Magnetic nanoparticles as an effective adsorbent for removal of fluoride–a review

Abstract

Fluoride concentration more than 1.5mg/L in drinking water can create various health issues and can lead to various human diseases. Adsorption is considered as one of the best technique for fluoride removal. Poor adsorption capacities, long contact time, high dosage, extremely low or high pH are the major drawbacks of various adsorption processes. In recent years several surface modified magnetic nanoparticles paves the way for effective removal of fluoride from water. The review fundamentally assesses the potential use of different surface modified magnetic nanoparticles (MNPs) for the effective removal of fluoride from contaminated water. High fluoride adsorption capacity of 91.04 mg/g at pH value of normal water is seen in case of Ce–Ti@Fe3O4 magnetic nanoparticle whereas the adsorption capacity of Zr based MNP is as high as 158 mg/g at very low water pH. Interestingly, Fe3O4 encapsulated Zr (IV)–poly (acrylamide) magnetic nanomaterials exhibit very high fluoride adsorption capacity of 124.5 mg/g in normal water. Though the magnetic assistance makes the whole separation process easy in using magnetic material adsorbent, there are still challenges like reusability, toxicity regarding the material selection, environmental impact etc.