“…Kaolinite, montmorillonite, and their poly and tetra butyl ammonium derivatives were used for removing Cd (II) from aqueous solution [11]. The removal of metal ions from aqueous solutions by adsorption has been reported by various studies: Pb(II), Zn(II), Cd(II), and Cu(II) onto natural clay [12]; radio nuclides (137Cs) on kaolinite [13]; Pb(II), Cu(II), Fe(III), Mn(II), and Zn(II) onto kaolinite clay [14]; Cd(II), Cu(II), Pb(II), and Zn(II) onto waste calcite sludge [15]; Zn(II), Cd(II), Pb(II), and Cu(II) onto natural Jordanian zeolite [16]; Pb(II), Cu(II), Cd(II), and Ni(II) onto Iranian natural zeolite [17]; Pb(II) and Cd(II) onto clay mineral beidellite [18]; and Zinc(II) onto modified Brazilian gray clay [19].…”