental data was Avrami, with the k av parameter increasing with the initial concentration from 0.076 to 0.231 (min −1 ) n av . The nature of adsorption was found to be homogeneous, and it occurs in a monolayer. The fluoride removal performance for the prepared adsorbent was higher than granular activated alumina, showing that supporting Fe-Al-La at the alumina surface increased its fluoride adsorption capacity from 16 to 42% at the same experimental conditions. Finally, the influence of co-existing ions Cl − , SO 4 2− , and NO 3 − was evaluated in fluoride adsorption, and the material presented great selectivity to fluoride. Thus, Fe-Al-La/AA adsorbent is a promising material for fluoride removal from water. Graphical Abstract