EXECUTIVE SUMMARY Savannah River National Laboratory (SRNL) performed a series of laboratory-scale experiments that examined copper-catalyzed hydrogen peroxide (H 2 O 2 ) aided destruction of organic components, most notably tetraphenylborate (TPB), in Tank 48H simulant slurries. The experiments were designed with an expectation of conducting the process within existing vessels of Building 241-96H with minimal modifications to the existing equipment.Results of the experiments indicate that TPB destruction levels exceeding 99.9% are achievable, dependent on the reaction conditions. The following observations were made with respect to the major processing variables investigated. A lower reaction pH provides faster reaction rates (pH 7 > pH 9 > pH 11); however, pH 9 reactions provide the least quantity of organic residual compounds within the limits of species analyzed. Higher temperatures lead to faster reaction rates and smaller quantities of organic residual compounds. A processing temperature of 50 °C as part of an overall set of conditions appears to provide a viable TPB destruction time on the order of 4 days. Higher concentrations of the copper catalyst provide faster reaction rates, but the highest copper concentration (500 mg/L) also resulted in the second highest quantity of organic residual compounds. The data in this report suggests 100-250 mg/L as a minimum. Faster rates of H 2 O 2 addition lead to faster reaction rates and lower quantities of organic residual compounds. An addition rate of 0.4 mL/hour, scaled to the full vessel, is suggested for the process. SRNL recommends that for pH adjustment, an acid addition rate 42 mL/hour, scaled to the full vessel, is used. This is the same addition rate used in the testing. Even though the TPB and phenylborates can be destroyed in a relative short time period, the residual organics will take longer to degrade to <10 mg/L. Low level leaching on titanium occurred, however, the typical concentrations of released titanium are very low (~40 mg/L or less). A small amount of leaching under these conditions is not surprising and is consistent with a previous study. Analyses of the post-reaction residual material indicate that slurry initially adjusted down to a pH 7 produced a greater degree of energetic material than material initially adjusted to a pH of 9. 2 No more than 140 g/m 3 of mercury was indicated in reactor head spaces at anytime. An estimation of less than 1% of the initial mercury was vaporized in each experiment. A limited number of replicate tests were performed to determine experimental reproducibility. These tests indicate a reasonable degree of reproducibility.The conclusion of the simulant testing has provided a set of reaction conditions that can destroy the TPB and phenylborates quickly. While longer times will be required to degrade the residual organics, the reactions appear to perform in a consistent manner. A real waste test or tests are recommended and further investigation into the use of phosphoric or formic acid is warranted.
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