Abstract
Thermal activation of attapulgite was investigated. Attapulgite calcined at 6000C was used as an adsorbent for heavy metals in AMD. The effect of solid loading, residence time and adsorption temperature was investigated. Activated attapulgite showed that it could remove more than 99% of Fe, Cu, Co and Ni from AMD. Langmuir isotherm gave the best fit for the adsorption process with maximum adsorption capacities of 8.97, 0.20, 0.32 and 0.32 for Fe, Ni, Cu and Co respectively. The adsorption of Cu and Ni was thermodynamically. The results show that thermally activated attapulgite has potential as an adsorbent for heavy metals from AMD.