Retention of heavy metals (Pb, Cd, Cr and Zn) by a sand area of Agadir: Equilibrium and kineticR. Aba-aaki, M. Ez-zahery, S. Et-taleb, R. El Haouti, M.S. Hamma and N. El AlemMATEC Web of Conferences, 5 (2013) 04020DOI: https://doi.org/10.1051/matecconf/20130504020