Phenanthrene Sorption onto Kaolinite; Heavy Metals and Organic Matter Effects

Several factors effect on sorption of polycyclic aromatic hydrocarbons (PAHs) in soil. Coexistence of metals and organic matter of soil are among important affecting factors on sorptive behavior of PAHs. This research investigated the effect of organic matter content and heavy metals (lead, nickel and zinc), on sorption of phenanthrene onto kaolinite. For this purpose, sorption of the organic matter to the kaolinite clay was investigated through batch experiments. Six types of soils in presence and absence of metals at different levels organic matter were prepared for assessment of phenanthrene sorption. Obtained data for phenanthrene sorption were well described by linear Freundlich isotherm. Making comparison between linear distribution coefficients (Kd) of phenanthrene for six prepared soils showed that heavy metals and organic matter can increase the sorption of phenanthrene. Heavy metals coexisting with organic matter have a synergic effect on phenanthrene Kd increment. A model to predict the sorption of phenanthrene onto kaolinite was developed and verified using obtained experimental data.