Determination of fluoride biosorption from aqueous solutions using Sargassum hystrix algae

The aim of this study was to determine Sargassum hystrix algae’s efficiency in fluoride removal from aqueous solutions. In a series of batch experiments, the experimental parameters were studied using the dried algae: initial biosorbent dose (0.8–64 g/L), initial fluoride concentration while the mass of biosorbant dose (g/L) ratio to initial fluoride concentration (mg/L) was fixed at 5 ratios in the range of 400–8,000, contact time, pH, activation temperature and the presence of competing anions. The highest removal biosorption was at 40 g/L of biosorbent at 60 min contact time and initial fluoride concentration of 5 mg/L (100% fluoride removal); competing anions and activation temperature had no significant effect on the fluoride biosorption by biosorbent. The biosorption was found to be better fitted to the Freundlich model and follows a pseudo-second-order kinetic model. Finally, it was concluded that the Sargassum hystrix algae can be used as an environmental friendly, cheap and effective biosorbent from aqueous solutions.