ELECTROKINETIC CHARACTERISTICS OF SOME METAL SULFIDE WATER INTERFACES

Electrokinetic characteristics of some environmentally important metal sulfides, namely, ZnS(s), CdS(s), PbS(s), PbS(s), HgS(s), CuS(s), Cu2S(s), FeS(s), FeS2(s), COS(s), MoS(s), Sb2S3(s), As2S3(s), MoS(s), and S(s), were studied. Most metal sulfides have less than 3.O isoelectric point (IEP) values. The electrical double layer (EDL) structures of ZnS(s), CdS(s), and HgS(8) were investigated further. Various factors that may affect the electrokinetic behaviors of metal sulfides were studied. Crystal structure, crystal field stabilization energy, and the ratio of cationic charge to ionic radii, Z/R, were found to affect IEPs, in a way analogous to that of metal oxides.