Fluoride ions sorption using functionalized magnetic metal oxides nanocomposites: a review

Abstract

Fluoride is an anionic pollutant found superfuous in surface or groundwater as a result of anthropogenic actions from improper disposal of industrial efuents. In drinking water, superfuous fuoride has been revealed to trigger severe health problems in humans. Hence, developing a comprehensive wastewater decontamination process for the efective management and preservation of water contaminated with fuoride is desirable, as clean water demand is anticipated to intensify considerably over the upcoming years. In this regard, there have been increased eforts by researchers to create novel magnetic metal oxide nanocomposites which are functionalized for the remediation of wastewater owing to their biocompatibility, costefectiveness, relative ease to recover and reuse, non-noxiousness, and ease to separate from solutions using a magnetic feld. This review makes an all-inclusive efort to assess the efects of experimental factors on the sorption of fuoride employing magnetic metal oxide nanosorbents. The removal efciency of fuoride ions onto magnetic metal oxides nanocomposites were largely infuenced by the solution pH and ions co-existing with fuoride. Overall, it was noticed from the reviewed researches that the maximum sorption capacity using various metal oxides for fuoride sorption was in the order of aluminium oxides >cerium oxides > iron oxides > magnesium oxides> titanium oxides, and most sorption of fuoride ions was inhibited by the existence of phosphate trailed by sulphate. The mechanism of fluoride sorption onto various sorbents was due to ion exchange, electrostatic attraction, and complexation mechanism.