The sorption of Fe2+ onto unbleached kraft fibre was investigated at different conditions such as pH, temperature, and concentrations. The sorption, which increased with concentration and temperature, followed the Langmuir isotherm. Thermodynamically, the process was spontaneous and endothermic. It was found that the precipitation of Fe2+ was highly dependent on pH and reached 100% when pH exceeded similar to 8. (c) 2006 Elsevier Inc. All rights reserved.