Experimental study of the adsorption of fluoride by modified magnetite using a continuous flow system and numerical simulation Article uri icon

abstract

  • This study used fixed-bed column experiments to examine the potential and effectiveness of modified magnetite with aluminum or lanthanum to remove fluoride ions from fluoride solutions and drinking water. A fixed bed column test was conducted to simulate the actual condition of adsorption in a continuous manner in a filtration process. Fixed-bed column experiments were carried out at a bed depth of 1.3 cm and a flow rate of 1 mL min−1. The breakthrough curves obtained for fluoride ion adsorption from aqueous solutions and drinking water were fitted to Thomas, Bohart–Adams, Yoon and Nelson, and Yan models. The significant influence of bed height, flow rate, empty bed contact time, and initial fluoride concentration on removal were used for simulation of breakthrough curves. The impact of common ions present in drinking water on the adsorption of fluoride was investigated. The regeneration of the column was performed by eluting with 0.01 M Ca(OH)2, NaCl, NaOH or Na2SO4 solution after the adsorption studies. Thomas, Yoon–Nelson and Yan models were found suitable for the normal description of breakthrough curves in the experimental conditions, whereas the Adams–Bohart model was able to explain only the initial part of the dynamic behavior of the column system. Simulation results indicate that the breakthrough point (tp) decreases as the flow rate and initial fluoride concentration increase, and bed height is directly proportional to fluoride removal. It was concluded that modified magnetite can be effectively used as a sorbent for the removal of fluoride ions. © 2017 Institution of Chemical Engineers

publication date

  • 2017-01-01