Desjardins, S.; J.A. Landry, J.P Farrant. 1999. Effects of Water and pH on the Oxidative Oligomerization of Chloro and Methoxyphenol by a Montmorillonite Clay. Journal of Soil Contamination. 8(2) : 175-195.
Abstract
It has long been known that clays and other soil fractions can catalyse the oxidative oligomerization of several organic contaminants. However, contaminants bearing deactivating substituents (i.e., -NO2 or -Cl groups) are reluctant to partial oxidation by clays. The objectives of the present research are to enhance the catalytic capacity of clays to partially oxidize such contaminants into oligomers. Laboratory results show that the addition of metallic iron and or nickel to clays - previously acid treated - enhance their catalytic capacities to oligomerize nitro and chloro aromatic compounds. Mass spectrometric results - as measured with a Liquid Chromatography / Mass Spectrometer - indicate that the products formed have molecular masses ranging from 300 to more than 900. It is believed that deactivating bearing group compounds first undergo a reduction (via acid and metallic iron and nickel addition) followed by partial oxidation by the clay mineral. Laboratory blanks indicate that clay minerals are essential for the partial oxidation process to occur. These products - by virtue of their sizes, partitioning coefficients and solubilities - are unlikely to migrate in soils.