Method of removing organic contaminants from air and water with organophilic, quaternary phosphonium ion-exchanged smectite clays

A method to prevent organic contaminants from reaching ground water supplies by disposing a quaternary phosphonium ion-exchanged clay within or on the soil, or within a bentonite clay water barrier, to prevent the penetration of petroleum-based contaminants through the clay, the ion-exchanged clay including a quaternary phosphonium ion-exchanged cation of the formula:

• ##STR6## wherein X.sup.- is selected from the group consisting of Cl.sup.-, Br.sup.-, and I.sup.- ;
• wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are organic moieties selected from the group consisting of short chain alkyl moieties (C.sub.1 -C.sub.4);
• long chain alkyl moieties (C.sub.4 -C.sub.20);
• substituted alkyl moieties having 1 to about 20 carbon atoms;
• substituted or unsubstituted cycloalkyl moieties;
• substituted or unsubstituted aryl moieties;
• substituted or unsubstituted alkaryl moieties;
• alkenes;
• alkynes;
• aldehydes;
• ketones;
• alcohols;
• carboxylic acids;
• esters;
• ethers;
• cyclic ethers;
• and combinations thereof.