Preparation of cellulose acetate supported zero-valent iron nanoparticles for the dechlorination of trichloroethylene in water

Chlorinated hydrocarbons are an immense concern for human health and the environment because they are highly toxic and are present in many contaminated sites. Zero-valent iron has been shown to be very effective for the dechlorination of chlorinated olefins and paraffins. This behavior is enhanced when the particle size is in the nanometer range. The activity of these nanoparticles is very high, and thus supporting the particles is important to preserve their chemical nature by inhibiting oxidation until they can be contacted with the chlorinated stream. In this paper, we present the preparation of membrane (cellulose acetate) supported zero-valent iron nanoparticles. The highly active nanoparticles were synthesized in a water-oil micro-emulsion, mixed with cellulose acetate-acetone solution, and then formed into a porous membrane by phase inversion. The unsupported iron particles and membrane supported iron particles were characterized using transmission electron microscopy. Batch experiments were conducted to characterize the activity of the supported zero-valent iron nanoparticles to dechlorinate trichloroethylene in water, as well as to investigate synergistic effects of the polymer support matrix.