Characterization, Leaching, and Filtration Testing for Tributyl Phosphate (TBP, Group 7) Actual Waste Sample Composites

Abstract

The tributyl phosphate sludge (TBP, Group 7) is the subject of this report. The Group 7 waste was anticipated to be high in phosphorus as well as aluminum in the form of gibbsite. Both are believed to exist in sufficient quantities in the Group 7 waste to address leaching behavior. Thus, the focus of the Group 7 testing was on the removal of both P and Al. The waste-type definition, archived sample conditions, homogenization activities, characterization (physical, chemical, radioisotope, and crystal habit), and caustic leaching behavior as functions of time, temperature, and hydroxide concentration are discussed in this report. Testing was conducted according to TP-RPP-WTP-467. ObjectivesThe test objectives are summarized in Table S.1 along with a discussion of how the objectives were met. Several objectives (in gray shading lighter than header shading) did not specifically apply to the scope provided in this report; they will be reported in companion reports as indicated in the controlling test plan. Y Group 7 contained a significant amount of P. The P behavior for the Group 7 composite during caustic leaching was characterized as a function of time, temperature, and free-hydroxide concentration.The P removal results can be found in Sections 3, 4, and 5.6) Determine the ultrafiltration flux before and after caustic and oxidative leaching over the operating range of solids concentrations during the leaching processes at 25°C when sufficient actual waste sample is available for testing the filtration behavior.Y Ultrafiltration (CUF) testing was performed on the Group 7 solids. The CUF testing was performed before leaching using slurries with both low-and high-solids contents. The high-solids slurry was obtained by blending wastes from AY-102 with the Group 7 slurry. Further CUF testing was performed after caustic leaching. During these tests, the ultrafiltration flux was determined as a function of transmembrane pressure and axial velocity. The CUF tests were conducted at ambient temperature. There was no oxidative leach performed on this waste type; therefore, there was no CUF testing done on post oxidative-leach materials.All the CUF testing results are discussed in Section 5. The solids characterization results are distributed throughout the report at the specific relevant sections. Test ExceptionsNo test exceptions applied to this work. Results and Performance Against Success CriteriaThe test plan delineated several success criteria, which are listed in Table S.2. Selected criteria were relevant to the test scope included in this report; the other criteria that are outside of the reported scope are shaded. Not applicable. The Group 7 sample did not have significant amounts of boehmite.5) The dissolution rate and the extent of dissolution of chromium in the actual waste solids are determined as a function of temperature and over a range of NaOH concentrations of interest to oxidative leaching. The NaMnO 4 dosage will be predetermined for the oxidation of the chromium in the waste solids. The associated uncert...

Properties Important to Mixing for WTP Large Scale Integrated Testing

“…22,36,37,38,39 This hysteresis has been cited as potential evidence for time-dependent rheological behavior of Hanford wastes. 37,38,39 The IP suggests that the LSIT program could consider the progressive variation in the degree of thixotropic and rheopectic behavior as potential characteristics to explore during Limits of Performance testing.…”

“…37 This is not an unusual amount of flow curve hysteresis for a slurry sample, particularly for systems containing a significant fraction of large particles. A subsequent flow curve of the Group 7 sample at 60 °C instead of 25 °C showed almost no hysteresis.…”

Filtration Understanding: FY10 Testing Results and Filtration Model Update

“…Destructive analysis of the filter was necessitated, in part, by observations of irreversible filter fouling in actual waste testing (Lumetta et al 2009;Edwards et al 2009;Fiskum et al 2009;Shimskey et al 2009a;and Shimskey et al 2009b), in integrated PEP testing , and in the current testing (see Section 5.2). The rationale for destructive testing shall be provided in the conclusions to this report.…”

“…It should be noted that if the assumed best flux for PEP were taken to be lower than 0.1 GPM/ft², then the deviation in initial flux caused by a 1 GPM/ft² would be lower. This is important, as initial filter flux for actual Hanford wastes generally fall below 0.1 GPM/ft² Edwards et al 2009Shimskey et al 2009b;Lumetta et al 2009). As such, the estimated 14% deviation from ideal waste or simulant associated with a 1 GPM/ft² benchmark may be conservative such that deviation for actual waste slurries may be less.…”

Crossflow Filtraton: Literature Review

“…One slurry consisted mostly of tributyl phosphate and was initially at a solids loading of 10 wt% UDS (Edwards et al, 2009). The leaching process in this experiment was carried out at temperatures ranging from 40 to 80ºC with sodium concentrations between 0.25 and 3 molar.…”