Characterization leaching tests

As an example of such an integrated approach, a case study is reported in which a soil from a former smelter and scrapyard was investigated. The case study demonstrates the importance of an investigative approach that employs a range of analytical techniques to evaluate toxic metal distribution and mobility. It showed that total element analyses of separated size fractions, characterization leaching tests such as sequential extractions, and detailed electron microscope analysis can provide complementary information on the location and chemistry of toxic metals in soils. 

Dacheux, N., Thomas, A. C., Chassigneux, B., Pichot, E., Brandel, V. Genet, M. 1999. Study of Th4(P04)4P207 and solid solutions with U(IV), Np(IV) and Pu(IV) Synthesis, characterization, sintering and leaching test. Materials Research Society Symposium Proceedings, 556, 85-92. 

Present leaching behaviour can be characterized, although the applicability of many leach tests with fly ash is doubtful. Special tests are often more appropriate. For example, Fig. 5 shows a simple packed bed, through which lea-chant percolates and which acts like a lysimeter leachate can be sampled periodically through the... 

MCC-1 Static Leach Test, Materials Characterization Center, submitted to the Materials Review Board, by Pacific Northwest Laboratory, Operated for the U.S. Department of Energy by Battelle Memorial Institute,... 

Briefly recalled, the WASTOXHAS approach consists in characterizing the ecotoxicological hazard potential of contaminant fluxes from waste leachate obtained under defined conditions with two different dynamic leaching procedures laboratory simulated leaching tests and field leaching tests. The approach developed below considered a specific scenario that simulates a waste deposit receiving rain or run-off water (Perrodin et al., 2002). 

J. Sa-nguanruksa, R. Rujiravanit, P. Supaphol, and S. Tokura, Porous polyethylene membranes by template-leaching technique preparation and characterization. Polymer Testing 23, 91-99 (2004). 

Regarding procedures for characterization of waste, harmonization on various objectives and leaching/extraction test methods is undertaken by European Standardization Network CEN, Technical Committee (TC) 292, and a distinction is made between three types of leaching tests which will be applied in different circumstances (Van der Sloot et al. 1997, Van der Sloot 1998, 2002) ... 

Actually basic characterization tests are developed as standards combining percolation test and pH static leach test. 

For applications in the rain trap system, the results of the EPA s toxicity characterization leaching procedure (TCLP) indicate that none of the tire products tested exceeds proposed TCLP regulatory levels. Most compounds detected are found at trace levels, (near method detection limits), from 10 to 100 times less than TCLP regulatory limits and U.S. EPA drinking water standard maximum contaminant level (MCL) values. The Florida Department of Environmental Regulation released its final report on tire teachability in potential usage environments. The study, which evaluates the leachability of shredded tires in different aquatic environments, finds that scrap tires pose no harmful effects when used in applications that are above the water table [14]. 

US-EPA provides two leaching test methods. One is the Toxicity Characteristic Leaching Procedure (EPA SW 846 Method 1311), and is called the TCLP for short. The other is the Synthetic Precipitation Leaching procedure (EPA SW—846 Method 1312), and is called the SPLP. The TCLP is intended to simulate dissolution of waste materials inside a landfill, and is the only leaching test specified by the regulation for characterization of the hazardous waste (40 CFR 261.24 Toxicity Characteristic, waste code D004-D043) under the Resource Conservation and Recovery Act (RCRA). 

F. Castro and G. Pereira Characterization of the Nickel Laterite Sample and Guidelines for Column Leach Tests Project AMIRA P986, (Vale Mineral Development Center, Brazil, 2009). 

Modified hotocatalysts were prepared using commercial and synthesized Ti02. The modification was carried out in two different methods, i.e. platinization with H2PtCl6 solution and metallization with leached solution from wasted catalytic converter. They were characterized by UV-DRS, BET, and XRD and tested their catalytic performance for decomposition and oxidation of TCE in liquid phase. 

Since mild activation conditions appear to be important, a number of solution activation conditions were tested. PAMAM dendrimers are comprised of amide bonds, so the favorable conditions for refro-Michael addition reactions, (low pH, high temperature and the presence of water) may be able to cleave these bonds. Table 1 shows a series of reaction tests using various acid/solvent combinations to activate the dendrimer amide bonds. Characterization of the solution-activated catalysts with Atomic Absorption spectroscopy, FTIR spectroscopy and FTIR spectroscopy of adsorbed CO indicated that the solution activation generally resulted in Pt loss. Appropriate choice of solvent and acid, particularly EtOH/HOAc, minimized the leaching. FTIR spectra of these samples indicate that a substantial portion of the dendrimer amide bonds was removed by solution activation (note the small y-axis value in Figure 4 relative... 

The physical properties of lead and several of its compounds are listed in Table 3-2. Lead readily tarnishes in the atmosphere but is one of the most stable fabricated metals because of its corrosive resistance to air, water, and soil (Howe 1981). A waste that contains lead or lead compounds may (or may not) be characterized a hazardous waste following testing by the Toxicity Characteristic Leaching Procedure (TCLP) as prescribed by the Resource Conservation and Recovery Act (RCRA) regulations. 

The supported aqueous phase methodology was applied to the system Pd(OAc)2/5 TPPTS, a catalytic precursor for the Trost-Tsuji reaction. The characterization of the solid by 31P MAS NMR confirms the presence of Pd°(TPPTS)3 as the main surface species. The catalytic properties of the solid were tested for the allylic substitution of E-cinnamylethylcarbonate by different nucleophiles such as ethyl acetoacetate, dimethyl malonate, morpholine, phenol, and 2-mercapto-pyridine. The absence of palladium leaching was demonstrated, and having solved the problem of water leaching from the solid to the organic phase, the SAP-Pd catalyst was successfully recycled several times without loss in its activity. It was used in a continuous flow experiment which... 

The diffusion coefficient Dx can be expressed as a function of the concentration of the specific constituent in the pore fluid [158]. Figure 8 shows four relationships between the non-dimensional pollutant concentration and Dn (the molecular diffusion coefficient). These show the strong influence from both in characterizing the shape of the relative pollutant concentration profile. Leaching-column test information shows that case (4) in Fig. 8 is the more likely profile (i.e., Dn= ae bc). Using this function in Eq. (90), the final governing equation for (X)+ will be ... 

EN 12457-1 (2003) Characterization of waste - Leaching - Compliance test for leaching of granular waste materials and sludges - Part 1 One-stage batch test at a liquid to solids ratio of 2 L/kg for materials with high solids content and with a particle size below 4 mm (with or without size reduction), CEN/TC292/WG2, European Committee for Standardization, Brussels. 

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