An investigation into arsenic(V) removal from aqueous solutions by hydroxylapatite and bone-char

Abstract

AbstractArsenic(V) removal from aqueous solution following addition of either a mixture of synthetic hydroxylapatite and baryte or bone-char is discussed. Arsenic concentrations of 4, 10 and 100 mg/l were investigated and additions of 0.2—10 g/l of solid (hydroxylapatite, baryte or bone-char) were tested, at an initial pH of either 5 or 7. Although the mixture of hydroxylapatite and baryte had a small influence on arsenic concentrations, bone-char was found to be a very effective sorbing agent for arsenic(V). Packed-column studies to investigate the bone-char capacity, followed by leaching tests were carried out. The capacity of bone-char was found to be superior to that of granular activated carbon. The experiments presented here indicate that the mechanism involved is adsorption rather than co-precipitation.