Abstract: A novel modified clay sorbent and method of treating industrial effluents to remove trace pollutants, such as dioxins, biphenyls, and polyaromatics such as benzo(a)pyrene and pentachlorophenol. The novel clay sorbent has a composite structure in which the interlayer space of an expandable clay, such as smectite, is filled with polyvalent or multivalent inorganic cations which forces weaker surfactant cations to locate on the surface of the clay in such an orientation that the resulting composite is hydrophilic in nature. A specific example is cetylpyridinium-hydroxy aluminum-montmorillonite. In certain embodiments, a non-expanding clay, such as kaolinite, is used and surfactant cations are necessarily located on an external surface of the clay. A specific example is cetylpyridinium-kaolinite.

Abstract: Modified clay is a general purpose sorbent for the removal of trace organic pollutants from process effluent streams. An expandible smectite clay, such as montmorillonite, is placed in an aqueous suspension to expand the layers. The expanded clay is then treated with an excess of a solution of hydroxy-aluminum, in particular, a hydroxy-aluminum solution having an OH.sup.- /Al ratio of about 2.54 and a pH in the vicinity of 4.5. The weight of clay to volume of hydroxy-aluminum solution may vary from about 1:10 and 1:25. The treated clay is filtered, washed, dried, and powdered by techniques well known in the art, and then the entire treatment sequence is repeated. The modified, powdered clay removes organic pollutants from industrial effluent in the ppb-ppq range. In particular, the modified clay is useful in removing traces of PCBs and Dioxin.