Hydrous ferric oxide as an adsorbent in water treatment: Part 3: Batch and mini-column adsorption of arsenic, phosphorus, fluorine and cadmium ions

Freshly prepared granular ferric hydroxide using both a freeze/thaw and ambient temperature synthesis route are compared with a commercially available product for the adsorption of trace arsenic from water. The interference of competing ions, namely phosphate and fluoride has been studied in both batch and column mode. The effect of interfering anions is discussed in relation to the adsorption isotherms in the pH range 4–9. Also, breakthrough curves are examined to show the effect of anionic interference in packed column operation. The amphoteric nature of granular ferric hydroxide is illustrated by the adsorption of cadmium from water under controlled pH conditions.