ИСТИНА

Focus of study was on determination of surface charge characteristics of clay grounds while creating protective electrokinetical barriers from them. Electrokinetical barrier represents clay barrier at which opposite walls potential difference is created. The barrier works on the way of toxicant migration as a semipermeable diaphragm what binds toxicants and passes water. Electrokinetical properties of studied clays were characterized by point of zero charge (p.z.c.), point of zero net proton charge (p.z.n.p.c.) and ζ-potential values of clay particles at different pH. Three types of clay grounds were studied: kaolinite, illite and smectite. Suspensions of the above clays were studied by microelectrophoresis and acid-base potentiometric titrations. It is established that clay barrier adsorbs essentially cationic toxicants at pH>p.z.c. and it bounds anionic toxicants at pH<p.z.c. Therefore barriers made of Cambrian illite clay may be used for protection from alkali toxicants. Makharadzian montmorillonite is efficient to use in protective barriers against acidic toxicants.