Hydraulic conductivity of palm oil contaminated Kaolin: A pilot study

Sriraam, A.S., Raghunandan, M.E., and Ram Chandar, K. (2016)., 8th International Perspective on Water Resources and the Environment, Colombo, Sri Lanka. Paper No. IPWE2016/054 (full paper on CD)., 2016

Oil contamination of soil is one of the typical environmental hazards acknowledged for its significant impact on the soil health, quality and environment. Contamination of clays and clayey soils aided by oil spills have demonstrated substantial influence on their engineering behaviour, particularly focussing on the soil-texture and micro-pores. Flow through palm-oilcontaminated-clays (PCC) in one such behaviour that dictates the time dependent flow of water through the tortuous drainage paths within the strata. Correlations between theoretical studies and experimental results have been extensively studied highlighting the boundary effect, pressure distribution in two-phase flow; however effect of oil contamination on the relative hydraulic conductivity of clays is yet ambivalent. The main aim of this paper is to study the flow behaviour through PCC’s expressed in terms of hydraulic conductivity (k). Henceforth the vertical flow of water through semi-infinite PCC half-space is simulated using 1D FE model. The input parameters include the basic geotechnical properties of kaolin clay mixed with 0, 10, 20, 30 and 40% refined palm oil by dry weight of kaolin. The analysis considers PCC strata as a homogeneous porous medium with void size as a variable. Also the model defines PCC particles as a hypothetical material with similar mean diameter unlike the laboratory conditions (random floc-shape due to presence of oil). The values for ksat corresponding to PCC’s were obtained using the falling head permeability measurement in a 1D oedometer setup. The observations from the laboratory experiments showed a proportional increase in the ksat values with oil content when compared for a remoulded PCC prepared at 10kN/m3 unit weight.