摘要 |
<p>A process of immobilizing environmentally noxious organic, particularly aromatic, substances by absorbing same on a layered clay mineral modified by exchange with a quaternary ammonium compound, thereby increasing the spacing between the layers and rendering the adsorption surfaces hydrophobic. After adsorption of the organic compounds the spacing between the layers of the layered clay mineral is reduced by a layer spacing reducing agent, and subsequently the clay mineral comprising the organic compounds is mixed with a hardenable inorganic binder and the whole is hardened. A typical example of a modifying agent is a quaternary ammonium compound, and of a layer spacing reducing agent an alkaline substance, such as sodium hydroxide. Typical clay minerals are chosen among the smectite minerals, tectosilicates and phyllosilicates, preferably monthmorillonite clay is used. The inorganic binder may be a calcium hydroxide compound or a calcium containing cement, preferably containing fly ash.</p> |