Bromate removal from aqueous solutions by nano crystalline akaganeite (β-FeOOH)-coated quartz sand (CACQS)

We investigated the feasibility of nano crystalline akaganeite (β-FeOOH)-coated quartz sand (CACQS) for bromate removal from aqueous solutions. Batch experiments were carried out as a function of various operational conditions such as adsorbent dosage (20–160 g/L), initial pH (3–12), contact time (1–240 min), initial bromate concentration (0.6–10 mg/L) and temperature (288 K, 298 K and 308 K). The uptake rate of bromate was rapid and the adsorption was almost saturated within 20 min. The adsorption kinetics can be described by the pseudo-second-order equation. The maximum adsorption capacity of the adsorbent for bromate removal was 37.8 μg/g at 298 K. The data fit well with the Langmuir model. Optimum bromate removal was observed between pH 3 and 10. Analysis of the adsorption thermodynamics showed that the adsorption of bromate by CACQS was spontaneous, exothermic and occurred due to physisorption.

► We used nano crystalline akaganeite-coated quartz sand (CACQS) for bromate removal.
► We make clear the necessary adsorption parameters for bromate removal by CACQS.
► The optimum bromate removal was observed over a wide pH range.
► The equilibrium time was short compared with other adsorbing materials.