Migration of Heavy Metals in Saturated Sand and Bentonite/Soil Admixture |
| |
| Authors: | Irene M. C. Lo Alex F. T. Luk Xiaoyun Yang |
| |
| Affiliation: | 1Associate Professor, Dept. of Civil Engineering, The Hong Kong Univ. of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
2Graduate Student, Dept. of Civil Engineering, The Hong Kong Univ. of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
|
| |
| Abstract: | Heavy metal migration through compacted, saturated sand and bentonite/soil admixtures were investigated using kinetic, batch sorption tests, and column tests. Sorption of Pb, Zn, and Cd at pH 5 by bentonite is found to be 411.2, 163.4, and 71.8 mL/g, respectively. The permeability of the compacted sand (8×10?4?cm/s) is found to be 6 orders of magniture higher than that of bentonite/soil admixture (about 8×10?10?cm/s) when permeated with metal solutions under an effective stress of 34.5 kPa (5 psi). The permeation of metal solutions into bentonite/soil admixture columns does not result in a significant increase in permeability. Experimental results of batch sorption and hydraulic conductivity tests were also analyzed with a computer-based simulation model, POLLUTE, to determine the transport parameters (effective porosity, dispersion coefficient, retardation) of chloride ions and heavy metals in a homogeneous compacted sand and bentonite/soil admixture using a curve fitting technique. |
| |
| Keywords: | Bentonite Admixtures Hydraulic conductivity Sorption Heavy metals Sand |
|
|
