摘要 |
<p>A method is described for capturing ecologically harmful substances, both of organic and inorganic nature, by absorbing these substances on a zeolite or on a swellable, layered clay which has been modified with hydroxyaluminium to form an aluminium-rich zeolite or a pillared clay containing pillars of aluminium hydroxide complexes, said aluminium-rich zeolite or aluminium-pillared cationic or anionic clay having been treated, prior to the absorption, with a salt of an inorganic acid, preferably with a phosphate. If the treatment is carried out with a salt of a rare earth element, superpillars are formed in the clay, as a result of which a clay having a great absorbency in addition to a large rate of flow is obtained. By treating the pillared clay with a quaternary ammonium compound, a doubly modified clay is formed which is exceedingly suitable for treating material which has been polluted with a combination of organic and inorganic ecologically harmful substances, and in particular polluted with heavy metals.</p> |