Comparative kinetics and thermodynamic studies of fluoride adsorption by two novel synthesized biopolymer composites.

Fluoride (F-) contamination in water is of immense concern and has far-reaching effects. Among the many technologies available for fluoride removal, adsorption is the most popular. In this study, two new biopolymers (pectin and alginic) based trimetallic oxide (Fe-Al-Ni) composites were synthesized, characterized, and their suitability for fluoride adsorption has been evaluated. Fluoride adsorption capacity (Qe) and removal time were tested for contaminated water using both the adsorbents. The Qe of PFAN and AFAN was found to be 285 and 200 mg/g respectively, calculated from Langmuir isotherm. The investigation indicated that PFAN displayed a much higher Qe (285 mg/g) for F- than that of AFAN. The presented investigation is the first report in which pectin biopolymer-based trimetallic oxide composite is used for the adsorption study of F- ions from water. This study also illustrates that the pectin opens a new class of biopolymer composites with higher adsorption capacity as compared to presently used biopolymer-based composites.