Int. J. Environment and Sustainable Development, Vol. 11, No. 1, 2012 3 Copyright © 2012 Inderscience Enterprises Ltd. Mercury mobility and availability in highly contaminated solid wastes from a chlor-alkali plant Yailen Busto* Study Center of Applied Chemistry, Faculty of Chemistry and Pharmacy, Central University “Marta Abreu” of Las Villas, Camajuani Road, Km 5 1/2, 54830, Santa Clara, Villa Clara, Cuba E-mail: BustoYera.Yailen@ugent.be E-mail: yailenb@uclv.edu.cu *Corresponding author Filip Tack Department of Applied Analytical and Physical Chemistry, Ghent University, Coupure Links 653, B-9000 Ghent, Belgium E-mail: filip.tack@ugent.be Xiomara Cabrera Chemical Engineering Department, Faculty of Chemistry and Pharmacy, Central University “Marta Abreu” of Las Villas, Camajuani Road, Km. 5 1/2, 54830, Santa Clara, Villa Clara, Cuba E-mail: qfx@uclv.edu.cu Abstract: This article suggests an approach of sustainable development in Cuba based on the environmental impact assessment of mercurial sludge generated by a chlor-alkali Cuban plant. It consists of a study of mercury mobility and availability in the sludge samples using sequential extraction procedure. High values of total mercury content (2320 ± 40 mg/kg) in the sludge sample as well as in the toxicity characteristic leaching procedure (TCLP) extract (0.46 ± 0.02 mg/l) were obtained. The highest Hg concentration (52.2 ± 1.5%) was found in the mobile fraction (F1 + F2) indicating a high risk of Hg mobilisation by the presence of water-soluble and exchangeable mercury compounds such as HgCl 2 , HgSO 4 and HgO. The water-soluble fraction (F1) accounts for the 13.7 ± 0.8% of total Hg representing a significant environmental risk due to its easy availability in environmental weathering conditions. The mercury fractionation analyses clearly demonstrate that the chlor-alkali Cuban plant does not represent a sustainable technology from environmental point of view. Furthermore, this study highlights the presence of a wide range of mercury compounds which represents a significant parameter for developing a sustainable technology to treat the mercurial sludge generated by the chlor-alkali Cuban plant.