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 (Q) and removal time were tested for contaminated water using both the adsorbents. The Q 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 Q (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.