Migration of Chromium Through Black Cotton Soil Amended with Ground Granular Blast Furnace Slag

Abstract

The aim of this work is to assess the suitability the locally available black cotton soil amended with industrial waste material such as blast furnace slag in the context of using them as liner materials. The black cotton soil (BCS) and Ground Granulated Blast furnace Slag (GGBS) are mixed in three ratios, 90:10, 80:20 and 70:30 and hydraulic conductivity of these mixtures have been tested using falling head method. The hydraulic conductivity of soil with 30% GGBS is the lowest and satisfies the hydraulic conductivity criteria of 10-7 cm/s or less for liner application. Soil column tests are conducted to determine the transport parameters of chromium through the optimized soil mixture. The transport parameters of chromium through optimized mixture was found to be diffusion coefficient D = 3.9x10-6 cm2/s and retardation factor R = 4.964. BCS with 30% GGBS mixture with a hydraulic gradient of 0.3 and can be used as liner to contain chromium ion as it gives a breakthrough time of more than 100 years for a liner thickness of 1m.