Effect of used motor oil on the growth of Zea mays

Abstract

Motor oil is considered to be one of pollutants that threaten the environment in appropriate disposal ways of used oil could leak to soil and water causing contamination with poly aromatic hydrocarbons (PAH) and toxic metals. Used motor oil (UMO) affects chemical, physical and biological system of soil where plants could accumulate many PAH and toxic metals. The main purpose of this study is to determine morphological changes of treated Zea mays with different volumes of UMO. Sulfur concentration was determined in soil, shoot and root as an indication factor for the presence of PAH. Zea mays grains were planted in triplicates in soil with different oil treatments; control, 3, 5, 7, 10 ml. Plant height was measured and number of leaves counted every two days after 2 weeks from germination. Plants were isolated from soil, separated into shoot and root and air dried followed by ovum dry. The relative growth rate and root / shoot ration were calculated. Sulfur concentration was determined in all samples by using ASTM D_4294_98. Data were analyzed by ANOVA test on SAS program. The results showed that morphological changes had a slight difference among samples. Relative growth rate is not stable among all oil treatments. All R/S ratios for all treated samples was above control except 5 %. Sulfur concentration was varied between different treatment of oil in shoot and root with P<0.0168. All treated samples with different concentrations of oil were above control. On the other hand, there was no significant difference between root and shoot. Sulfur is a good indication of the presence of aromatic hydrocarbons in plant.