Engineering Commons^™

Heavy Metal Adsorption On Iron Oxide And Iron Oxide-Coated Silica : Macroscopic, Spectroscopic, And Modeling Studies, Ying Xu

Dissertations

To accurately model metal mobility and bioavailability in soils and sediments, systematic sorption studies are needed using representative and well-characterized minerals. Two important surfaces are iron oxide and silica, which are ubiquitous and associated with one another in the environment playing important roles in metal distribution. The objectives of this research are to develop models for predicting speciation and mobility of toxic trace metal ions in groundwater, soils, and sediments when competing ions are present. A model system for soils and sediments, iron oxide-coated silica, was synthesized; the degree of coatings was highly sensitive to the particle size of silica …

Adsorption Capabilities Of Adsorbents For Selected Toxic Air Pollutants, Richard Michael Vaccaro

Theses

The relative adsorption capacities of seven toxic, volatile organic air pollutants of either proven or suspected carcinogenic potential were tested on various adsorbents. Tests were run at flow velocities similar to those set in field sampling. This allows for extrapolation of test results to actual ambient air sampling systems. Experimentation was performed using a gas chromatograph (G.C.) equipped with a flame ionization detector. Sample introduction was carried out using the "displacement method" where the sample is introduced to the adsorbent cartridge as a plug.

Incipient elution volumes (V_N), normalized for bulk adsorbent packing volume, were obtained at various …