An-Najah Staff

Today interest of public regarding environmental pollution has raised concerns because of adverse impacts on various parts of environment such as soil, plants, drinking water, air pollution and aquatic life. This thesis focuses on studying environmental impacts of used engine oil; these impacts are on soil and water. The main aim of this research is to study heavy metals of used engine oil that come during engine operation and the possibility of polluting soil and ground water. In this study: five liters of used engine oil and similar amount of new engine oil (15W-40) was bought from SHELL station in Nablus. Amount of red soil was collected from area 500 m2 in Shufa village 4 km to the east of Tulkarm, after performing soil tests (pH, texture, moisture, and organic matter) it was filled in three columns 140 cm long and 15.24 cm(six inches) diameter. Used and new engine oil samples were digested, centrifuged and filtrated, and concentration of Zn, Pb, Cr, Mn and Cu were measured by flame atomic absorption spectroscopy. Concentrations of Zn and Pb into the depths of soil columns (used, new and 50ppm stock solution) were measured. Results clarified that there is an obvious difference in the concentration of metals studied in this research between used and new engine oil: zinc concentration is 23.23ppm, Pb is 0.6 ppm, Mn is 34 ppm Cr 0.097 ppm and Cu 0.072ppm in used oil while zinc concentration is 3.9 ppm, Pb 0.4 ppm, Mn 28.8, Cr 0.064 ppm and Cu is 0.01 ppm in new engine oil respectively. Effect of temperature on adsorption was investigated in the range (15 – 45oC) and results showed that maximum removal is at 45oC. Effect of pH indicated that maximum removal of both Zn and Pb was at pH13. Also maximum adsorption is reached at 10 ppm. Increasing adsorbent (soil) dosage from 0.5 to 3g showed that maximum adsorption of both Zn and Pb onto soil occurred at 3 g of soil. Equilibrium concentration happened at 90 minutes. Soil column experiment was performed by adding two litters of used engine oil to the first column, similar amount of new oil to the second and amount of 50 ppm solution to the third column, and adding distilled water to each column for five days gradually until water was leached, distribution of zinc and lead was studied in the three columns, results showed significant concentrations of Pb and Zn in the effluent. Equilibrium adsorption data were studied using Lanqmuir and Freiundlich models to study adsorption process at equilibrium and the results showed that both Lanqmuir and Frendlich fit data of Zn and Pb adsorption onto soil. In order to investigate adsorption behavior of Zn and Pb on soil, three kinetic models; Psedo-first order, Psedo-second order and intra- particle diffusion models were applied to fit kinetic data, rate constants and correlation coefficients were computed for the three models, results indicated that Pseudo-second –order model is more suitable to describe the adsorption process qe (exp) is more close to qe calculated meaning chemisorption process or ion exchange . Thermodynamic parameters such as Gibbs free energy, standard enthalpy and standard entropy change were calculated for both zinc and lead; the results indicated that adsorption process is spontaneous and endothermic.