Leaching laboratory studies

Soil monitoring data in the peer reviewed literature could not be located. It can be predicted that chloroform contamination occurs at hazardous waste sites where chloroform-containing leachate moves through the soil to groundwater. An explanation of the lack of data results from the fact that any chloroform in the soil is expected to either rapidly volatilize or leach. Laboratory studies using a variety of different soil types document the effectiveness of volatilization in removing chloroform from soils (Park et al. 1988). 

Dodd, D. J. R., Golomb, A., Chan, H. T. Chartier, D. 1981. A comparative field and laboratory study of fly ash leaching characteristics. In Conway, R. A. Malloy, B. C. (eds) Hazardous Solid Waste Testing First Conference, ASTM Special Technical Publication 760. ASTM, Philadelphia, PA, 164-185. 

Laboratory studies of leach rates would most conveniently be done on samples of about 1 g (. e. 0.1 to 10 g range) of waste-However the measurement of very low leach rates vlO ... 

Laboratory studies of tritium leaching from Sedan ejecta have shown that a front of almost undiluted soil water is pushed from a soil column when the column is leached with successive aliquots of water. A sample of ejecta was obtained from the maximum tritium zone at 4 feet on Sedan crater lip. This material was placed in four long glass columns, 72 mm. in diameter and 30 cm. long. Separate aliquots of water (equal to 1 inch of rainfall) were poured on the top of the soil columns each day. The column was allowed to drain, and each aliquot of leachate was collected daily and assayed for tritium. Figure 5 shows the elution of tritium from one of the large columns of Sedan ejecta. Each data point in Figure 5 represents the concentration of tritium in the daily collection of leachate. 

Note Values are in mg/kg except as indicated. All samples except the Bluewater Mill sample acquired their initial acidities and solutes because of pyrite oxidation. The Bluewater Mill tailings solution is derived from sulfuric acid leaching of uraniferous sandstone ore. Although listed as Fe(III), iron concentrations in the Bluewater Mill solution and Coal A leachate are total iron values. Except for Bluewater Mill and Coal A laboratory studies. Eh and pH values were measured in the field. All samples were filtered through 0A5foa filters prior to acidification, except for Well 201. 

Variations in p may be explained in light of the behavior of ferric oxyhydroxides in laboratory studies. The two ground waters in and adjacent to the outcrop area with pHs near 5 (wells 103 and 187) are supplied with H+ ions by reactions already noted. The acidity tends to leach away the less stable oxyhydroxides, raising pQ values close to 43. In the water from well 104 (pH = 5.64), precipitation is occurring at relatively low Fe2+ concentrations so that pQ is rather low (41.0). Comparatively high pQ values (42.5-42.9) are found with maximum ferrous... 

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