Batch extraction tests

TABLE III Percent separation yields obtained from HDEHP batch extraction tests on simulated and fully active HAW solutions... 

Thermodynamic calculations and batch extraction tests showed that the Np(IV)-Pu(IV) and Np(VI)-Pu(VI) systems are unstable for solution concentrations practical for solvent extraction. Products of radiolysis provide a mechanism for oxidation of Np(IV) and reduction of Np(VI) and Pu(VI). Batch extraction experiments showed that the reaction rates of destabilizing reactions are fast enough that the systems cannot be stabilized for a practicable time for plant processing (8). 

Figure 7. Basic steps involved in the standard batch hot-water flotation (batch extraction) test. (Reproduced from reference 52. Copyright 1989 Alberta Oil Sands Technology and Research Authority.)...

Figure 5. Illustration of the steps involved in determining the surface, interfacial, and other properties of dispersed bitumen drops, solid particles, and gas bubbles in aqueous solutions from batch extraction tests.

Natural Surfactants and Interfacial Properties. The action of the natural process surfactants has been studied in some detail [100-104]. The impact arises due to their adsorption at surfaces and interfaces, by which they alter surface electric charges and interfacial tensions. Figure 5 shows an example of the steps involved in determining the surface, interfacial, and other properties of dispersed bitumen drops, solid particles, and gas bubbles in aqueous solution. The samples analysed would be based on batch extraction tests involving different oil sand types and different process conditions. 

In order to validate the hypothesis mentioned above, the Ni retention capacity of the Lac Tio waste rock was estimated using a batch sorption test performed on a fresh (C1) and weathered (C4) sample, followed by a 3-step Sequential Extraction Procedure (or SEP). The batch sorption test was done using a 10 mg/L Ni solution with an initial pH of 6, an ionic force adjusted to 0.05 M with NaN03 and with a liquid/solid ratio of 25. Some of the batch sorption results are presented in Figure 3. 

The same statistical procedures were used here to evaluate the effects of humics on batch and continuous LLE. A base extraction procedure (19) was required for processing methylene chloride extracts prior to GC injection in order to protect the GC column from contamination by humics. This process led to losses of 2,4-dichlorophenol and the chlorinated biphenyls. Therefore, these compounds were not used in the evaluation of the CLLE in the presence of humics. All other compounds were not affected by the base extraction procedure. The ANOV procedure tested each compound for changes in concentration by comparing early batch extraction recoveries (from freshly prepared solution) to later ones (after the 12.5-L extraction). This process was done separately for Parts 1 and 2. It was therefore possible to test each compound for time-dependent decreasing concentration with and without the presence of humics. 

A test method for the batch extraction of treated or untreated solid waste or sludge, or solidified waste, to provide an indication of the leaching potential (ASTM D-5233) is also available. The goal of this test method is to provide an extract for measurement of the concentration of various analytes and therefore may be applied to a study of the smaller molecules that reside within the coal matrix. This test method, as written, is intended to provide an extract suitable for measurement of the concentration of analytes that will not volatilize under the conditions of the test method and may appear to offer limitations on the use of coal, but the test method does describe a procedure for performing a batch extraction of a solid. Again, the sampling and handling requirements that may be associated with the analysis of coal should also be applied to the method. 

ASTM D-5233. Standard Test Method for Single Batch Extraction Method for Wastes. 

Modolo, G., Asp, H., Schreinemachers, C., Vijgen, H. 2007. Development of a TODGA based process for partitioning of actinides from a PUREX raffinate Part I Batch extraction optimization studies and stability tests. Solvent Extr. Ion Exch. 25 (6) 703-721. 

Four bioassays a) 30 min acute bacterial test (Vibrio fischeri) b) 72h algal test (Pseudokirchneriella subcapitata) c) Acute (24h) and chronic (28d) crustacean test (Daphnia magna) d) 48h plate incorporation AMES test (Salmonella typhimurium his-with TA 97a, 98, 100, 102) Industrial solid waste leachates Batch leaching test with demineralized water followed by paper filtration (crude leachate), Liquid/liquid extraction (organic extract), lyophilization (lyophilized extract. pH adjusted according to tolerance of organisms and 0.22 pm filtration for AMES test... 

One useful aspect of the ISE approach is the ease with which selectivity testing can be performed. Once the polymer is employed as the active ingredient in a polymer membrane electrode, the binding can be examined by measuring the potential of a cell as outlined below. We have seen that the selectivity obtained by batch extraction procedures gives the same affinity series as that measured by using the polymer in an electrode [11]. 

An excess of allergen and labeled anti-IgE is used in the test in order to minimize interference by non-IgE antibodies. It should be remembered that the test is semiquantitative because the composition of allergen extracts can vary from batch to batch and test sera can contain IgE antibodies with a range of titers and avidities. 

Batch extraction of the particle fractions were performed using the U.S. EPA EP-toxicity test and a modified version developed in our laboratories. The 2 main differences in these tests are 1) the EP-toxicity test uses 0.5 N acetic acid to enhance leaching whereas the modified test uses 17.4 N glacial acetic acid and 2) the EP-toxicity test limits the amount of acid added to keep the pH at 5.0 + 0.5 to 40 ml so that the actual pH of the leaching medium may be well above pH 5.0 if additional acid is needed, whereas there was no limit as to how much 17.4 N acetic acid could be added to keep the pH at 5.0 + 0.5 in the modified test. The samples were placed on a shaker-table in a controlled temperature room (20 C) the pH was monitored and adjusted over a 24 hour period as specified in the EP-toxicity test procedure[ 9 ]. 

Since thermodynamic nonidealities are of the essence for phase separation in liquid-liquid systems, and such nonidealities contribute to multicomponent interaction effects, it may be expected that liquid-liquid extraction would offer an important test of the theories presented in this book. Here, we present some experimental evidence to show the significance of interaction effects in liquid-liquid extraction. The evidence we present is largely based on experiments carried out in a modified Lewis batch extraction cell (Standart et al., 1975 Sethy and Cullinan, 1975 Cullinan and Ram, 1976 Krishna et al., 1985). The analysis we present here is due to Ej-ishna et al. (1985). The experimental system that will be used to demonstrate multicomponent interaction effects is glycerol(l)-water(2)-acetone(l) this system is of Type I. The analysis presented below is the liquid-liquid analog of the two bulb gas diffusion experiment considered in Section 5.4. 

Quantitative and (hopefully, at least) qualitative considerations are helpful in characterizing a liquid-liquid system for a potential extraction application. Batch shakeout tests are frequently the easiest way to determine basic feasibility by simply measuring the primary and secondary break times and by analyses to measure the compositions of the equilibrated phases. Such tests are readily conducted by mixing small volumes of each phase in a vial, which is then vigorously agitated and placed on a lab bench to settle. The resulting behavior of the liquid-liquid mixture depends on physical properties and system characteristics. The greater the density difference and interfacial tension between the two liquid phases, for example, the more rapidly the phases tend to separate. More viscous systems separate more slowly. 

Some measurements have been reported (38) for froths produced using a standard lab-scale hot-water process simulation test, known as the batch extraction unit (BEU), shown in Figure 7 (52). The batch extraction unit described elsewhere (53) simulates the commercial hot-water flo-... 

Batch, recirculating batch, extractive semibatch, semicontinuous flow, continuously stirred tank (CSTR) and continuous packed bed reactors have alt been succesfully tested as enzyme reactors for SCFs (Figure 4.9-1). References to helpful descriptions for designing small-scale reactors for enzymatic studies are collected in Table 4.9-1. 

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