Phyicochemical Processes Controlling Source Term from Tank Residuals

Abstract

Executive Summary: The research carried out under this EMSP program was aimed at developing spectroscopic probes for measuring diffusion of O 2 and H 2 O in porous media and simulated waste samples. The focus was on the preparation of silica and metallic based nanoparticles with reporter molecules or ions incorporated or attached as systems that could effectively probe diffusion of the systems of interest. During the research program we developed many new synthetic procedures for the production of nanoscopic silicas and metals. In fact we published a research article focused on the preparation of metallic nanoparticles using a completely green chemistry method. This paper literally started a novel area of research that other researchers are now following, namely, a totally green approach to the synthesis of metallic nanoparticles. This had not previously been accomplished although others had envisioned a method such as this, previous systems always relied on a passivation agent, a reducing agent or a solvent that was not environmentally benign. The particular system used metal ions, starch as a nanoparticle stabilizer and glucose as a metal reducing agent. This approach or modifications of it to prepare other nanomaterials will have a positive impact on the environment as nanomaterials become more widely used in consumer products. The metallic nanoparticle preparation, in particular is robust and produces particles that are dispersible in aqueous systems for years. To our knowledge this also is a significant accomplishment since the shelf-life of many nanoparticle systems is days