Hydrous ferric oxide as an adsorbent in water treatment: Part 1. Preparation and physical characterization

The preparation and physical characterization of granular ferric hydroxide as an adsorber of arsenic and other ionic species from aqueous solutions is discussed. The aim of the work is the preparation of granular ferric hydroxide in robust form using a temperature controlled freeze/thaw procedure. This procedure is described in detail and the physical properties of the derived material are compared with a commercially available product and a sample of granular ferric hydroxide prepared under ambient conditions. The importance of pH control, washing and dewatering are addressed and confirmed by SEM, XRD and nitrogen adsorption surface area measurements.