LAUSR

Elemental profiling of oil sludge and nearby soil is an essential task because these samples -are prone to contain toxic elements which can cause hazardous effects. Therefore, these samples must be analyzed to control the environmental pollution. This paper focuses on the elemental profiling including toxic metals of oil sludge and nearby cultivated soil samples collected from the Attock Refinery Limited Rawalpindi, Pakistan by using laser induced breakdown spectroscopy. The laser beam of a 1064 nm wavelength from a nanosecond Q-switched Nd:YAG laser was focused on the surface of the sample, and an emission spectrum was obtained with the help of a LIBS2000 spectrometer covering the spectral range between 200 and 700 nm. Results obtained through analyzing the characteristic emission lines of different elements have confirmed the presence of 18 elements in oil sludge and 15 elements in the soil. For quantification of the detected elements, a calibration-free method based on local thermodynamic equilibrium and an optically thin plasma model was employed. Plasma parameters, such as electron number density and temperature were calculated for the purpose of subsequent calculations. The concentration of the detected elements in terms of weight percentage in oil sludge was 1.3% Al, 0.88% Ba, 2.0% Ca, 0.02% Ce, 0.63% Co, 18.26% Fe, 0.51% Mg, 0.76% Mn, 6.88% Mo, 5.80% Na, 13.87% Ni, 0.08% Si,1.29% Sr, 13.24% Ti, 8.35% W, 17.83% Cr, 8.25% Cs and 0.07% Li. While the concentration of detected elements in terms of weight percentage in the nearby soil sample was 1.45% Al, 1.35% Ba, 21.11% Ca, 0.01% Ce, 0.11% Co, 19.48% Fe, 1.58% Mg, 1.13% Mn, 3.76% Mo, 8.53% Na, 20.41% Ni, 0.08% Si, 4.25% Sr, 4.44% Ti and 12.28% W. This study suggests that monitoring of the petroleum wastes and nearby sites is necessary to minimize the environmental pollution.