Effective removal of fluoride ions from aqueous solution by marine microalgae as natural biosorbent

Abstract

In this study, the phytoremediation technology from marine source Dunaliella salina was chosen to eliminate fluoride ions from aqueous solution by Adsorption isotherm, Kinetics and RSM optimization methods. Marine microalgae were collected, identified and mass cultured then its physical characteristics, functional groups and surface microstructure was examined by FT-IR, NMR, XRD and SEM analysis also the same was performed on post treated bioadsorbent. Fluoride removal was optimized by different conditions through response surface methodology and kinetics modelling also performed. Several active functional groups were noticed in IR spectra and NMR of pre and post treated microalgal biosorbent. Many micropores, crystalline structure, voids were observed in pre-treated and lesser in post treated bioadsorbent, removal process was optimized by temperature, pH, dose and time and its showed high influence of removal process. The fluoride removal process was optimized by response surface methodology, Langmuir Isotherm, Freundlich Isotherm, Temkin isotherm, Pseudo I order, Pseudo II order and Intra particle diffusion and revealed that the F ions removal mechanism clearly. Microalgae are novel, low-cost and effective bio based innovative methods which are sustainable for the bioremediation of fluoride from water bodies and industrial wastewaters.