Leaching Batch Test and XRD Characterized OPC Treated Lead Contaminated Soil

The metal leaching behaviour of synthetically prepared contaminated soil containing 792 μg/g lead was investigated after the addition of cement. The leaching behaviour of lead was investigated using 5 grams of the soil thoroughly mixed with 0.1g of the stabilizing material in a polypropylene container to which 50ml of either deionized water,0.01M HNO3 or 0.1M HNO3 was added. The mixture was shaken on a flat bed shaker for 2h, and then filtered using a Whatman No 542 filter paper. The lead concentration in the filtrate was determined by inductively coupled plasma-atomic emission spectrometry. When deionised water or 0.1MHNO3 was used, the concentration of lead in the leachate was less than 1% of the added lead in the soil. In similar experiments with 0.1M HNO3 lead retention in the presence of Portland cement was 90%. Results from the analysis of X-ray diffraction measurements on soil samples retained on the filter paper showed the formation of lead sulphate and lead carbonate when Portland cement is used to stabilize the lead contaminated soil.