Fluoride ion removal using amine modified polymeric resin: Batch and column studies

Abstract

The treatment of water containing pollutants by the solvent impregnated resin was found to be an effective method and caught the attention of the researchers. Here, the study was focused on the separation of fluoride ions from water using Aliquat-336 modified Amberlite XAD-4 resin in batch and continuous mode of operation. Batch studies were conducted to see the impact of resin dosage (2.5–27.5 g/L), pH (2–12), time (0–120 min), temperature (298–323 K), and initial fluoride concentration (1.8–13 mg/L) on the capability of the resin. Freundlich isotherm (R2 = 0.986) and pseudo-second-order model (R2 = 0.999) matched the equilibrium and kinetic data, respectively. Column experiments were designed using the two-level full factorial design considering inlet fluoride concentration (5–10 mg/L), volumetric flow rate (3–5 mL/min), and length of the bed (3–5 cm) as the design variables, and their effect was studied on the breakthrough time, saturation time, and effluent volume. Three regression models were obtained to predict the characteristics of the breakthrough curve with R2 close to one. The Thomas model (R2 = 0.952) best explained the trend of the breakthrough curve. The p-values (p less than 0.05) obtained using MINITAB software indicates that all the prime factors (coF,QandH) affect the breakthrough time.