Roles of solid components on the sorption of trichloroethylene (TCE) onto natural solids from the vapor phase

The sorption of trichloroethylene (TCE) from the vapor phase was investigated by batch sorption experiments. The role of solid components in natural solids was evaluated with a model solid phase system, consisting of six individual model solid phases (humic acid, montmorillonite, kaolinite, amorphous aluminosilicate gel, amorphous iron oxides, and amorphous manganese oxides) and two binary model solid phases (montmorillonite with amorphous aluminosilicate gel and montmorillonite with amorphous iron oxides). Experimental results indicated that swelling clays, which are represented by the montmorillonite, are a dominant sorbent in natural solids. The amorphous metal oxides of aluminosilicate and iron effectively block the sorption site of the swelling clay. The water associated with model solid phases (i.e., moisture content) reduces the sorption. The reduction rate, normalized with respect to the sorption onto each model solid phase of zero moisture content, is greater for the inorganic model solid phases than for humic acid. The sorption experiments with natural solids observed a greater reduction rate for the natural solid of low organic carbon content. Therefore, it was hypothesized that moisture content of the swelling clays in a natural solid is smaller than that of the organic matter.