Adsorption of endotoxin from aqueous solution using bone char.

The aim of this study is the removal of endotoxin from aqueous solution using bone char (BC) as an adsorbent material. The BC was prepared from cattle animal bone by pyrolysis in a furnace at 850 degrees C. The morphology and physico-chemical characteristics of the adsorbent were investigated. Kinetic studies revealed that the adsorption of endotoxin is rapid. The adsorption mechanisms in the endotoxin-BC had a significant contribution from film diffusion. The maximum adsorption efficiency achieved is 98% at an adsorbent dose of 40 g L(-1) with an initial endotoxin concentration of 80 Eu mL(-1). The results show that the Langmuir isotherm adsorption equation model describe the experimental adsorption isotherm with good accuracy. A survey of the regeneration capabilities showed that the BC could be regenerated and rendered endotoxin free by heating at 350 degrees C for 30 min. The results suggest that BC could be used as effective adsorbent for endotoxin removal.