Highlights
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- Recent developments in fluoride removal from water by adsorption are reviewed.
- Four technical strategies are proposed for designing of adsorbents.
- Transfering the adsorption process to industrial scale is urgently needed.
- Fluoride adsorption and desorption in field condition need further investigation.
Abstract
Fluoride contamination in water environment due to natural and artificial activities has been recognized as one of the major problems worldwide. Developing effective and robust technologies for excess fluoride removal from water environment becomes highly important. Among the commonly used treatment technologies applied for fluoride removal, adsorption technique has been explored widely and offers a highly efficient simple and low-cost process for fluoride removal from water. This review reports the recent developments in fluoride removal from water environment by adsorption methods. Studies on fluoride removal from aqueous solutions using various carbon materials are reviewed. It is evident that various adsorbents with high fluoride removal capacity have been developed, however, there is still an urgent need to transfer the removal process to industrial scale. Regeneration studies need to be performed in more extent to recover the adsorbent in field conditions, enhancing the economic feasibility of the process. Based on the review, four technical strategies of adsorption method including nano-surface effect, structural memory effect, anti-competitive adsorption and ionic sieve effect can be proposed. The design of adsorbents through these four strategies can greatly improve the removal efficiency of fluoride in water and provide guidance for the development of new efficient methods for fluoride removal in the future.
Graphical abstract
*Original abstract online at https://www.sciencedirect.com/science/article/abs/pii/S2213343720308654